Introduction to Universal Gear Shaving

Break down Maintenance Of Cutter Head Of Churchill Universal Gear Shaving Machine

Mechanical Dept, Production Tech,BEC,BGK

INTRODUCTION TO UNIVERSAL GEAR SHAVING

MACHINE


Maximum O.D

8.75" 22mm.

Pitch 4 to 16 DP 6 to 1.75 Module

Maximum Length

between centers

with standard

fixed headstock

and hydraulic *18" *457 mm.

tailstock

Maximum table

traverse at 4" 100mm.

0°

at 1.5 28mm.

90°

Cutter Centre to Min. 4.50" 114~3mm.

work centre

Max. 9.8" 249mm.

Cutter Speeds 61 to 222 r.p.m. in 14 Steps (with 9"

Cutter Head)

Table Feed Rates .623" (15.8 mm.) to 6.37" (162 mm.)


TECHNICAL INFORMATION:

MACHINE GS 8"

WORK:-

Machine capacity:-

*This capacity can be increased to accommodate long shaft components.


.~

Cutters:--

Maximum 9.625" 244mm. Outside

Diameter

Bore Diameter 2.500" 63.5mm.

Motors:--

Main Drive 3.5 H.P. x 1,450 r.p.m.

Knee 0.66 H.P. x 940 r.p.m.

Hydraulic 0.50 H.P. x 3,00 r.p.m.

Coolant Pump 0.66 H.P. x 1,000 r.p.m.

Clarifier Magna Drum Magnetic

Type ,

Overall Dimensions:-

Length 83" (2,108 cm.)

Width 65" (1,611 em.)

Height 81~" (2,064 cm.)

Weight 9,200 (4,173 kg.)



MACHINE HISTORY:


••• Machine Churchill Shaver

Code GSG02

Hydraulic oil SS68

System pressure 10 bar

Type of lubricant Oil

Lubrication pressure 2bar

Coolant type R.G. Cutting Oil

Air pr 5-6 bar.

Electrical power 3 phase 415 volts

6 H.P .

C.P Value 2.19. .

Type of Hazardous

Waste generated R.G. Cutting Oil


INTRODUCTION TO GEAR SHAVING

Gear shaving is the most widely used productive method of finishing spur and

helical gears following the gear cutting operation, but prior to heat treatment. It

is a cutting and not a cold working process in which metal is removed from the

gear tooth profile by a rotary cutter resembling a helical gear. Each tooth of the

cutting tool is serrated to provide a series of cutting edges.

The reasons for the wide acceptance of gear shaving as a necessary process in

the sequence of operations for producing gear are:-

Shaving is the most economical means of correcting gear cutting errors such as

index, helix angle, tooth profile, eccentricity and also improving surface finish.

Gear shaving is the most effective way of removing over stressed surface metal

because shaving cuts are light enough to remove metal without inducing further

strains .

The gear cutting process, whether hobbing or shaving, invariably cold works the

surface metal of gear teeth and includes unequal internal stains in the metal. In

the hardening process these strains are release and result in distortion which is

unpredictable in both amount and direction.

The shaving process removes this overstressed metal on the tooth surfaces, thus

heat treatment distortion results only from the inherent character of the metal

itself which can successfully be predicated and compensated.

Thus the hardened shaved gear is a finished product requiring no further

operation


The work gear, mounted on an arbor between live centers, is driven and guided by the

cutter; there is no other drive connection between them, thus no dependence is placed on

the accuracy of gear trains or other mechanical elements in the shaving operation.


Literature Survey.

Churchill Machine tool company,

The Churchill Machine Tool Company Limited began as the manufacturing

subsidiary[1] of the machine tool importers Charles Churchill & Company Limited

founded in the early 1900s by US-born Charles Churchill (1837–1916).[2] Created out of

the personal bankruptcy of Charles Churchill, the company developed to become one of

the largest British importers of machine tools from the USA and a major manufacturer of

such tools, initially under licence and later of its own development.

The original business importing American machine tools into Britain began with Charles

Churchill as sole proprietor and later as a partnership with two others. It became a

limited company in 1889. In 1906 a separate company, The Churchill Machine Tool Co

Ltd, was established with the purpose of adapting tools imported by Charles Churchill &

Co Ltd. The former expanded, producing American tools under licence and then

manufactured tools of its own design, in particular precision surface grinders and similar

engineering machinery. In 1918 The Churchill Machine Tool Co Ltd relocated its

factories onto a single site at Broadheath, near Altrincham.

The two companies initially remained closely linked, with common a chairman

and board members, including Arthur Chamberlain. In the early 1930s a series of board

disagreements within Charles Churchill & Co Ltd led to Arthur Chamberlain resigning

as chairman of that company. He remained chairman of The Churchill Machine Tool Co

Ltd and the two companies diverged. Charles Churchill & Co Ltd changed from a sales

organisation to become a manufacturer. Thereafter, both companies manufactured

machine tooling, and Charles Churchill & Co Ltd became a group of companies. By the

1960s significant rationalisation took place in British manufacturing, with companies

merging or being taken over in an attempt to achieve benefits from economies of scale

and pooled resources. The Churchill Machine Tool Co Ltd was taken over by

the Birmingham Small Arms Company; which merged with Alfred Herbert Ltd, with

production moving to Coventry. Coincidentally, Charles Churchill & Co Ltd was taken

over by Tube Investments (TI).


http://en.wikipedia.org/wiki/TI_Group

http://en.wikipedia.org/wiki/Coventry

http://en.wikipedia.org/wiki/Alfred_Herbert_(company)

http://en.wikipedia.org/wiki/Birmingham_Small_Arms_Company

http://en.wikipedia.org/wiki/Board_of_directors

http://en.wikipedia.org/wiki/Altrincham

http://en.wikipedia.org/wiki/Broadheath,_Greater_Manchester

http://en.wikipedia.org/wiki/Surface_grinder

http://en.wikipedia.org/wiki/Licence

http://en.wikipedia.org/wiki/Machine_tool


The Churchill Machine Tool Co Ltd ceased trading in the early 1970s along with several

other companies in the Alfred Herbert group, during a period of huge contraction of the

manufacturing sector in Britain's economy. A part of the Charles Churchill & Co Ltd

group became Matrix Churchill through a convoluted corporate process.

History:

Charles Churchill,

Charles Churchill was born in the United States, in Hamden, Connecticut, on 8 July

1837.[3] His father was Willis Churchill, described as "a mechanic of rare ability, original

in the style of his goods and in his process of manufacture", [4] who had been

manufacturing brass surgical instruments at a time when such instruments were all

imported to the US. Willis Churchill founded a factory manufacturingauger drill bits

which was so locally prominent that the area of Hamden in which it was situated was

called Augerville.[5]

Charles Churchill, 1837–1916

Charles worked in his father's auger manufacturing business but when Willis went to

London in 1861 to supervise the installation of wire-covering machinery being exported

by Thompson, Langdon & Co of New York City, Charles soon followed and, once there,


http://en.wikipedia.org/wiki/Matrix_Churchill

http://en.wikipedia.org/wiki/File:Charleschurchill.jpg

http://en.wikipedia.org/wiki/File:Charleschurchill.jpg


spotted a business opportunity for himself as he saw the interest that the US-made

equipment generated. By the time of his death his businesses had a presence in

London, Manchester, Glasgow, Birminghamand Newcastle-on-Tyne and was "a giant

machine-importing business".[6]

Gear shaping.

Gear shaping is a machinery process for generating teeth by a corresponding

cutter. Gear shaping has become a convenient operation and one of the most versatile of

all gear cutting operations.

Shaping a gear.

The types of cutters used for gear shaping can be grouped into about four categories:

disk, hub, shank, and helical cutters. The cutters are essentially gears that are used to

form the teeth. This method of gear cutting is based on the principle that any two gears

will mesh if they are of the same pitch, proper helix angle, and proper tooth depth and

thickness.

Process Characteristics:

By using a gear-shaped corresponding cutter that is rotated (in relation to a blank gear)

produces the gear teeth. The cutters that are rotated are timed with the workpiece. This

process produces internal gears, external gears, and integral gear-pinion arrangements.


http://en.wikipedia.org/wiki/File:GearDiagram.jpg


Process schematic

The developing process of gear shaping involves a toothed disk cutter which reciprocates in

axial rotations. The workpiece (or blank gear) rotates on a second shaft (spindle). The

workpiece is correspondent with the cutter and it gradually feeds into the cutter while rotating.

If a two-step process is used, all tooth spaces are partially cut before the finishing.

Set up and equipment

The machine used for gear shaping generally consists of a base, column spindle, and an

arbor. The gear cutter is then mounted on the spindle, and the gear blank is mounted on

the arbor. The cutter reciprocates up and down while the work piece(gear blank) is

gradually fed into the cutter. At the end of each cutting rotation, the spindle is retracted

slightly to discourage anymore cutting into the new cut teeth of the gear.

3.4.



COMPANY PROFILE

D

Y

N

A

M

A

TIC TECHCNOLOGIES LIMITED THE

BEGINNING:-

Dynamatic technologies limited (D.T.L) was incorporated on march 8, 1973,

Promoted by Mr. J.K.MALHOUTRA & UDAYANT MALHOUTRA

(President, Chairman, and Proprietor).

D.T.L was established with technical collaboration from Dowty Hydraulic

Limited, U.K.

It was then known as DYNAMATIC HYDRAULICS LIMI TED.

In 1984, it indigenized the technology and ended its collaboration with Dowty,

becoming one of the key players in the Hydraulic field in India and worldwide.

Product range covers over 2800 varieties of Hydraulic Gear Pumps and

Hydraulics systems.

Also they diversified application In the Defence & Aerospace sectors and in

Metallurgy.

Main manufacturing plant as well as head office is situated at Dynamatic Park,

Bangalore.

Another state of the art manufacturing facility is being setup at Nagpur,

Maharashtra.



DYNAMATIC TODAY

Largest producer of Hydraulic gear pumps in Asia and one of the top five in

worldwide.

Dynamatic® is the market leader in the field of hydraulics. Dynamatic® products literally reach every conceivable hydraulic user in India, enjoy very high brand recognition and large the Indian market with a share of70%.

They now stand as a medium scale, precision engineering ISO 9001 certified

Company and they have now already certified ISO 9001:2000 and EMS

14001:2004 certification.

Dynamatic® has once of the most extensive marketing networks for hydraulic

products in India, with 16 branches and scores of distributors and stockiest

spread across the length and breadth of the country.

AGRICULTURALHydraulic Gear Pumps manufactured by Dynamatic® have varied applications including

Agricultural Tractors. Dynamatic® is an original equipment manufacturer for all major

Tractor manufacturers in India including MAHINDRA & MAHINDRA, PUNJAB

TRACTORS, SANE DEUTZ-FAHR, ESCORTS LIMITED, BAJA TEMPO

LIMITED, L&T JOHN DEERE, NEW HOLLAND INDIA Etc.

INDUSTRYThe company enjoys the share of the Industrial Market for Hydraulic Gear Pumps in the

country. Dynamatic® pumps are used Machine tool and various other fluid power

systems. The company's customers include BEML, GODREJ & BOYCE, TELCO,

ASHOK LEYLAND, HINDUSTAN MOTORS, and GREAVES & ETC.



INFRASTRUCTURE

Keeping in the mind the country's thrust on infrastructure development,

Dynamatic® has specially developed an entire range of high pressure Gear Pumps

having application in various Earth Moving & Material Handling equipment Like

Bulldozers, Excavators, Drill Rigs, etc. Dynamatic' s customers in this segment include

CATERPILLAR INDIA, INGERSOLL RAND, L&T, and Etc. currently; there are

no indigenous manufactures for such Gear Pumps: the Company has developed

breakthrough products for this segment and exports to grow this market rapidly in the

near future.

EXPORTS

Dynamatic® Exports its products to over several countries across the world and

its products are universal acknowledged to be world-class. Dynamatic® products are

used as Original Equipment in USA, UK, Canada, and Germany & South Korea.

Recently they have also bagged the National award for excellence in indigenization

of Defence equipments, awarded by Ministry of Defence.

They have also undertaken a plan of vertical integration through which two Foundry

and Heat treatment facilities have been set up.

Their manufacturing . facilities are very good and incorporated the latest

production technologies. This had enabled then to achieve strategic cost & quality

advantages required to succeed in the global company.



1.

DYNAMATIC VISION

Their vision is to achieve global leadership through total customer satisfaction. They

constantly strive to improve, expand and innovate themselves to attain the highest

quality standards. Their goal. is to increase product features and improve production

consistency which reducing inefficiencies and lowering cost through the use of

innovative technologies.

DYNAMATIC TECHNOLOGIES is the largest producer of HYDRAULIC PUMPS

in South Asia & One of the top ten worldwide. Their manufacturing facilities are state-

of-the-art, incorporated the latest process technologies. Additionally, they have

diversified into a number of related areas, creating a unique, vertically integrated

manufacturing structures, this has enabled to achieve strategic cast and quality

advantages, required succeeding in the global economy. .

DYNAMATIC HYDRAULICS

A) MOBILE HYDRAULICSThey manufacture a wide range of Hydraulic Gear Pumps, Hydraulic Valves & other

Hydraulic element conforming to SAE, BIS and / or DIN standards. They state-of-the-

art manufacturing plant is very flexible. Hence, they can meet varied customer needs

with a range of over 2800 different Hydraulic Pumps, with displacement of 1.23cc/rev to

150 cc/rev. pumps are produced in both cat iron & aluminium. The applications include

Agricultural Tractors, Constructed Equipments, and Material Handling

Equipments, mining and Drilling Equipments.

B) FLUID POWER SYSTEMSThey provide custom tailored solutions for their customers. Their 'product range from

simple Hydraulic Pumping units to sophisticated Maririe power packs, complex aircraft

ground support systems to turnkey industrial installation. Design-build-install-

maintained, energy designs, saving designs, robotics, built in IT interface & controls.



DYNAMETAL

A) Aluminium Alloy Casting The Dynamatic Foundry manufacturing high casting made from various aluminium

alloys. They can supply both gravity casting as well as pressure die-casting. Their

activity facilities meet the highest international ecological standard.

B) Heat TreatmentDynametal owns sophisticated Heat Treatment facilities for producing Hydraulic,

Automotive, and Aerospace parts. A wide variety of metals & alloys are processed at

temperature range iron- 70 to + 1000c. Process includes solutionizing, precipitations

hardening (aluminium), carbonitriding, case hardening,through hardening, sub-zero

treatments, stress reliving, spherodized annealing (ferrous).

DYNAMATIC AEROSPACE

Dynamatic Aerospace produces exacting Airframe Structures and precision Aerospace

components. Instituted in 1995, this division is currently headed by Air Cmde, Ravish

malhotra, one of India's two cosmonauts.

Dynamatic Aerospace has successfully executed important projects for Defence

agencies of national importance like DRDO, HAL, Etc. products include the wing and

rear Fuselage of LAKSHY A, India's pilot less target Aircraft, and Ailerons Flaps for

the wings for the HJT-36 intermediate Jet Trainer. This is the first time such

capabilities have been developed in the Indian privates sector, and this division is now

taking up development of major Airframe structures for the Sukhoi 30MKI Fighter-

Bomber.

Dynamatic Aerospace Produce the hydraulic Transmission system for India's T-72

Battle Tanks, Steering Control System, Turret Control System and Brake Actuating

System for Arjun Main Battle Tank.

Dynamatic Aerospace is considered to be one of the most reliable quality vendors to

the DRDO and presented with the Creative Partner Award for the year 1998-99 by

DRDO, ADE and ASIEO. The Aircraft Division of HAL in Bangalore also presented

this division the HAL Best Vendor Award for 2003- 04.



MAIN SECTIONS OF DYNAMATIC TECHNOLOGY LIMITED:

1) Design.

2) Heat Treatment.

3) Production.

4) Assembly and Testing .

. 5) Quality Control.

6) Maintenance.

7) Research and Development.



8) Packing & Distribution.

9) Dynamatic Aerospace.

PRODUCTS:

1

)

G

e

a

r

P

u

m

p

s

.

2

)

L

i

f

t

A

c

t

u

a

tors.

3)Hydraulic Valves.

4)Other Engineering products for,

i) Aircraft systems.

ii) Battle tanks

iii)Satellite Launch Vehicles

iv)Marine Applications.



INTRODUCTION TO MAINTENANCE.

Maintenance is the combination of any actions carried out to retain an item or

restore it to an acceptable condition.

It is not a mere repair activity.

OBJECTIVES OF MAINTENANCE

To maximize availability and reliability of Machinery & Equipment.

To extend useful life of assets by minimizing wear &tear and deterioration.

To ensure safety of personnel using facilities.

Maintenance of any device, equipment, system, product or process, makes it suitable

for the given particular task. This requires periodical testing of the system under

consideration. One of the main purposes of testing is to ensure that the system

conforms to an agreed specification, when operating under stared environment

conditions.

Specification is a detailed description of the required characteristic of the system.

The requirement should be contained in the performance specification section of

manufacturer's sales leaflets and instruction manuals.

Periodical checks carried out during the maintenance schedule will reveal the

shortcomings with reference to the specifications and thereby give way for avoiding

breakdown



Specification may include the following

1) Type and family

2) Brief description and intended application

3) Outline drawing showing dimension.

4) Most important electrical characteristics and absolute maximum rate

values of voltage, current and power, including figures, graphs and

characteristic curves.

5) Details of manufacturing inspection (if any).

6) Figures of reliability or failure rate.

Approach to maintenance

Six step procedure as below

1) Collect the evidence

2) Analyze the evidence

3) Locate the fault

4) Identify the real cause

5) Repair the fault

6) Test the system.



IMPORTANCE OF MAINTENANCE

1) The importance of plant maintenance varies with the plant and its productions.

2) Equipment breaks down leads to an inevitable loss of production. If a piece of

equipment goes out of order in a flow production factory the whole line will

soon come to a halt. Other production lines may also stop unless the initial fault

is cleared. This result is an immediate loss in productivity and diminution of

several thousand rupees per hour of output.

3) An improperly maintained or neglected will sooner or later require expensive

and frequent repairs, facilities (such as transportation facilities),buildings etc.,

wear out and need to be maintained to function properly.

a. Plant maintenance plays a prominent role in production management because

plant break down creates problem such as

o Loss in production time.

o Rescheduling of production.

o Spoilt materials.

o Damages in process materials.

o Failure to cover overheads and need for

overtime.



2.3.4.5.TYPES OF MAINTENANCE

Maintenance may be classified in to following categories:

1) Break down maintenance.

2) Corrective maintenance.

3) Scheduled maintenance.

4) Planned maintenance.

5) Productive maintenance.

4) Preventive maintenance.

BR EAK DOWN MAINTENANCE

Breakdown maintenance implies that repairs are made after the equipments are out of

order and it can not perform its normal function any longer. After repairing the faults.

Maintenance engineer do not attend the equipment until another failure occurs. Break

down maintenance practice is economical for those (non- critical) equipments whose

down time and repair cost is less this way than other type of maintenance. Break down

generally occurs at in opportunity times. So the disadvantages of break down

maintenance are reduction of output, increased chances of accidents, less safety to

workers and machines, more spoiled material and direct loss of profit. So break down

maintenance practice cannot be employed to the critical equipments and also the

equipments and also the equipment which are regulated by statutory provisions, for

examples cranes, lift, hoists and pressure vessels.



6.

CORRECTIVE MAINTENANCE

In this type maintenance, a study of failure of equipment in service may

warrant a change in design, Material or working conditions of the equipment

and corrective steps are taken.

SCHEDULED MAINTENANCE

Scheduled maintenance is a stitch-in-time procedure aimed at avoiding

breakdowns. Scheduled maintenance practice incorporates inspection,

lubrication, repairs and over haul of certain equipment, which if neglected

can result in break downs. These inspections, lubrication, servicing etc, of

the equipment are included in predetermined schedule.

PLANNED MAINTENANCE

It is an advance over the scheduled maintenance practice. Planned

maintenance visualizes' the contained in a nature job determines the best

method to be adopted, estimates the time, material and cost involved, assigns

jobs to individuals etc., it provides a system of feed back of information

necessary changes in the original plan.

PREDECTIVE MAINTENANCE

It is comparatively a newer maintenance technique. It makes use of human

sense or other sensitive instruments such as:

Audio gauges.

Vibration analyzer.

Amplitude meter.

In predictive maintenance equipment conditions are measured periodically or

on a continuous basis and this enable maintenance men to take a timely

action as equipment adjustments, repair or over haul. Predictive maintenance

extends the service life of equipment without fear of failure.

Rotary shaving cutters operate at high speeds up to 400 ft. per minute. The feed is fine

and the cutter is restricted to a definite zone contact. The cutter removes fine hair like

shavings from the gear tooth surfaces. Because of the fine cuts, the tool pressure is low

and, therefore, there are fewer tendencies to cold working the gear tooth.

The relationship of the axis of the cutter to the axis of the work is crossed. In other

words, they are set at an angle approximately equal to the difference of their helical

angles, usually in the range of 10° -- 15°. This is primarily to obtain a free cutting action

with a minimum of contact pressure, thus eliminating a burnishing effect.




The Churchill Gear Shaver is a Universal Diagonal shaving machine. This means that the machine is

suitable for shaving operations by any of the following methods:-

1. Conventional Shaving

2. Diagonal Shaving

3. Underpass Shaving

4. Crown Shaving

5.Taper Shaving

1. CONVENTIONAL SHAVING - Generally for Gears with face widths wider than 1 1/2". In

this method, although gears are shaved using the "Crossed Axes" principle, there is a zero traverse

Angle. In other words, the table moves to the right and left parallel to the column face of machine. The

work is fed across the cutter at a feed rate of from .005" (0.13 mm.) to .020" (0.50 mm.) per rev. of the

work. The length of total would be equal to, or a little longer than, the face width of the gear. At the

end of each stroke, the table automatically changes direction of traverse and at the same time the

rotation of the cutter is automatically reversed

The knee of the machine is fitted with automatic differential up-feed and the control dogs can

be set to utilize a progressively. Diminishing up-feed. At each reversal of the table, the knee of the

machine is automatically fed upwards, for example, a 6DP Gear could be shaved with as many as 6

passes, with up-feed increments per pass of .0015" .0015" .001" and .0005" plus a free pass without

feed. These figures would apply to a stock removal of .003" on tooth thickness, and, therefore, would

vary according to the work to be produced. At the end of the cycle, the table automatically returns to

the correct backlash position for unloading and loading.

2.DIAGONAL SHAVING - Generally for Gear with face widths of 1 1/2" or less. This method of

shaving differs from Conventional shaving chiefly in the direction in which the work is fed through

and under the cutter. For Diagonal shaving the feed is at an angle with the axis of the gear instead of in

line with that axis. The Angle of feed is adjustable. Traverse angles of approximately 55° are normally

selected for "open." gears. When the cutter is wider than the Gear face or from a chart where the Gear

face is wider than the cutter. It is often possible to improve surface finish by small variations to the

traverse angle setting and this can be quickly and easily undertaken on the Churchill Shavers. Diagonal

shaving generally requires a maximum number of four strokes of the table which, combined with the

shorter length of stroke and Auto up-feed, give a reduced shaving time. Using this method there is

more even wear on the cutter because the point of crossed axis is automatically moved across the cutter

face width.


3) UNDERPASS SHAVING - Basically, this method is diagonal shaving using a 90° traverse

angle whereby an extremely short table stroke is obtained. The work piece starts in backlash

condition, moves into a minimum centre position, through to another backlash condition and then

automatically returns. This method is generally reserved for shaving shoulder gears where it is

necessary to overcome interference problems between cutter and work piece.

When underpass shaving, the table stroke is extremely short, consequently crown shaving from

the table movement is not possible. For this class of work Crowning if required must be

incorporated into the shape of the shaving cutter. Because there is practically no table stroke it

is advisable to use Differential Shaving Cutters for Underpass shaving, i.e. the Serrations are

produced to develop a helix around the cutter instead of creating a series of annular grooves.

4. CROWN SHAVING- The main cause of tooth failure and gear noise is what is known

as "end bearing", that is a concentration of stress at the ends of the tooth, where its strength is

least and the tooth vulnerable to shock failure and the effects of fatigue. End bearings may

result from misalignment in assembly, deflection of shafts or mountings under load, excessive

run out or heat distortion. Crowing the tooth form has proven to be the most effective antidote

for "end bearing" and is applicable to both spur and helical gears.

A Crowned tooth has both its horizontal section and its vertical profile modified. A

pitch line section of a crowned tooth would show the tooth thinner at the ends than at the

centre or at the point where maximum thickness is desired.

5. CROWN SHAVING- To achieve or eliminate taper or to adjust the zero angle and

parallelism of the table, a vertical micro adjuster screw is used to tilt the table in relation to the

knee and cutter spindle axis.



MACHINE DESCRIPTION

Machine column The machine column is of rigid 'C' frame construction onto which the various sub-assemblies are

mounted.

Compartments are provided at the left hand side for the hydraulics, at the right for the coolant pump

unit and change gears, and at the rear for the electrics. The hydraulic oil reservoir is a separate tank

housed within the column below the hydraulic compartment. Coolant oil is contained in the base of

the machine and the coolant clarifier is attached to the right hand side of the column foot.

Knee and Table

The knee and table assembly is carried. on vertical ways on the front of the column and the nut

through which the knee elevating screw operates is fastened onto a facing on the foot of the column.

A motor mounted externally on the left hand side of the knee provides the power for both up-feed and

table traverse motions. The doors on the knee give access to the swivel slide adjustment, the trips for

table traverse and up-feed setting, and also to the table cross feed change gears.

Cutter Head and Cutter Head Drive

The Cutter Head is attached to a facing on the underside of the column head and is driven by a

brake motor through the Cutter Head Drive Unit. Motor and Drive Unit are housed in the column

head. Access to the Cutter Head Drive Change Gears is through the hinged lid on top of the box



PREVENTIVE MAINTENANCE-G8"MECHANICAL CHECKS AND · FREQUENCY

1 Cutter Head ---3 Monthly

1) Check and record spindle radial run out by applying dial indicator against cutter mounting

diameter and turning spindle by hand. (This necessitates the removal of change gear in cutter

head drive unit).

2) Check and record spindle axial run out by applying dial indicator against spindle face and

turning spindle by hand.

3) Check and record axial run out under load by applying dial indicator to a ball bearing at end

of spindle and when running machine under load.

4) Check and record spindle straightness by applying dial indicator to outboards bearing

diameter of spindle, turning by hand.

5) Check oil seals for leaks. Replace seal MIS 30 if leakage is excessive.

NOTE: -- A. If T.I.R. for checks 1, 2 and 3 exceeds".0002(.005mm)

a) Tighten 6 socket head screws in cover GS.B.4069 which carries the rear race.

b) Remove cover GS.C.4070 and adjust locknut SP.l 050/3 until repeat checks 1

and 2 give 0/".0002 max. (0/005mm)

NOTE: -- B. Check 4 should not exceed ".0005 (.012mm)

NOTE: -- C. If new cutter head is installed, check that length of cutter mounting diameter of

spindle is parallel to the table surface with .0002. (.005mm) this applies only to conventional

machines. With universal type machine, this alignment is corrected if necessary by a slight

adjustment to the taper shaving unit

2. Head & Tailstocks - 3 Monthly then every 6 Months

1) Check and record Tailstock spindle radial run out by applying dial gauge to bore of tooling

location diameter and turning spindle by hand.

2) Check and record spindle axial run out by applying dial gauge to tooling location face and

turning spindle by hand.

NOTE: Check 1. TIR should not exceed .0002. (.005mm)

Check 2. TIR should be .0002. (.005mm) These bearings are matched sets and the setting of

their preload is automatic on tightening lock nut SP.1029/4. Should the T.I.R. for check for 1



or 2 be excessive, then replace the matched sets of bearings. There is no corrective adjustment.

3) Check oil seals for leaks. Replace if hydraulic leakage is excessive.

3. Knee - All models - 6 monthly

If machine is fitted with taper gib on vertical slides:-

1) Remove gib and check for galling, score mark or wear of scraping marks.

2) Clean, oil and replace gib.

3) Press, gib in until it bottoms; back off slightly using lower locknut, lock gib. If machine is not

fitted with taper gib on vertical slides

4) Remove keep strip and check for galling, score marks or wear of scraping by removing four

holding down bolts.

5) Clean, oil and replace strip.

6) Lock the four holding down bolts.

4. Knee - All Models - Yearly 1) Check for wear between input worm GS.D.3022 and worm wheel GS.D3023. Replace worm

wheel if wear is excessive.

2) Check for wear between elevating screw worm GS.D.3983 and worm wheel GS.D.3021.

Replace worm wheel if wear is excessive.

3) Check for wear between table traverse trip disc worm GS.D.3024 and helical gear GS.D.3025.

Replace helical gear if wear is excessive.



5. Knee & Table - Yearly

1) Remove table by first removing crowing and taper shaving unit.

2) Check that table feed screw locknut is correctly adjusted after removing swivel bracket

GS.B.4375.

3) Check for excessive backlash between table feed screw and nut. Loosen screws and rotate

backlash adjusting nut, clockwise, until all backlash is removed. Tighten screws.

4) Check bush GS.D.4910 for wear. If play is excessive renew bush.

5) Check trunnions and table for wear and scoring.

6) Clean, oil and replace swivel bracket and guide bracket.

7) Replace crowning unit and table.

8) Check alignment to final chart.

6. Crowning Unit - yearly

Check fit of pin tongue in cam slot. If wear exceed 0".0015 (.0381 mm) grid cam slot parallel

and central and fit pin with an oversize tongue with a maximum of".0003 (.0762 mm)

clearance in cam slot.

7. Couplings - 6 Monthly

1) Check knee, cutter head, coolant and hydraulic pump

coupling keys and keyways for wear.

2) Lubrication - 3 Monthly

3) Check operation of lubrication pump in knee by

disconnecting oil feed lines and observing oil flow

(with knee motor running).

4) Yearly

5) Clean lubrication pump filter.



APPROCH TO MAINTENANCE OF GEAR

SHAVING CUTTER HEAD

EVIDECE COLLECTED:

Machine is not giving required surface finish, found scratch marks on the gear.

Tolerance = -15 microns, Actual= -14to-16 micron.

Out board bearing support (60) is found broken.

Cutter head assembly is giving abnormal bearing sound. Checked all lubrication point and

found it is ok.

EVIDENCE ANALYSIS:

Machine is not giving require surface finish .

• Checked the run out of cutter, allowed-2.5 microns, actual- out of limit. ..

• Checked tailstock run out, allowed-8 microns, and actual-6 microns

• Checked headstock centre run out, allowed-8 microns, and actual-6 microns

•Checked alignment between headstock and tailstock, allowed-l0 microns, actual -8 microns.

LOCATING THE FAULT Since out board bearing support and check nut are broken, cutter head assembly is giving abnormal

bearing sound and all other geometrical test is ok, problem is with cutter head assembly

REAL CAUSES

Bearings are damaged

Check nut 55 broken

Out board bearing support 60 broken



FAULT REPAIRING PROCEDURE

Preparations for Dismantling:

Before dismantling we should follow the below procedures

Disconnect the power supply & remove fuse carries from cabinet.

Disconnect all the hydraulic power connections.

Disconnect coolant pipe connections

Arrange the required tools & equipments for dismantling

Arrange the racks or the tray for keeping the machine parts in sequence order for

easy usage

Keep cotton waste for cleaning. Start dismantling procedures.



HEAD STOCK REMOVING PROCEDURE:-

Roughly clean the machine.

>- Remove the cutter cover by loosening nut (61, 4nos.) & dove pin (64, 2nos.).

Remove broken spindle nut (55). - Remove cutter

Remove coolant connections (33, 34, 35&36).

Remove tail stock hydraulic connections.

Remove limit switch from tail stock.

Remove head & tail stock from the table. '

Remove coolant guard.

Remove the dial indicator which is used for lead setting.

Provide wood support for removing the head.

Loose cutter head mounting nut (3 &4, 4nos. each)

Remove the wooden support one by one & slightly pull down the head to the

hydraulic trolley

Move the head to maintenance department work table.



ITEM DESCRIPTION NO ITEM DESCRIPTION NO OFF OFF

1 CUTTER HEAD 1 14 1/4" UNC. UNB. 1

CAPHD. SCR.

1 1/2" L

2 TEE BOLT 4 15 GEAR SHAFT 1

3 3/4"UNC. HEX 4 16 ? "x1/4" RECT 1

NUT KEY I?" L.

RND.ENDS

4 3/4" DIA. 4 17 SPACER 1

WASHER.

5 SPIGOT 1 18 TIMEN 'PREC. 2

HOUSING 2' BRG.

19150/19268

6 5/16" DIA. 1 19 HELICAL GEAR 1

DOWEL l3/4"L 23 T

7 SWIVEL GEAR 1 20 LOCKNUT 2

8 5/16" DIA. 1 21 10UNC. UNB. 2

DOWEL I" L. CAPHD.

SCREW I" L.

9 ? " UNC. UNB. 4 22 TIMEN 'PREC. 2

CAPHD. SCR. 2' BRG.

33/4"L 17118/17244

10 SPLINED 1 23 LOCKNUT 2

GEAR SHAFT -

11 SPACER 1 24 10UNC. UNB. 2

CAPHD.

SCREW I" L.

12 TIMEN 'PREC. 2 25 BEAARING 1

2' BRG. HOUSING

12175/12303

13 LOCKNUT 1 26 5/16" UNC. 6

UNB.CAPHD.

SCREW 2 1/4" L.

PART NOS



27 ? "DIA. 2 43 7 /16"x9/32" 1

DOWEL. 2? " L RECTKEY.

1 1/2"L. RND.

ENDS

28 OIL SIGHT 1 44 LOCKNUT 1

WINDOW

TWCALC4610

29 1/2" B.S.P. UNB. 1 45 10UNC. UNB. 1

PIPE PLUG CAPHD.

SCREW 1 1/4" L.

30 COVER PLATE 1 46 TIMENPREC. 1

'0' BRG.

. 28150/28300

31 GASKET 47 LOCKNUT 1

32 10UNC. UNB. 48 10UNC. UNB. 1

CAPHD. CAPHD.

SCREW 3/4" L. SCREW I" L.

33 COOLANT 49 1/4" B.S.P. UNB. 1

BLOCK PRESSURE

PLUG.:

34 GACO '0' 50

RINGRII0.

35 1/4" UNC. UNB. 4 51 SPACERS 1

CAPHD.

SCREW 3/4" L.

36 FILTON 1 52 LOCKING 1

SWIVEL JOINT SPACER

NO 14833

37 1/2" B.S.P. ? " T 4 53 LOCKING KEY 1

MALE ELBOW

ENOTS Yl13

38 ? "DIA 1 54 10UNC. UNB. 1

NYLON CSK SCREW 1/2"

TUBING 2'-6' L

39 CUTTER 1 55 SPINDLE NUT 1

SPINDLE



56 COVER PLATE 1 68 END CAP 2

57 GASKET 1 69 SHIM 2

58 10UNC. UNB. 9 70 10UNC. UNB. 8

CAPHD. CAP HD.SCR 1/2"

SCREW?" L. L.

59 1 71 GACOOIL 2

SEAL M1 150206

5/16"

60 OUTBOARD 1 72 TIMENPREC. 2

BEARING '0' BRG.

SUPPORT 19150/19268

61 STUDW.D.S. 4 73 1/8" B.S.P L/O 1

405 - 20 21/4" L ENOTS GREASE

NIPPLE

62 1/2" UNC. HEX. 4 74 INTERMEDIATE 1

NUT GEAR SHAFT

(HARDEN)

63 1/2"DIA STD. 4 75 INTERMEDIATE 1

WASHER GEAR

(HARDEN)

64 LOCATING 2 73 1/8" B.S.P L/O 1

DOWEL ENOTS GREASE

NIPPLE

65 PLAIN BUSH 2 74 INTERMEDIATE 1

BRT P6? " GEAR SHAFT

lID.3/4"L

66 BEARING 1 75 INTERMEDIATE 1

SLEEVE - GEAR

67 TRUARC 1

RETAINER

5100-150



DISMANTLING:-

Cleaned the whole unit.

Removed the drain plug (49) & take out the oil.J

Removed front bearing cover by losing counter shank screws (7 & 8, 9nos.

each).

Removed rear cover (30) by loosening screws (32, 6 nos.) & gasket (310.

Removed chunk nut (23 & 47) by losing lock screws (24 & 48).

Removed bearing housing (25) from the head by loosing cap head screws (26,

6nos.) & dovel pins (2nos.).

Removed check nut (20 & 44) by loosing locking screws (21 & 45).

Pulled out the spindle (39) & key (40).

Removed the bolts (9, 4nos.) & dovel pins (2nos.) for removing dovel gear

assembly.

Pulled out the spigot housing (5) from the unit.

Pulled out gear shaft (15), key (16), helical gear (19),helical gear (42) & key

(43).

Removed the lock nut 13 after loosing lock screw (14).

Pulled out splined gear shaft (10) from the housing.

Removed end caps (68,2nos.) or cutter cover by removing cap head screw

(70, 8nos.) and seals (71, 2nos.).

Pulled out bearings (72, 2nos.).

Removed the bearings (12, 2nos.) from splinted shaft (10).

Removed the bearings (18 & 22) from gear shaft (15) &

from bearing housing (25).



Removed the bearing (41) from spindle & bearing (46)

from housing.

LEANING AND INSPECTION

All the parts are cleaned thoroughly by using diesel and after cleaning inspect

the parts to find out damages.

OBSERVATIONS:-

1) Threads of spindle (39) worn out.

2) Cutter locking nut (55) broken.

3) Check nut (47) broken.

4) All the bearings are damaged, found deep mark on the

bearings rollers & inner portion of bearings out race.

5) Check the bevel gears & helical gears. [Found it is ok].

6) Check key suiting [key (40) found some play].

7) Cutter cover (60) is broken.

LIST OF SPARES:-1) OUTBOARD BEARING SUPPORT (60) - 1 NO.

2) TIMKEN PRECISION '0' BEARING 19150/19268

(72) - 2 NO.


(41) -1 NO.


(46) -1 NO.


(22) - 2 NO.


/



7) TIMKEN PRECISION '2' BEARING 12175/12303 (12) - 2

NO.

8) KEY (40)-1 NO.

9)SPINDLE NUT (55) - 1 NO.

10) LOCK NUT (47) -1 NO.

11)GACO OIL SEAL M1150206/16" (72) - 2 NO.

CORRECTIVE ACTIONS

1) Take the drawing of cover (60) as per sample & give order for a new one.

2) Temporally weld the same cover after making a fixture.

3) Order all bearings & oil seals required.

Preparation for Assembling

Before assembling we should follow the below

procedures,

Reap all threaded holes, remove the chips & clean the holes with

thinner and good quality cotton waste.

Use emery paper & oilstone to remove the rust & small burrs.

Clean the surface with thinner and good quality cotton.

Apply oil in light thickness to the cleaned surface Arrange spare parts



ASSEMBLING

Inspected bearings & match the check nut with spindle & shaft, found ok.

Thoroughly clean all the related parts & cutter head.

Assembled the outer ring of bearings (22, 18, 46, 41, and 12) to the

housing.

Assembled the spindle bearing inner race.

Inserted the spindle through the housing with key & helical gear (42).

Assembled the gear shaft (15) bearing & insert through the housing with

key & helical gear (19).

Placed the check nut of both spindle & shaft (44&20) respectively for

locking helical gear.

Assembled the bearing housing _ to the head with cap head screws (26,

6nos.).

Assembled the inner race of bearing (46 & 22) to the spindle shaft & gear

shaft.

Placed the check nut of both spindle shaft & gear shaft (47 & 23)

respectively & pre loaded.

Checked radial face run out & axial play of spindle. Correct the run out

with in 0.004mm.

Face run out - 0.002 mm.

Axial play - 0.015 mm.

Assembled the spindle gear shaft into the housing with new bearings. Place

the lock nut and load. Rotate the splined shaft & find the movement ok.



Assembled the spigot housing to the spindle head.

Checked the bevel gear meshing.

Pushed back the mounting bolts (9).

Rotated the spline shaft manually & find it is ok.

Pasted silicon gel on the face of the cover plate (56).

Placed the cover plate & lock using CSK screws (58, 9nos.).

Pasted silicon gel in the rear side cover plate (30) & lock using CSK screws

to the bearing housing (25).

Assembled bearings (72, 2nos.) to the out board bearing support & placed

the bearing sleeve.

- HEAD STOCK MOUNTING PROCEDURE

1) Taken the head stock to machine bed using a hydraulic trolley.

2) Provided wooden packing & slowly up the head and match with T bolt.

3) Put the mounting nut (3 & 4) and rigidly fix it to the machine.

4) Put the drain plug & fill the oil.

5) Fixed the headstock & tailstock to the table.

6) Fixed the limit switch; given hydraulic connections & coolant connections.

7) Fixed the cutter cover.

8) Fixed the coolant guard.

9) Given all hydraulic & coolant connections dismantled at the time of cutter

removing. Put fuse & give power supply.



CUTTER MOUNTING AND WORK PIECE ACCURACY

TESTING

SETTING U P - O perati o n A

Mount Cutter

1. Cutter Space r It is necessary to ensure that the centre of face width of the cutter is

coincident with the vertical head. The centre line is 1" (25.4 mm.)

from the shoulder of the arbor.

To arrive at the correct spacer width applies the following

expression:-

SPACER WIDER =1" (25.4 mm.}- 1/2 Cutter Face Width.

Seven standard spacers are supplied with each machine and are as

follows:- 3/16”,1/4”,1/2”,3/4”

2. CutterWhen not in use the cutters should be stored in individual wooden

boxes or placed on a flat wooden board or similar surface.

Care must be taken when handling the cutter to avoid knocking the

teeth. against hard objects. Damage can easily result from such

contact.

Having selected the cutter, first ensure that the machine spindle and

spacer faces, and also the bore and faces of the cutter are thoroughly

clean.

If the cutter has been used before, check also that the serrations are

clean and free form swarf



Place the cutter spacer and then the cutter onto the spindle. In the manufacture of

Churchill cutters, the plain face is the datum face, and this face should be located

towards the cutter spindle shoulder. The cutter should be a close sliding fit. If there is

any tightness, examine the key for burrs.

Tighten the spindle nut and secure with Locking Pad. Check the cutter datum face for

run out. This should not exceed .0001" per inch of cutter radius. Clean the facing on the

cutter head and mount the outboard bearing housing



SETTING UP-Operation B

Set Cutter Head Angle

The approximate cutter head setting angle is equal to the helix

angle of the gear minus the helix angle of the cutter.

Example 1

Helica l Gear

Helix Angle of gear =30° RH

Helix Angle of cutter-15° LH

Approximate cutter head setting angle - 300RH 15°LH=15°RH

Example 2

Spur Gear

Helix Angle of gear-O

Helix Angle of cutter = 15° RH

Approximate cutter head setting angle =0-

15°RH=15°LH

Having made this calculation, loosen the four bolts on the underside

of the cutter head flange and rotate the head to the required angle.

This is done by means of the square headed adjusting worm shaft

situated immediately above the cutter head, using the handle

provided in the tool kit.

Clamp the cutter head bolts.

Checked tail stock center run out Allowed-8 microns

Actual- 6 microns

Checked headstock center run out Allowed-8 microns



Actual- 6 microns

Checked alignment between headstock & tailstock Allowed-l0 microns for 150 mm

Actual- 8microns for 150 mm

WORKING ACCURACY TESTING

Working accuracy tests establishes the capability of the machine as regard to machining

of few test pieces under control machining condition.

Working accuracy test done for the following component and found the machine is

capable the specified tolerance in continuous production .

• Tolerance- 15 microns

• Found actual-14 to 16 microns.



5.6.

CONCLUSION

A system of Preventive Maintenance tries to minimize the problem of Breakdown

Maintenance, provide them regular inspection and minor repairs there by reducing the

danger of unanticipated break down. The underlying principle of preventive

maintenance is that "Prevention Is Better than Cure".

By applying Preventive Maintenance, Machine Breakdown will be reduced so

availability of the machine will be increased, hence total productivity will be increased

and also decreased the total coast of the production. so that profit will be increase.

Team working is imperative for the success of project implementation as the project

include members of different personal background. Typically there are mechanical,

electrical, electronics engineers, specialist, Consultants in the relevant fields, Trainees

etc.

A common purpose and vision is essential" to achieve the required goal. The final

outcome will depend on the effective utilization and combination of different skills,

Talent and responsibilities.

The Knowledge that we have gained in the institute and industry during our training

helped us to successfully complete our project.

Once again we convey our gratitude to all the staff members of

DYNAMIC TECNOLOGY LTD. who have helped us to complete this project work.



References:

1. The 2009-2014 World Outlook for Gear Shaper Cutters and Gear Shaving Cutters

for Machine Tools and Metalworking Machines. ICON Group International, Inc.

(September 27, 2008)

2. Nabekura, M. et al., Gear Cutting and Grinding Machines and Precision Cutting Tools

Developed for

3. Gear Manufacturing for Automobile Transmissions, Mitsubishi Heavy Industries

Technical Review Vol. 43 No. 3 (2006) pp. 41-47

4. Katsuma, T. et al., Advanced Dry-Cutting Gear Shaper SE25A and Super Dry II

Coating, Mitsubishi Heavy Industries Technical Review Vol. 42 No. 1 (2005) pp. 46-47

5. Davenport-Hines, Richard Peter Treadwell (1990). Capital, Entrepreneurs and Profits.

Routledge. ISBN 978-0714633862.

6. Floud, Roderick C. (2006) [1976]. The British Machine Tool Industry, 1850–1914.

Cambridge, UK: Cambridge University Press. ISBN 978-

0521025553. OCLC 2089096. LCCN 2006-275684,LCCN 75-046133, ISBN

0521212030.

7. Lloyd-Jones, Roger & Lewis, Myrddin John (2006). Alfred Herbert Ltd. and the British

machine tool industry, 1887–1983. Aldershot, England: Ashgate. ISBN 978-0-7546-

0523-2.OCLC 60393261.

8. Rolt, L.T.C. (1965), A Short History of Machine Tools, Cambridge, Massachusetts, USA:

MIT Press, LCCN 65-12439. Co-edition published as Rolt, L.T.C. (1965), Tools for the

Job: a Short History of Machine Tools, London: B. T. Batsford, LCCN 65-080822.

9. Churchill Machine Tool Co. (1956). The story of The Churchill Machine Tool Co. Ltd.: a

history of precision grinding. Manchester: Churchill Machine Tool Co. Ltd

10. ̂ "Charles Churchill and Son, Charles Henry, Dead". American Machinist (New York: Hill Publishing Co.) 44 (12): 395. 23 March 191


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BIBLIOGRAPHY

1. Jagadish

2.


Introduction to Universal Gear Shaving

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