CA1290144C - Streamlined production of electric motor armatures and stators - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Two production lines for the manufacture of armatures or stators for electric motors are separated over at least part of their length by a common partition. The juxta-posed proximity of the two production lines allows operations on articles on both lines to be carried out simultaneously by equipment mounted on a common operating head. Shuttles are provided upstream and downstream of coil winding areas so that armature or stator bodies from one production line can be automatically diverted to a winder on the other production line and returned when wound. The height of the laminations is determined by picking a stack close to the maximum height permissible, measuring this height and, if necessary, removing a lamination via a vacuum line mounted on a measuring head.
After winding, the ends of the magnetic wires on the armature are stripped using a laser. The dual highway style production lines provide economy in floor space and operators, and by use of the transfer shuttles enable bottlenecks of one line to be handled by the other line.

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Description

129~ 4 Case 5077 STREAMLINED PRODUCTION OF ELECTRIC MOTOR
ARMATURES AND STATORS

FIELD OF THE INVENTION

This invention relates to the manufacture of electric motors, particularly to methods and production lines for the production of armatures and stators.

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An electric motor essentially comprises an armature assembly and a stator assembly both of which are individually produced on separate production lines after which the armature and the stator assemblies are assembled together.
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~; In order to make two lectric motors of different ;sizes ~ for example with armatures of 47mm and 57mm diameter, it has been the practice to have four separate and distinct production lines, i.e. two for the armatures and two for the stators.

Each production line occupies a substantial floor space.
Furthermore, ea h production line has its own independent equipment and its own staff.

~UMMARY OF rHE INVEN~TON

One asp ct of the present invention, at least in its pre~erred embodiments, aims to reduce the floor space oacupied ~y suah production lines by 60 to 70~ and, -at the same ~ime, reduce staffing levels by 25 to 50~.

Accord;ng to one aspect of the invention there is provid~ o production Iines for the manufacture of .
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armatures or stators for electric motors separated along at lea~t part of the length thereof by a common partition. The pair of production lines being designated for the production of one of the two major subassemblies of electric motors, i.e. either the armatures or the stators.

By placing the production lines close together many operations can be carried out using a common operating head thereby ~ubstantially red~cing duplication of operating mechanisms~

; Preferably, one or more shuttles are provided for transferring~ articles from one production line to the other and ~vice-versa. Preferably, the shuttles are disposed one upstream and one downstream of the coil winding areas.

This has ignificant advantages, particularly where there a temporary~demand for the increase in production~of ons type of motor. Thus, for ~xample, if there is a temporary increased demand~for 47mm armatures, one or more coil winders~ on the 57mm production line can be assigned to 47mm winding duty. A number of 47mm ~;` armatures can then be ;transferred to the 57mm production line by the~shuttle,~wound on ~he conscripted winder and returned to the 47mm line downstream of the winding`~area.

The armatures and/or stators can be transported on pallets which are prePerably provided with identifying means, such as identifying lnserts, which enable them to be ldentified as they approach an operating station.
When the quaue to the winder on the 57mm production line 3~ .is not ~ull, a signal is sent to a shuttle which diverts the appropriate number of units from the 47mm production line. As these units pass through the 57mm winding area , .: : "

~l29~ 4 they are ignored by all the winders with the exception of the conscripted winder which identifies them and admits them to its queue. The wound units are similarly idenkified as they approach the downstream shuttle and are xeturned to the 47mm production line.

In both armature and stator manufacture, an end member is first laid on an assembly pallet. The end member is then covered with a stack of laminations~ The total height of the stack must be within a prescribed range. Heretofore, it has been the practice to pick a stack with a height about the minimum of the range, check the height and, if nec~ssary, add a further lamination. This requires a first stacker station, a measuring station and a second stacker station.

According to another aspect of the present invention, there is provided a method of obtaining a stack of armature or stator laminations of a height within a defined range, which method comprises the steps of picking a tack close to the maximum height permitted, checking the height of the stack, and removing a lamination if the measured height is greater than the maximum height.

Pre~erably, the height of the stack is measured with a measuring head and the lamination is removed, if necessary, with means associated with the measuring head.
Advantageously, the means comprises a vacuum line.

It will be appreciated that by using this techni~ue only one stacker st~tion is required thereby making useful ~avings both in capital cost and in production line length. The discarded laminations can, of course, be reoycled to the stacker.
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~;~90144 Once the windings are completed, it is necessary to make electrical contact between the magnetic wire used in the winding and either the commutator ring in the case of the armature or terminals in the case of the stator. This may be achieved in several ways.

A further aspect of the present invention provides a method of ~tripping the ends of magnetic wire on an armature or a stator, which method comprises the step of subjecting the ends of the magnetic wire to a laser beam.
Although the magnetic wires could be individually indexed into position and the laser activated, in the case of an armature, it i~ preferred to place a mirror between the main winding and the~ends of the magnetic wire on the armature and rotate the armature beneath the laser.
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The present invention~also provides buffer storage which comprises a platform for supporting electric motors or parts thereof in layersj and means which, as said :
; plat~orm is loaded, lower said platform so that it remains substantially horizontal at all times.
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Preferably, the buffer storage comprises means ~which lower the platform at a rate such that when the;platform i~ covered ~ith a layer of articles thé tops of the articleB lie in substantially~ the same plane ~as ~the platform before the artioles were applied~
Advantageously, each end of the platform may be supported by a reapective belt which passes upwardly and over a respective wheel and is connected, at the other end thereo~ to at least ons respective spring. Pre~erably, the belta are provided with spacer members at vertically ~paced locations to facilitate the loading of the buffer storage. Advantageously, the wheèls may be provided with teeth and the belts are provided with teeth which mesh with the teeth on said wheels. Preferably, the wheels .
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1.~901~4 are mounted fast with respect to other toothed memb~rs and 6aid other toothed members are interconnected by a chain arranged in a figure of eight configuration so that any vertical movement at one end of the platform is accompanied by an equal movement at the other end thereof. Advantageously, the platform may be scalloped to receive a row of armatures therein.

According to another aspect of the present invention, there is provided a method of simultaneously producing similar subassemblies for two different motor specifications, comprising the steps of advancing subassemblies of first and second specificat:ions along ~;~ two sid~ by side production lines, one for each specification, and at a winding station transferring some of the subassemblies from one production line to the other line and winding coils thereof on the other line,~
and thereafter returning these:~same subassemblies~back to said one line, whereby the ;rate of production of the~
subassemblies on said one line ls increased.

Other objects, features and :advantages of the~ present invention will bécome more~ ully apparent ~rom the : following detailed description o~ the preferred: ;
:~ embodiments, the ~appended claims and the accompanying , drawings.

BRI~F ~ESCRIPTION QE-T~ AwIN~

` In the accompanying drawing~: :
~ FIGURE 1 is a block diagram showing the layout o~
: Fi~s. 2A to G;
: FIGURES 2A to G show a schématic layout of a dual : 30 highway armature production line;
FIGURE 3 is a schematic cross-section of two elevators taken along line III-III of Fig. 2A;

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~9~144 FIGURE 4 is a perspective view of an armature assembly pallet;
FIGURE 5 is a schematic cross-section taken along line V-V of Fig. 2A;
FIGURE 6 is a schematic plan view of an assembly pallet awaiting end fibre placement;
FIGURE 7 is a fragmentary cross-section showing part of an armature provided with a slot liner about to be cut as the first stage in a cut and tuck operation:
FIGURE 8 is a view similar to Fig. 7 but showing the first step of the tuck operation;
~: ~IGURE 9 Qhows the second step of the tuck ~: ~ operation:
FIGURE lO is a schematic side elevation of a~trickle~
: station;
FIGURE 11 is~a~block diagram showing the layout of : ~ Figs. 12A to C; :~
~; : FIGURES 12A, B~and:C show a schematic layout of a~
dual highway stator production line;
FIGURE 13 is a perspective view of a stator assembly pallet;
: FIGURE 14: is a plan~ view of:the~ stator assembly : pallet loaded with a stack of laminations;
25 : FIGURE 15 iB a side elevation of the stator assembly : pallet ~immediately after winding;
~IGURE 16 i9: ~a perspective view of~a buf~er storage ~or armatures;
FIGURE 17 is a perspective view o~ part of a buffer storage for gears; and FIGURE 18 is a plan view showing the buffer storage . of Fig. 16 in use.

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: , ~. ;; . , ~2901~4 ~AILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment of complete armature and 6tator production lines according to the present invention are illustrated in Figs. 1 through 18. For ~ase of understanding, various sQctions or aspects of these production lines will be separately described with the use o~ appropriate subheadings.

DUAL HIGHWAY ARMATURE PRODUCTI~N LTNE

Referring to Figs. 2A to 2G there is shown a dual highway armature production line which is generally identified by reference numeral 1. Figs. 2A to 2G should be taken ln se~uence together as a single drawing as schematically indicated in Fig. 1.
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The dual highway armature production line 1 comprises two conveyors 2 and 3 which are separated by a stationary partition 4. The conveyors 2 and 3 are driven at the same speed by separate and distinct variable speed motors (not shown).

EL~VATOR

Two elevator 5 and 6 are arranged at the beginning of the production line to raise armature assembly~pallets to the~
level o~ conveyors 2 and 3, respectively. Each elevator has a plurallty of trays 7 (Fig. 3) which can each aacommodate two armature assembly pallets. The elevators 5 and 6 are independently controllable and can together raise 3600 armature assembly pallets per hour to the level of the conveyor~ 2 and 3. The armature assembly pallets are transferred to the conveyors 2 and 3 by plungers ~not shown).

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~291~)~44 ARMATURE ASSEMBLY PALLETS

Fig. 4 shows an armature assembly pallet which is generally identified by reference numeral 8. The armature assembly pallet is made of mild steel and comprises a base 9 which is approximately 63mm wide, 75mm long and 25mm deep. The top of the base is provided with two upward~y extending pins lO and ll which are relieved adjacent the base 9. The pins lO and ll are disposed to either side of a counterbored hole 12. A similar counkerbored hole 13 is disposed adjacent the countexbored hole 12. One side of the base 9 is provided wlth a 610t 14 which accommodates an identifying insert ; 15. The base is provided with a positioning arrangement which comprises a horizontally extending bore 16~and a~
cut-ou~ 17.

As s~hown in Fig. 5, the bottoms of the bases 9~of the~ -armature assembly pallets rest on their respective~;~
~` conveyors 2 and 3, while the ~ides are confined~between ~ ;
~ide members 18 and beam l9 which supports the 6tationary 20 ; partition 4. The~instal1ation shown is intended for the~
simultaneous production of armatures having; a nominal diameter of 57mm~;and 47mm. The;identifying~inserts 15 on the armature assembly pallets are appropriately coded~and the armature assembly pallets intended for the production of 57mm armatures pass along conveyor 2, whi~le those~
intended for the production of 47mm armatures pass along aonveyor 3.

ND FIBRE PLACEMENT

Th~ ~irst stage in making an armature is the construction 30 of the armature core assembly. As the empty armature assembly pallets are carried down the dual highway ~armature production line l by conveyors 2 and~ 3 they ~ !

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,. ~ ' ' ' ~29~1~4 enter station 20 (Fiy. 2A). The followiny events then occur on the armature assembly pallet 8 on conveyor 2.

As the armature assembly pallet enters the station 20 it engages a 8top 21 (Fiy. 6) which projects across the path of the conveyor 2. When engagement is sensed, an arm 22 i moved to the right so that a shot pin 23 enters the horizontally extending bore 16 in the armature assembly pallet 8 and urges it against the stationary partition 4.
Once the armature assem~ly pallet 8 is in position, a moulded end ~ibre is lowered onto the armature assembly pallet 8 with a low vertical pressure slide (not shown).
The moulded end fibre is made of plastics material and comprises a hub with outwardly projecting spokes which are correctly orientated with respect to the armature 1~ assembly pallet 8 by the slide. An escapement alternately holds ~ack and releases the moulded end fibre in correct timing with the slide so that a moulded end ~ fibre can be pressed onto an armature assembly pallet~8 : ~ as soon as it is correctly loca~ed. Once the moulded end fibre i8 in position the~arm 22 is withdrawn to allow the armature assembly pallet 8 to continue its journey. The arm 22 is then advanced so that the stop 2~ is ready to sense the next armature assembly pallet.

While this is happening, conventional end fibre placement 25 iB per~ormed on the armature assembly pallet on conveyor - 3. The total time taken ~or armature assembly pallet trans~er and placement o~ the end fibre is about 2.25 seconda.

S~AC~ER STATION

~0 The ar~ature assembly pallets pass to a stacker station 24 where they are~ sensed and detained in pairs to each side of the stationary partition 4. A dispenser 25 is .
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~290~at4 disposed to each side of the production line. Each dispenser contains a plurality of stacks 26 of armature laminations 27 (Fig. 2A~. Each stack 26 is biased upwardly again6t retaining fingers by a damped piston and cylinder arrangement (not shown). In use a common operating head moves ~our universal grippers into a position ~uch that two universal grippers are positioned over two stacks 26 of one dispenser 25 and two universal grippers are positioned over two stacks 26 of the other dispenser 25. As the universal grippers move into position they displace the retaining fingers thereby allowing the armature laminations 27 to rise into the universal grippers. The grippers are then raisecl until they reach an air cylinder stop which determines the height of the stack to be removed. This height is set at the maximum height in the acceptable range of heights~.
The grippers and the gripped stacks are ~then removed upwardly sufficiently rapidly to enable the retaining Pingers to move into place above the remaining armature laminations without displacing ~urther laminations.~

The stacks of armature laminations are placed on the armature as~embly pallets between~the pins lO and 11 and over the counterbored hole 12~ Once the ~tacks of armature laminations are correctly positioned, the armature assembly pallets are released and continue down the pro~uctlon line.

SPLIT $TACK S~ATIOM

The assembly pallets then enter a split stack station 28 ~Fig. 2A) where they are sensed and detained in pairs to each side of the etationary partition 4. A common operating head having two bars pivotally mounted thereon and having a gripper at both ends thereof descends onto the stacks so that the grippers on each ba~ grip the top :

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75% of armature laminations on successive armature assa~bly pallets. ~he common operating head is then raised and the bars are rotated through 180 degrees by a common chain drive. The common operating head is then lowered and the armature laminations released. The common operating head is then raised by a small distance and the grippers actuated so that the grippers on each bar grip the top 25% of the armature laminations on successive armature assembly pallets. The operating head is then raised, the bars rotated through a further 180 degrees and the armature laminations replaced. As a result of this operation inaccuracies in the manufacture of the armature laminations tend to be balanced out.

MEASURING STACK

The armature assembly pallets then pass to a measuring station 29 (Fig. 2A) where they are sensed and detained individually to each side of the stationary partition 4.
A common operating head with individually adjusted ~easuring heads descends onto the stacks. If a stack exceeds the maximum height permissible a vacuum line leading to the pertinent measuring head is actuated and an armature lamination removed fxom the relevant stack.
~he removed armature lamination is then returned ko the ~tacker station for re-use.

OTHE~ END FIBRE PLACEMENT

The armature assembly pallets then pass to station 30 (Fig. 2B) where they are sensed and detained in pairs to each ~ida of the stationary partition 4. End ~ibres are then placed over the upper end of each armature in a manner ~i~ilar to that described with reference to 8tation 20~

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~290144 SHAFT INSULATION PLACEMENT STATION

The armature assembly pallets then pass to station 31 (Fig. 2B) where they are sensed and detained individually to each side of the stationary partition 4. A tube 32 is fed horizontally toward each armature assembly pallet, cut to length and then moved into a vertical position.
Each tube is then pressed through the top end fibre, the stack o~ armature laminations and the bottom end fibre by a common operating head. The tube 32 comes to rest in the counterbore portion oP the counterbored hole 12 (Fig. 4) in the respective pallet.

SHAFT P~I~CEMENT STATION

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The armature assembly palle~s then pass to station 33 (Fi~. 2B~ where they are sensed and detained in pairs to each side of the stationary partition 4. ~ A common operating head simultaneously presses a sha~t through each shaft insulation tube. The shafts come to rest adjacent the bottom of the counterbored holes 12. The shafts are arranged in plastic chain carriers which align ~; 20 the ~hafts with the shaft insulation tubes. ~ The operating head then presses the sha~ts out of the carrier, through a guide member into~the shaft insulation~
tube.
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The armature assembly pallets then pass to a slot lining ~takion 34 (~ig. 2B) where the outer periphery of the a~a~ure laminations is provided with an insulating lining. This can be aahieved conventionally (as shown) or ~y transferring the~assembly in counterbored hole 12 to ~unterbored hole 13 ~(Fig. 4) and inserting pre-pun~i! ; lot liners into the slots either individually or :

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in pairs on opposite sides of the armature.

COMMUTATOR PLACEMENT STATION

The armature assembly pallets then pass to station 35 (Fig. 2C) where ~hey are sensed and detained individually to each side of the stationary partition 4. A common operating head descends and the armature assemblies are indexed to an appropriate position. A commutator ring i6 then placed on the upper end of each armature assembly.
The commutator rings are supplied ~rom two vessels both disposed to one and the same side of the production line.
Thïs ha~ the advantage of increasing access to the production line on the opposite side to the vessels.

The completed armature core assemblies then pasa to a ;
buffer zone 36 (Fig. 2C) where the cores are removed ~rom the armature assembly pallets which are returned~to the elevators 5 and 6 (Fig. 2A~.

WINDING AREA

The completed armature core assemblies are transferred~
from the buffer zone 36 to winding pallets and pass to a winding area 37 (Fig. 20) which comprises a multiplicity of "flow through" dual winders 38. The windlng pallets enter a winder 38 with the armatures substantially vertiaal and their commutator rings uppermost. An overhead chuck descends and grips the armature which is fed into the winding loop. The armature core assembly is then wound with magnetic wire in the conventional manner.
Th2 wound armature is removed from the winding loop and is returned to the conveyor 3' which is about 1 metre higher than the input conveyor. ~ The ends of each wire are wound~around respective tangs on the commutator ring during the~winding operation.

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SHUTTLE S~ATIONS

Shuttle stations 71 and 72 are provided both upstream and downstream of the winding area 37. Each shuttle station 71, 72 functions to transfer selected winding pallets from one production highway to the other, the pallets so transferred passing through gaps 4a in the dividing partition 4. The selected pallets are pushed transversely from one side of the partition to the other by air cylinders, each pallet so transferred engaging against a stop when the trans~er is completed.~ Endless belt cross conveyors may be employed in place of the air cylinders. Winding of the armature coils at the winders 38 is the slowest operation in the production line, and for that reason multiple winders 38 are employed. Should one of the dual production lines have a heavier winding~
load than the other, then a parcentage of the armatures~
on the production line ha~ing~this heavier winding load can be transferred by the upstream shuttle 71 to the ;~ other production line and the coils of the transferred armatures wound~ on one of the~ winders of the other ; production ~line.~ After winding, these transferred a~natures are then returned to their original production line by the downstream shuttle 72. The winder of~ the other production line 80 used can be changed in winding specification should this be necessary. Identification inserts in the pallets are used to enable the conscripted winder to identify transferred armatures, and also for the downstream shuttle 72 to select these transferred armatures for return to their original production line.
The upstr2am shuttle 71 can eelect the armatures to be transferred on a numerical basis, e.q. every tenth armakure. More than one winder 38 can be so conscripted if production conditions or requirement would benefit from thi~. For example, in an extre-ne situation when all the winders for one production line ~ere inoperative,~or .. : , .

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example by failure of a common drive, then temporarily half the winders o~ the other production line could be conscripted to keep both production lines operating, but at a reduced rate.

Similar pairs of shuttle stations can be provided upstream and downstream of any other operational stations in the production lines to provide similar versatility of production with these stations~

INSULATION REMOVAL STATION

l~ The winding pallets then pass to an insulation removal station 39 (Fig. 20) where they are sensed and detained individually to each side of the stationàry partition 4.
A mirror is placed immediately over the end of the armature windings and the wound armature is rotated through 360 degrees beneath a low power pulsed laser. As the laser hits the insulated magnetic wire the insulation vaporises leaving a cleanly stripped wire in the vicinity of the tangs. A hood is provided to extract the fumes.
The mirror protects the ends of the armature windings.

CRIMPING STAn'ION
The winding pallets then pass to a crimping station 40 ~Fig. 20) where they are sensed and detained individually to each side of the stationary partition 4. A common operating head descends and the tangs of each commutator rlngs are then crimped to their respective uninsula~ed wires by crimping tools which each comprise a plurality of crimping heads which are electrically insulated from one another. This enables the armature windings to be electrically tested during the crimping operation.
' As an alternative to crimpingl the wires may be fused to ' ' .~ .

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their respective tangs. For this purpose the winding pallet is correctly positioned. The wound armature is then raised so that the c~mmutator ring is disposed between two horizontally opposed weld heads. The wound armature is then indexed and the weld heads activated to fuse two wires to their respective tangs. The armature is then reindexed and the process repeated until all the wires have been fused to their respective tangs.
Finally, the armature is returned to its winding pallet.

SLOT LINING FINISHING - CUT AND TUCK

The wind~ng pallets then pass to a slot lining ~inishing station 41 (Fiq. 2E~ where they are sensed and detained individually to each side of the stationary partition 4.
A common operating head descends and the following operations are performed on ea~h lining. As indicated in Fig. 7, the slot liner 42 initially extends around the entire peripheral surface of the armature.
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In the first stage a pair of ~aws 43, 44 descend and ~ever the slot line 42 at locations 45 and 46. The ends of the 810t liner spring outwardly under their own resiIience. The jaw 4~ then moves to the left and i5 biased towards the centre of the armature. The jaw 43 enters the opening 48 of the slot 49. As it moves from its initial position the jAW 43 displaces the cut portion of the ~lot liner 42 to the position shown in Fig. 8.
The ~aw 43 i then retracted and jaw 4~ is moved to the right and biase~ into the opening 48 as shown in Fig. 9.
Jaw 44 is then retracted leaving slot 49 completely lined. The armature is then indexed and the procedure repeated for all the slots. ~t will be noted from Fig. 7 that a ~mall portion of the slot liner 42 lying between jaw 43 and 44' (the position of jaw 44 after reindexing) is not used. This is simply blown away and disposed of.

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TRICKLE STATIQN
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The winding pallets then pass to the trickle station 50 (Figs~ 2E and 10) where the wound armatures are removed from the winding pallets which are returned to the beginning of the winding area.

The wound armatures are moved outwardly to a pick and place robot ~1 which orientates the armatures horizontally. The armatures are presented to the respective robot 51 two at a time as indicated in Fig.
2E. The robots 51 place the armatures in chucks on conv~yor belts 52, as indicated by the arrows 51a.
Should either conveyor 52 be full, then the respective robot 51 places the armatures in a buffer outside the full conveyor 52, as indicated by ~he arrows 51b. The robots~ 51 wil1 draw from these buffers when no armatures are~béing supplied to the robots. ; At ~the end; of the trickle station is a vertical cooling tower 56 (Fig. 2F).
~ter cooling, the armatures are transferred to walking bQam c:onveyors 58. : ~
: , ~ The trickle station 50 and cooling tower 56 are~ further il}ustrated diagrammatlcally 1n Fig. 10 which is a side view taken from the left side of Figs. 2E and 2F.;~The armatures, carried in chucks 52a, are first moved by the conveyor 52 downwards and then through a preheating oven 53 in which they are preheated. Next they pass through trickle zune 54 where drops of molten insulating resin are trickled onto the armatures~ The res,in pe~neates the ~tructure by capillary action. Then the armatures~are pas~ed by the conveyor 52 through a curing zone 55. ~he armature are then transferred to a vertically extending conveyor in the coo}ing tower 56. After being cooled, the armatures are unloaded at location 57 onto the walking beam conYeyor 58. ~ ~

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COMMUTATOR TURN

Returning to Fig. 2F, the armatures are next fed by the conveyor 58 into a commutator turn station 60 where they are rotated while a brush is applied to the commutator 5 ring.

FAN PLACEMENT

The armatures then pass to a fan placement station 61 ~Fig. 2F) where they are sensed and detained individually to each ~ide of the stationary partition 4. A common operating head then places t~e fans on the armature shaft~ on the respective lines.

The armatures are then transferred by a pick and place unit 62 (Fig. 2F~ to a measuring station 63. The armatures are then transferred to balance line pallets which enter an elevator 64 (Fig. 2G). The balance line pallets leaving elevator 64 enter a halancing station 65 (Fig. 2G). The balance is ~irst ohecked at station 66 and any corrective action written to a magnetic memory on the balance line pallet. The armature then pa~ses to an indexing station where the armature is indexed prior to enterlng a milling station 67 where material is removed ~rom the circumference of the rotor. Finally, the balance of the armature and the electrical connections are tested at station 68 (Fig. 2G).

Reject units are marked and are automatically diverted to the side at diverter station 69 (Fig. 2G). Where further balancing is required the reject unit is returned -to ~tation 66 (Fig. 2G). Where there is an electrical fault, the units can be checked manually and repaired where practical.

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The completed armatures are unloaded by robots at the end (Fig. 2G) of the dual highway production line apparatus, and the empty balance line pallets returned for further use.

The arrangement thus far described has significant advantages over the prior art. In particular, each highway may be dedicated to the production of an armature of a specific size or specification. However, many operations may be carried out in unison on both production lines using the same operating head.
Furthermore, considerable capital expenditure is saved in the area o~ the trickle station where the cost of a large single tricXle station servicing both production lines is very much less than the cost of two separate trickle~
tatione as previously required.

Further, although each highway may be dediGated to a speci~ic armature specification, when one highway is working at a higher production rate than the other, some of the armatures o~ the higher production rate highway can be transferred to the lower production rate highway for one or more operations to be performed, and then returned to their ori~inal highway. In this way, the overall production rate of the dual highway can be increased when more of one specification of the~armature is require than another specification. The same approach is al~o used in stator assembly production as will be describe~ later.

Where~r po6~ible, equipment ~or performing operations on the armatures o~ both production lines should be placed ; 30 to one side o~ the dual highway, thereby maximising operator access from the other side of the dual highway.

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~ 29~1~44 While the arrangement thus far described has significant advantages over the prior art in steady 6tate operation, its main advantage comes when there is a ~sudden demand for one or other of the two armatures. Normally the bottlenec~ in any armature production line is the winding area. If there is a sudden demand then this can only be met within the capacity of the winding area. In the arrangement described, when a high demand, for example for 47mm armatures arises, a winder normally on the 57mm production line i5 assigned for winding 47mm armatures.
When this winder is ready, a signal is sent to the shuttle 71 which taXes armatures from the 47mm production line until the queue to the winder is full. Thereafter the queue is replenished to keep the winder queue full.
The winder recognises the 47mm armatures by virtue of their identity inserts. Conse~uently, 57mm armatures are not admitted to the winder queue. The wound 47mm armatures pass down the 57mm production line until th y approach the shuttle 72 where they are identified and returned to the 47mm line.
Similarly, armatures can be shuttled from the 57mm production line to the 47mm production line and back again if required.

The production of stators according to the invention will now be described.

DUAL H~G~RY STATOR PRODUCTION LINE

Referring to Figs. 12A to C, there is shown a dual highway stator production line which is generally ident$fied by reference numeral 101. The dual highway 30stator production line 101 comprises two conveyors 102 and 103 which are separated by a stationary partition 104. The conveyors 102 and 103 are driven at the same :

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speed by separate and distinct variable speed motors ~not shown).

ELEVATOR

Two elevators 105 and 106 ~Fig. 12A) are arranged to raise stator assembly pallets to the level of conveyors 102 and 103 respectively. The elevators 105 and 106 are similar to the elevators 5 and 6 in Figs. 2A and 3.

STATOR ASSEMBLY PALLETS
. .
Fig. 13 shows a stator assembly pallet which is generally identified by referen~e numeral 108. The stator assembly pallet is made of mild steel and compri~ses a base 1os which is approximately 75mm wide and 75mm 1ong. The~top~
~: : of the base los is provided with two upwardly extending~
lamination locators 110 and lll~which~are~disposed::to:;:
either 6ide o~ a bore 112. The top of::the base~ lO9 is;~
~ also provided with four upwardly extend:ing wire:clips ~: :
; ~ 113a, b, c and d. One side of the base 109 is provided with a:slot 114 which accommodates an identifying insert 115. : The bottom of the ~base is provided ~with a ao positioning arrangement which comprises a vertically extending bore 116. : ~ ~ :
:
BOTTOM END RING ~LACEME~T

The ~lr~t stage in making the stator i5 bottom end ring placement which occurs at station 120 (Fig. 12A). As each ~tator pallet on each conveyor 102, 103 enters the : station 120 it is identified and held Past by a locator : ~ pin entering vertically extending bore 116. A common : : operating head moves into position and the bottom~end:
~: ~ rings are then placed over the ~respective holes 112~and ~: : ::: : : `: ; ~: :

.~ .. ~ . . . -., - :. .
. . : . - . ..

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'', ' ." .. , . ,~. ,'' ' . ~ ', lZ90~1l44 the stator assembly pallets released.

STACKER STATION

The stator assembly pallets pass to a stacker station 124 (Fig. 12A) where they are sensed and detained in pairs to each side of the stationary partition 104. A dispenser 125 is disposed to each side of the production line.
Each dispenser contains a plurality of stacks 126 of stator laminations 127. The stator laminations are loaded onto the stator assembly pallets in a manner analogous to the operation of the stacker station on the armature production line described hereinbefore.

SPLIT STACK STATION

The stator assembly pallets then enter a split st~c~
;~ ~ station 128 (Fig. 12A)~where the stacks are treated in~a~
~ manner similar to the armature laminations in `~the armature split stack station 28 (Fig. 2A).; Fig. 14 is~a plan view of the stator assembly pallet immediately after this operation.

MEASURING STATION
:~ :
20 ~ The ~stator; assemb~ly pallets then pass to a measuring~
~tation 129 (Fig. 12A) where the height of each stack is measured and, i~ necessary, one lamination removed by a vacuum head.

SLOT LINER PLACEMENT

~`~ 25 The stator assembly pallets then pass to slot insulation ; placement stations 130 (Fig. 12A) where they are sensed a~d detained. A placement head is lowered onto each stack and injects the slot liners after the pallet has . .
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1290~44 been indexed into position.

OP END RING PLACEMEMT
:
The stator assembly pallets then pass to station 131 (~ig. 128) where they are ~ensed and detained in pairs to each ~ide of the stationary partition 104. A common operating head moves downwardly and ~places the top end xing assemblies on the tops o~ the ætacks.

WINDING A~A

: The ~tator assembly pallet~ then pass to winding area 137 (FigO 12B~ where the field windings are applied in the ~anner ~et out in United States Patent No. 4,6:12,702 issued Septem~er 23, 1986 to the a~signee herein.
' ; Essentially, once each ~tator assembly pallet~i- in the ~winding position a pair of clamps descend to hold it ; ~irmly in place. A pair of ~.ollow needles: 138 (Fig. 153 conta$ning ~agnetic wire rise upwardly through the bore 112 in the ~tator ~ssembly pallet 109 and through the:
entre of the ~tack of~tator laminations. The needles :~ ~ 20 138 pause at the:top o~ their travel while tooIing 6ecures the ends of the magne ic wire to wire clips 113a : and 113b. ~he needles ~38, which are ~ccentrically o~fset with respect to the longitudinal central axis of the stator, then proceed ~o move upwards and downwards, 2S pivoting alt~rnately in a olockwise and ~n anti-clockwise ~ense at the end of each movement to create the field winding~ without ~he employment oP temporarily positioned winding forms. At the end of this process, the needles 138 ag~in pause at~the top of their travel while tooling ~ecures the other ~nd of the wires to the-reamining wire clips:ll3c And 113d. : : : :
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. . ..
, ~29~

COIL LEAD ASSEMBLY

The ~tator assembly pallets then pass to a coil lead assembly ~tation 140 (Fig~ 12B~ where a tool grasps the start and end lead portions of the magnetic wire, removes them from the wire clips, loops them over strain reliefs in the top end ring, and turns them around terminal hooks thereon. Excess wire is then cut off and removed.

TERMINAL FUSE STATION

The ~tator assemblies on the 47mm production line then pass to a station 141 (Fig. 12B) where the wires are fused to the terminals. For this purpose the stator assembly pallet is correctly positioned. The stator is then raised so that the terminals are disposed between two horizontally opposed weld heads~ The stator is then indexed and the weld heads activated to fuse two wires to their respective terminals. The armature is then reindexed and the process repeated. Finally, the stator is returned to its pallet.

CRIMPING STATION

The etator assembly pallets on the 57mm production line pass into a crimping station 142 (Fig. 12B~ where the terminals are crimped around the magnetic wires and a aontlnuity aheck made.

BONDING STATION

The stator assembly pallets then pass into a bonding station 143 (Fig. 12C) where the terminals are connected to a source of electricity. As the windings heat they melt an adhesive coating applied to the stator laminations~ When the current is switched off the . , - ' ' ~2~

adhesive hardens thereby bonding the stator lami~ations together.

TEST

Finally, the completed stator is tested at station 144 (Fig. 12C). The stators which pass the test are unloaded by robots and the stator assembly pallets returned to the start of the stator production line. A load leveler storage maga~.ine 145 containing tested stators is shown being loaded by a robot arm 146. Standby empty magazines 147 are al60 shown. When loaded, the storage magazines are then transferred to a storage area.

SHUTTLE STATIONS
:
As with the armature production line, shut~les 171 and 1~2 (Fig. 12B) are provided immediately upstream and downstream of the winding area 137 so that production o~
one type of stator can be increased a~ the expens~ of the other. Thus, to increase the production of 57mm stators, a wind~r on the 47mm production line may be allocated for 57mm winding duty. The winder has its own internal queue. When the queue is not fuIl a signal is sent to the shuttle 171 which transfPrs a palle~ ~rom the~57mm production line, past the highway dividing partition 104 through a gap 104a therein, to the 47mm production line.
When the stator assembly pallet carrying the 57mm stator body arrives, it is identified by its identity insert and admitted to the aonscripted winder. When the wound stator approaches the downstream shuttle 172, it is recogniced and re~urned across the partition 104 through a gap therein to the 57mm production line.

Although the shuttles~ have been placed upstream and downstream of the winding areas they could additionally , '' ' ' . ' , ' ' ' .
' . ~ ' , 12910~4qL

or alternately be placed in other locations. The shuttles i71 and 172 are the same as the shuttle 71 and 72 in the armature production line.

The armature and ~tator production lines described above ~ave an estimated 60 to 70% of the floor space occupied by separa~e production lines used in the prior art.
Furthermore, labour can be reduced by between 25 and 50%
since one machine minder can watch the production of two different armatures or two different stators simultaneously.

BUFFER STORAGE

Referring to Fig. 16 there is shown a buffer storage whi~h i~ generally identified by reference numeral 200.
The bu~fer StQrage 200 comprises a trolley 201 arranged to run on rails 202. The trolley 201 is provided with two platforms 203 and 204 which are arranged side by side. The platform 203 is supported by two belts 205, 206, the longitudinal edges of which are providecl with toothed strips 207, 208; 209 and 210 respectively. The toothed strips 207, 208 pass over toothed wheels 211, 212 which are secured fast on a shaft 213. Similarly, the toothed strips 209, 210 pass over toothed wheels 214, 215 which are secured fast on a parallel shaft 216. A gear wheel 217 is mounted fast on the end o~ the shaft 2:L3 and i8 connected to a gaar wheel 218, fast on shaft 216, by a chain 219 which i5 arranged in the shape of a ~igure ei~ht. The free end of the belt 205 is connected to ~he ~ase of the trolley 201 by means of a pair of wires 223, 224 vhich pass around puIleys 225, 226 and pulleys 227, 228 attached to springs 221 and 222. Similarly, the free end 229 of the belt 206 is connected to the ~ase of the trolley by means of a pair of wires 232, 233 which pass around pulleys 234, 235 and pulleys 236, 237 attached to :- ~ . ~ ' .

. .
, ., ~ . .

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1290~.44 springs 234, 231. Platform 204 is supported by a mechanism similar to platform 203. Both platforms 203 and 204 are scalloped as shown to receive a plurality of armatures. The lengths o~ the support wires are adjusted so that the platforms 203 and 204 are substantially level with the top of the inset portion 201A of the trolley 201 when the trolley 201 is unladen.

In use, armatures are progressively loaded onto the scalloped platforms 203, 204 and, as the weight of th~
load increases, so the respective platform lowers. By the time the platform has one complete row of armatures thereon, the platform has descended by an amount such that the tops of the armatures thPreon are now approximately level with the inset portion 201A of the trolley 201. Another layer of armatures can then bs placed on the first layer and so on until the buffer storage 200 is full, each platform being loaded independently. As armatures are removed from the buffer storage 200, the respective platform 203, 204 rises, so that at any given time an automatic pick and place unit will have no difficulty in gripping in sequence the next armature.
.
Spacers (not shown) are mounted at spaced~ vertical intervals on the belts 205, 206 to facilitate placement f armatures, bearing in mind that alternate rows are o~fset from one another by one half the diameter of the armature. The platPorm 203 is kept horizontal by the ahain 219 which ensures that any rotation of toothed wheels 214 and 215 is matched by~ an equal and opposite rotation o~ toothed wheels 211 and 212. The springs 22~, 222, 230 and 231 are, of course, chosen to give the de~ired load~extension ratlo required.

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:,, . : . : ;

lZ9~L4g The trolley arrangement shown in Fig. 17 is generally similar to ~hat shown in Fig. 16, except that four pins 244 are mounted fast with respect to the base of the trolley and extend through holes 245 in a platform. This arrangement is primarily intended for the storage of gears and the like which are stacked on the platform with the pins extending upwardly through the centers of the stacks.

Fig. 18 shows the buffer storage 200 of Fig. 16 in use in an armature production line. In particular, the trolley 201 ls rolled into place on rails 202 beneath a robot 246. In steady state operation, the robot 246 simply transfers armature core assemblies from armature assembly pallets in line 247 to winding pallets in line 248. If the winding line 248 is fully uccupied, the robot 246 transfers armature core assemblies ~rom the assembly pallets in line 247 to the buffer storagë 200. For this purpose the robot 246 has intelligent ~'X" and "Y" axls movement and can consequently progressively load the buffer storage 200. If the winding line becomes free when no armature core assemblies are available on line 247, then the robot 246 takes an armature from the buf~er 6torage 200. The robot's memory may be programmed so that it carries a complete inventory o~ the buffer storage 200. By extending the travel of the robot 246, single robot 246 may service three winding lines in addition to a single armatura assembly line.

Tha bu~fer storage for gears shown in Fig. 17 can similarly be incorporated in the armature production line at a station for mountlng gears on the armature shafts.

-: . . - . ., -~.............. ~
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,:

'' .i' ~ ': ~, ~290~4 The above described embodiments, of course, are not to be construed as limiting the breadth of the present inven~ion. Modifications, and other alternative construc-tions, will be apparent which are within the ~pirit and scope of the invention as defined in the appended claims.

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Claims (18)

1. Apparatus for manufacturing major subassemblies of electric motors, comprising:
two production lines disposed side by side and separated along at least part of the length thereof by a common partition;
either production line being capable of performing at least one operation on subassemblies being produced on the other production line; and means for transferring at least some of the sub-assemblies from one to the other side of said partition for enabling said one operation to be performed on the transferred subassemblies, and wherein each said production line includes a coil winding station, said at least one operation comprises coil winding, and said transferring means is disposed upstream of said coil winding station, said coil winding station comprising a plurality of coil winders.

2. The apparatus of claim 1 , further comprising return transfer means, disposed downstream of said coil winding station, for transferring said transferred subassemblies back to their original production line on said one side of said partition.

3 . The apparatus of Claim 1, including means for automat-ically actuating said return transfer means on the approach of said transferred subassemblies to cause the transferred subassemblies to be returned to their original production line.

4. The apparatus of Claim 1, further comprising return transfer means, disposed downstream of said transferring means, for transferring said transferred subassemblies from said other side of said partition back to said one side thereof.

5. The apparatus of Claim 1, wherein said partition is stationary.

6. The apparatus of Claim 1, wherein said transferring means comprises a shuttle.

7. The apparatus of Claim 2, including buffer storage means for storing parts of the electric motors, said buffer storage means comprising a horizontal platform for supporting said parts in layers, and means for lowering said platform as the latter is loaded and for maintaining said platform horizontal as it is lowered.

8 . The apparatus of claim 7, wherein:
each end of said platform is supported by a respec-tive belt which is connected at one end to the platform, passes upwardly and over a respective wheel, and is connected at the other end to a spring;
each said wheel is provided with teeth which mesh with teeth of the respective belt; and the respective wheels are spaced apart and intercon-nected by a chain arranged in a figure eight configura-tion, whereby any vertical movement of one end of said platform is accompanied by an equal vertical movement at the other end of said platform.

9. The apparatus of Claim 8, wherein said platform is scalloped to receive a row of armatures.

10. Apparatus for manufacturing articles such as armatures or stators of electric motors, comprising:
a pair of longitudinally extending production lines disposed side by side in a dual highway configuration with a stationary partition separating the production lines along a substantial portion of the length thereof:
said production lines including conveyors for moving the articles therealong;
a plurality of operating stations disposed along said production lines for carrying out a series of operations at spaced apart locations therealong;
one of said operating stations on each line compris-ing a coil winding station having a plurality of coil winders;
transferring means, disposed upstream of said coil winding station, for transferring articles from either production line to the other production line, said transferring means moving said articles from one side of said partition to the other side thereof through a gap in said partition; and return transfer means, disposed downstream of said coil winding station, for returning articles transferred by said transferring means to their original production line.

11. The apparatus of Claim 10, wherein:
another of said operating stations comprises a trickle station having means for heating the articles and for trickling resin onto the heated articles, and a cooling tower for subsequent cooling of the articles, said cooling tower being vertically disposed and being common to both said production lines; and robot means, associated with each production line at an upstream end of said trickle station, for changing the articles from a horizontal disposition to a vertical disposition and for diverting said articles to a buffer zone if said trickle station is full.

12. A method of producing subassemblies for two electric motors of different specifications, comprising the steps of:
advancing the subassamblies during production thereof along production lines extending side by side, sub-assemblies to a first specification advancing along one production line and subassemblies to a second specifica-tion advancing along the other production line;
winding coils on said first specification sub;
assemblies on said on production line and winding coils on said second specification subassemblies on said other production lines; and transferring some of said first specification subassemblies from said one production line to said other production line prior to said winding step, winding coils of said some subassemblies on said other production line, and subsequently returning said some subassemblies to said one production line, whereby the rate of production of said first specification subassemblies is increased.

13. The method of Claim 12, wherein said subassemblies are armatures.

14. The method of Claim 12 , wherein said subassemblies are stators.

15. The method of Claim 12, including the step of forming a stack of lamination for each subassembly of a height within a defined range, said forming step comprising:
picking a stack of laminations close to a maximum height permitted;
checking the height of the stack; and removing a lamination if the checked height is greater than said maximum height.

16. The method of Claim 15, wherein the height of the stack is measured with a measuring head and the lamination is removed, if necessary, by vacuum.

17. The method of Claim 12 , including a wire stripping step on both production lines subsequent to said winding step, said stripping step comprising stripping ends of magnet wire employed in said coils by subjecting said ends to a laser beam.

18. The method of Claim 17, including the step of placing a mirror between each coil and the ends of the magnet wire thereof and rotating the coil beneath said laser beam.