The present invention relates to improved solutions for processing dynamo-electric machine components (e.g., armatures or stators for electric motors, generators, or alternators).
Dynamo-electric machines include a rotating cylinder called the armature in a stationary part called the stator. The stator is a thick-walled tube (core or yoke) that surrounds the armature, which is also called the rotor. The stator has windings that produce a rotating magnetic field in the space occupied by the rotor. This magnetic field interacts, for example, with current passed through windings in the armature to generate forces that turn the armature. Conversely, when the armature is rotated by an external prime mover, the stator magnetic field induces a voltage in the windings.
The armature and stator windings are wire coils wound on ferromagnetic pieces or cores (poles). These poles, for example, in the case of a stator, extend radially inward from the inner surface of the stator core or yoke. The radially inward extending poles usually have rectangular cross sections that fan or extend out into what are known as pole heads or shoes. Adjacent longitudinal slots formed along the inner surface of the stator core or yoke may define the poles. Alternatively, longitudinal ferromagnetic pieces (pole cores) may be mounted on the inner surface of the stator core or yoke. Conventional joining techniques, such as dovetail joints, may be used to securely mount the pole cores. The dimensional tolerances of the stator and the armature, the pole configurations, and wire coil-winding properties (such as wire size, pitch, number of turns) all contribute or determine the operational characteristics of the dynamo-electric machine.
In stator manufacturing, the stator wire coils are often injected or wound using automated machinery that includes a wire dispenser or needle mounted on a moving arm. The wire dispenser travels back and forth through the stator bore alongside a pole, dispensing wire stretches that are deposited on the pole sides and ends to form a wire coil. However, such winding operations can be difficult, inconvenient or slow because of the limited geometrical access to the pole sides through the confines of a stator bore. The detrimental effect of the limited geometrical access for wire coil winding may be more pronounced for multiple-pole stators.
Wire winding operations through the stator bores may be avoided by assembling stators using subassemblies, one of which has the pole sides extending out from an inner structure. Wire coils may be wound on such a subassembly from outside its bore using flyer-type winders that are conventionally used, for example, to wind armature coils. Becherucci et al. European publication EP 1020975, and Taguchi et al. U.S. Pat. No. 4,818,911 (both of which are hereby incorporated by reference in their entireties herein) disclose multi-pole stator subassemblies on which the wire coils may be wound by flyer-type winders.
The two references respectively show single and two-section hollow annular inner casings (e.g., casing IC,
Consideration is now being given to ways of providing solutions for improving dynamo-electric machine component manufacturing processes. Attention is directed toward methods and apparatus for assembling stators from subassemblies that permit stator wire coils to be wound using flyer-type winders, and in particular from subassemblies of the types similar to those described above.
In accordance with the principles of the invention, methods and apparatus for the fabrication of dynamoelectric machine components from multiple parts or segments are provided. The inventive methods and apparatus may be used for improving the manufacturing processes used in making or assembling components from multiple part subassemblies.
A pallet-based transportation system is provided for the fabrication of stators from multi-part inner subassemblies on which stator wire coils may be wound using flyer-type winders. The inner subassemblies are made from one or more plastic tube section and several stator pole pieces around which wire coils are wound. These multiple-part inner subassemblies may lack structural strength or rigidity until the final fabrication steps. Outer casings or support rings are fitted on the inner subassemblies to finalize the usable stator structure.
The pallet for carrying multiple-part stator subassembly includes support or seating structures for holding the subassembly in an upright orientation, and fixtures for referencing the radial positions of stator poles in the subassembly. The support structures and the referencing fixtures are designed to hold the stator subassembly through all the fabrication stages involves in making the inner subassembly from plastic tube sections, stator poles, and wire coils.
The seating or support structures and the radial position referencing fixtures are coaxial cylindrical structures that are disposed around an aperture in the pallet. The support structures have an inner ledge surface on which a stator subassembly can be seated in an upright orientation. The referencing fixtures are a circular array of spaced-apart vertical slats, which abut stator pole pieces in the seated in the uprightly seated stator subassemblies. The referencing fixtures may be detachable. The support structures and the radial position referencing fixtures provide structural strength and rigidity to stator subassemblies that lack the same.
A lift mechanism operates though the aperture in the pallet to raise seated stator subassembly to a work position in a flyer-type wire coil winder. The lift mechanism includes an expanding collet whose clamps operate through the spacings in the circular array of the radial position referencing vertical slats to grip and firmly hold the stator subassembly poles. The lift mechanism presents the firmly held poles in proper alignment for wire coil winding by a winding head in the winder.
A specific winding head can be used for winding wire coils in pockets adjoining the presented poles. The specific winding head includes a flyer arm and one or more pairs of movable wire guides. A pair of wire guides is shaped to include sloped wire-running portions extending into wire drop surfaces for controllably placing wire turns at specific locations in pockets. This pair of wire guides may be used for depositing layered and tightly wound wire coils. The other pairs of wire guides are utilized direct or guide wire dispensed by the flyer over geometrical obstructions into the pocket in which the wire coil is being wound.
Another lift mechanism is used in conjunction with the pallet for compression fitting of the stator inner subassembly in the stator outer casing. Another lift mechanism includes a pair of movable press blocks on opposite sides of a centering ring. The centering ring and one of the movable blocks are designed to sandwich and hold the stator outer casing in an upright orientation. The other movable block is designed to operate from below the pallet to lift and push the stator inner subassembly into the sandwiched stator outer casing. The centering ring has tapered bore structure to align and radially compress the inner subassembly as it is pushed into the sandwiched stator outer casing. The tapered bore structure includes channels or grooves to receive dovetail pins or other locking structures on the surface of the inner casing. The channels or grooves are designed to align and direct the received dovetail pins or other locking structures into corresponding dovetail slots in outer casing.
Further features of the invention, its nature, and various advantages will be more apparent from the following detailed description of the preferred embodiments and the accompanying drawings, wherein like reference characters represent like elements throughout, and in which:
a is a view similar to that in
b is a cross sectional view of the structures shown in
a and 5b are views similar to those in
a and 8b are enlarged sectional views of the top portions of the lift mechanism of
In several of the accompanying drawings, which show sectional views, hatching or shading of various sectional elements may have been omitted for clarity. It will be understood that this omission of hatching or shading in the drawings is for the purpose of clarity in illustration only.
The present disclosure provides solutions for uniform and reproducible manufacturing of dynamo-electric machine components. The disclosed solutions relate to the processing of subassemblies that include multiple parts or segments. The disclosed solutions include inventive features to enhance control of the dimensions of fabricated parts. The inventive features may be built into the subassembly structures, their transport systems, and/or the processing tools. The disclosed solutions may find application in manufacturing processes where it is important to maintain the integrity of the geometrical configuration of the multiple parts in a subassembly during the processing steps.
In order that the invention herein described may be easily understood, the subsequent description is set forth in the context of the manufacture of stators using multiple-part stator inner subassemblies or casings (see, e.g.,
A disclosed manufacturing solution includes transport systems, which preserve the geometrical configuration of multiple parts in a stator subassembly while advancing the stator subassembly from one processing step to the next. The transport systems use a pallet for carrying the multiple-part stator subassembly to work positions in various processing tools. An embodiment of the pallet for carrying the multiple-part stator subassembly is described herein, preliminarily in the context of the fabrication of a multiple pole stator inner subassembly or casing, with reference to
It will be understood that support structure 12 need not contact all end surfaces of a supported stator subassembly to maintain the latter in a desired upright position. Annular edge portions 12′ may be designed to be suitably discontinuous to accommodate various geometric aspects or features of stator subassemblies. For example, support structure 12 sidewalls (and edge portions 12′) may be broken as suitably spaced vertical sections or pillars. The pillar heights and the inter-pillar spacings may be suitably designed to accommodate the bottom portions of wire coils wound around stator poles 70 of an uprightly seated stator inner subassembly.
In addition to edge portions 12′ of support structure 12 that are used to reference edge portions of an uprightly seated stator subassembly, pallet 10 includes a removable fixture 13 that serves as a radial position reference for parts of the supported stator subassembly.
Fixture 13 may, for example, have a cylindrical structure that extends upward from pallet 10 through the annulus of support structure 12 and through the bore of any supported stator subassembly. The tubular sides of fixture 13 may, for example, be a circular array of spaced-apart slats or strips 13′. Adjacent slats 13′ in the array may be separated by a spacing or passageway 13′″. Passageways 13″ provide clearance for the operation of external workpiece-handling tools (such as collet clamps 24′
Fixture 13 may be releasably fastened to pallet 10 using conventional mechanical arrangements.
It will be understood that the various dimensions of a specific fixture 13 and a support structure 12 may be designed for use with stator subassemblies of specific size or type. Fixture 13 and support structure 12 on pallet 10 may be suitably replaced or changed to correspond to the particular size or type of stator that is being manufactured.
Continuing with the description of the fabrication process of the multiple pole stator inner casing, reference is again made to
a, 5b, and 6 show stator inner subassembly or casing 60 with the joined tube sections.
Multiple-pole stator inner casing 60 shown in
Winder 20′ may have a winding head 52 for depositing a wire coil around any one of poles 70 of raised inner casing 60. Optionally winder 20′ may include several winding heads for winding wire coils around several poles simultaneously (see e.g., Becherucci et al. EP 1020975). Exemplary winding head 52 includes a flyer 20 and winding guide 21 mounted on a shaft 22.
In operation, flyer 20 rotates on shaft 22 around one of poles 70 of raised casing 60 to deposit wire turns in pocket 62 adjoining the subject pole. During the operation, winding guide 21 is suitably positioned in alignment with subject pole 70 and flyer 20, to direct wire dispensed by flyer 20 into pocket 62. Shaft 22 also may be used to translate flyer 20 and winding guide 21 to and fro in directions 22′ and 22′ to deposit wire at different depths in pocket 62. To facilitate this to and fro movement, winding guide 21 may have a suitable shape with hollow central portion or cutout abutting subject pole 70. The central cutout, for example, cutout 21c, permits unhindered movement of winding guide 21 in directions 22′ and 22″ over the ends of pocket 62 adjoining subject pole 70 (
At the winding station, exemplary apparatus 23, which may be used for lifting or raising inner casing 60 to the work position in winder 201, is placed underneath pallet 10 (
a, 8b and 9 show several components of apparatus 23, namely support cylinder 24, frame tube 25, and central shaft 26. The three components have concentric cylindrical structures with central shaft 26 and frame tube 25 as the innermost and outermost components, respectively.
Support cylinder 24 has an expanding collet-like gripping structure at its upper end. The collet-like structure may be designed to grip and firmly hold multiple-pole stator inner casing 60. Annularly spaced finger-like clamp portions 24′, which extend upwardly from tubular portions of support cylinder 24, form the collet-like structure. The number of clamps 24′ may correspond to the number of poles 70 present in casing 60. Each clamp 24′ may be intended to engage a corresponding one of poles 70. Further, the collet-like gripping structure may be designed to operate through the common bores of inner casing 60 and fixture 13. Accordingly, the diameter of the collet-like structures (unbiased) may be less than the inner diameter of fixture 13. Additionally, the widths of clamps 24′ and the inter-clamp spacings may be designed so that clamps 24′ can freely move without interference through spacings 13″ between slats 13′ of fixture 13 (
Lengths of support cylinder 24 below the collet-like structures also may have a diameter, which is smaller than the inner diameter of fixture 13. In which case, the smaller-diameter lengths of support cylinder 24 also can pass through the bore of fixture 13. Alternatively, lengths of support cylinder 24 below the length necessary to insert the collet-like structures up to the top of casing 60 may have a diameter that is larger than the inner diameter of fixture 13. Support cylinder 24 shown herein, for example, in
Apparatus 23 may be suitably configured so that the three concentric cylindrical components (support cylinder 24, frame tube 25 and central shaft 26) can, individually or in various combinations, move vertically. Support cylinder 24 also may rotate. Conventional motor drive or actuator arrangements may be used to move the various components.
Further, bearings 30 are mounted in frame 25 to enable smooth rotation of support cylinder 24 around axis X. A motor 29 is mounted on enclosure 25′ for controlled rotation of support cylinder 24. Motor 29 may impart rotary motion to support cylinder 24 through the combination of meshed gears 28 and 24″ that are respectively mounted on a shaft of motor 29 and the bottom of support cylinder 24. Gears 28 and 24″ are enclosed in enclosure 25′.
In the operation using apparatus 23 to raise stator inner casing 60 from pallet 10 to the work position in winder 20′, a preliminary procedure involves firmly gripping casing 60 with the collet-like structure atop support cylinder 24. In preparation of this procedure, with support cylinder 24 below pallet 10 (
With clamps 24′ in position adjacent to spacing 13″ in the bore of casing 60, actuator 3-3 retracts or pulls shaft 26 downward so that frusto-conical plug 26′ engages and biases clamps 24′. Biased clamps 24′ expand radially outward and deflect through spacings 13″ to contact pole shoe 72 surfaces. By design expanded or deflected clamps 24′ radially press against pole shoes 72, and thereby firmly grip inner casing 60.
In the operation to raise casing 60, after the preliminary procedure for firmly gripping casing 60 with clamps 24′ is completed, actuator 35 drives guides 31″ upward. Consequently, frame tube 25 (which rests in external tube 31) and concentric inner structures 24 and 26 all move upward. Their upward movement lifts gripped casing 60 from pallet 10. In the process, ledge surface 24′″ of support cylinder 24 pushes fixture 13 free of spring-loaded fastening ball 14, and thus detaches fixture 13 from support structure 12. Detached fixture 13 may rest on ledge surface 24′″ (
Using another embodiment of apparatus 23, stator inner casing 60 may be raised to the work position without having to detach and carry along fixture 13. In this embodiment lengths of support cylinder 24′″ below the collet-like structures have a small diameter which permits passage into fixture 13 bore (not shown). After inner casing 60 has been firmly gripped by clamps 24′ (
Stator inner casing 60, which has been raised using either embodiment of apparatus 23, further may be rotationally indexed around axis X. Motor 29, may be used to turn support cylinder 24 to index raised inner casing 60. The indexing may, for example, sequentially present poles 70 one by one for wire coil winding by flyer 20.
For specific wire coil winding applications, specific winders (other than winder 20′ described above) may be used. A winder 120′, which has additional mechanical features for controlling the wire coil deposition in the pockets of raised stator inner casing 60, is described herein with reference to
Winder 120′ may advantageously be used for depositing layered and tightly wound wire coils in pocket 62 adjoining subject pole piece 70 that has been indexed or presented for wire coil winding.
In the operation of winder 120′, flyer arm 120 rotates around axis 102 in direction D1, and dispenses tensioned wire W into coil pocket 62. A length of tensioned wire W stretches from flyer arm 120 to that portion of a wire coil turn, which is already deposited or formed in coil pocket 62. Guide portions or surfaces 100a and 101a, cooperatively alternate in intercepting wire W as flyer arm 120 rotates around axis 102. The intercepted wire W runs down portions or surfaces 100a (or 101a) and is dropped along terminal drop surfaces 100b (or 101b) into pocket 62. The dropped wire is deposited in pocket 62 along the foot of the drop surfaces. Thus, wire turns may be deposited at specific locations in pocket 62 by aligning drop surfaces 100b and 101b with those specific locations. This operational capability of winder 120′ may be used to control the deposition of wire in pocket 62 and, for example, to wind wire coils in successive layers. The controlled deposition of wire coils in pocket 62 in successive layers may be advantageous in obtaining tightly wound coils and in achieving desirable high wire turn occupancy.
The wire turns shown in
As the layered wire coil deposition process progresses, guides 100 and 101 (and flyer arm 120) are controllably moved laterally along directions X1 (or X2) to advance their foot positions (e.g., drop position Hi) to place the impending wire turn adjacent to the most recently deposited wire turn in a layer. For orderly buildup of the wire layer, the lateral guide and flyer movements, which may be continuous or intermittent, are synchronized with the rotational position of flyer 120 around axis 102. Further, during the wire layer deposition, surfaces 100b and 101b may be positioned sufficiently close to the top surface of the partially deposited wire layer (e.g., layer L2) to preclude the possibility of dropped wire slipping underneath surfaces 100b and 101b and over previously deposited turns (e.g., in area AW1). It will be understood that if necessary or advantageous, outer or front sidewalls PS of pocket 62 may have suitable cutouts PA to provide clear passages for the lateral movement of guides 100 and 101 while keeping guides surfaces 100b and 101b close to the top surfaces of the developing wire coil (
For a well-stratified multilayer wire coil, the first turn of an upper layer (e.g., layer L2) may be placed vertically above the last or final wire turn of the preceding completed layer (e.g., layer L1). To achieve this, after the final wire turn in the completed layer is deposited, the separation of guides 100 and 101 in directions Y1 and Y2 perpendicular to the plane of the completed layer may be increased. The increase may be calibrated to raise the bottom ends of guides 100b and 101b to the top of the new layer so that their respective drop positions (e.g., position Hi) are now on top of the final wire turn in a completed layer. Then the first turn of the new upper layer may be placed in the raised drop positions above the final turn of the completed layer. Subsequent wire turns in the new layer may deposited while moving the guide surfaces 100b and 101b laterally in directions X1 (or X2), as described previously.
In some winding applications, depending, for example, on specific stator geometry and dimensions or desired wire coil specifications, additional or supplemental wire guides also may be used. The supplemental guides may be used to direct or guide tensioned wire W in advantageous orientations to pocket 62. The supplemental guides may, for example, be used to overcome geometrical obstructions in the path of wire W.
In operation, supplementary guides 200 and 201 intercept wire W dispensed by flyer 120. Suitably shaped running surfaces on the guides 200 and 201 redirect the intercepted wire toward pocket 62. The intercepted wire may be redirected at suitable angles to the areas of pocket 62, where guide portions 100b and 101b are located to deposit wire turns. This use of supplementary guides 200 and 201 prevents wire snagging or catching by the interfering adjacent pole structures and allows tensioned wire W to be pulled around the innermost areas (R1) of pocket 62 at desirable pull angles by flyer 120.
Similarly, supplementary guides 300 and 301 may be used to guide or direct wire W to over come geometrical obstructions near the outermost areas (R2) of pocket 62.
After the winding operations (using, e.g., winder 20′ or 120′) are complete, stator inner casing 60 may be lowered to rest on support structure 12 on pallet 10. The lowering process may be conducted by suitable operation of apparatus 23. For brevity the lowering process is not described herein in any detail. However, it will be understood that the lowering process may, for example, generally proceed by suitably reversing some or all of the steps in the raising process described previously with reference to
Lowered stator inner casing or subassembly 60 with wire coils wound in pockets 62 around poles 70 may be transported on pallet 10 to a workstation for fitting or locking inner casing 60 in a matching outer casing or support ring 44. Matching outer casing 44 may have complementary dovetail slots along its inner surface that match dovetail pins 76 extending radially from inner casing 60. A press unit 40 may be used for press-fitting inner and outer casings 60 and 44 together. Features of press unit 40 and its operation in conjunction with pallet 10 are described herein with reference to
With reference to
Press unit 40 also includes centering assembly 43. Assembly 43 may have an annular or ring-like structure, which may have a tapered bore. Assembly 43 may be made up of matching half portions, namely movable members 43′ and 43″. Movable members 43′ and 43″ have open positions-away from axis 40′. Members 43′ and 43″ may close around axis 40′, for example, in the manner of a clamshell, or by other suitable motion. In their closed or ring-like configuration members 43′ and 43″ may support upright outer casing 44 in a cylindrical seat centered on axis 40′. Further backing block 42 may be lowered on outer casing 44 seated on closed members 43′ and 43″to firmly hold outer casing 44 in a fixed upright position. Conventional drive means (not shown) may be used to move the various block or members in press unit 40.
Members 43′ and 43″, include dovetail guide ways, channels, or grooves along their inner cylindrical surfaces (in closed position), which lead to the dovetail slots in uprightly seated outer casing 44. The dovetail channels may be designed to suitably align and direct all dovetail pins 76 of casing 60 into corresponding or complementary dovetail slots of outer casing 44 seated on members 43′ and 43″. For example, upper channel portions 43a may have dovetail cross sectional dimensions that are the same or identical to the dimensions of the dovetail slots in outer casing 44. Further, portions 43a may have a vertical orientation with channel sides aligned with the sides of corresponding dovetail slots in outer casing 44. Lower channel portions 43b may have dovetail cross sectional dimensions that are larger or wider at the bottom opening, but which taper or grade down to the dimensions of upper portions 43a over the length of lower portions 43b. Additionally, lower portions 43b may start at a greater radial distance from axis 40′ than vertical upper portions 43a and then slant or curve into the latter.
In the operation using press unit 40 to fit and lock inner casing 60 in matching outer casing 44, pallet 10 carrying the former is brought to rest over block 41. Pallet 10 may be aligned so that the common central axis of support structure 12 and inner casing 60 coincides with axis 40′ (
As the upward movement of block 41 continues, channels 43b receive dovetail pins 76 of inner casing 60. Received dovetail pins 76 are pushed up through channels 43b and 43a. In the process channels 43b and 43a align received dovetail pins 76 and direct them into the corresponding dovetail slots of outer casing 44. Aligned dovetail pins 76 slide into the corresponding outer casing dovetail slots as inner casing 60 is pushed up and pressed into outer casing 44 (
In an alternate fitting procedure using pallet 10 in conjunction with suitably modified press 40, outer casing 44 may be pushed down over inner casing 60. Press 40 may be suitably modified, for example, by enabling additional downward movement of members 43′ and 43″. In this alternative procedure, first, block 41 may be raised to firmly support pallet 10 carrying inner casing 60. Matching outer casing 44 may be seated upright, sandwiched between block 42 and closed members 43′ and 43″. Then the entire upper assembly (42, 44, 43′ and 43″) may be lowered to push or press outer casing 44 over inner casing 60. In this process, channels 43a and 43b may function in a manner similar to that described above to gather and direct dovetail pins 76 into corresponding dovetail slots in outer casing 44.
In either fitting procedure, after inner casing 60 is assembled or fitted in outer casing 44, members 43′ and 43″ may be disengaged and returned to their open positions. Then block 41 may be activated to disengage or lower pallet 10 carrying the assembled stator casing to a rest position on belts 11.
One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation. It will be understood that terms like “forward” and “backward”, “front” and “rear”, and other directional or orientational terms are used herein only for convenience, and that no fixed or absolute orientations are intended by the use of these terms.
This application claims the benefit of U.S. provisional application No. 60/352,116, filed Jan. 25, 2002, and U.S. provisional application No. 60/374,675, filed Apr. 22, 2002.
Number | Date | Country | |
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60352116 | Jan 2002 | US | |
60374675 | Apr 2002 | US |