Process for Assembly of Motor-Generators

Abstract

A process for assembling a brushless motor-generator includes assembling a rotor formed from two spaced apart rotor portions having magnetic poles that drive magnetic flux circumferentially through the rotor portions and back and forth across an armature airgap formed between the rotor portions. An air core armature is formed by coating a substantially nonmagnetic armature form with a tacky adhesive layer, and winding armature windings into a winding pattern onto the substantially nonmagnetic form using wire made of multiple individually insulated conductor strands that are electrically connected in parallel but are electrically insulated from each other along their length when located inside the armature airgap, wherein the strands of said wire are diametrically held together by an outer serve. The winding of the armature form includes sequentially applying pressure to sections of said wire against the tacky adhesive layer.

Claims

1. A process for assembly of a brushless motor-generator comprising: assembling a rotor formed from two spaced apart rotor portions having magnetic poles that drive magnetic flux circumferentially through said rotor portions and back and forth across an armature airgap formed between said rotor portions. forming an air core armature by coating a substantially nonmagnetic armature form with a tacky adhesive layer, and winding armature windings into a winding pattern on to said substantially nonmagnetic form using wire comprised of multiple individually insulated conductor strands that are electrically connected in parallel but are electrically insulated from each other along their length when located inside said armature airgap, wherein said strands of said wire are diametrically held together by an outer serve; said winding comprising sequentially applying pressure to sections of said wire against said tacky adhesive layer, wherein tack of said tacky adhesive layer holds said wire to said substantially nonmagnetic armature form while during the winding process, in said winding pattern later required for magnetic torque generation; and inserting said air core armature into said armature airgap and mounting said air core armature to a stator of said motor-generator for production of magnetically induced torque between said rotor and said stator.

2. A process for assembly of a brushless motor-generator as described in claim 1, wherein: said tacky adhesive layer comprises a film adhesive.

3. A process for assembly of a brushless motor-generator as described in claim 2, wherein: said film adhesive comprises a B-staged thermoset polymer film.

4. A process for assembly of a motor-generator as described in claim 1, wherein: said multiple individually insulated conductor strands of said wire comprise a layer of thermoplastic polymer coating and said strands are heated and bonded to each other after said wire has been adhered in said winding pattern to said substantially nonmagnetic armature form.

5. A process for assembly of a brushless motor-generator as described in claim 1, wherein: said windings are applied to said substantially nonmagnetic armature form by a parallel kinematic robot that forms said winding pattern and applies pressure to said wire against said tacky adhesive layer on said substantially nonmagnetic armature form.

6. A process for assembly of a brushless motor-generator as described in claim 5, wherein: said winding pattern is formed using a payout roller that rolls said wire onto said tacky adhesive layer while applying said pressure.

7. A process for assembly of a brushless motor-generator as described in claim 1, wherein: said motor-generator comprises a radial armature airgap and said substantially nonmagnetic armature form comprises a tube; said process further comprises over-wrapping said windings with a hoop tensioned layer that radially squeezes said wire against said tacky adhesive layer after completion of said winding pattern; wherein said tensioned layer is applied with a tension force per axial length exerting radial compression on said substantially nonmagnetic armature form that is less than the first diametral critical buckling load of said tube.

8. A process for assembly of a brushless motor-generator comprising: assembling a rotor formed from two spaced apart rotor portions having magnetic poles that drive magnetic flux circumferentially through said rotor portions and back and forth across an armature airgap formed between said rotor portions; forming an air core armature by coating a substantially nonmagnetic armature form with a tacky adhesive layer, and winding armature windings into a winding pattern on to said substantially nonmagnetic form using wire comprised of multiple individually insulated conductor strands that are electrically connected in parallel but are electrically insulated from each other along their length when located inside said armature airgap; said windings being applied to said substantially nonmagnetic armature form by a parallel kinematic robot that moves in said winding pattern, dispenses said wire and sequentially applies pressure to sections of said wire against said tacky adhesive layer, wherein tack of said tacky adhesive layer holds said wire to said substantially nonmagnetic armature form while during the winding process, in said winding pattern later required for magnetic torque generation; and inserting said air core armature into said armature airgap and mounting said air core armature to a stator of said motor-generator for production of magnetically induced torque between said rotor and said stator.

9. A process for assembly of a brushless motor-generator as described in claim 8, wherein: said motor-generator comprises a radial armature airgap and said substantially nonmagnetic armature form comprises a tube; said parallel kinematic robot comprises parallel arms that move a winding head to dispense said wire and to apply pressure to said wire against said tacky adhesive layer on said substantially nonmagnetic armature form; said process further supporting said substantially nonmagnetic armature form by an additional motorized axis to rotate about the axis of said tube while adjacent to said winding head and allowing formation of said winding pattern of said windings around the circumference of said tube.

10. A process for assembly of a brushless motor-generator as described in claim 8, wherein: said parallel kinematic robot utilizes a spring force pressure compensating head to reduce variation of said pressure applied to said wire against said tacky adhesive layer on said substantially nonmagnetic armature form while applying said windings.

11. A process for assembly of a brushless motor-generator as described in claim 8, wherein: said parallel kinematic robot moves a winding head to dispense said wire and to apply pressure to said wire against said tacky adhesive layer on said substantially nonmagnetic armature form; and said winding pattern is formed using a payout roller that rolls said wire onto said tacky adhesive layer while applying said pressure.

12. A process for assembly of a brushless motor-generator as described in claim 8, wherein: said wire is dispensed from a spool that feeds said parallel kinematic robot, whereby said spool remains rotationally stationary to dispense wire and a tensioner adds tension to said wire after being dispensed from said spool.

13. A process for assembly of a brushless motor-generator as described in claim 8, wherein: said substantially nonmagnetic armature form is comprised of a fiber reinforced polymer.

14. A process for assembly of a motor-generator as described in claim 8, wherein: said multiple individually insulated conductor strands of said wire comprise a layer of thermoplastic polymer coating and said strands are heated and bonded to each other after said wire has been adhered in said winding pattern to said substantially nonmagnetic armature form.

15. A process for assembly of a brushless motor-generator comprising: assembling a rotor of a motor-generator; forming an air core armature by coating a stator portion with a tacky adhesive layer, and winding armature windings into a winding pattern using wire comprised of multiple individually insulated conductor strands that are electrically connected in parallel but are electrically insulated from each other along their length when located inside said armature airgap, said winding comprising sequentially applying pressure to sections of said wire against said tacky adhesive layer, wherein tack of said tacky adhesive layer holds said windings to said stator portion while during the winding process, in said winding pattern later required for magnetic torque generation; and assembling said stator portion with said rotor for production of magnetically induced torque between said rotor and said stator.

16. A process for assembly of a brushless motor-generator as described in claim 15, wherein: said windings are applied to said stator portion by a parallel kinematic robot that forms said winding pattern and applies pressure to said wire against said tacky adhesive layer on said stator portion.

17. A process for assembly of a brushless motor-generator as described in claim 16, wherein: said tacky adhesive layer comprises a pressure sensitive adhesive film.

18. A process for assembly of a brushless motor-generator as described in claim 17, wherein: said parallel kinematic robot moves to apply said windings to said stator portion in a serpentine winding pattern wherein windings of a single phase are wound by traversing multiple times around the circumference of said stator portion.

19. A process for assembly of a brushless motor-generator as described in claim 15, wherein: said tacky adhesive layer comprises a B-staged thermoset polymer film which is further cured to increase the bond strength of said wire to said stator portion after completion of said winding pattern of said winding process.

20. A process for assembly of a brushless motor-generator as described in claim 15, wherein: said parallel kinematic robot utilizes a spring force pressure compensating head to reduce variation of said pressure applied to said wire against said tacky adhesive layer on said stator portion while applying said windings.

Description

DESCRIPTION OF THE DRAWINGS

[0019] The invention and its many advantages and features will become better understood upon reading the following detailed description of the preferred embodiments in conjunction with the following drawings, wherein:

[0020] FIG. 1 is a cross-sectional drawing of a radial gap air core motor-generator in accordance with the invention;

[0021] FIG. 1A is a cross-sectional drawing of the end view of the motor-generator rotor of FIG. 1;

[0022] FIG. 2 is a perspective drawing of an armature manufacturing process for production of armatures for use in the radial gap air core motor-generator of FIG. 1 in accordance with the invention;

[0023] FIG. 2A is a schematic drawing of the preferred winding pattern of the radial gap air core armature of FIG. 2;

[0024] FIG. 3 is an elevation drawing of an air core armature winding machine for use in the production process of FIG. 2;

[0025] FIG. 4 is a cross-sectional drawing of an axial gap air core motor-generator in accordance with the invention;

[0026] FIG. 5 is a perspective drawing of an armature manufacturing process for production of armatures for use in the axial gap air core motor-generator of FIG. 4 in accordance with the invention;

[0027] FIG. 6 is a comparison chart between different types of tacky adhesive layers for use in the armature manufacturing process in accordance with the invention.

[0028] FIG. 7 is a schematic drawing of the cross-section of wire for use in an air core motor-generator in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] Turning to the drawings, wherein like reference characters designate identical or corresponding parts, FIG. 1 shows an air core motor-generator 30 comprised of a rotor 31 and a stator 32. The rotor 31 is constructed of two concentric spaced apart steel rotor cylinders 33, 34 that are attached to a hub 35. The hub 35 is supported by center shaft 36 journaled for rotation by bearings 37, 38. The bearings 37, 38 are mounted in housing end plates 39, 40 which are connected together by outer housing tube 41. Attached to the rotor tubes 33, 34 are circumferential alternating polarity permanent magnet arrays 42, 43 that drive magnetic flux back and forth between the rotor tubes 33, 34 and an armature airgap 44 created between the rotor tubes. Located within the armature airgap 44 is an air core armature 45 that is attached to the stationary housing end plate 39. The air core armature 45 is constructed of a nonmagnetic form tube 46 that extends into the armature airgap 44 and is used to support multiple phase winding active lengths 47. The windings 47, 48, 49 are wound with wire comprised of multiple strands that are electrically connected in parallel but are electrically insulated from each other along their length when located inside the armature airgap 44. The strands are preferably held together and protected against insulation damage by an outer serve 324, as shown in FIG. 7. The winding active lengths 47 are adhered to the form 46 through use of a pressure sensitive adhesive 50 during the winding process. The pressure sensitive adhesive 50 may preferably comprise a B-staged thermoset film adhesive that is adhered to the form 46 prior to winding and is preferably warmed to increase adhesion of windings active lengths 47 to the form 46 during winding. The windings 47, 48, 49 comprise active lengths 47 that are run axially with multiple phases lying in a single layer and are located within the armature airgap 44 and receive the magnetic flux from the magnetic arrays 42, 43. The windings 47, 48, 49 also comprise end turns 48, 49 that run circumferentially, overlap multiple phases and are located outside of the armature airgap 44. An outer tensioned overwrap 51 of fiberglass/epoxy may also be used to wrap the windings active lengths 47 and preferably compress them to shrink the required thickness of the armature airgap. After winding, the windings active lengths 47 are preferably permanently secured to the form either through curing the film adhesive 50, by the overwrap 51, or by both.

[0030] A schematic drawing of the end view of the rotor of the radial gap air core motor-generator of FIG. 1 is shown in FIG. 1A. The rotor 31 is comprised of two spaced apart rotor portions 33, 34 constructed of steel and having magnets 42, 43 that drive magnetic flux circumferentially, as shown at 60, 61 through the rotor portions and radially, as shown at 62 across the armature airgap 44.

[0031] An apparatus for production of armatures for use in the air core motor-generator of FIG. 1 in accordance with the invention is shown in FIG. 2. The process comprises the use of a parallel link robot such as a delta robot 71, shown in more detail in FIG. 3, in which the major mechanical axes act on the robot faceplate in parallel rather than in series. This allows for both quick and precise movements and as such delta robots are currently used predominantly for pick and place operations for order fulfillment. As shown in FIG. 2, the delta robot is uniquely used to place specially constructed wire and to also feed out the wire and to uniquely apply pressure to the wire against an armature stator 45, wherein the stator has an applied pressure sensitive adhesive to hold the windings temporarily in a shape for later electromagnetic torque production. The windings of multiple phases are wound onto the stator and the pressure sensitive adhesive holds the active length portions of the windings temporarily in place during the winding process. The end turns, which do not generate electromagnetic torque with the rotor, are located outside of the magnetic airgap and are necessarily overlapping.

[0032] As shown in FIG. 2, the armature manufacturing process 70 uses a delta robot 71 to wind special multiple individually insulated strand conductor wire 74 from a spool 72 on to an air core armature 45. The spool can be of conventional rotating outer pull type or more preferably a non-rotating version such as center pull to eliminate the effects of rotating spool inertia and tension control variation during the high speed winding process. The delta robot has a payout head 73 that feeds out the wire 74 and pressures the active length windings 47 against the pressure sensitive adhesive 50 on the armature form 46. At each end of the form 46, the payout head 73 forms the end turns 48, 49. The windings 47, 48, 49 are preferably wound as serpentine patterns whereby each phase is constructed by winding multiple times around the circumference of the armature 45. The benefit of this winding pattern is a minimized windings length and resistance and also a minimum number of required electrical connections. In an additional preferred embodiment, each of the phases is wound consecutively and is subsequently cut to produce each separate phase winding. After completing a single phase, the payout 73 can feed out a loop of extra wire before starting the winding of the next phase and this loop can be cut after completion of the winding process to yield individual phases having leads. The winding process also includes a headstock 75 with chuck 76 that holds the armature form 46 and rotates precisely and in unison with the motions of the payout to create the windings pattern. To minimize the twisting in the wire 74 between the spool 72 and payout 73, it may be desirable that the winding direction of the headstock 75 be alternated between the winding of successive phases. After winding is completed, the windings are preferably permanently secured either by curing the adhesive, overwrapping the windings or other means. It is also possible that a pressure sensitive adhesive could be used that has sufficient adhesion and temperature capability that does not require curing. However, a crosslinked thermoset adhesive would generally provide the highest strength and temperature capability.

[0033] A schematic drawing of the preferred winding pattern of the radial gap air core armature of FIG. 2 in accordance with the invention is shown in FIG. 2 A. The air core armature is comprised of a fiberglass reinforced polymer tube 46. Windings comprise active length portions 47, that will be located within the magnetic flux for torque generation, and end turns 49 and 49 at the ends of the form. The winding wire 74 is adhered to the circumference of the form 46 in a serpentine path using the tackiness of the pressure sensitive adhesive film. Typical construction most commonly winds three phases of windings.

[0034] A schematic drawing of the apparatus 71 for air core armature manufacturing for use in the production process of FIG. 2 in accordance with the invention is shown in FIG. 3. The manufacturing machine 71 comprises a delta robot with 3 axes motors 81, 82, 83 that are attached to a support plate 80 and together move the faceplate 86 in Cartesian coordinates through the use of parallel arms 84, 85. Armature winding speeds of up to 10 meters per second may be possible by the use of parallel links as opposed to serial link type robots. An additional payout directional axis device 87 may be attached to the faceplate 86 that can control the windings out-feed direction. Attached to the payout directional axis device 87 can also include a pressure control head 88 that enables more uniform pressure of the payout 73 to the windings when adhering them to the pressure sensitive adhesive. The pressure sensitive head 88 can be a spring, pneumatic cylinder or other mechanism that regulates the pressure between the wire and armature form during the adhering the active length portions 47 to the armature form 46.

[0035] The windings wire 74 is fed into the center of the delta robot 71 through pulley wheels 92, 93 and travels perpendicularly to the faceplate 86. Holes in the faceplate 86, payout directional axis device 87 and pressure control head 88 allow the wire to feed directly to the payout 73. Pulley wheels 89, 90 feed out the wire 74 to the armature 45, control the windings direction and apply pressure to the wire to adhere active length portions 47 to the pressure sensitive adhesive 50 on the armature form 46. A wire feed system such as pinch rollers 91 can be included to pull the wire 74 from the spool and to force feed the wire out the payout 73. The wire feed system 91 enables the looping required at end turns 48, 49 of the windings.

[0036] As shown in FIG. 4, the armature 245 of the axial gap air core motor-generator 230, is constructed as a flat disk. The axial gap motor-generator 230 is comprised of a rotor 231 and a stator 232. The rotor 231 is formed from two spaced apart steel disks 233 and 234 that are connected by a central hub 235. The rotor 231 is journalled for rotation by bearings 237 and 238 which are supported by the housing end plates 239, 240. Outer housing tube 241 connects the housing end plates 239, 240 and also supports the air core armature 245 within the armature airgap 244 through mount connection 246. The air core armature 245 comprises active length portions 247 and inner and outer end turn portions 248, 249. Located on the two rotor disks are permanent magnets 242, 243 that drive magnetic flux circumferentially through the rotor portions 233, 234 and across the armature airgap 244. It is also possible to utilize rotor disks 233, 234 not constructed from steel, wherein the magnets 242, 243 would utilize a Halbach array to conduct the flux circumferentially on the rotor.

[0037] A schematic drawing of an armature manufacturing process for production of armatures for use in the axial gap air core motor-generator of FIG. 4 in accordance with the invention is shown in FIG. 5. The manufacturing process 200 uses a parallel kinematic robot 71 to wind the windings wire 74 onto the air core armature 245. The armature form 201 is constructed of a flat sheet of fiberglass reinforced epoxy with a surface layer of B-staged epoxy film adhesive 202. To increase the tackiness of the film adhesive 201 while winding, the ambient temperature may be increased. The parallel kinematic robot 71 has a payout head 73 with payout roller 90 that forms the winding pattern 203 by moving in the desired pattern and applying pressure to the windings wire 74 against the tacky adhesive layer 202 and substantially non-magnetic form 201. After completion of winding the air core armature 245, it is preferably over cured to increase the lap shear strength between the winding wire 74 and form 201.

[0038] Polymer adhesives are available in a wide range of types. There are two critical requirements for the tacky adhesive layer for use in accordance with the invention, which are lap shear strength in operating conditions of the motor-generator and the tackiness at ambient or winding temperature during the winding manufacturing process. A comparison chart between different types of tacky adhesive layers for use in the armature manufacturing process in accordance with the invention is shown in FIG. 6. Structural adhesives such as B-staged epoxy film 302 show high lap shear strength compared to pressure sensitive adhesives such as acrylic tape 303. However there is a tradeoff with between operating strength and the winding process ease. B-staged epoxy film 305 shows much lower tackiness at ambient temperature 304 than the acrylic tape 306, making the windings more difficult to adhere to the substantially non-magnetic forms. Low tackiness can be overcome through increasing the temperature during the winding process. Likewise, low lap shear strength can be overcome with the addition of tensioned overlap layer. One advantage of the pressure sensitive adhesive is the lack of requiring curing. New polymer adhesive formulations are now available that are hybrids and can also be advantageously used.

[0039] A schematic drawing of the cross-section of wire for use in an air core motor-generator in accordance with the invention is shown in FIG. 7. The wire 320 is comprised of multiple individually insulated conductor strands 322 that are electrically connected in parallel but are electrically insulated from each other along their length 323 when located inside said armature airgap. This construction uses insulation 323 to isolate the small strands 322, which may be several hundred in number, from each other electrically when exposed to the changing magnetic field in the armature airgap. The benefit is that while the strands of the wire 320 may be electrically in parallel by connections outside of the magnetic flux, they are precluded from generating large eddy current losses in the armature airgap. To prevent damage to the strand insulation 323 of the actual strands 322, an outer serve 324 is preferably used to hold the wire bundle 320. Serves can include Mylar tape, nylon thread and other constructions. An additional benefit of the outer serve 324 is that it facilitates high speed winding process by the parallel kinematic robot. In some cases, it can be further desirable to apply a layer of thermoplastic coating 321 on top of the strand insulation 323. The coating 321 can be used to bond the strands 322 together through heating and increase the rigidity of the flexible windings with the form after the completion of the winding patterns on the form.

[0040] Obviously, numerous modifications and variations of the described preferred embodiment are possible and will occur to those skilled in the art in light of this disclosure of the invention. Accordingly, I intend that these modifications and variations, and the equivalents thereof, be included within the spirit and scope of the invention as defined in the following claims, wherein I claim: