JP6583047B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine installed between an engine (internal combustion engine) of an industrial vehicle and an oil pump.

  There is an industrial vehicle such as a forklift that drives an oil pump using an engine (internal combustion engine) and a rotating electric machine as drive sources. For example, when the rotating electrical machine operates as a generator, the engine serves as a drive source for the rotating electrical machine and the oil pump, and the rotating electrical machine charges the battery. When the rotating electrical machine operates as an electric motor, at least the rotating electrical machine among the engine and the rotating electrical machine serves as a drive source for the oil pump. The oil pump generates hydraulic pressure for cargo handling. The battery serves as a power source for the rotating electrical machine and the traveling motor. Moreover, the power unit comprised by an engine, a rotary electric machine, and an oil pump is described in patent document 1, for example.

  In the rotating electrical machine installed between the engine and the oil pump, the internal space of the housing member is not sealed, and internal air cooling with the rotation of the rotor is possible. In addition, a damper is provided between the rotating shaft of the rotating electrical machine and the drive shaft of the oil pump to absorb torque fluctuations generated between them. In recent years, a resin damper having an elastic resin member is sometimes used as a damper advantageous in cost and weight reduction.

JP 2009-71905 A

  In a rotating electrical machine in which the internal space of the housing member is not sealed, there is a problem that foreign matter from the outside easily enters the internal space. Moreover, when using a resin damper, an elastic resin member is weak to heat. For this reason, there has been a problem that the performance of the elastic resin member is deteriorated due to heat generated by the iron loss of the rotor core of the rotor entering the resin damper from the rotating shaft. In Patent Document 1, the sealed internal space of the housing member is cooled by the cooling oil, but since the resin damper is not provided, the problem of the present invention does not occur.

  The problem to be solved by the present invention is to provide a rotating electrical machine capable of suppressing entry of foreign matter into the internal space of a housing member and suppressing heat input from a rotating shaft to a resin damper.

  According to a first aspect of the present invention, there is provided a housing member interposed between an engine housing of an engine of an industrial vehicle and a member on an oil pump side, a stator provided in the housing member, a rotatable member disposed in the housing member, and A rotary shaft connected to the output shaft of the engine, a rotor provided on the rotary shaft, a cover member provided so as to cover an opening end surface of the housing member on the oil pump side, a rotary shaft and a drive shaft for the oil pump And a resin damper having an elastic resin member that absorbs torque fluctuation generated between the rotating member and the rotating shaft, a plate member adjacent to the oil pump side of the cover member is provided, and the cover member and the plate member Is connected to the inner space of the housing member on the radially inner peripheral side and to the outside of the housing member on the radially outer peripheral side Formed vent passage structure, heat radiation fins for radiating heat of the plate member is provided in the plate member.

  According to this configuration, since a labyrinth-structured air passage is formed between the cover member and the plate member, foreign air can enter the internal space of the housing member while allowing internal air cooling along with the rotation of the rotor. Can be suppressed. Moreover, since the heat radiation fin is provided in the plate member, the heat transmitted from the rotor to the plate member via the rotation shaft can be radiated by rotating the plate member together with the rotation shaft. Thereby, the heat input from the rotating shaft to the resin damper can be suppressed.

  In addition, one part of the plate member can serve both functions of suppressing entry of foreign matter into the internal space of the housing member and suppressing heat input from the rotating shaft to the resin damper. For this reason, compared with the structure which provides a complicated cooling mechanism, the reliability of a rotary electric machine can be improved, achieving simplification of a structure.

  In a second aspect based on the first aspect, the heat dissipating fin is formed on the surface of the plate member on the oil pump side. According to this configuration, the heat of the plate member can be efficiently radiated to the space on the oil pump side.

  According to a third invention, in the first invention, the cross-section in the circumferential direction of the plate member is formed into a wave shape, so that heat radiating fins having a wave shape in the circumferential direction are formed on both surfaces of the plate member. According to this configuration, the surface area of the plate member can be increased, and the heat of the plate member can be efficiently radiated to the space and the air passage on the oil pump side. Moreover, a plate member can be easily formed, for example by press molding of a metal plate.

According to a fourth invention, in any one of the first to third inventions, a plate member is fastened to the rotating shaft together with a member on the input side of the resin damper. According to this configuration, the plate member can be easily assembled to the rotating shaft together with the input side member.

It is the schematic which shows the power unit concerning Embodiment 1. FIG. It is sectional drawing which shows an electric motor. It is sectional drawing which shows the peripheral part of the cover plate of an electric motor. It is a perspective view which decomposes | disassembles and shows the resin damper and cover plate of an electric motor. It is a front view which shows a cover plate. It is sectional drawing which shows a part of cover plate. It is sectional drawing which shows a part of cover plate concerning Embodiment 2. FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Embodiment 1]
Embodiment 1 will be described. In this embodiment, the electric motor for forklifts used for the power unit of the forklift as an industrial vehicle is illustrated. FIG. 1 is a schematic view showing a power unit. As shown in FIG. 1, the power unit 10 includes an engine 12, an electric motor 14, and an oil pump 16. For convenience, the description will be made with the engine 12 side as the rear side and the oil pump 16 side as the front side.

  One end (front end) of the crankshaft 19 of the engine 12 projects from the front side of the engine housing 18. A connecting shaft portion 19 a having a small diameter is formed coaxially at the protruding end portion of the crankshaft 19. The crankshaft 19 corresponds to an “output shaft” in this specification. The engine housing 18 includes a cylinder block, a crankcase, a cylinder head, a cylinder head cover, an oil pan, and the like (not shown).

  The pump shaft 21 of the oil pump 16 protrudes from the rear surface side of the pump housing 20. A small-diameter connecting shaft portion 21 a is coaxially formed at the front end portion (rear end portion) of the pump shaft 21. A pump support member 22 that supports the oil pump 16 is coupled to the rear side of the pump housing 20 by fastening or the like. The pump support member 22 is formed in a conical cylinder shape that gradually expands from the front side toward the rear side. The pump support member 22 is formed with an opening 22a that communicates the internal space 23 with the outside. The pump shaft 21 corresponds to a “drive shaft” in this specification. The pump support member 22 corresponds to the “member on the oil pump side” in this specification. The pump housing 20 itself may be used as a member on the oil pump side. The internal space 23 and the opening hole 22a of the pump support member 22 are collectively referred to as “the space on the oil pump 16 side”. The formation position, opening shape, number, size, etc. of the opening hole 22a may be set as appropriate.

  The electric motor 14 will be described. FIG. 2 is a cross-sectional view showing the electric motor. The motor housing 25 includes a housing body 26, an end plate 27, and a motor cover 28. The housing body 26 is formed in a cylindrical shape. Further, the end plate 27 is formed in an annular plate shape. The end plate 27 is coupled to the housing body 26 by fastening or the like so as to close the rear opening end surface. The motor cover 28 is formed in an annular plate shape. The motor cover 28 is coupled to the housing body 26 by fastening or the like so as to close the front opening end face. A cylindrical tube portion 29 protruding rearward is formed at the hole edge of the hollow hole of the motor cover 28. The front end surface of the cylindrical portion 29 is close to the front end surface of the later-described rotor 35 with a predetermined gap therebetween.

  The motor housing 25 is coupled between the engine housing 18 (specifically, a cylinder block) and the pump support member 22 by fastening or the like. That is, the engine housing 18, the motor housing 25, and the pump housing 20 (including the pump support member 22) are integrated. A cylinder block is coupled to the end plate 27. The pump support member 22 is coupled to the motor cover 28. The motor housing 25 corresponds to a “housing member” in this specification. The motor cover 28 corresponds to a “cover member” in this specification.

  A ring-shaped stator 31 is fixedly arranged in the housing main body 26. The stator 31 is formed by winding a coil around a stator core (not shown). A hollow shaft-shaped motor shaft 32 is rotatably disposed at a central portion in the radial direction in the housing body 26. A disc-shaped flange 33 extending outward in the radial direction is integrally formed at the rear end portion of the motor shaft 32. An outer peripheral portion of the flange 33 extends into a space portion between the end plate 27 and the stator 31. A starter ring gear (not shown) is provided on the outer periphery of the flange 33. The motor shaft may be a solid shaft.

  On the motor shaft 32, a ring-shaped rotor 35 is fixedly arranged. The rotor 35 rotates integrally with the motor shaft 32. The rotor 35 is formed by arranging a plurality of magnets (not shown) along the circumferential direction on the outer periphery of a rotor core (not shown). The rotor 35 and the stator 31 are arranged coaxially. The outer peripheral surface of the rotor 35 and the inner peripheral surface of the stator 31 (specifically, the stator core) are opposed to each other via a predetermined air gap. The electric motor 14 corresponds to the “rotary electric machine” in this specification. The motor shaft 32 corresponds to a “rotating shaft” in this specification. The electric motor 14 is a bearingless motor that does not have a bearing that rotatably supports the motor shaft 32 on the motor housing 25. Further, when the engine 12 is started, the engine 12 is started by rotating the flange 33 together with the motor shaft 32 via a ring gear by a starter motor (not shown).

  A resin damper 38 is provided on the front end surface of the motor shaft 32 via a cover plate 45 described later. FIG. 3 is a cross-sectional view showing the periphery of the cover plate of the electric motor, and FIG. 4 is an exploded perspective view showing the resin damper and cover plate of the electric motor. As shown in FIG. 4, when the resin damper 38 is provided, a plurality of (for example, four) screw holes 36 are formed at equal intervals in the circumferential direction on the front end surface of the motor shaft 32.

  The resin damper 38 includes one connecting member 39, a plurality of (for example, four) divided connecting members 40, and one elastic resin member 41. The connecting member 39 is made of metal and includes a hollow shaft-shaped shaft portion 39a and a plurality of (for example, four) projecting pieces 39b that project radially outward from the shaft portion 39a in the radial direction. Moreover, the division | segmentation connection member 40 is metal, and is formed so that arrangement | positioning is possible between the protrusion pieces 39b adjacent to the circumferential direction of the connection member 39, respectively. The split connecting member 40 is formed with a bolt insertion hole 40 a penetrating in the axial direction (front-rear direction).

  The elastic resin member 41 is made of a rubber elastic material made of resin that can be elastically deformed. The elastic resin member 41 includes four cylindrical divided portions 41a, eight flat plate-like portions 41b that project radially outward from the circumferential edge of the cylindrical divided portion 41a, and a circumferential direction. And four fan-like plate-like portions 41c laid between the flat plate-like portions 41b adjacent to each other in the circumferential direction between the cylindrical division portions 41a adjacent to each other. The elastic resin member 41 is integrated by being fitted into the connecting member 39. That is, the cylindrical divided portion 41 a of the elastic resin member 41 is fitted between the protruding pieces 39 b adjacent to the shaft portion 39 a of the connecting member 39 in the circumferential direction. Further, the flat plate portion 41 b is overlapped on both side surfaces of the protruding piece 39 b of the connecting member 39 in the circumferential direction. Further, the fan-shaped plate portion 41 c is overlapped on the rear end surface of the protruding piece 39 b of the connecting member 39. A member in which the elastic resin member 41 is integrated with the connecting member 39 is referred to as a damper main body 42.

  In order to provide the resin damper 38 on the motor shaft 32, first, each divided connecting member 40 is fastened to the motor shaft 32. That is, the mounting bolts 43 are respectively inserted into the bolt insertion holes 40 a of the divided connecting members 40, and the mounting bolts 43 are fastened to the screw holes 36 of the motor shaft 32. For the mounting bolt 43, for example, a hexagon socket head cap screw is used. Subsequently, the fan-shaped plate-like portion 41 c of the elastic resin member 41 of the damper main body 42 is fitted between the divided connecting members 40 adjacent in the circumferential direction. Thereby, the flat plate-like part 41b of the elastic resin member 41 is interposed between the protruding piece 39b of the damper main body 42 and the split connecting member 40, respectively. In this way, the damper main body 42 is combined with the split connecting member 40. Accordingly, the resin damper 38 is coaxially disposed with respect to the motor shaft 32. Further, the circumferential facing surfaces of the split connecting member 40 and the flat plate portion 41b of the elastic resin member 41 are in contact with or in close proximity to each other in a surface contact manner. The split connecting member 40 corresponds to an “input side member” in this specification.

  As shown in FIG. 2, the connecting shaft portion 19 a of the crankshaft 19 of the engine 12 is splined into one end portion (rear end portion) of the motor shaft 32. Thereby, the crankshaft 19 and the motor shaft 32 are connected so that power transmission is possible. Further, the front end portion (the end portion on the connection shaft portion 19 a side) of the crankshaft 19 is fitted into the hollow hole of the end plate 27 with a predetermined gap therebetween.

  The connecting shaft portion 21 a of the pump shaft 21 of the oil pump 16 is spline-fitted into the shaft portion 39 a of the connecting member 39 of the resin damper 38. Thereby, the connection member 39 of the resin damper 38 and the pump shaft 21 are connected so as to be able to transmit power. In addition, the elastic resin member 41 of the resin damper 38 absorbs torque fluctuation generated between the motor shaft 32 and the pump shaft 21 by elastic deformation. Further, the crankshaft 19, the motor shaft 32, the resin damper 38, and the pump shaft 21 rotate around the same axis.

  A cover plate 45 is sandwiched between the motor shaft 32 and the split connecting member 40 of the resin damper 38. As shown in FIG. 4, the cover plate 45 is made of metal and has a stepped disk shape. The cover plate 45 includes an annular plate-shaped small-diameter side disk portion 45a, a cylindrical tube-shaped portion 45b extending forward from the outer peripheral portion of the small-diameter-side disk portion 45a, and a radial direction from the front end of the tube-shaped portion 45b. It has an annular plate-shaped large-diameter side disc portion 45c that extends outwardly in a coaxial manner. A plurality of (for example, four) bolt insertion holes 45d are formed at equal intervals in the circumferential direction in the small diameter side disk portion 45a. The bolt insertion hole 45d is disposed so as to be aligned with the screw hole 36 of the motor shaft 32. The small-diameter side disc portion 45a may be formed in a disc shape having no hollow hole. FIG. 5 is a front view showing the cover plate, and FIG. 6 is a sectional view showing a part of the cover plate.

  On the front side surface of the large-diameter side disc portion 45c of the cover plate 45, a large number of heat radiation fins 46 are integrally formed radially. The radiating fin 46 has a quadrangular cross section and extends linearly in the radial direction of the large-diameter disk portion 45c (see FIGS. 5 and 6). The radiating fins 46 are arranged at equal intervals in the circumferential direction. The cover plate 45 is made of a highly conductive material and a metal material such as aluminum or copper that easily conducts heat. The cover plate 45 is formed by press molding, forging, casting or the like. Further, the cross-sectional shape, number, size, etc. of the heat radiating fins 46 may be set as appropriate. The cover plate 45 corresponds to a “plate member” in this specification.

  As shown in FIG. 2, the small-diameter disk portion 45 a of the cover plate 45 is disposed between the motor shaft 32 and each of the divided connecting members 40, and is attached to the motor shaft 32 together with the divided connecting members 40 by mounting bolts 43. It is concluded. Thereby, the cover plate 45 is fixed coaxially between the motor shaft 32 and each divided connection member 40. The mounting bolts 43 are respectively inserted through the bolt insertion holes 40a of the divided connecting members 40 (see FIG. 3).

  As shown in FIG. 3, the cylindrical portion 45 b of the cover plate 45 is fitted into the cylindrical portion 29 of the motor cover 28 with a predetermined gap. Each divided connecting member 40 is disposed in the tubular portion 45b. The large-diameter disk portion 45c faces the front side surface of the motor cover 28 in parallel with a predetermined gap. Further, a labyrinth air passage 47 is formed between the motor cover 28 and the cover plate 45. The ventilation path 47 includes a cylindrical space portion 47 a between the cylindrical portion 29 and the cylindrical portion 45 b and a disk-shaped space portion 47 b between the opposed surfaces of the motor cover 28 and the cover plate 45. The cylindrical space 47a and the disk-shaped space 47b communicate with each other in an L-shaped cross section. The cylindrical space 47 a is in communication with the internal space (reference numeral 30) of the motor housing 25. Further, the disk-shaped space 47b on the outer peripheral side in the radial direction of the air passage 47 is communicated with the outside via a space (the internal space 23 and the opening hole 22a) on the oil pump 16 side (see FIG. 2). The cylindrical space portion 47a corresponds to the “space portion on the radially inner peripheral side of the air passage” in the present specification. The disk-shaped space 47b corresponds to the “space on the radially outer peripheral side of the air passage” in the present specification.

  In the power unit 10 (see FIG. 1), when the electric motor 14 operates as a generator, the engine 12 serves as a drive source for the electric motor 14 and the oil pump 16, and the electric motor 14 charges the battery. Further, when the electric motor 14 operates as an electric motor, at least the electric motor 14 of the engine 12 and the electric motor 14 becomes a driving source of the oil pump 16. The oil pump 16 generates a hydraulic pressure for cargo handling. The battery is a power source for the electric motor 14 and the traveling motor.

  Further, internal air cooling is performed as the rotor 35 rotates through a ventilation path 47 formed between the motor cover 28 and the cover plate 45. Further, since the air passage 47 is formed in a labyrinth structure, entry of foreign matter from the outside into the internal space 30 of the motor housing 25 is suppressed. Further, heat generated due to iron loss of the rotor core of the rotor 35 enters the cover plate 45 via the motor shaft 32. When the motor shaft 32 and the cover plate 45 of the electric motor 14 are integrally rotated, the heat is transferred from the heat radiation fins 46 of the cover plate 45 to the outside through the space on the oil pump 16 side (the internal space 23 and the opening hole 22a). Heat is dissipated. For this reason, heat input from the motor shaft 32 to the resin damper 38 is suppressed.

  According to the electric motor 14 for forklift described above, the air passage 47 having a labyrinth structure is formed between the motor cover 28 and the cover plate 45. For this reason, it is possible to suppress the entry of foreign matter into the internal space 30 of the motor housing 25 while enabling internal air cooling accompanying the rotation of the rotor 35. In addition, heat radiating fins 46 are provided on the cover plate 45. For this reason, when the cover plate 45 rotates together with the motor shaft 32, heat transmitted from the rotor 35 to the cover plate 45 via the motor shaft 32 can be radiated. Thereby, heat input from the motor shaft 32 to the resin damper 38 can be suppressed.

  Further, one part of the cover plate 45 can serve both functions of suppressing entry of foreign matter into the internal space 30 of the motor housing 25 and suppressing heat input from the motor shaft 32 to the resin damper 38. For this reason, compared with the structure which provides a complicated cooling mechanism, the reliability of the electric motor 14 can be improved while realizing simplification of the structure.

  The heat radiation fins 46 are formed on the surface of the cover plate 45 on the oil pump 16 side, that is, the front side surface. Therefore, the heat of the cover plate 45 can be efficiently radiated to the outside through the space on the oil pump 16 side (the internal space 23 and the opening hole 22a).

  A motor cover 28 is fastened to the motor shaft 32 together with the divided connecting member 40 of the resin damper 38. Therefore, the motor cover 28 can be easily assembled to the motor shaft 32 together with the divided connecting member 40.

[Embodiment 2]
A second embodiment will be described. Since this embodiment adds a change to the cover plate of Embodiment 1, the change part is demonstrated and the overlapping description is abbreviate | omitted. FIG. 7 is a sectional view showing a part of the cover plate. As shown in FIG. 7, in the cover plate of this embodiment (reference numeral 50 is attached), the heat radiation fin 46 of the first embodiment is omitted, and the large-diameter disk part (reference numeral 50c is attached) by press molding. The cross section in the circumferential direction is formed in a wave shape. Thereby, the radiation fin (code | symbol, 51 is attached) which makes a wave shape in the circumferential direction is formed in both surfaces of the cover plate 50. As shown in FIG. Accordingly, the surface area of the large-diameter disk portion 50c of the cover plate 50 can be increased, and the heat of the cover plate 50 can be efficiently radiated to the outside through the space on the oil pump 16 side and the air passage 47. Further, the cover plate 45 can be easily formed by, for example, press forming a metal plate.

[Other technical matters]
The present invention is not limited to the embodiments, and can be modified without departing from the gist of the present invention. For example, the electric motor 14 of the present invention can be applied not only to a forklift but also to a construction machine such as a hydraulic excavator. The electric motor 14 may be a motor having a bearing that rotatably supports the motor shaft 32 on the motor housing 25. Further, the shape of the resin damper 38 is not limited to the split type, and may be an integrated type as long as the resin damper 38 can absorb torque fluctuations by the action of the resin. Moreover, the radiation fin should just have a function which thermally radiates the heat of a cover plate, and the arrangement position, shape, number, size, etc. may be changed suitably. For example, the heat radiating fins may have a bellows shape. Further, the cover plate 45 may be integrally formed with the motor shaft 32.

12 ... Engine 14 ... Electric motor (rotary electric machine)
16 ... Oil pump 18 ... Engine housing 19 ... Crankshaft (output shaft)
21 ... Pump shaft (drive shaft)
22 ... Pump support member (oil pump side member)
25 ... Motor housing (housing member)
28: Motor cover (cover member)
31 ... Stator 32 ... Motor shaft (rotating shaft)
35 ... Rotor 38 ... Resin damper 40 ... Split connection member (input-side member)
41 ... elastic resin member 45 ... cover plate (plate member)
47 ... Ventilation path 46 ... Radiating fin 50 ... Cover plate (plate member)
51 ... Radiating fins

Claims (4)

A housing member interposed between an engine housing of an engine of an industrial vehicle and a member on the oil pump side;
A stator provided in the housing member;
A rotating shaft rotatably disposed within the housing member and connected to an output shaft of the engine;
A rotor provided on the rotating shaft;
A cover member provided to cover an opening end surface of the housing member on the oil pump side;
A rotary electric machine comprising: a resin damper having an elastic resin member that absorbs torque fluctuation generated between the rotary shaft and the drive shaft of the oil pump;
The rotating shaft is provided with a plate member adjacent to the oil pump side of the cover member,
Between the cover member and the plate member is formed a labyrinth-structured air passage communicating with the inner space of the housing member on the radially inner peripheral side and communicating with the outside of the housing member on the radially outer peripheral side,
The rotating electrical machine, wherein the plate member is provided with a radiation fin for radiating heat of the plate member. The rotating electrical machine according to claim 1,
The rotating electric machine is characterized in that the heat dissipating fins are formed on a surface of the plate member on the oil pump side. The rotating electrical machine according to claim 1,
A rotating electric machine characterized in that a heat dissipating fin having a wave shape in the circumferential direction is formed on both surfaces of the plate member by making the cross section in the circumferential direction of the plate member into a wave shape. The rotating electrical machine according to any one of claims 1 to 3,
The rotating electrical machine, wherein the plate member is fastened together with a member on the input side of the resin damper to the rotating shaft.

Images