JP2009121550A - Motor power device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce machining cost by dispensing with male screw machining of a rotor shaft when a hollow shaft of an electric motor in a motor power device is supported in a case via a bearing. <P>SOLUTION: The hollow rotor shaft 31 is required to be formed of material having high rigidity because the high rigidity is requested, then it is hard to machine the male thread screwed into a nut for retaining a ball bearing 29 on the outer periphery. However, the ball bearing 29 is held and secured between an end face of a large diameter part 31a of the rotor shaft 31 and a stopper ring 109 pressed into the rotor shaft 31 so as to dispense with machining the male screw in the rotor shaft 31 so that machining cost can be reduced using the material having high rigidity in which it is hard to machine for the rotor shaft 31. Since a circlip 108 is mounted between the ball bearing 29 and the stopper ring 109, the ball bearing can be retained at a predetermined position even in the worst case where the stopper ring 109 is loosened. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a motor-type power unit in which rotation of a rotor shaft of an electric motor is transmitted to a differential gear through a reduction gear, and one of a pair of output shafts of the differential gear is disposed inside the rotor shaft.

Such a motor-type power unit is known from Patent Document 1 below. One end of the hollow rotor shaft of the electric motor of the motor-type power unit is supported by a partition that defines the mission storage chamber and the electric motor storage chamber via a ball bearing, and the other end is the transmission of the electric motor storage chamber. It is supported via a ball bearing on a wall portion far from the storage chamber.
JP 2005-278319 A

  By the way, when a shaft is generally supported by a support member via a ball bearing, the shaft is inserted into an inner race of a ball bearing in which an outer race is press-fitted into a support hole formed in the support member, and one side surface of the inner race is a shaft. The other side of the inner race is fastened and fixed with a nut that is screwed onto a male screw formed on the shaft.

  However, since the rotor shaft of the motor-type power unit is hollow and thin, it must be made of a high-hardness material to ensure strength. For this purpose, a male screw that engages the nut that fastens the inner race is processed. There was a problem that it was difficult to do. In order to avoid this, it is conceivable to increase the hardness by machining the external threads on the rotor shaft to increase the hardness. However, the thin rotor shaft is likely to be cracked or chipped during the carburizing process. Will occur.

  The present invention has been made in view of the above circumstances, and when supporting the hollow rotor shaft of the electric motor of the motor-type power unit to the case via the bearing, the male screw processing of the rotor shaft is not required and the processing cost is reduced. The purpose is to reduce.

  To achieve the above object, according to the first aspect of the present invention, the rotation of the rotor shaft of the electric motor is transmitted to the differential gear through the reduction gear, and one of the pair of output shafts of the differential gear is transmitted. In the motor-type power unit arranged inside the rotor shaft, a large-diameter portion provided with a reduction gear that transmits rotation of the rotor shaft to the speed reducer in a partition wall that partitions a case that houses the electric motor and the differential gear The motor-type power unit is characterized in that a bearing for supporting the rotor shaft on the partition is sandwiched between an end face of the large-diameter portion and a stopper ring press-fitted into the outer periphery of the rotor shaft. Is proposed.

  According to the invention described in claim 2, in addition to the configuration of claim 1, a circumferential groove is formed in the rotor shaft between the bearing and the stopper ring, and a circlip is mounted in the circumferential groove. A motor-type power unit characterized by the above is proposed.

  The motor / mission case 16 of the embodiment corresponds to the partition wall of the present invention, the ball bearing 29 of the embodiment corresponds to the bearing of the present invention, and the first reduction gear 40 of the embodiment corresponds to the deceleration of the present invention. Corresponding to the gear, the left drive shaft 48 and the center shaft 49 of the embodiment correspond to the output shaft of the present invention.

  According to the configuration of the first aspect, since the hollow rotor shaft that houses the output shaft inside is required to have high rigidity, it is necessary to configure the material with a high hardness. Therefore, the nut that holds the bearing on the outer periphery is screwed. It is difficult to process a mating male screw. However, by fixing the bearing between the large-diameter portion of the rotor shaft and the stopper ring press-fitted into the rotor shaft, there is no need to process a male screw on the rotor shaft, and the high-strength that is difficult to thread on the rotor shaft. Processing costs can be reduced while allowing the material to be used. In addition, since the rigidity of the rotor shaft is increased by press-fitting the stopper ring, the support of the rotor shaft by the bearing can be ensured.

  According to the second aspect of the present invention, since the circlip is attached to the circumferential groove formed in the rotor shaft between the bearing and the stopper ring, even if the stopper ring press-fitted into the rotor shaft is loosened, The bearing can be held in place.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 14 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view (sectional view taken along line 1-1 of FIG. 2) of a motor type power unit, and FIG. 2 is a sectional view taken along line 3-3 in FIG. 2, FIG. 4 is a sectional view taken along line 4-4 in FIGS. 1 and 3, and FIG. 5 is a line 5-5 in FIGS. 6 is an arrow view taken along line 6-6 in FIGS. 1 and 3, FIG. 7 is an enlarged view of part 7 of FIG. 1, FIG. 8 is an enlarged view of part 8 of FIG. 1, and FIG. Part enlarged view. 10 is a cross-sectional view taken along line 10-10 in FIG. 9, FIG. 11 is a view taken in the direction of arrows 11-11 in FIG. 3, FIG. 12 is a view taken in the direction of arrows 12-12 in FIG. FIG. 14 is an explanatory diagram of the action at the time of turning of the vehicle corresponding to FIG.

  As shown in FIGS. 1 and 3, the motor type power unit used as a power unit of an electric vehicle includes an electric motor 11, a speed reducer 12, and a differential gear 13, and the outer shell is the left end in the vehicle width direction. , A motor / transmission case 16 coupled to the right end of the mission case 14 with bolts 15, a motor center case 18 coupled to the right end of the motor / mission case 16, and a motor center A motor side case 20 coupled to the right end of the case 18 with bolts 19..., A center shaft bearing support 22 coupled to the right end of the motor side case 20 with bolts 21. The intermediate case 24 is composed of . The electric motor 11 is housed in the motor / mission case 16, the motor center case 18 and the motor side case 20, and the speed reducer 12 and the differential gear 13 are housed in the mission case 14 and the motor / mission case 16.

  The electric motor 11 includes a stator 25 fixed to the inner peripheral surface of the motor center case 18 and a rotor 26 that is rotatably disposed inside the stator 25. The stator 25 is composed of a plurality of stator cores 27 made of laminated steel plates arranged in the circumferential direction, and a plurality of coils 28 wound around the outer periphery of the stator cores 27. The rotor 26 includes a rotor shaft 31 rotatably supported by ball bearings 29 and 30 on the motor / mission case 16 and the motor side case 20, respectively, a rotor core 32 made of laminated steel plates fixed to the rotor shaft 31, and a rotor core. 32 and a plurality of permanent magnets 33 embedded in the outer peripheral portion of 32. The rotor core 32 is formed with a plurality of through holes 32a penetrating therethrough in the axial direction.

  The speed reducer 12 includes a speed reducer shaft 36 supported by a roller bearing 34 and a ball bearing 35 on the transmission case 14 and the motor / mission case 16, respectively. The speed reducer shaft 36 includes a second speed reduction gear 37, a parking gear. 38 and a final drive gear 39 are provided. The first reduction gear 40 provided at the left end of the rotor shaft 31 meshes with the second reduction gear 37 of the reduction gear shaft 36, and the final drive gear 39 of the reduction gear shaft 36 engages with the final driven gear 41 of the differential gear 13.

  The differential gear 13 is differentially supported on a transmission case 14 and an intermediate case 24 via taper roller bearings 42 and 43, respectively, and a differential case 44 is rotatably supported on a differential case 44 via a pinion pin 45. A pair of differential pinions 46 and 46 and a pair of differential side gears 47 and 47 simultaneously meshing with both of these differential pinions 46 and 46 are provided, and the final driven gear 41 is fixed to the outer periphery of the differential case 44. .

  A left drive shaft 48 whose right end is splined to the left differential side gear 47 extends through the differential case 44 and the transmission case 14 to the left in the vehicle width direction. A center shaft (half shaft) 49 whose left end is splined to the right differential side gear 47 extends through the differential case 44, the transmission case 14, and the hollow rotor shaft 31 to the right in the vehicle width direction. A right drive shaft 51 is splined to the center shaft 49 supported on the right end of the center shaft bearing support 22 via a ball bearing 50.

  Therefore, when the electric motor 11 is driven, the torque of the rotor shaft 31 is changed from the first reduction gear 40 → the second reduction gear 37 → the reduction gear shaft 36 → the final drive gear 39 → the final driven gear 41 → the differential case 44 → the differential pinion 46, 46 → transmitted to the differential side gears 47, 47 and distributed to the left drive shaft 48, the center shaft 49 and the right drive shaft 51 at a predetermined ratio according to the turning state of the vehicle and the like.

  Next, the lubrication system of the electric motor 11, the speed reducer 12, and the differential gear 13 will be described.

  As shown in FIGS. 1 to 3 and 7, the oil pump 61 that supplies oil to the electric motor 11, the speed reducer 12, and the differential gear 13 is a trochoid pump, and is a circular shape formed on the left side surface of the motor / mission case 16. An outer rotor 62 rotatably supported by the pump chamber 16a, an inner rotor 63 having external teeth meshing with the inner teeth of the outer rotor 62, a pump shaft 64 rotatably supporting the inner rotor 63, a motor / A pump cover 66 fixed to the left side surface of the transmission case 16 with a bolt 65 and closing the pump chamber 16a is provided. A pump shaft 64 supported on the motor / mission case 16 at the right end is a ball provided on the pump cover 66. A pump drive gear 68 that penetrates the bearing 67 and is provided at the left end thereof. Meshed with the first reduction gear 40.

  The suction port 16 b of the oil pump 61 communicates with the oil storage chamber 71 at the bottom of the motor / mission case 16 and the transmission case 14 via an oil suction passage 16 c provided in the motor / mission case 16 and a strainer 69. A discharge port 16d of the oil pump 61 is provided with an oil storage chamber at the bottom of the motor / mission case 16 and the transmission case 14 via an oil discharge passage 16e provided in the motor / mission case 16 and a relief valve 70 (see FIG. 3). And a tapered roller bearing 43 that supports the right end of the differential case 44 through an oil passage 72 (see FIG. 3) made of a pipe material and an oil supply passage 24 a formed in the intermediate case 24.

  A high-pressure oil supply passage 16f (shown by a chain line in FIGS. 1 and 3 and a broken line in FIG. 5) extending upward from the discharge port 16d of the oil pump 61 to the inside of the motor / transmission case 16 is a hollow speed reducer shaft 36. The oil supply passage 36a formed in the interior of the transmission case 14 is communicated with the oil supply passages 14a and 14b of the transmission case 14. The oil branched into the oil supply passage 14 a is discharged from the oil supply pipe 73, and the meshing portion of the final drive gear 39 and the final driven gear 41, the ball bearing 35 and the ball bearing 29 are lubricated and returned to the oil storage chamber 71. The oil branched to the oil supply passage 14b is returned to the oil storage chamber 71 after lubricating the roller bearing 34 and the differential gear 13, and the oil branched from the oil supply passage 14b to the oil supply passage 14c is the left tapered roller bearing. 43 is lubricated and returned to the oil storage chamber 71.

  The oil supply passage 16g branched from the upper end of the high pressure oil supply passage 16f of the motor / mission case 16 is supplied from the oil supply passage 18a formed in the wall portion of the motor center case 18 into the wall portion of the motor side case 20. After lubricating the ball bearing 30 that supports the right end of the rotor shaft 31 through the passages 20a, 20b, and 20c, oil return passages 20d and 20e formed in the wall portion of the motor side case 20 and the wall portion of the motor center case 18 The oil return passage 18b, the oil return passage 16i formed in the wall of the motor / transmission case 16, the oil return passage 14f formed in the wall of the transmission case 14 and the opening 14g are returned to the oil storage chamber 71. The oil supply passage 20f branched from the oil supply passage 20c of the motor side case 20 lubricates the ball bearing 50 that supports the right end of the center shaft 49 through the oil supply passage 22a formed in the center shaft bearing support 22, It joins the oil return passage 20d and is returned to the oil storage chamber 71.

  As apparent from FIG. 3, the electric motor storage chamber 74 defined by the motor / mission case 16, the motor center case 18 and the motor side case 20 is divided into a right chamber 74 a and a left chamber by the stator 25 and the rotor 26 of the electric motor 11. It is partitioned into 74b. The right chamber 74a and the left chamber 74b communicate with each other through the through holes 32a formed in the rotor core 32. However, during the operation in which the rotor 26 rotates at high speed, oil cannot substantially pass through the through holes 32a. Therefore, the right chamber 74a and the left chamber 74b communicate with each other through an oil communication hole 18c formed in the wall portion of the motor center case 18. The left end of the oil communication hole 18c of the motor center case 18 is located below the mission storage chamber 75 (that is, the oil storage chamber 71) defined by the motor / transmission case 16 and the transmission case 14, and the motor / transmission case 16 and the transmission case. 14 communicate with each other through oil communication passages 16h and 14d and an opening 14e.

  As apparent from FIGS. 8 and 11, the resolver 76 of the electric motor 11 includes a disk-shaped resolver rotor 77 provided at the right end of the rotor shaft 31 and bolts 78 to surround the outer periphery of the motor side case. 20 and a plurality of resolver coils 79 fixed to 20. A plurality of convex portions 77a ... and concave portions 77b ... are alternately formed on the outer periphery of the resolver rotor 77, and the size of the air gap between the convex portions 77a ... and the concave portions 77b ... and the resolver coils 79 is magnetized. Thus, the rotational position of the electric motor 11 can be detected.

  The resolver rotor 77 fitted to the outer periphery of the rotor shaft 31 is fixed by being sandwiched between a pair of stoppers 80 and 81 press-fitted on both sides in the axial direction, and protrudes from the outer periphery of the stopper 80 on the left side. The flange 80a faces the inner periphery of the annular magnetic shield 82 that is fastened to the motor side case 20 with the bolts 78 with a slight gap. The magnetic shield 82 is for preventing the magnetism generated by the electric motor 11 from acting on the resolver coils 79 and affecting the detection accuracy, and is arranged so as to block between the electric motor 11 and the resolver coils 79. Is done.

  The ball bearing 30 that supports the right end of the rotor shaft 31 to the motor side case 24 includes an inner race 30b and an outer race 30c that support a plurality of balls 30a, and oil flows between the inner race 30b and the outer race 30c. A shield 30d is provided to prevent this. Accordingly, the oil supplied from the oil supply passage 20c of the motor side case 20 is held in the first oil chamber 83 defined by the shield 30d of the ball bearing 30, the flange 80a of the stopper 80, and the magnetic shield 82. The ball bearing 30 can be effectively lubricated.

  The oil supplied from the oil supply passage 22 a of the center shaft bearing support 22 is partitioned by the flange 80 a of the stopper 80, the magnetic shield 82, and the seal member 84 disposed between the center shaft 49 and the center shaft bearing support 22. The ball bearing 50 can be effectively lubricated by being held in the second oil chamber 85.

  Next, breathing of the electric motor storage chamber 74 and the mission storage chamber 75 will be described.

  As shown in FIG. 3, the second oil chamber 85 communicates with the breather passages 20g and 20h of the motor side case 20, and the right chamber 74a of the electric motor storage chamber 74 communicates with the breather passage 20h via the breather passage 20i. Further, the breather passage 20h communicates with the first breather chamber 86, which is the upper portion of the mission storage chamber 75, through the breather passage 18d of the motor center case 18 and the breather passage 16j of the motor / transmission case 16. A small-capacity second breather chamber 87 is formed above the first breather chamber 86. The first and second breather chambers 86 and 87 communicate with each other through a communication hole 16m, and the second breather chamber 87 is connected via a breather pipe 88. Communicate with the open air. The left chamber 74b of the electric motor storage chamber 74 and the mission storage chamber 75 communicate with each other through a communication hole 16k (see FIGS. 2, 3, and 5) formed in the motor / mission case 16.

  As is clear from FIG. 6, the oil supply passage 18 a, the oil return passage 18 b, the oil communication passage 18 c and the breather passage 18 d are formed in the wall portion of the motor center housing 18 so as to be spaced apart in the circumferential direction.

  Next, the structure of the parking mechanism 89 that restrains the rotation of the rotor shaft 31 of the electric motor 11 will be described.

  As is apparent from FIGS. 2, 3, 9 and 10, the parking mechanism 89 that restrains the parking gear 38 and prevents the rotation of the rotor shaft 31 of the electric motor 11 includes the motor / mission case 16 and the intermediate. A parking pole 91 having one end pivotally supported by a support shaft 90 installed between the cases 24 is provided. The parking pole 91 has a direction in which a locking claw 91a at the tip is separated from a locking recess 38a of the parking gear 38. Is biased by a torsion spring 92.

  A drive shaft 93 and a stopper shaft 94 are installed between the motor / transmission case 16 and the transmission case 14, and an operation lever 95 fixed to the drive shaft 93 protruding outside from the transmission case 14 is a shift lever in the vehicle interior (not shown). Connected to A detent plate 96 is fixed to the drive shaft 93, and a pair of drive levers 97, 97 are supported so as to be relatively rotatable. The drive levers 97, 97 are pressed against the pressed portion 91b of the parking pole 91. The contactable drive pin 98 is fixed. On the outer peripheral surface of the detent plate 96, there are formed a groove 96a with which the stopper shaft 94 is engaged, and a plurality of concave portions 96b. The drive levers 97, 97 are biased by the torsion spring 99 with respect to the drive shaft 93 in the counterclockwise direction of FIG. 9, that is, in the direction in which the drive pin 98 abuts against the pressed portion 91 b of the parking pole 91.

  One end of a detent arm 101 is pivotally supported on a support shaft 100 installed between the motor / transmission case 16 and the transmission case 14, and a locking pin 103 provided between a pair of support plates 102, 102 fixed to the other end is provided. The detent arm 101 is urged by a coil spring 104 provided between the detent plate 96 and the drive shaft 93 so as to engage with any one of the recesses 96b of the detent plate 96.

  Therefore, when the shift lever is operated to the parking position, the operation lever 95 swings counterclockwise from the chain line position in FIG. 9 to the solid line position, and the drive shaft 93 moves from the chain line position together with the detent plate 96 and the drive levers 97 and 97. Swings counterclockwise to the solid line position. At this time, the swingable range of the detent plate 96 is restricted by the engagement between the groove 96 a and the stopper shaft 94. When the drive levers 97 and 97 swing, the drive pin 98 provided at the tip thereof presses the pressed portion 91b of the parking pole 91, so that the parking pole 91 swings around the support shaft 90 in the clockwise direction. When the engaging claw 91a attempts to engage with one engaging recess 38a of the parking gear 38, the driving lever is not in phase when the engaging recess 38a of the parking gear 38 is out of phase with the engaging claw 91a. 97 and 97 stand by while staying at the position of the chain line in FIG. 9 while compressing the torsion spring 99. Then, at the moment when the phase of the engaging recess 38a of the parking gear 38 matches the locking claw 91a, the drive levers 97, 97 are swung to the solid line position by the elastic force of the torsion spring 99, and the drive pin When 98 presses the pressed portion 91b of the parking pole 91, the locking claw 91a engages with the engaging recess 38a of the parking gear 38, and the rotation of the parking gear 38 is restrained.

  At this time, the locking pin 103 of the detent arm 101 urged by the coil spring 104 is engaged with one of the recesses 96b of the detent plate 96, whereby the return of the detent plate 96 is restricted. When the shift lever is moved from the parking position, each component of the parking mechanism 89 is moved from the solid line position in FIG. 9 to the chain line position, thereby releasing the parking brake.

  By the way, the final driven gear 41 of the differential gear 13 receives a meshing reaction force indicated by an arrow A in FIG. 4 from the final drive gear 39 of the speed reducer 12, and the meshing reaction force and the transmission case 14 that supports both ends of the differential gear 13 and It is received by the intermediate case 24. At this time, if the rigidity of the intermediate case 24 is insufficient, the support of the differential gear 13 becomes unstable, and the meshing state of the final driven gear 41 and the final drive gear 39 deteriorates, and smooth power transmission may not be performed. There is sex.

  However, since the high-rigidity motor / mission case 16 and the intermediate case 24 are integrally connected by the support shaft 90 of the parking pole 91 in the direction in which the meshing reaction force acts (see arrow A in FIG. 4). The support shaft 90 can increase the rigidity of the intermediate case 24, thereby increasing the support rigidity of the differential gear 13 so that power can be transmitted smoothly.

  As is apparent from FIGS. 3 and 10, the support shaft 90 is formed of a stepped shaft having a large diameter portion 90a on the right side and a small diameter portion 90b on the left side, and the large diameter portion 90a is relatively rigid. Since the small motor 90 is supported by the high motor / mission case 16 and the small-diameter portion 90b is supported by the intermediate case 24 having relatively low rigidity, the reinforcing effect of the intermediate case 24 by the support shaft 90 can be further enhanced.

  Further, as is apparent from FIG. 4, the intermediate case 24 fixed to the inner surface of the transmission case 14 with six bolts 23... Has an upper opening 24b and a lower opening 24c in the upper left part and the lower right part in the figure. The transmission case 14 and the intermediate case 24 are separated from each other at the upper opening 24b and the lower opening 24c without contacting each other. However, since the transmission case 14 and the intermediate case 24 are coupled by the three bolts 23 in the direction of the arrow A where the meshing reaction force acts, the intermediate due to the provision of the upper opening 24b and the lower opening 24c. The rigidity reduction of the case 24 can be minimized, and the support rigidity of the differential gear 13 can be ensured.

  As apparent from FIGS. 3, 11 and 12, the motor side case 20 is formed with an opening 20j closed by the center shaft bearing support 22, and the resolver 76 can be accessed through the opening 20j. The center shaft bearing support 22 coupled to the motor side case 20 with five bolts 21... Has an opening 22b that is opened and closed by a lid member 105 (see FIG. 3), and is connected to the resolver 76. The coupler 106 is fixed with one bolt 107 so as to face the opening 22b. One of the five bolts 21 (1) for fixing the center shaft bearing support 22 is partially hidden behind the coupler 106.

  By the way, when the center shaft bearing support 22 is separated from the motor side case 20 for maintenance of the resolver 76, the resolver fixed to the motor side case 20 side is required unless the coupler 106 is removed from the center shaft bearing support 22 in advance. There is a possibility that the harness 106a connecting the cord 76 and the coupler 106 is pulled and damaged.

  However, according to the present embodiment, unless the bolt 107 is loosened in advance and the coupler 106 is separated from the center shaft bearing support 22, the five bolts 21 for fixing the center shaft bearing support 22 to the motor side case 20 are included. Therefore, after the coupler 106 is removed from the center shaft bearing support 22, the center shaft bearing support 22 is removed from the motor side case 20, and the harness 106a of the coupler 106 is damaged. It can be surely prevented.

  Further, the resolver 76 for detecting the rotational position of the rotor shaft 31 of the electric motor 11 is not disposed between the differential gear 13 and the electric motor 11, and the anti-differential gear 13 side of the electric motor 11, that is, the motor side case 20 and the center shaft. Since it is arranged between the bearing support 22 and the center shaft bearing support 22 is separated from the motor side case 20, the resolver 76 can be completely exposed and its maintenance can be easily performed.

  As shown in FIGS. 1 and 7, the ball bearing 29 that supports the left end of the rotor shaft 31 on the motor / mission case 16 includes an inner race 29b and an outer race 29c that support a plurality of balls 29a. A shield 29d is provided between the race 29b and the outer race 29c to prevent oil from flowing. The ball bearing 29 is a circumferential groove formed on the outer periphery of the rotor shaft 31 with the right end in contact with the end surface of the large-diameter portion 31 a provided on the first reduction gear 40 side of the rotor shaft 31. It is locked by a circlip 108 fitted to 31b, and an annular stopper ring 109 is fixed to the right side thereof by press-fitting. At this time, a concave portion 109 a into which the circlip 108 is fitted is formed on the left side surface of the stopper ring 109.

  Since the hollow rotor shaft 31 that accommodates the center shaft 49 inside is inevitably thin, it is necessary to form it with a high hardness material in order to ensure the required strength. Therefore, it is difficult to process a male screw on the outer periphery of the rotor shaft 31, and it becomes impossible to fix the ball bearing 29 between the nut and the large-diameter portion 31a that are screwed to the male screw. However, in this embodiment, the rotor shaft 31 is fixed by sandwiching the inner race 29b of the ball bearing 29 between the stopper ring 109 press-fitted into the rotor shaft 31 and the end surface of the large-diameter portion 31a of the rotor shaft 31. The ball bearing 29 can be securely fixed while eliminating the need to machine a male screw and balancing the strength and workability of the rotor shaft 31.

  Moreover, since the circlip 108 is mounted in the circumferential groove 31b formed in the rotor shaft 31 between the ball bearing 29 and the stopper ring 109, even if the stopper ring 109 press-fitted into the rotor shaft 31 is loosened, the circlip 108 Thus, the ball bearing 29 can be held at a predetermined position. Further, the stopper ring 109 is press-fitted into the rotor shaft 31 so that the rigidity of the rotor shaft 31 is increased and the support by the ball bearing 29 can be ensured.

  Next, the lubricating action and breathing action of the embodiment of the present invention having the above-described configuration will be described.

  When the pump shaft 64 of the oil pump 61 is rotated by the pump drive gear 68 that meshes with the first reduction gear 40 provided on the rotor shaft 31 of the electric motor 11, the volume of the working chamber formed between the outer rotor 62 and the inner rotor 63 is increased. The oil continuously changes, and the oil in the oil storage chamber 71 is sucked in through the oil suction passage 16c and the suction port 16b, and discharged from the discharge port 16d to the high-pressure oil supply oil passage 16f formed in the motor / mission case 16. Is done. The high-pressure oil supply oil passage 16f extends substantially linearly upward, and a part of the oil branched into two branches near the upper end of the high-pressure oil supply oil passage 16f passes through an oil supply passage 36a formed inside the speed reducer shaft 36 and is transmitted. The oil is supplied to the oil supply passages 14a and 14b of the case 14 to lubricate the speed reducer 12 and the differential gear 13, and another part of the branched oil passes through the oil supply passages 16g, 18a, 20a, 20b and 20c, The right end of the rotor shaft 31 and the right end of the center shaft 49 are lubricated.

  Thus, since the high pressure oil supply oil passage 16f connected to the oil pump 61 is extended substantially linearly upward, the high pressure oil supply passage 16f is made short and simple to reduce the oil flow resistance. The driving load of the oil pump 61 can be reduced. In addition, the oil branched into two branches from the vicinity of the upper end of the high pressure oil supply oil passage 16f is supplied by gravity to the lubricated parts on the electric motor storage unit 74 side and the transmission storage unit 75 side, so that the stored oil is repelled and lubricated. In addition to being able to minimize energy loss compared to the case of supplying to the section, the lubricated parts on the electric motor storage section 74 side and the transmission storage section 75 side are evenly lubricated with the minimum amount of oil. be able to.

  A part of the oil discharged from the oil pump 61 driven by the electric motor 11 is supplied to the mission storage chamber 75 to lubricate and cool the gears and the bearings. It is returned to the oil storage chamber 71 at the bottom. The other part of the oil discharged from the oil pump 61 is supplied to the electric motor storage chamber 74 to lubricate and cool the bearings and the electric motor 11 and then returned to the bottom of the electric motor storage chamber 74. At this time, since the right chamber 74a and the left chamber 74b of the electric motor storage chamber 74 communicate with each other via the oil communication path 18c (see FIG. 3), the oil levels of the right chamber 74a and the left chamber 74b are the same. Since the bottom of the electric motor storage chamber 74 and the oil storage chamber 71 of the mission storage chamber 75 communicate with each other via the oil communication passages 16h and 14d and the opening 14e (see FIG. 3), the oil in the electric motor storage chamber 74 is communicated. The oil level in the oil storage chamber 71 of the mission storage chamber 75 is the same (see the oil level L in FIGS. 1 and 3).

  By the way, when the vehicle turns left, a centrifugal force in the right direction in the vehicle width acts, so that the oil in the mission storage chamber 75 passes through the opening 14e and the oil communication passages 14d and 16h as shown in FIG. It flows into the storage chamber 74. At this time, if a communication hole made of a simple opening is formed in the motor / transmission case 16 constituting the partition walls of the electric motor storage chamber 74 and the mission storage chamber 75, almost all of the oil in the mission storage chamber 75 is almost completely contained in the electric motor storage chamber. 74, the oil hardly remains in the mission storage chamber 75, which not only hinders the lubrication of the differential gear 13 and the like, but also the amount of oil in the electric motor storage chamber 74 becomes excessive, and the rotor 26 Therefore, there is a problem that the oil agitation resistance is increased and the loss of driving force increases.

  However, according to the present embodiment, the opening 14e (see FIG. 3) for communicating the mission storage chamber 75 and the electric motor storage chamber 74 is connected to the oil storage chamber 75 side from the motor / mission case 16 constituting the partition wall. Since it is formed at a position separated by the length of the passages 16h and 14d, oil is held between the opening 14e and the motor / mission case 16 even when the vehicle turns left as shown in FIG. be able to. As a result, while maintaining the minimum required oil in the mission storage chamber 75 and ensuring the lubrication performance of the differential gear 13 and the like, excessive oil flows into the electric motor storage chamber 74 and the oil stirring resistance by the rotor 26 is reduced. The increase can be prevented.

  In addition, since the electric motor storage chamber 74 and the mission storage chamber 75 communicate with each other through the oil communication paths 16h and 14d, oil can be moved back and forth, and the oil level management is stabilized by using the electric motor storage chamber 74 as an oil server. Can be made.

  When the vehicle turns left, as shown in FIG. 14, the oil in the mission storage chamber 75 passes through the opening 14g and the oil return passages 14f, 16i, 18b, 20e, 20d, and the first and second oil chambers 83, 85. Flow into. At this time, if a communication hole made of a simple opening is formed in the motor / transmission case 16 constituting the partition walls of the electric motor storage chamber 74 and the mission storage chamber 75, almost all of the oil in the mission storage chamber 75 is first and second. Since the oil flows into the two oil chambers 83 and 85, there is a problem that almost no oil remains in the mission storage chamber 75 and the lubrication of the differential gear 13 and the like is hindered.

  However, according to this embodiment, the opening 14g (see FIG. 1) for communicating the mission storage chamber 75 and the first and second oil chambers 83, 85 is provided from the motor / mission case 16 constituting the partition wall to the mission storage chamber. Since the oil return passages 16i and 14f are separated from each other by the length of the oil return passages 16i and 14f on the 75 side, even when the vehicle turns left as shown in FIG. It can hold oil. Thereby, the minimum required oil can be held in the mission storage chamber 75 and the lubricating performance of the differential gear 13 and the like can be ensured.

  In addition, the first and second oil chambers 83 and 85 and the mission storage chamber 75 communicate with each other through the oil return passages 20d, 20e, 18b, 16i, and 14f. The oil recovery to 75 can be stabilized, and the oil distribution of each part can be optimized.

  Further, since the magnetic shield 82 is disposed on the resolver 76 on the electric motor 11 side, the magnetic shield 82 shields the magnetism generated by the electric motor 11 so that the detection accuracy of the resolver 76 can be improved. The first oil chamber 83 is defined by the ball bearing 30 with the shield 30d on the left side of the magnetic shield 82, and the second oil chamber 85 is defined on the right side of the magnetic shield 82 via the seal member 84. The ball bearing 30 that supports the rotor shaft 31 is effectively lubricated with the oil held in the oil chamber 83, and the ball bearing 50 that supports the center shaft 49 is effectively lubricated with the oil held in the second oil chamber 85. be able to.

  The ball bearing 30 that supports the rotor shaft 31 having a high rotational speed needs lubrication with the oil stored in the first oil chamber 83, but the ball bearing 50 that supports the center shaft 49 having a low rotational speed has the second oil chamber 85. Lubrication with oil that passes through is sufficient. Therefore, the oil buffering function can be provided using the space of the second oil chamber 85, and separation of oil and air and early return of oil can be achieved.

  When oil lubricated by the ball bearings 30, 50 flows into the electric motor storage chamber 74, there is a problem that the oil agitating resistance by the rotor 26 increases, but there is a problem between the first oil chamber 83 and the electric motor storage chamber 74. Since the shield 30d for partitioning by the bearing 30 and reducing the oil flow is provided in the ball bearing 30, the inflow of oil from the first oil chamber 83 to the electric motor storage chamber 74 can be reliably reduced. Moreover, since the space between the second oil chamber 85 and the first oil chamber 83 is shielded by using the magnetic shield 82 of the resolver 76, the second oil chamber 85 flows into the electric motor storage chamber 74 via the first oil chamber 83. The amount of oil to be reduced can also be reduced, and the oil stirring resistance by the rotor 26 can be more effectively reduced.

  Furthermore, since the upper part of the second oil chamber 85 communicates with the breather passage 20g, the oil and air can be effectively separated in the second oil chamber 85.

  In FIG. 3, the breathing air in the first and second oil chambers 83 and 85 communicating with each other is the first in the upper part of the mission storage chamber 75 in the route of breather passage 20g → breather passage 20h → breather passage 18d → breather passage 16j. It communicates with the breather chamber 86. Further, the breathing air in the right chamber 74a of the electric motor storage chamber 74 communicates with the first breather chamber 86 at the upper part of the mission storage chamber 75 through the route of the breather passage 20i → the breather passage 18d → the breather passage 16j. Also, the breathing air in the left chamber 74b of the electric motor storage chamber 74 passes through the communication hole 16k (see FIGS. 2, 3 and 5) penetrating the motor / mission case 16 and is first in the upper part of the mission storage chamber 75. It communicates with the breather chamber 86.

  The breathing air supplied from the electric motor storage chamber 74 to the first breather chamber 86 as described above merges with the breathing air generated in the mission storage chamber 75, and from there, the communication hole 16m (see FIGS. 2 and 3). The oil mist contained in the breathing air is finally separated and returned to the oil storage chamber 71 by gravity, and only the air is passed through the breather pipe 88 from the second breather chamber 87. Through the atmosphere.

  As described above, of the electric motor storage chamber 74 and the mission storage chamber 75 partitioned by the motor / mission case 16, the left chamber on the mission storage chamber 75 side with the electric motor storage chamber 74 sandwiching the rotor 26 of the electric motor 11. 75b and a right chamber 75a opposite to the mission storage chamber 75. The left chamber 75b communicates with the mission storage chamber 75 through a communication hole 16k formed in the motor / mission case 16, and the right chamber 75b and the first chamber 75b are connected to each other. The upper part of the mission storage chamber 75 through the breather passages 20g, 20h, 20i, 18d, and 16j formed in the wall portions of the motor side case 20, the motor center case 18, and the motor / mission case 16 with the second oil chambers 83 and 85. The first breather chamber 86 is communicated with the second breather chamber 86 through the communication hole 16m. 7, and the second breather chamber 87 is communicated with the atmosphere via the breather pipe 88, so that the first and second breather chambers 86 and 87 that are part of the mission storage chamber 75 are connected to the electric motor storage chamber 74. The oil mist can be separated from the breathing air generated in both the transmission storage chamber 75 and the mission storage chamber 75, and the structure of the breather device is simplified compared to the case where the breather device is provided in the electric motor storage chamber 74 and the transmission storage chamber 75, respectively. can do.

  Further, since the communication hole 16k formed in the motor / mission case 16 opens in the back surface of the intermediate case 24, the breathing air that has flowed into the mission storage chamber 75 from the left chamber 74b of the electric motor storage chamber 74 through the communication hole 16k. Can be made to collide with the back surface of the intermediate case 24 to effectively separate the oil mist. In addition, since the reduction gear 12 and the differential gear 13 are housed inside the mission storage chamber 75, a labyrinth is constituted by these components, and the oil mist separation effect in the mission storage chamber 75 is promoted.

  Further, long breather passages 18d and 16j having a long overall length communicating the first and second oil chambers 83 and 85 and the right chamber 74a of the electric motor storage chamber 74 with the first breather chamber 86 are formed to have a small diameter (8 mm), and the electric motor storage. The short communication hole 16k that allows the left chamber 74b of the chamber 74 to communicate with the first breather chamber 86 has a large diameter (16 mm). The reason is as follows.

  When the oil is biased to the right chamber 74a side of the electric motor storage chamber 74 due to a left turn or right inclination of the vehicle, the oil is agitated by the rotor 26 of the electric motor 11 and oil mist is easily generated. Therefore, by forming the breather passages 18d and 16j that communicate the right chamber 74a of the electric motor storage chamber 74 with the first breather chamber 86 with a long and small diameter, it is difficult for oil mist contained in the air to pass through the oil mist. The separation effect is enhanced.

  On the other hand, when the vehicle turns to the right or leans to the left, the oil biased to the left flows into the mission storage chamber 75, so that the amount of oil that accumulates in the left chamber 74b of the electric motor storage chamber 74 is reduced. The amount of oil mist generated by stirring in the rotor 26 of the electric motor 11 is reduced. Accordingly, even if the communication hole 16k for communicating the left chamber 74b of the electric motor storage chamber 74 with the first breather chamber 86 is formed to be short and large in diameter, the amount of oil mist flowing into the first breather chamber 86 is small. It can be suppressed.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

Longitudinal sectional view of motor-type power unit (cross sectional view taken along line 1-1 of FIG. 2) 2-2 line view of FIG. 1 and FIG. 3-3 sectional view of FIG. 4 and 4 arrow view of FIG. 1 and FIG. 1 and 3 taken along line 5-5 6 and 6 arrow view of FIG. 1 and FIG. 7 enlarged view of FIG. 8 enlarged view of FIG. 9 enlarged view of FIG. Sectional view taken along line 10-10 in FIG. Fig. 11 is a view taken along line 11-11 in Fig. 3. 12-12 arrow view of FIG. Action explanatory diagram at the time of turning of the vehicle corresponding to FIG. Action explanatory diagram at the time of turning of the vehicle corresponding to FIG.

Explanation of symbols

11 Electric motor 12 Reducer 13 Differential gear 16 Motor / mission case (bulk)
29 Ball bearing
31 Rotor shaft 31a Large diameter portion 31b Circumferential groove 40 First reduction gear (reduction gear)
48 Left drive shaft (output shaft)
49 Center shaft (output shaft)
108 circlip 109 stopper ring

Claims (2)

The rotation of the rotor shaft (31) of the electric motor (11) is transmitted to the differential gear (13) via the speed reducer (12), and one of the pair of output shafts (48, 49) of the differential gear (13) is transmitted. In the motor type power unit arranged inside the rotor shaft (31),
A reduction gear (40) for transmitting the rotation of the rotor shaft (31) to the speed reducer (12) is provided in a partition wall (16) that partitions a case that houses the electric motor (11) and the differential gear (13). And a bearing (29) for supporting the rotor shaft (31) on the partition wall (16) is press-fitted into the outer periphery of the large diameter portion (31a) and the rotor shaft (31). A motor type power unit characterized by being sandwiched and fixed between the stopper ring (109).   A circumferential groove (31b) is formed in the rotor shaft (31) between the bearing (29) and the stopper ring (109), and a circlip (108) is mounted in the circumferential groove (31b). The motor-type power unit according to claim 1.

Images