JP2009079625A - Driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device whose construction for introducing oil to inside a rotating shaft along the radial direction of the rotating shaft is such that the oil amount of an oil storage part is not increased and is compact. <P>SOLUTION: A rotor 11 of a driving motor 4 is arranged so as to scrape oil in an oil storage part arranged within a case 3 as it rotates is constituted so as to introduce the oil scraped by the rotor 11 to the inside of a rotating shaft 15 and to supply it from inside the rotating shaft 15 to a lubrication object member B for lubrication, the oil storage part 38 for storing the oil scraped by the rotor 11 is formed so as to contact the outer periphery of the rotating shaft 15 by a pair of wall bodies 39 opposing the axial direction of the rotating shaft 15, and an oil introducing part 45 introducing the oil in the oil storage part 38 to the inside of the rotating shaft 15 along the radial direction of the rotating shaft 15 is arranged in the rotating shaft 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the present invention, a drive motor having a rotating shaft rotatably supported by a case and a rotor rotatably supported by the rotating shaft is housed in the case, and the rotor is rotated with rotation. The oil is stored in the oil storage section provided in the case so that the oil swept up by the rotor is introduced into the rotary shaft and supplied to the lubrication target member from the rotary shaft. And a drive device configured to lubricate.

The drive device as described above is used as, for example, an in-wheel type drive unit provided in an electric vehicle or the like, and is provided in a wheel rim of the drive wheel so as to rotationally drive the drive wheel.
In such a drive device, in addition to the drive motor, a speed reduction mechanism is housed in the case, and the rotation from the drive motor is reduced by the speed reduction mechanism and output from the output shaft. A braking mechanism such as a drum brake is provided on the wheel side between the wheel rim and the case, and the rotation of the output shaft is braked by the braking mechanism.

In a conventional drive device, for example, it is required to supply and lubricate a lubrication target member such as a speed reduction mechanism or a bearing that rotatably supports a rotating shaft. Therefore, the inside of the case is used as a sealed space, and the lower space in the case is used as an oil storage unit. The oil in the oil storage unit is lifted up by the rotation of the rotor and supplied to the lubrication target member for lubrication. Thus, lubrication is performed using the rotation of the rotor, so that an oil pump or the like is not required, and the configuration is simplified and the cost is reduced (see, for example, Patent Documents 1 and 2).
In the ones described in Patent Literatures 1 and 2, an oil passage that flows oil along the axial direction of the rotation shaft, and a communication hole that communicates the oil passage with the outer periphery of the rotation shaft. Is provided. The oil pumped up by the rotor is introduced into the oil passage inside the rotating shaft, and the oil is spouted from the oil passage to the outer periphery of the rotating shaft through the communication hole using the centrifugal force accompanying the rotation of the rotating shaft. Oil is supplied to a lubrication target member such as a mechanism. For this purpose, the rotating shaft is housed in the case with a gap between the end of the rotating shaft and the inner wall of the case, and the oil swirled by the rotor between the end of the rotating shaft and the inner wall of the case An oil receiver that receives the oil and guides it in the axial direction of the rotating shaft is provided, and the oil swept up by the rotor by this oil receiver is introduced into the rotating shaft from the end of the rotating shaft along the axial direction of the rotating shaft. is doing.

JP 2007-57015 A JP 2001-173762 A

  In the drive devices described in Patent Documents 1 and 2, the rotation shaft is housed in the case with a space between the end of the rotation shaft and the inner wall of the case, so that the end of the rotation shaft and the inner wall of the case An oil receiver can be provided between the two. However, for example, in order to brake the rotation of the rotation shaft of the drive motor, a braking mechanism may be provided on the vehicle body side instead of the wheel side. In this case, the rotation shaft is provided so that the end portion protrudes outward from the case. Therefore, as in Patent Documents 1 and 2, in order to introduce oil from the end of the rotary shaft into the rotary shaft along the axial direction of the rotary shaft, oil is supplied from the end of the rotary shaft to the rotary shaft. A member for introduction into the interior is provided in a state of projecting outward from the end of the rotating shaft projecting outside the case. As a result, there arises a problem that the size of the rotary shaft is increased.

  Therefore, a through-hole is provided along the radial direction so that the outer periphery of the rotary shaft communicates with the inside of the rotary shaft, and oil is introduced into the rotary shaft along the radial direction of the rotary shaft through the through-hole. It is possible to do. Thereby, a through-hole can be provided in the center side rather than the edge part of a rotating shaft in the axial center direction of a rotating shaft, and it can prevent becoming large in the axial center direction of a rotating shaft. However, since the rotating shaft rotates, the centrifugal hydraulic pressure acts due to the centrifugal force associated with the rotation of the rotating shaft, and simply by providing a through hole along the radial direction of the rotating shaft, the oil is rotated by the centrifugal hydraulic pressure. There is a possibility that it cannot be introduced into the shaft. In addition, by increasing the amount of oil stored in the oil reservoir, more oil is lifted by the rotor and more oil is introduced into the rotating shaft from the through hole, so that the centrifugal hydraulic pressure acts. However, it is conceivable to introduce oil into the rotary shaft along the radial direction of the rotary shaft. However, in this case, as the amount of oil in the oil reservoir increases, there is a problem that drag loss increases when the oil in the oil reservoir is lifted by the rotor.

  The present invention has been made paying attention to such a point, and an object of the present invention is to increase the amount of oil in the oil reservoir in a structure in which oil is introduced into the rotary shaft along the radial direction of the rotary shaft. This is to provide a drive device that can be reduced in size.

  To achieve this object, the drive device according to the present invention is characterized in that a drive motor having a rotating shaft rotatably supported by a case and a rotor rotatably supported by the rotating shaft is provided in the case. The rotor is provided so that the oil stored in the oil storage section provided in the case is swept up with rotation, and the oil swept up by the rotor is disposed inside the rotating shaft. The drive device is configured to be supplied to the lubrication target member from the inside of the rotary shaft and lubricate, and between the pair of wall bodies facing in the axial direction of the rotary shaft, An oil reservoir is formed so as to be in contact with the outer periphery of the rotating shaft, and the oil reservoir for collecting the oil pumped up by the rotor is formed on the rotating shaft along the radial direction of the rotating shaft. Of the rotating shaft It lies in is provided an oil inlet portion for introducing a.

According to this configuration, the oil reservoir and the oil introduction portion for introducing the oil into the inside of the rotating shaft along the radial direction of the rotating shaft are located more centrally than the end of the rotating shaft in the axial direction of the rotating shaft. Can be provided. Thereby, compactization can be achieved in the axial center direction of the rotating shaft. The oil swirled by the rotor is temporarily stored in an oil reservoir formed so as to be in contact with the outer periphery of the rotating shaft. As a result, the own weight hydraulic pressure acts due to the weight of the oil accumulated in the oil reservoir. Even if the centrifugal oil pressure acts due to the centrifugal force accompanying the rotation of the rotating shaft, the oil introducing portion can introduce the oil in the oil reservoir into the rotating shaft by its own weight oil pressure. Moreover, since the oil in the oil reservoir is stored in the oil reservoir, the amount of oil stored in the oil reservoir can be reduced. Thereby, the drag loss at the time of scooping up the oil of an oil storage part with a rotor can also be reduced.
As a result of having the above-described configuration, the drive device of the present invention has a structure in which oil is introduced into the rotary shaft along the radial direction of the rotary shaft, and is compact in the axial center direction of the rotary shaft. The member to be lubricated can be lubricated without increasing the amount of oil in the reservoir.

  A further characteristic configuration of the drive device according to the present invention is that the oil reservoir includes a throttle with a reduced cross-sectional area through which oil flows.

  According to this configuration, it becomes difficult for oil to flow downstream from the throttle, and it is easy to accumulate oil upstream from the throttle in the flow direction of oil. Thereby, the oil can be accurately stored in the oil reservoir, and the self-weight hydraulic pressure can be accurately applied by the weight of the accumulated oil.

  According to a further characteristic configuration of the drive device according to the present invention, the oil reservoir is configured such that the oil reservoir is more than the centrifugal oil pressure acting by the centrifugal force associated with the rotation of the rotating shaft at a predetermined rotational speed. The depth at which the oil is stored is set so that the self-pressure hydraulic pressure acting due to the weight of the oil stored in the oil increases.

  In this way, by setting the depth at which oil is stored in the oil reservoir, the self-weight hydraulic pressure can be made larger than the centrifugal hydraulic pressure due to the rotation of the rotating shaft at a predetermined rotational speed, and the oil in the oil reservoir can be reliably It can be introduced inside the rotating shaft. Therefore, the lubrication target member can be reliably lubricated.

  According to a further characteristic configuration of the drive device according to the present invention, one of the pair of wall bodies is formed by an inner wall of the case, and the other is formed by a plate-like member fixed to the inner wall of the case. It is in a certain point.

  According to this configuration, one of the wall bodies can be formed using the inner wall of the case, and the other wall body can also be formed simply by fixing the plate-like member to the inner wall of the case. Therefore, formation of the oil reservoir is simplified.

  A further characteristic configuration of the drive device according to the present invention is that the plate-like member is provided so as to cover a recess formed in the inner wall of the case.

  According to this configuration, in forming the oil reservoir, the plate-like member is simply provided so as to cover the concave portion of the inner wall of the case, but the periphery is continuously formed by the concave portion and the plate-like member. Can be covered. For example, if the inner wall of the case is flat and a flat plate-like member is provided so as to face the inner wall, the oil reservoir cannot be formed, and the case wall and the plate-like member can be formed by another member. It is necessary to cover the gap. According to the present configuration, since there is no need for this, the oil reservoir can be easily and reliably formed.

  A further characteristic configuration of the drive device according to the present invention is that the plate-like member has an outer end in the rotational axis radial direction fixed to an inner wall of the case, and an inner end in the rotational axis radial direction is the It exists in the point provided so that it may be pressed by the inner wall side of the said case by the bearing member of the said rotating shaft supported by the inner wall of a case.

  According to this configuration, the plate member can be supported in a stable posture by using the pressing force of the bearing member while securely fixing the outer end portion of the plate member in the rotation axis radial direction. As a result, the oil reservoir can be accurately formed, oil leakage from the plate member and the bearing member can be suppressed, and oil can be accurately stored in the oil reservoir.

  According to a further characteristic configuration of the drive device according to the present invention, the oil reservoir includes the pair of wall bodies, the bearing member of the rotating shaft supported by the inner wall of the case, and the oil in the oil reservoir. It is in the point formed from the sealing member which blocks | prevents flowing out of a case.

  According to this configuration, when the oil reservoir is formed, the oil reservoir can be formed simply by providing a pair of wall bodies while using the existing bearing member and seal member. Thereby, the number of members added to form the oil reservoir can be reduced, and the configuration can be simplified and the cost can be reduced.

  According to a further characteristic configuration of the drive device according to the present invention, the oil reservoir portion includes a first reservoir portion that receives and accumulates the oil pumped up by the rotor, and a radial direction of the rotating shaft more than the first reservoir portion. A second reservoir portion that is located on the inner side in the axial center direction of the rotating shaft and communicates with the oil introduction portion, and a communication portion that communicates the first reservoir portion and the second reservoir portion. And a seal member for preventing the oil in the oil reservoir from flowing out of the case is disposed so as to overlap the first reservoir in the axial direction of the rotating shaft. is there.

  According to this configuration, the oil reservoir portion is accurately formed from the first reservoir portion, the communication portion, and the second reservoir portion, and the seal member and the first reservoir portion are overlapped in the axial direction of the rotation shaft. It is arranged. Accordingly, the seal member can be provided while forming the oil reservoir without projecting the seal member outside the case in the axial direction of the rotation shaft, and the rotation shaft can be made compact in the axial direction. be able to.

  A further characteristic configuration of the drive device according to the present invention lies in that a dripping rib is provided on the inner wall of the case for dripping the oil swirled by the rotor into the oil reservoir.

  According to this configuration, the oil scraped up by the rotor can be efficiently stored in the oil reservoir by the dropping rib. Therefore, the lubrication target member can be efficiently lubricated while utilizing the rotation of the rotor.

  According to a further characteristic configuration of the drive device according to the present invention, the rotating shaft is provided such that an end of the rotating shaft protrudes outward of the case, and a portion of the rotating shaft protrudes outward of the case. A braking mechanism for braking the rotation of the rotating shaft is provided.

  In this way, in order for the braking mechanism to brake the rotation of the rotating shaft, even if the rotating shaft is provided so that the end of the rotating shaft protrudes outward from the case, the oil swirled by the rotor is placed inside the rotating shaft. It can introduce and lubricate the object to be lubricated. In addition, according to this configuration, the braking mechanism brakes the rotation of the rotating shaft. Therefore, if a deceleration mechanism that decelerates the rotation of the rotating shaft and transmits it to the output shaft is provided, the deceleration mechanism reduces the speed. It is also possible to brake the rotating shaft of the previous drive motor. Therefore, as compared with the conventional driving device, the braking torque that needs to be applied as a braking mechanism can be reduced, and the configuration can be simplified and the cost can be reduced. In the conventional drive device, the rotation of the drive motor is decelerated by the speed reduction mechanism and the transmitted output shaft is braked by the braking mechanism. Therefore, the output shaft after being decelerated by the speed reduction mechanism must be braked. However, a braking mechanism that can apply a large braking torque is required.

  A further characteristic configuration of the drive device according to the present invention is such that the main body portion and the oil reservoir portion of the braking mechanism overlap in the circumferential direction of the rotating shaft and in the axial direction of the rotating shaft. It is in the point which has been arranged.

  As described above, in providing the oil reservoir, the brake mechanism main body having a predetermined size in the axial direction of the rotating shaft is positioned differently in the circumferential direction of the rotating shaft and in the axial direction of the rotating shaft. By disposing the oil reservoir portion so as to overlap with each other, it is possible to further reduce the size of the rotating shaft in the axial direction.

  A further characteristic configuration of the drive device according to the present invention is that a reduction mechanism that reduces the rotational speed of the rotary shaft and transmits it to the output shaft is provided on the outer periphery of the rotary shaft as the member to be lubricated.

  In this way, by arranging the speed reduction mechanism on the outer periphery of the rotating shaft, for example, only by providing a communication hole that communicates the inside and the outer periphery of the rotating shaft, the oil introduced into the rotating shaft can be used to rotate the rotating shaft. Oil can be supplied to the speed reduction mechanism using the accompanying centrifugal force. Thereby, lubrication of the speed reduction mechanism can be performed accurately.

  A further characteristic configuration of the drive device according to the present invention is such that the rotor, a rotational position sensor that detects the rotational position of the rotor, and the oil reservoir are arranged adjacent to each other along the axial direction of the rotational shaft. The stator of the driving motor fixed to the case is arranged so as to overlap the rotational position sensor in the axial direction of the rotating shaft.

  As described above, when the oil reservoir is provided, the rotor, the rotational position sensor, and the oil reservoir are arranged so as to be adjacent to each other along the axial direction of the rotation shaft. They can be arranged well, and the drive device can be made compact. In addition, since the stator is disposed so as to overlap the rotational position sensor in the axial direction of the rotating shaft, it is possible to further reduce the size in the axial direction of the rotating shaft.

An embodiment of a drive device according to the present invention will be described with reference to the drawings.
The drive device according to the present invention is, for example, a drive unit 1 housed in a wheel rim 2 of a drive wheel as shown in FIG. The drive unit 1 is used as an in-wheel type drive unit provided in, for example, an electric vehicle.
The drive unit 1 houses a drive motor 4 and a planetary gear 5 in an integral case 3 composed of a first case 3a and a second case 3b divided into two. The case 3 is suspended from the vehicle body via a suspension device. The first case 3 a is provided with an output shaft (axle) 6 so as to protrude outward from the first case 3 a, and the output shaft 6 is rotatably supported by an angular bearing 7. A hub 8 for fixing the wheel rim 2 is splined to the output shaft 6, and the output shaft 6 is secured to the output shaft 6 by a nut 9.

  The drive motor 4 is an electric motor composed of, for example, a brushless DC motor. The drive motor 4 includes a stator 10 fixed to the second case 3b, and a rotor 11 that is rotatably supported by a rotation shaft 15 in a state of facing the stator 10 with a minute gap. The drive motor 4 outputs a rotational force as a motor and also functions as a regenerative brake. The second case 3b has an opening 13 for the multi-hole seal connector 12, and is electrically connected to a controller and a battery in the vehicle body. The stator 10 is composed of a large number of laminated core plates and coils wound around the stator core, and the rotor 11 is composed of a large number of laminated plates embedded with permanent magnets such as rare earth magnets. The drive motor 4 is not limited to a brushless DC motor, but may be another synchronous or induction AC motor, or a DC motor.

  The rotor 11 is fixedly supported on the outer peripheral surface of the rotor hub 14. The rotor hub 14 has a flange portion 14 a that extends radially inward of the rotary shaft 15, and the flange portion 14 a is fixed to the rotary shaft 15. The rotary shaft 15 is rotatably supported by the output shaft 6 and the second case 3b via ball bearings 16 and 17 at both ends thereof. A rotational position sensor S that detects the rotational position of the rotor 11 is provided between the flange portion 14 a of the rotor hub 14 and the second case 3 b in the axial direction of the rotational shaft 15. The rotational position sensor S is constituted by a resolver having a first detection body S1 provided on the flange portion 14a of the rotor hub 14 and a second detection body S2 having a coil fixed to the second case 3b. The rotational position sensor S detects, for example, the phase of the alternating voltage according to the relative angle of the first detection body S1 with respect to the second detection body S2 when alternating current is passed through the coil provided in the second detection body S2. The rotational position of the rotor 11 is detected. The rotational position sensor S is not limited to a resolver, and various sensors such as a Hall element sensor, an encoder, and a magnetic rotational sensor can be applied.

  The planetary gear 5 is housed between the rotor 11 and the rotary shaft 15 in the axial direction of the rotary shaft 15 on the first case 3 a side than the flange portion 14 a of the rotor hub 14 and in the radial direction of the rotary shaft 15. The planetary gear 5 is a speed reduction mechanism that consists of one simple planetary gear and that reduces the rotational speed of the rotary shaft 15 and transmits it to the output shaft 6. In the planetary gear 5, the sun gear 18 is an input element, the carrier 19 is an output element, and the ring gear 20 is a fixed element. The sun gear 18 is provided integrally with the rotary shaft 15 integral with the rotor 11 of the drive motor 4, the carrier 19 is provided integrally with the output shaft 6, and the ring gear 20 is fixed to the second case 3a. It is.

  The carrier 19 includes a carrier main body 21 that is formed integrally with one end of the output shaft 6 and a carrier cover 22 that is integrally fixed to the carrier main body 21. A plurality of pinion shafts 23 are disposed across the carrier main body 21 and the carrier cover 22, and the pinion 24 is rotatably supported on each of the plurality of pinion shafts 23 via a needle bearing. A ring-shaped member 26 having spline teeth 25 on the outer peripheral surface is fixed to the inner side surface of the first case 3a with bolts 27. The ring gear 20 has a stepped portion 28 that engages with the spline teeth 25 of the ring-shaped member 26, and the snapped ring 29 holds the stepped portion 28 in a state where the stepped portion 28 is engaged with the spline teeth 25. Thus, it is integrally fixed to the first case 3a.

  The rotating shaft 15 of the drive motor 4 is provided so that the end portion protrudes outward from the second case 3b. A braking mechanism 32 that brakes the rotation of the rotating shaft 15 is provided at a portion of the rotating shaft 15 that protrudes outward from the second case 3b. The braking mechanism 32 is constituted by a disc brake mechanism having a brake disc 33 and a brake caliper 34 equipped with a brake pad and a piston. The brake caliper 34 corresponds to the main body portion of the braking mechanism 32. A brake disc 33 fixing hub 35 is fixed to the rotary shaft 15, and the rotary shaft 15 is fixed by a nut 36 to prevent it from coming off.

  The wheel rim 2 fixing hub 8 side (left side in FIG. 1) is closer to the hub 8 for fixing the wheel rim 2 than the angular bearing 7 provided in the first case 3 a, between the outer wall of the first case 3 a and the inner wall of the hub 8 for fixing the wheel rim 2. The 1st oil seal 30 is attached to. On the other hand, a second oil seal 31 is mounted between the rotary shaft 15 and the second case 3b on the brake mechanism 32 side (right side in FIG. 1) with respect to the ball bearing 17 provided in the second case 3b. Thus, the inside of the case 3 is formed in a sealed space by the outer oil seal 30, the first case 3a, the inner oil seal 31, and the second case 3b. A predetermined amount of oil (lubricating oil) is sealed inside the sealed case 3, and as shown in FIG. 3, an oil storage portion 37 that stores oil is provided on the lower side in the case 3. .

  As shown in FIGS. 2 and 3, the rotor 11 of the drive motor 4 is provided so as to scoop up the oil R in the oil reservoir 37 as it rotates. In the vicinity of the inner wall of the second case 3 b in the axial direction of the rotary shaft 15, an oil reservoir 38 is provided for collecting the oil R lifted up by the rotation of the rotor 11. The rotary shaft 15 is introduced into the rotary shaft 15 by an oil introduction portion 45 that introduces the oil R in the oil reservoir 38 along the radial direction of the rotary shaft 15 into the rotary shaft 15. An oil passage 46 for allowing the oil R to flow along the axial direction of the rotary shaft 15, and an oil ejection communication hole 47 for connecting the oil passage 46 and the outer periphery of the rotary shaft 15 are provided. The oil introduction part 45 is a communication hole provided at a plurality of locations in the circumferential direction of the rotary shaft 15 so as to allow the oil reservoir part 38 and the oil passage 46 to communicate with each other. The oil introduction part 45 has a diameter larger than that of the oil ejection communication hole 47. It is.

  When the oil is swept up by the rotation of the rotor 11, the oil R is supplied to the stator 10 to cool the stator 10, or the oil R is supplied to the lubrication target member B such as the planetary gear 5 and each bearing for lubrication. The oil R lifted up by the rotation of the rotor 11 is once stored in the oil reservoir 38 and introduced into the oil passage 46 inside the rotary shaft 15 from the oil introduction portion 45 as indicated by an arrow in FIG. At this time, since the own weight hydraulic pressure acts due to the own weight of the oil R accumulated in the oil reservoir portion 38, the oil introduction portion 45 has a predetermined rotation speed even if the centrifugal hydraulic pressure acts due to the centrifugal force accompanying the rotation of the rotating shaft 15. Then, the oil R in the oil reservoir 38 can be introduced into the rotary shaft 15 by its own hydraulic pressure. Thereafter, the oil R flows through the oil passage 46 in the axial center direction of the rotary shaft 15, and then is jetted from the oil communication hole 47 to the outer periphery of the rotary shaft 15 using the centrifugal force generated by the rotation of the rotary shaft 15. 5 and supply to the lubrication target member B such as each bearing and lubricate.

As shown in FIGS. 2 to 5, the oil reservoir 38 is formed so as to be in contact with the outer periphery of the rotating shaft 15 between a pair of wall bodies 39 facing in the axial direction of the rotating shaft 15. One of the pair of wall bodies 39 is formed by the inner wall of the second case 3b, and the other is formed by a plate-like member 40 fixed to the inner wall of the second case 3b.
Returning to FIG. 1, the inner wall of the second case 3 b is formed in a stepped shape having a first step portion 41 and a second step portion 42 in order from the radially outer side of the rotating shaft 15, and the second step portion 42. A recess 43 is formed on the inner side in the radial direction of the rotary shaft 15. Therefore, as shown in FIG. 6, the plate-like member 40 is formed in a flat plate shape and is provided so as to cover the concave portion 43 formed on the inner wall of the second case 3b. As a result, the oil reservoir 38 is easily and accurately formed using the recess 43 on the inner wall of the second case 3b.

  In order to attach the plate-like member 40 to the recess 43 on the inner wall of the second case 3b, the outer end 40a in the radial direction of the rotary shaft 15 and the inner end 40b in the radial direction of the rotary shaft 15 are formed by bending. The plate-like member 30 has an outer end 40 a in the radial direction of the rotary shaft 15 fixed to the inner wall of the second case 3 b with a bolt 44, and an inner end 40 b in the radial direction of the rotary shaft 15 is fixed to the rotary shaft 15. It is provided so as to be pressed against the inner wall side of the second case 3b by a ball bearing 17 which is a bearing member. The ball bearing 17 is supported by being fitted into a boss portion 49 formed to protrude from the inner wall of the second case 3b. The boss portion 49 is formed with a notch for forming the communication portion 38c of the oil reservoir portion 38, and the inner end portion 40b of the plate-like member 40 is inserted and fixed in the notch. Thus, the inner end portion 40b of the plate-like member 40 is provided so as to abut against the side surface of the ball bearing 17 and be pressed against the inner wall side of the second case 3b. Accordingly, the plate-like member 40 can be supported in a stable posture by using the pressing force by the ball bearing 17 while the outer end portion 40a in the radial direction of the rotary shaft 15 is securely fixed by the bolt 44. For this reason, the oil reservoir 38 can be accurately formed, oil leakage from the plate-like member 40 and the ball bearing 17 can be suppressed, and oil can be accurately stored in the oil reservoir 38.

  The oil reservoir 38 includes a first reservoir portion 38a that receives and stores the oil pumped up by the rotor 11, a radially inner side of the rotary shaft 15 and a central side in the axial center direction of the rotary shaft 15 relative to the first reservoir portion 38a. A second reservoir portion 38b that is located on the hub 8 side in the axial direction (left side in FIG. 1) and communicates with the oil introduction portion 45, and a communication portion 38c that communicates the first reservoir portion 38a and the second reservoir portion 38b. And consists of The communicating portion 38c is formed in a shape that bends from the end side to the center side in the axial direction of the rotary shaft 15, and has a reduced cross-sectional area through which oil flows. In this way, the oil reservoir 38 includes a communication portion 38c as a throttle. Since the communication portion 38c is a throttle, oil is easily collected in the first reservoir portion 38a, and the oil can be accurately accumulated in the oil reservoir portion 38.

  Since the second reservoir portion 38b is located closer to the center side in the axial center direction of the rotary shaft 15 than the first reservoir portion 38a, the first reservoir portion 38a and the outer periphery of the rotary shaft 15 are arranged in the radial direction of the rotary shaft 15. A space is created between them. Therefore, a second oil seal 31 as a seal member is provided in the space, and the first reservoir 38 a and the second oil seal 31 are arranged so as to overlap in the axial direction of the rotating shaft 15. Accordingly, the second oil seal 31 is not protruded outside the second case 3b in the axial direction of the rotary shaft 15, and the compactness is achieved in the axial direction of the rotary shaft 15.

  As described above, the oil reservoir 38 includes the pair of wall bodies 39 including the plate-like member 40 and the inner wall of the second case 3b, the ball bearing 17 as the bearing member of the rotating shaft 15, and the second oil seal as the seal member. 31 is formed. A first reservoir portion 38 a is formed by a pair of wall bodies 39, and a second reservoir portion 38 b is formed from the ball bearing 17 and the second oil seal 31. Thus, while using the ball bearing 17 and the second oil seal 31 provided for rotatably supporting the rotating shaft 15 and preventing oil from flowing out of the second case 3b, a pair of walls is used. By providing the body 39, the oil reservoir 38 can be easily and accurately formed. In addition, since the second oil seal 31 and the inner wall of the second case 3b are arranged so as to overlap in the axial direction of the rotary shaft 15, the oil reservoir portion can be made compact while achieving compactness in the axial direction of the rotary shaft 15. 38 can be formed. Further, since the ball bearing 17 is thicker in the axial direction of the rotary shaft 15 than the inner wall of the second case 3b, the second reservoir portion 38b is connected to the first reservoir portion 38a while utilizing the difference in thickness. It can be more easily formed on the center side in the axial direction of the rotary shaft 15 (the hub 8 side in the axial direction, the left side in FIG. 1).

  As shown in FIG. 3, a dripping rib 48 is provided on the inner wall of the second case 3 b for dripping the oil swirled by the rotor 11 to the oil reservoir 38. As shown by the arrows in FIG. 3, the oil scooped up along the rotation direction of the rotor 11 hits the dropping rib 48 and drops toward the oil reservoir 38 positioned below the dropping rib 48. As a result, the oil scraped up by the rotor 11 can be efficiently stored in the oil reservoir 38.

Returning to FIG. 1, in providing the oil reservoir 38, the rotor 11, the rotational position sensor S, and the oil reservoir 38 are disposed adjacent to each other along the axial direction of the rotary shaft 15. Thereby, it can arrange | position efficiently in the limited space in case 3, and the drive unit 1 can be made compact. Moreover, the stator 10 is arranged so as to overlap with the rotational position sensor S in the axial direction of the rotary shaft 15. In other words, the rotational position sensor S is radially inward of the rotational shaft 15 relative to the stator 10 and the end of the rotational position sensor S adjacent to the rotor 11 in the axial direction of the rotational shaft 15 faces the stator 10 side. It is arranged to enter. Thereby, the compactness in the axial center direction of the rotating shaft 15 can be further achieved.
In the braking mechanism 32, the brake caliper 34 and the oil reservoir 38 corresponding to the main body of the braking mechanism 32 are overlapped at different positions in the circumferential direction of the rotating shaft 15 and in the axial direction of the rotating shaft 15. Is arranged. That is, the second case 3b is not shaped similarly in the circumferential direction, but has a shape in which other portions than the portion forming the oil reservoir 38 are recessed inward. A brake caliper 34 having a predetermined size is arranged in the axial direction of the rotary shaft 15 in a space formed by the depression of the second case 3b. As a result, even when the braking mechanism 34 is provided in a portion of the rotating shaft 15 that protrudes outward from the second case 3b, the brake caliper 34 may be disposed so as not to protrude in the axial direction of the rotating shaft 15. It is possible to further reduce the size of the rotary shaft 15 in the axial direction.

  As described above, by providing the oil reservoir 38, even if the centrifugal oil pressure acts due to the centrifugal force associated with the rotation of the rotating shaft 15, the oil weight acting on the oil reservoir 38 is used. The oil in the oil reservoir 38 is introduced into the rotary shaft 15. Therefore, the oil reservoir 38 has a depth H for storing oil so that its own hydraulic pressure is greater than the centrifugal hydraulic pressure generated by the rotation of the rotating shaft 15 at a predetermined rotational speed (see FIG. 5). Here, it is preferable that the predetermined rotation speed is, for example, the upper limit rotation speed of the designed rotation shaft 15. In other words, even when the rotating shaft 15 is rotated at the upper limit number of rotations, the self-weight hydraulic pressure is larger than the centrifugal hydraulic pressure due to the rotation of the rotating shaft 15, so that the oil in the oil reservoir 38 is always supplied to the rotating shaft 15. Can be introduced inside.

FIG. 7 shows the relationship between the depth H at which oil is stored in the oil reservoir 38 and the self-weight hydraulic pressure that acts due to the own weight of the oil accumulated in the oil reservoir 38. The self-weight hydraulic pressure increases as the depth H for storing oil is increased. For example, if the depth H for storing oil is 25 (mm), the self-weight hydraulic pressure at that time is 127.6 (N / m ² ). FIG. 8 shows the relationship between the number of rotations of the rotating shaft 15 and the centrifugal hydraulic pressure acting by the centrifugal force accompanying the rotation of the rotating shaft 15. The centrifugal hydraulic pressure increases as the rotational speed of the rotary shaft 15 increases. For example, when the rotational speed of the rotary shaft 15 is 175 (rpm), the centrifugal hydraulic pressure becomes 127.6 (N / m ² ).
For example, if the design upper limit number of rotations of the rotating shaft 15 is 175 (rpm), the maximum value of the centrifugal hydraulic pressure acting by the centrifugal force accompanying the rotation of the rotating shaft 15 is 127.6 (N / m ² ). Therefore, at this time, the depth H at which oil is stored in the oil reservoir 38 is set to 25 (mm) so that the self-pressure oil pressure is greater than the centrifugal oil pressure. In this way, by setting the depth H in which the oil is stored in the oil reservoir 38, the oil introduction portion 45 can be stored in the oil reservoir by its own hydraulic pressure even if the centrifugal oil pressure is applied by the centrifugal force accompanying the rotation of the rotating shaft 15. The oil in the portion 38 can be reliably introduced into the rotary shaft 15, and the lubrication target member B can be reliably lubricated.

[Another embodiment]
(1) In the above embodiment, for example, the oil reservoir 38 can be formed by providing a pair of wall bodies facing the axial center direction of the rotary shaft 15 separately from the inner wall of the second case 3b. For example, another external case may be provided outside the second case 3b, and the outer wall of the second case 3b and the inner wall of the outer case may be a pair of opposing wall bodies, and the oil reservoir 38 may be formed therebetween. . In this case, a through hole is provided in the second case 3b, and the oil scraped up by the rotor 11 flows out from the through hole to the outside of the second case 3b and is stored in the oil reservoir 38. Thus, how to form a pair of wall bodies can be changed as appropriate.

(2) In the above embodiment, for example, the oil reservoir 38 is formed by fixing an oil reservoir forming member having a U-shaped cross section by bending both ends to the inner wall of the second case 3b. it can. Thus, in forming the oil reservoir 38, the plate-like member 40 is not limited to be provided so as to cover the recess 43 formed in the inner wall of the second case 3b.

(3) In the above embodiment, the oil reservoir 38 is constituted by the first reservoir portion 38a, the communication portion 38c, and the second reservoir portion 38b. For example, the oil reservoir 38 is arranged in the radial direction of the rotary shaft 15. It can also be formed as a linear passage along. Thus, how the oil reservoir 38 is configured can be changed as appropriate.

(4) In the above embodiment, the communication portion 38c of the oil reservoir 38 is used as a throttle. For example, by reducing the cross-sectional area of the oil reservoir 38 toward the lower side in the oil flow direction, It is also possible to make a stop over the entire reservoir 38.

  The present invention is configured such that oil swirled by a rotor is introduced into a rotating shaft, supplied to a lubrication target member from the inside of the rotating shaft, and lubricated, and the oil is arranged along a radial direction of the rotating shaft. As a structure to be introduced into the inside of the rotary shaft, various drive devices such as an in-wheel type drive device provided in an electric vehicle or the like that can be made compact without increasing the amount of oil in the oil reservoir. Can be adapted to.

Sectional drawing of the drive unit which is a drive device which concerns on this invention 1 is an enlarged view of the main part of FIG. Diagram showing the second case IV-IV sectional view of FIG. VV sectional view of FIG. The perspective view which shows the attachment state of the plate-shaped member in an oil reservoir part The graph which shows the relationship between the depth H which accumulates oil in an oil reservoir part, and the self-weight hydraulic pressure which acts by the dead weight of the oil which accumulates in an oil reservoir part A graph showing the relationship between the rotational speed of the rotating shaft and the centrifugal hydraulic pressure acting by the centrifugal force accompanying the rotation of the rotating shaft

Explanation of symbols

3 Case 4 Drive motor 5 Reduction mechanism (planetary gear)
DESCRIPTION OF SYMBOLS 10 Stator 11 Rotor 15 Rotating shaft 17 Bearing member (ball bearing)
31 Seal member (second oil seal)
32 Braking mechanism 34 Brake mechanism body (brake caliper)
37 oil reservoir 38 oil reservoir 38a first reservoir 38b second reservoir 38c communicating portion 39 pair of wall bodies 40 plate-like member 43 recess 45 oil introducing portion 48 dropping rib B lubrication target member S rotational position sensor

Claims (13)

A drive motor having a rotating shaft rotatably supported by the case and a rotor rotatably supported by the rotating shaft is housed in the case;
The rotor is provided so as to scoop up the oil in the oil storage part provided in the case with rotation,
A drive unit configured to introduce and lubricate oil swirled by the rotor into the rotary shaft and supply the lubrication target member from the rotary shaft;
Between a pair of wall bodies facing in the axial direction of the rotating shaft, an oil reservoir for storing oil swirled by the rotor is formed so as to contact the outer periphery of the rotating shaft;
The drive device in which the rotation shaft is provided with an oil introduction portion that introduces oil in the oil reservoir portion into the rotation shaft along a radial direction of the rotation shaft.   The drive unit according to claim 1, wherein the oil reservoir includes a throttle with a reduced cross-sectional area through which oil flows.   The oil reservoir has an oil pressure such that a self-weight oil pressure acting by a self-weight of the oil accumulated in the oil sump portion is larger than a centrifugal oil pressure acting by a centrifugal force accompanying the rotation of the rotating shaft at a predetermined rotational speed. The driving device according to claim 1 or 2, wherein a depth for storing the pressure is set.   One of said pair of wall bodies is formed in the inner wall of the said case, and the other is formed with the plate-shaped member fixed to the inner wall of the said case. The drive device described.   The drive device according to claim 4, wherein the plate-like member is provided so as to cover a recess formed in an inner wall of the case.   The plate-like member is a bearing member of the rotating shaft in which an outer end portion in the rotating shaft radial direction is fixed to an inner wall of the case, and an inner end portion in the rotating shaft radial direction is supported by the inner wall of the case. The drive device according to claim 4 or 5, wherein the drive device is provided so as to be pressed against the inner wall side of the case.   The oil reservoir includes the pair of wall bodies, a bearing member of the rotating shaft supported by the inner wall of the case, and a seal member that prevents the oil in the oil reservoir from flowing out of the case. The drive device according to any one of claims 4 to 6, wherein the drive device is formed from. The oil reservoir includes a first reservoir portion that receives and accumulates the oil pumped up by the rotor, and is radially inward of the rotary shaft and closer to the center in the axial center direction of the rotary shaft than the first reservoir portion. A second reservoir portion that is located and communicates with the oil introduction portion, and a communication portion that communicates the first reservoir portion and the second reservoir portion;
8. A seal member for preventing oil in the oil reservoir from flowing out of the case is disposed so as to overlap the first reservoir portion in the axial direction of the rotary shaft. The driving device according to any one of the above.   The drive device according to any one of claims 4 to 8, wherein a dripping rib is provided on the inner wall of the case for dripping the oil that has been lifted up by the rotor into the oil reservoir. The rotating shaft is provided such that an end thereof protrudes outward of the case,
The drive device according to claim 1, wherein a braking mechanism that brakes rotation of the rotary shaft is provided at a portion of the rotary shaft that protrudes outward from the case.   The driving device according to claim 10, wherein the main body portion and the oil reservoir portion of the braking mechanism are arranged at different positions in the circumferential direction of the rotating shaft and overlapping in the axial direction of the rotating shaft.   The drive device according to any one of claims 1 to 11, wherein as the lubrication target member, a speed reduction mechanism that reduces the rotational speed of the rotation shaft and transmits it to the output shaft is provided on the outer periphery of the rotation shaft. The rotor, a rotational position sensor that detects the rotational position of the rotor, and the oil reservoir are arranged so as to be adjacent along the axial direction of the rotational shaft,
The drive device according to any one of claims 1 to 12, wherein a stator of the drive motor fixed to the case is disposed so as to overlap with the rotational position sensor in an axial direction of the rotation shaft. .

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