JP2007107717A - Power transmission and power output device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device which can transmit rotational power efficiently only by gear meshing, and is inexpensive in simple composition. <P>SOLUTION: An internal gear 1 and an external gear 4 are provided on an eccentric shaft 2a with an input shaft 2 and on an coaxial output shaft 5 with the input shaft 2, respectively, wherein a pair of opposing second plates 11a, 11b between a side of the internal gear 1 and an inner surface of an end plate 6 of an outer ring 7 and a first plate 12 between the pair of the second plates are provided and the first plate is connected to the internal gear 1 and the pair of second plates are fixed to the end plate 6. A pair of opposing circled ball guiding recessed parts 18, 19 are formed at both sides of the first plate and at the facing side of the second plates, wherein the ball guiding recessed parts 18 of the first plate are formed by displacing with a dimension which corresponds to an eccentric amount of the eccentric shaft 2a in an eccentric direction with respect to the eccentric shaft, with the ball guiding recessed parts 19 of the second plates and a ball 20 is interposed between the facing pair of the ball guiding recessed part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission device and a power output device.

  Patent Document 1 or Patent Document 2 discloses a power transmission device in which the first shaft and the second shaft are arranged on the same shaft and the rotation of the first shaft is transmitted to the second shaft with a large reduction ratio. What has been known is conventionally known.

  In the power transmission device described in Patent Document 1, a first external gear and a second external gear are provided on the eccentric shaft portion of the input shaft, and the first external gear swings around the first internal gear fixed on the same axis. The second internal gear is provided on the output shaft arranged coaxially with the input shaft, and the second external gear is meshed with the second external gear so that the second external gear is swung around. The revolution movement of the gear is transmitted as the rotation movement of the second internal gear, and the rotation movement of the second internal gear is extracted to the output shaft.

  In the power transmission device described in Patent Document 2, the external gear provided on the eccentric shaft portion of the input shaft meshes with the internal gear fixed on the same axis so as to swing around, and the external gear on the input shaft side is engaged. A plurality of circular concave portions are provided in the end surface portion of the output shaft and the end surface portion of the output shaft, and steel balls are disposed between the concave portions to transmit the rotation of the internal gear to the output shaft. In order to allow the internal gear to swing, one circular recess is formed with a large diameter so that the steel ball can move, and the other recess is approximately the same diameter as the steel ball so that the steel ball is fixed. Is formed.

JP-A-5-10401 JP-A-6-33995

  By the way, the power transmission device described in Patent Document 1 can efficiently transmit the rotational force of the input shaft to the output shaft only by meshing the gears without using the Oldham coupling having a sliding portion. Since it is necessary to provide two external gears on the eccentric shaft portion and two internal gears that mesh with these external gears on the fixed portion and the output shaft, there is a problem that the configuration is complicated and expensive.

  The power transmission device described in Patent Document 2 has a relatively simple configuration including an internal gear and an external gear that mesh with each other. Since the steel ball fixed by the other recess having the same diameter slides, there is a problem that rotational resistance due to friction is large and power transmission efficiency is low.

  An object of the present invention is to provide a power transmission device and a power output device that are capable of efficiently transmitting a rotational force only by meshing of gears and that are inexpensive with a simple configuration.

In order to solve the above problems, in the power transmission device according to the present invention, an outer ring,
A first shaft inserted into the outer ring and supported relatively rotatably, and provided with an eccentric shaft at a position located inside the outer ring, and inserted into the outer ring and coaxial with the first shaft. And a second gear rotatably supported by the eccentric shaft, a first gear rotatably supported by the eccentric shaft portion, and the outer ring or the second shaft. A second gear having a difference in the number of teeth, a member of the outer ring and the second shaft on the side where the second gear is not provided, and the first gear are provided between the first gear and centered on the eccentric shaft portion. A rotation preventing means for preventing rotation of one gear and causing the first gear to perform only a revolving movement around the first axis. The rotation preventing means includes the outer ring and the second shaft. Of the member on the side where the second gear is not provided faces the side surface of the first gear A pair of opposed ring-shaped second plates are attached to the first plate, a first plate disposed between the pair of second plates is connected to the first gear, and both side surfaces of the first plate and the pair of second plates A pair of opposing ball guide recesses for guiding the ball so as to be capable of circular movement is formed on each of the surfaces facing the first plate at intervals in the circumferential direction so that the orbital diameter of the ball is equal to the eccentric amount of the eccentric shaft portion. The ball guide recess on the first plate side is provided with a position shifted in the eccentric direction of the eccentric shaft portion by a dimension corresponding to the eccentric amount of the eccentric shaft portion with respect to the ball guide recess on the second plate side, A configuration is adopted in which a ball that can roll along each ball guide recess is incorporated between a pair of opposing ball guide recesses.

  In the power transmission device configured as described above, in the power transmission device in which the second gear is provided on the second shaft and the second plate is fixed to the outer ring, the eccentric shaft portion is rotated by the rotation of the first shaft in a state where the outer ring is fixed. When the shaft is rotated eccentrically, the first gear supported by the eccentric shaft portion rotates eccentrically about the first shaft. At this time, since the first gear is prevented from rotating about the eccentric shaft portion by the rotation motion preventing means, the first gear revolves around the first shaft, and the revolving motion of the first gear is the first. When the second gear rotates per revolution of the first gear, the second gear rotates by the difference in the number of teeth from the first gear and is transmitted to the second shaft, and the power input to the first shaft is transmitted. The speed can be reduced and transmitted to the second axis.

  Here, when the first gear is an internal gear, the second gear is an external gear, and the number of teeth of the first gear is larger than the number of teeth of the second gear, the second gear has the number of teeth of the first gear. It rotates in the direction opposite to the revolution direction by the difference. On the other hand, when the first gear is an external gear, the second gear is an internal gear, and the number of teeth of the first gear is less than the number of teeth of the second gear, the second gear has a difference in the number of teeth from the first gear. Only rotates in the same direction as the revolution direction.

  When the second shaft is fixed and the first shaft is rotated and the eccentric shaft portion is rotated eccentrically, the first gear revolves around the fixed second gear. At this time, since the first gear and the second gear have different number of teeth, the first gear rotates relative to the second gear by the difference in the number of teeth from the second gear per revolution, and the rotation is prevented from rotating. It is transmitted to the outer ring through the means, and the power input to the first shaft can be decelerated and transmitted to the outer ring.

  Here, the external teeth of the external gear and the internal teeth of the internal gear may be involute teeth, or the external teeth of the external gear may be trochoidal curve teeth and the internal teeth that mesh with the external teeth may be external pins. Like the latter, the external teeth are trochoidal curved teeth and the internal teeth are external pins, so that the meshing rate can be increased, and a power transmission device with excellent durability with less tooth breakage can be obtained. it can.

  In the power transmission device, the thrust force applied to the first plate connected to the first gear can be supported in a well-balanced manner by providing a pair of opposing ball guide recesses at equal intervals in the circumferential direction. Here, the ball guide recess may be formed of an annular groove or may be formed of a circular recess.

  A plurality of through holes are provided in the second plate on the first gear side of the pair of second plates at equal intervals in the circumferential direction, and the first gear and the first plate are connected by connecting pins inserted through the through holes. As a result, the power transmission device itself can be made compact by eliminating the need for an extra connection space, and the rotation of the first gear can be prevented in a well-balanced manner.

  In order to solve the above problems, in the power output apparatus according to the present invention, a casing fixed to the vehicle body side and an electric motor having a rotor rotatably provided in a stator fixed to the inner periphery of the casing And an input wheel in which an eccentric shaft portion is formed at the shaft end portion, and a hub shaft that is inserted into the input wheel and is rotatably supported. An external gear rotatably supported by the eccentric shaft portion, an internal gear fixed to the casing or hub shaft and having a difference in the number of teeth with respect to the external gear, and an internal gear of the casing and the hub shaft are provided. A torque transmission means provided between the outer member and the external gear for absorbing the revolving motion of the external gear and transmitting the rotational motion of the external gear to the hub shaft; and the shaft end of the hub shaft. Fitted and locked, for wheel mounting An output wheel having a lunge on the outer periphery, and an outer member having a vehicle body side mounting flange on the outer periphery and rotatably supporting the output wheel via a double row of balls, A pair of opposed ring-shaped second plates opposed to the side surfaces of the external gear are integrated with a member on the side of the hub shaft and casing where the internal gear is not formed, and disposed between the pair of second plates. The first plate is connected to the external gear, and the diameter of the orbit of the ball is equal to the amount of eccentricity of the eccentric shaft portion on both sides of the first plate and the surfaces of the pair of second plates facing the first plate. A pair of opposed ball guide recesses for guiding the balls so as to be capable of circular movement are formed at intervals in the circumferential direction, and the ball guide recesses on the first plate side are eccentric with respect to the ball guide recesses on the second plate side axis The eccentric shaft portion is provided with a position shifted in the eccentric direction by a dimension corresponding to the amount of eccentricity, and a rollable ball is incorporated between each pair of opposing ball guide recesses along each ball guide recess. The one that consists of was adopted.

  Here, the ball guide recess may be formed of an annular groove or may be formed of a circular recess.

  In the power output device configured as described above, in the power transmission device in which the internal gear is fixed to the casing and the second plate is fixed to the hub shaft, when the rotor is rotated by energizing the stator, the input wheel rotates together with the rotor. And the eccentric shaft part provided in the shaft end part of the input wheel rotates eccentrically. Due to the eccentric rotation of the eccentric shaft portion, the external teeth of the external gear supported by the eccentric shaft portion revolve around the rotational axis of the input wheel while meshing with the internal teeth of the internal gear one by one.

  At this time, since the number of external teeth of the external gear is smaller than the number of internal teeth of the internal gear, the external gear reverses the rotation direction of the input ring by the difference in the number of teeth between the internal gear and the external gear per rotation of the input ring. Rotating in the direction, the rotation motion is transmitted to the flange via the torque transmission means, and the hub shaft and the output wheel fixed to the hub shaft rotate at a reduced speed.

  Here, the external teeth of the external gear and the internal teeth of the internal gear may be involute teeth, the external teeth of the external gear may be trochoidal curve teeth, and the internal teeth of the internal gear may be external pins. As in the latter case, when the external teeth of the external gear are trochoidal curved teeth and the internal teeth of the internal gear are external pins, the meshing rate can be increased and the power output device is excellent in durability with little damage to the teeth. Can be obtained.

  In the power output device, the eccentric shaft portion formed on the input wheel has two, and the eccentric gear portion rotatably supports the external gear, and each of the internal gears meshed with the external gear is fixed to the casing, If torque transmission means is provided between the hub shaft and each external gear, the rotational power of the input wheel can be transmitted to the hub shaft and the output wheel from two paths, and the rotational power transmitted from one path can be transmitted. It is possible to reduce the load and transmit the rotational power more stably.

  Here, if the two eccentric shaft portions are provided with a 180 ° phase shift in the circumferential direction, vibrations generated by the eccentric rotation of the eccentric shaft portions can be canceled out, so that a power output device with less vibration is obtained. be able to.

  In the power transmission device according to the present invention, the first gear is rotatably provided on the eccentric shaft portion of the first shaft that is supported so as to be rotatable relative to the outer ring, and is relative to the outer ring or the outer ring. A second gear rotatably supported is provided with a second gear that has a difference in the number of teeth from the first gear and meshes with the first gear inside and outside, and the second gear of the outer ring and the second shaft is Rotation motion inhibition that prevents the first gear from rotating around the eccentric shaft portion during the revolution of the first gear around the first axis between the member not provided and the first gear. By providing the means, the power input to the first shaft can be decelerated and transmitted to one of the second shaft and the outer ring.

  In addition, since the rotation preventing means is provided between the outer ring and the second shaft on the side where the second gear is not provided and the first gear, the first gear and the second gear are engaged only. The power of one shaft can be decelerated and efficiently transmitted to one of the second shaft and the outer ring, and a power transmission device having a simple configuration with a small number of parts can be obtained.

  Furthermore, since the ball rolls along the two ball guide recesses when the first gear revolves, a power transmission device with low friction loss and high power transmission efficiency can be obtained.

  In the power output apparatus according to the present invention, rotation of the rotor causes one of the internal gear and the external gear to rotate by the difference in the number of teeth, and the rotation is fixed to the hub shaft and the hub shaft via the torque transmission means. Since the power is transmitted to the output wheel, the power of the electric motor including the stator and the rotor can be output to the output wheel with a large reduction ratio.

  In addition, since the speed reduction mechanism has a small number of parts including an internal gear and an external gear, a small and compact power output device can be obtained.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 show an embodiment of a power transmission device according to the present invention. As shown in FIGS. 1 and 2, an internal gear 1 as a first gear is rotatably supported by a needle roller bearing 3 on an eccentric shaft portion 2a of an input shaft 2 as a first shaft. An external gear 4 serving as a second gear having a smaller number of teeth than the meshing internal gear 1 is provided on an output shaft 5 serving as a second shaft disposed coaxially with the input shaft 2. The gear 1 swings around the external gear 4 on the output shaft 5 side. The input shaft 2 as the first shaft and the output shaft 5 as the second shaft are rotatably supported by ball bearings 8a and 8b on an outer ring 7 having an end plate 6, respectively.

  The internal gear 1 has a U-shaped cross-section that opens on the external gear 4 side, and an eccentric shaft portion is provided between the side surface of the internal gear 1 and the inner surface of the end plate 6 of the outer ring 7 facing the side surface. Rotation motion preventing means 10 is provided that prevents the rotation of the internal gear 1 around 2a and causes the internal gear 1 to perform only the revolving motion.

  The rotation motion preventing means 10 includes a pair of opposed ring-shaped second plates 11a and 11b and a ring-shaped first plate 12 provided between the pair of second plates 11a and 11b.

  Of the pair of second plates 11a and 11b, a cylindrical portion 13 is formed on the outer periphery of one second plate 11b toward the other second plate 11a. The pair of second plates 11 a and 11 b are fitted into a large-diameter hole portion 14 formed at the opening end of the outer ring 7 and are arranged coaxially with the input shaft 2. 7 is fixed to the end plate 6.

  On the other hand, the first plate 12 is arranged coaxially with the eccentric shaft portion 2 a and is connected to the internal gear 1 via a plurality of connecting pins 16. Here, each of the plurality of connecting pins 16 is inserted into each of the plurality of through holes 17 formed in one second plate 11b.

  As shown in FIGS. 4 (a), 4 (b), and 4 (c), on both side surfaces of the first plate 12, a ball guide recessed portion 18 formed of a plurality of annular grooves is provided as one centered on the eccentric shaft portion 2a. It is formed at regular intervals on the circle. On the other hand, on the surface of the pair of second plates 11a and 11b facing the first plate 12, as shown in FIGS. 4 and 5, a ball guide recess 19 made up of the same number of annular grooves as the ball guide recesses 18 is provided. Are formed at equal intervals on one circle centered on the input shaft 2.

  Here, in each of the ball guide recesses 18 and 19, the diameter R of the center circle of the groove width is made equal to the eccentric amount δ of the eccentric shaft portion 2a shown in FIG. Further, the ball guide recess 18 formed in the first plate 12 has an eccentric direction of the eccentric shaft portion 2a with respect to the ball guide recess 19 of the second plates 11a and 11b by a dimension corresponding to the eccentric amount δ of the eccentric shaft portion 2a. The balls 20 are incorporated in the overlapping portions of the ball guide recesses 18 and 19 that are displaced in the radial direction and face in the axial direction. The ball 20 can roll along each of the ball guide recesses 18 and 19.

  The ball guide recesses 18 and 19 are not limited to the annular grooves. For example, it may consist of a circular recess.

  The power transmission device shown in the embodiment has the above structure, and when the outer ring 7 is fixed, when the power is input to the input shaft 2 and the input shaft 2 is rotated, the eccentric shaft portion 2a rotates eccentrically. Accordingly, the internal gear 1 supported by the eccentric shaft portion 2a also rotates eccentrically.

  Due to the eccentric rotation of the internal gear 1, the first plate 12 connected to the internal gear 1 also rotates together with the internal gear 1, and the ball 20 is guided by the ball guide recess 18 of the first plate 12 and the ball guides of the second plates 11 a and 11 b. It rolls along each of the recessed part 19, and the internal gear 1 is prevented from rotating by the rolling. For this reason, the internal gear 1 revolves around the input shaft 2.

  Due to the revolution of the internal gear 1, the internal gear 1 meshes with the teeth of the external gear 4 one by one and transmits power to the external gear 4. At this time, the external gear 4 rotates in the direction opposite to the revolution direction of the internal gear 1 by the difference in the number of teeth from the internal gear 1 per revolution of the internal gear 1, and the output shaft 5 is rotated together with the internal gear 1. Decelerate and rotate.

Here, when the number of teeth of the internal gear 1 is Z ₁ and the number of teeth of the external gear 4 is Z ₂ , the reduction ratio of the output shaft 5 can be expressed by (Z ₁ −Z ₂ ) / Z ₂ .

  In the use as described above in which the outer ring 7 is fixed, the outer ring 7 serves as a stationary member, so that the power input to the input shaft 2 can be transmitted to the output shaft 5 while being decelerated.

  Further, when the output shaft 5 is fixed and the input shaft 2 is rotated and the eccentric shaft portion 2a is rotated eccentrically, the internal gear 1 meshes with the teeth of the fixed external gear 4 one by one and Revolve around the gear 4. At this time, since there is a difference in the number of teeth between the internal gear 1 and the external gear 4, the internal gear 1 rotates relative to the external gear 4 by the difference in the number of teeth from the external gear 4 per revolution, and the rotation is the ball. It is transmitted to the outer ring 7 via the ball 20 incorporated between the guide recesses 18 and 19, and the outer ring 7 rotates at a reduced speed.

  Thus, in the power transmission device shown in the embodiment, the power input to the input shaft 2 as the first shaft is decelerated and transmitted only to the output shaft 5 as the second shaft, or the output shaft 5 Can be decelerated and transmitted to one of the outer rings 7.

  Further, by providing a rotation motion blocking means 10 for blocking the rotation motion of the internal gear 1 between the inner gear 1 and the end plate 6 of the outer ring 7, the input shaft 2 of the input shaft 2 is only engaged with the internal gear 1 and the external gear 4. Power can be decelerated and efficiently transmitted to one of the output shaft 5 and the outer ring 7, and a power transmission device with a simple configuration with a small number of parts can be obtained.

  Furthermore, when the internal gear 1 revolves, the ball 20 rolls along each of the two annular ball guide recesses 18 and 19, so that a power transmission device with low friction loss and high power transmission efficiency can be obtained. it can.

  In the embodiment, the internal gear 1 is rotatably provided on the eccentric shaft portion 2 a of the input shaft 2, and the external gear 4 is provided on the output shaft 5, but the external gear can be freely rotated on the eccentric shaft portion 2 a of the input shaft 2. An internal gear may be provided on the output shaft 5. In this case, the rotation motion preventing means 10 is provided between the outer gear and the end plate of the outer ring.

  As described above, in the power transmission device in which the external gear is provided in the eccentric shaft portion of the input shaft and the internal gear is provided in the output shaft, when the outer ring is fixed and the input shaft is rotated, the output shaft is one of the input shafts. Each rotation (per revolution of the external gear) rotates in the same direction as the input shaft by the difference in the number of teeth between the external gear and the internal gear, and the power input to the input shaft is decelerated and transmitted to the output shaft. Can do.

  In the embodiment, each of the plates 11a, 11b, and 12 is provided with a plurality of ball guide recesses 18 and 19 on the same circumference, and one ball 20 is interposed between each of the ball guide recesses 18 and 19. These ball guide recesses 18 and 19 are not necessarily provided on the same circumference.

  As shown in the embodiment, ball guide recesses 18 and 19 are formed at equal intervals on the same circumference of the plates 11a, 11b, and 12, and the second plates 11a and 11b are arranged coaxially with the input shaft 2. By fixing the first plate 12 coaxially with the eccentric shaft portion 2a and connecting it to the internal gear 1, the opposing pair of ball guide recesses 18 and 19 can be adjusted to the eccentric amount of the eccentric shaft portion 2a. The position of the eccentric shaft portion 2a can be shifted in the eccentric direction by a corresponding amount so as to face each other.

  In FIG. 2, the internal teeth of the internal gear 1 and the external teeth of the external gear 4 are involute tooth shapes. However, as shown in FIG. 7, the external teeth 4 a of the external gear 4 are trochoidal curved tooth shapes and the internal teeth of the internal gear 1. It is good also considering 1a as an outer pin.

  As shown in FIG. 7, when the external tooth 4a of the external gear 4 is a trochoidal curve tooth shape and the internal tooth 1a of the internal gear 1 is an external pin, the meshing rate can be increased and the durability of the teeth being less likely to break. It is possible to obtain a power transmission device excellent in the above.

  Further, in the embodiment shown in FIG. 1, the internal gear 1 is rotatably supported by the eccentric shaft portion 2a, the external gear 4 is provided on the output shaft 5, and the opposed second plates 11a and 11b are fixed to the outer ring 7. However, the external gear is rotatably supported by the eccentric shaft portion 2a, an internal gear having more teeth than the external gear is provided on the inner periphery of the outer ring 7, and a pair of opposed second plates are fixed to the output shaft 5, A first plate provided between the second plates may be connected to the external gear.

  8 to 10 show a power output apparatus according to the present invention. As illustrated, a casing 31 is provided on the inboard side of the knuckle 30 as a vehicle body. The casing 31 is fixed to a flange 32a of an outer member 32, which will be described later, by tightening bolts 33, and an electric motor 34 is incorporated therein.

  The electric motor 34 includes a stator 35 attached to the inner diameter surface of the casing 31 and a rotor 36 incorporated inside the stator 35, and the rotor 36 rotates by supplying electric power to the stator 35. Yes.

  An input wheel 37 is fitted inside the rotor 36 and integrated with the rotor 36. The input wheel 37 has an outer cylinder part 37a fitted to the inner diameter surface of the rotor 36 and an inner cylinder part 37b, and eccentric shaft parts 38a and 38b are formed at both ends of the inner cylinder part 37b. The two eccentric shaft portions 38a and 38b are 180 ° out of phase in the circumferential direction, and external gears 40a and 40b are rotatably supported via needle roller bearings 39 outside the eccentric shaft portions 38a and 38b. .

  Internal gears 41a and 41b are provided on the outer sides of the external gears 40a and 40b, respectively. The internal gears 41 a and 41 b are arranged coaxially with the input wheel 37 so that one end thereof is positioned between the outer cylinder part 37 a and the inner cylinder part 37 b of the input ring 37. An outward flange 42 is formed at the outer end located outside from the side, and the flange 42 is fixed to the end plate 31 a of the casing 31.

  As shown in FIG. 9, the external teeth 43 of the external gears 40a and 40b and the internal teeth 44 of the internal gears 41a and 41b are involute teeth, and the number of teeth of the external teeth 43 is less than the number of teeth of the internal teeth 44. The portion meshes with the internal teeth 44.

  As shown in FIG. 8, a seal member 45 is installed between the inner ends of the internal gears 41 a and 41 b and the inner cylinder portion 37 b of the input wheel 37 to prevent leakage of lubricating oil to the coil portion of the stator 35. It is out.

  A hub shaft 46 is inserted inside the input wheel 37, and the hub shaft 46 and the input wheel 37 are relatively rotatably supported by rolling bearings 47 incorporated inside the eccentric shaft portions 38a and 38b. ing.

  Between the hub shaft 46 and the external gears 40a, 40b, there is provided torque transmission means 50 that absorbs the revolving motion of the external gears 40a, 40b and transmits the rotational motion of the external gears 40a, 40b to the hub shaft 46. ing.

  FIG. 10 shows torque transmission means 50 for transmitting the rotation of the external gear 40 a to the hub shaft 46. The torque transmission means 50 is engaged with a small-diameter shaft portion 46a provided at an end of the hub shaft 46 by engaging a pair of opposed ring-shaped second plates 51a and 51b, and is screw-engaged with the small-diameter shaft portion 46a. The first plate 53 disposed between the pair of second plates 51a and 51b is inserted into each of the plurality of through holes 54 formed in the one second plate 51b. It is connected to the external gear 40 a via the connecting pin 55.

Further, both side surfaces and a pair of second plate 51a, first plate 53 opposite to each inner diameter equal to the opposed pair of circular eccentric amount [delta] ₂ of the eccentric shaft portion 38a of the surface of 51b of the first plate 53 The ball guide recesses 56 and 57 made of recesses are provided at intervals in the circumferential direction, and the ball guide recess 56 on the first plate side is formed on the eccentric shaft portion 38a with respect to the ball guide recess 57 on the second plate 51a and 51b side. by a dimension corresponding to the amount of eccentricity [delta] ₂ is provided by shifting the positions in the eccentric direction of the eccentric shaft portion 38a, between the opposing pair of ball guides recesses 56 and 57, which can roll along the ball guide recesses 56 and 57 The ball 58 is incorporated.

  The ball guide recesses 56 and 57 may be formed as annular grooves as shown in FIG. 4 instead of circular recesses.

  The torque transmission means 50 for transmitting the rotation of the external gear 40b to the hub shaft 46 has the same configuration as the torque transmission means 50 shown in FIG. 10, and one second plate 51a is integrated with the hub shaft 46. It differs only in the point provided. For this reason, the same code | symbol is attached | subjected to the same component and description is abbreviate | omitted.

  As shown in FIG. 8, an output wheel 60 is fitted to the end portion of the hub shaft 46 on the outboard side. The output wheel 60 includes a hub wheel 61 and a bearing inner ring 62. The bearing inner ring 62 has a cylindrical portion 62a at an end thereof, and the cylindrical portion 62a is fitted into the hub wheel 61, and the diameter is increased from the inner diameter portion. It is integrated with the hub wheel 61 by caulking. On the other hand, a wheel mounting flange 63 is formed on the outer periphery of the hub wheel 61, and a wheel fixing bolt 64 is mounted on the wheel mounting flange 63.

  The output wheel 60 is configured such that the cylindrical portion 62 a of the bearing inner ring 62 and the hub shaft 46 are coupled by a spline 64 so as to rotate integrally with the hub shaft 46. The output wheel 60 is fixed to the hub shaft 46 by tightening a nut 65 that is screw-engaged with the screw shaft 46 b at the shaft end of the hub shaft 46.

  An outer member 32 is provided outside the output wheel 60, and the output wheel 60 is rotatably supported by double rows of balls 66 incorporated between the outer member 32 and the output wheel 60.

  The outer member 32 has a vehicle body mounting flange 32 a on the outer periphery, and the vehicle body mounting flange 32 a is abutted against the side surface of the knuckle 30 on the outboard side and is fixed to the knuckle 30 by tightening bolts 68. . The casing 31 is fixed to the vehicle body mounting flange 32a.

  The power output apparatus shown in the embodiment has the above-described structure. When the rotor 36 is rotated by supplying power to the coil of the stator 35 of the electric motor 34 shown in FIG. 8, the input wheel 37 is rotated together with the rotor 36. The eccentric shaft portions 38a and 38b rotate eccentrically.

  Due to the eccentric rotation of the eccentric shaft portions 38a, 38b, the external gears 40a, 40b supported by the eccentric shaft portions 38a, 38b also rotate eccentrically, and the external teeth 43 of the external gears 40a, 40b are internal to the internal gears 41a, 41b. It rotates around the hub axle 46 while meshing with the teeth 44 one by one.

  At this time, since the number of teeth of the external teeth 43 of the external gears 40a and 40b is smaller than the number of teeth of the internal teeth 44 of the internal gears 41a and 41b, the external gears 40a and 40b are inputted by the difference in the number of teeth from the internal gears 41a and 41b. The wheel 37 rotates in the direction opposite to the rotation direction.

  At this time, the first plate 53 also rotates together with the external gears 40a and 40b, and the ball guide concave portion 56 formed in the first plate 53 swings around, so that the ball 58 has the ball guide concave portion 56 and the second plates 51a and 51b. The outer gears 40a and 40b rotate through the balls 58, and the rotation motion is transmitted to the second plates 51a and 51b through the connecting pins 55. Then, the hub shaft 46 and the output wheel 60 rotate at a reduced speed.

Here, the internal gear 41a, _{Z 1} the number of teeth of the internal 44 of the 41b, the external gear 40a, the number of teeth of the external teeth 43 of 40b and _{Z 2,} reduction _{ratio, (Z 1 -Z 2) /} Z ₂ can be expressed.

  As described above, in the power output apparatus shown in FIGS. 8 to 10, the external gears 40 a and 40 b meshing with the fixed internal gears 41 a and 41 b by the rotation of the input wheel 37 that rotates integrally with the rotor 36 are the input wheels 37. Per rotation of the internal gears 41a and 41b and the external gears 40a and 40b, and the rotational movement of the hub shaft 46 and the second plate 51a and 51b via the connecting pin 55 and the second plates 51a and 51b. Since it is transmitted to the output wheel 60, the rotation of the electric motor 34 including the stator 35 and the rotor 36 can be output to the output wheel 60 with a large reduction ratio.

  Further, since the speed reduction mechanism has a small number of parts including the internal gears 41a and 41b and the external gears 40a and 40b, a small and compact power output device can be obtained. As shown in the embodiment, the input ring 37 is provided with an outer cylinder part 37a and an inner cylinder part 37b, and a part of the internal gears 41a and 41b is accommodated between the outer cylinder part 37a and the inner cylinder part 37b. As a result, the axial length of the power output apparatus can be made more compact.

  In the above description of the operation, power is supplied to the electric motor 34 to drive the electric motor 34, and the power from the electric motor 34 is transmitted to the output wheels 60 to which the wheels are attached. When decelerating or going down a hill, the power from the wheels may be converted into high rotation and low torque by the deceleration unit and transmitted to the electric motor 34, and the electric motor 34 may generate power. Furthermore, the electric power generated here may be used for the electric motor 34 or other electric devices provided in the vehicle after temporarily storing in the battery.

  In FIG. 8, the external teeth 43 of the external gears 40 a and 40 b and the internal teeth 44 of the internal gears 41 a and 41 b are involute teeth, but the external teeth 43 of the external gears 40 a and 40 b are trochoidal as in the case shown in FIG. 7. A curved tooth shape may be used, and the internal teeth 44 of the internal gears 41a and 41b may be external pins.

  In the embodiment shown in FIGS. 8 to 10, the internal gears 41 a and 41 b are fixed to the casing 31 and the torque transmission means 50 is provided between the external gears 40 a and 40 b and the hub shaft 46. An internal gear is provided, torque transmission means is provided between the external gears 40a, 40b and the casing 31, and the internal gear is rotated by the difference in the number of teeth from the external gear by the eccentric rotation of the eccentric shaft portions 38a, 38b. The shafts may be rotated together.

A longitudinal front view showing an embodiment of a power transmission device according to the present invention Sectional view along the line II-II in FIG. Sectional drawing which shows the rotation movement prevention means of FIG. (A) is a front view showing the first plate of FIG. 3, (b) is a sectional view taken along line IVb-IVb in (a), and (c) is a sectional view taken along line IVc-IVc in (b). (A) is a cross-sectional view taken along the line Va-Va in FIG. 3, and (b) is a cross-sectional view taken along the line Vb-Vb in FIG. Sectional view along line VI-VI in FIG. Sectional drawing which shows the other example of a gear-type speed reducer mechanism Longitudinal front view showing a power output apparatus according to the present invention Sectional view along line IX-IX in FIG. Sectional drawing which shows the torque transmission means of FIG.

Explanation of symbols

1 Internal gear (first gear)
2 Input shaft (first axis)
2a Eccentric shaft 3 Needle roller bearing 4 External gear (second gear)
5 Output shaft (second axis)
6 End plate 7 Outer ring 10 Rotating motion blocking means 11a Second plate 11b Second plate 12 First plate 16 Connecting pin 17 Through hole 18 Ball guide recess 19 Ball guide recess 20 Ball 31 Casing 32 Outer member 32a Car body mounting flange 34 Electric motor 35 Stator 36 Rotor 37 Input wheel 38a Eccentric shaft portion 38b Eccentric shaft portion 40a External gear 40b External gear 41a Internal gear 41b Internal gear 46 Hub shaft 50 Torque transmission means 51a Second plate 51b Second plate 53 First plate 56 Ball Guide recess 57 Ball guide recess 58 Ball 60 Output wheel 63 Wheel mounting flange 67 Car body mounting flange

Claims (12)

Outer ring,
A first shaft that is inserted into the outer ring and is relatively rotatably supported, and is provided with an eccentric shaft portion at a position located inside the outer ring;
A second shaft inserted into the outer ring, arranged coaxially with the first shaft, and rotatably supported;
A first gear rotatably supported by the eccentric shaft portion;
A second gear provided on the outer ring or the second shaft and having a tooth number difference with respect to the first gear;
Of the outer ring and the second shaft, provided between the member on the side where the second gear is not provided and the first gear, preventing the rotation of the first gear around the eccentric shaft portion, The first gear comprises a rotation preventing means for causing only the revolution movement around the first axis, and
The rotation movement preventing means is
A pair of opposed ring-shaped second plates is attached to a surface of the outer ring and the second shaft that is not provided with the second gear and is opposed to the side surface of the first gear. The first plate disposed between the two plates is connected to the first gear, and the orbital circle diameter of the ball is eccentric on each side surface of the first plate and the surface of the pair of second plates facing the first plate. A pair of opposed ball guide recesses for guiding the ball so as to be capable of circular motion so as to be equal to the eccentric amount of the shaft portion is formed at intervals in the circumferential direction, and the ball guide recess on the first plate side is formed on the second plate side. The position is shifted in the eccentric direction of the eccentric shaft portion by a dimension corresponding to the eccentric amount of the eccentric shaft portion with respect to the ball guide concave portion, and rolls along each ball guide concave portion between the pair of opposing ball guide concave portions. Possible ball pairs Power transmission device consisting of or configuration.   The power transmission device according to claim 1, wherein the second gear is provided on a second shaft, and the second plate is fixed to an outer ring.   The power transmission device according to claim 1, wherein the second gear is fixed to an outer ring, and the second plate is provided on a second shaft.   The power transmission device according to any one of claims 1 to 3, wherein the teeth of the first gear and the teeth of the second gear are involute teeth.   4. The power transmission device according to claim 1, wherein one of the teeth of the first gear and the teeth of the second gear has a trochoidal curved tooth profile, and the other tooth has a pin. 5.   The power transmission device according to claim 1, wherein the pair of opposed ball guide recesses are provided at equal intervals in the circumferential direction.   A plurality of through holes are provided at equal intervals in the circumferential direction in the second plate on the first gear side of the pair of second plates, and the first gear and the first plate are connected by connecting pins inserted into the through holes. The power transmission device according to any one of claims 1 to 6. A casing fixed to the vehicle body side;
An electric motor in which a rotor is rotatably provided in a stator fixed to the inner periphery of the casing;
An input wheel that is incorporated into the rotor and rotates integrally with the rotor, and an eccentric shaft portion is formed at the shaft end; and
A hub shaft that is inserted into the input wheel and is rotatably supported;
An external gear rotatably supported by the eccentric shaft portion;
An internal gear fixed to the casing or hub shaft and having a difference in the number of teeth with respect to the external gear;
Torque that is provided between the outer gear and the member on the casing and hub shaft on which the internal gear is not provided, absorbs the revolution of the external gear, and transmits the rotation of the external gear to the hub shaft. A transmission means;
An output wheel fitted to the shaft end of the hub shaft and prevented from rotating, and having a wheel mounting flange on the outer periphery;
It has a flange for mounting on the vehicle body on the outer periphery, and consists of an outer member that rotatably supports the output wheel via a double row of balls,
The torque transmission means is
A pair of opposed ring-shaped second plates opposed to the side surfaces of the external gear are integrated with a member on the side of the hub shaft and casing where the internal gear is not provided, and disposed between the pair of second plates. The first plate is connected to an external gear, and the diameter of the orbit of the ball is adjusted to the eccentric amount of the eccentric shaft portion on both sides of the first plate and the surfaces of the pair of second plates facing the first plate. A pair of opposing ball guide recesses for guiding the balls so that they can be moved circularly are formed at intervals in the circumferential direction, and the ball guide recesses on the first plate side with respect to the ball guide recesses on the second plate side A ball corresponding to the amount of eccentricity of the eccentric shaft portion is shifted in the eccentric direction of the eccentric shaft portion, and a rollable ball is incorporated along each ball guide concave portion between the pair of opposing ball guide concave portions. Structure Power output apparatus comprising a.   There are two eccentric shaft portions formed on the input wheel, the external gears are rotatably supported by the eccentric shaft portions, and the internal gears meshed with the external gears are fixed to the casing or the hub shaft, respectively. The power output device according to claim 8, wherein the torque transmission means is provided between a member on the side of the hub shaft on which the internal gear is not provided and each external gear.   The power output apparatus according to claim 8 or 9, wherein the two eccentric shaft portions are provided with a 180 ° phase shift in the circumferential direction.   The power output device according to any one of claims 8 to 10, wherein the internal gear is fixed to the casing, and the second plate is fixed to the hub shaft.   The power output apparatus according to any one of claims 8 to 10, wherein the internal gear is fixed to a hub shaft, and the second plate is fixed to a casing.

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