JP2008045601A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device preventing a load on an electric motor resulting from the associative rotation of the electric motor with the rotation of a wheel. <P>SOLUTION: In the power transmission device 1, a two-way clutch 4 provided on an intermediate shaft 3 transmits driving force with a roller 42 having linear contact with an outer ring member 44, and so it has less friction heat to be generated during the contact than a multiple disc clutch having discs in face contact with each other, thus reducing the amount of oil to be used, accordingly. As a result, the amount of oil existing between the roller 42 and the outer ring member 44 can be extremely reduced. Even when the two-way clutch is in a cut-off condition, the viscosity of the oil suppresses the occurrence of drag transmitted by the driving force, thus preventing the associative rotation of the electric motor with the rotation of the wheel to prevent a load on the electric motor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power transmission device, and more particularly to a power transmission device that can prevent a load from being applied to an electric motor as the electric motor rotates with the rotation of a wheel.

  In general, an electric vehicle using an electric motor as a drive source, or an electric vehicle using a fuel engine and an electric motor in combination as a drive source, an input shaft connected to the electric motor, an intermediate shaft connected to the input shaft, A power transmission device having a drive shaft coupled to the intermediate shaft is provided. In this power transmission device, the driving force of the electric motor rotates the wheels connected to the drive shaft while amplifying the drive torque via the input shaft, the intermediate shaft, and the drive shaft.

  By the way, in the power transmission device described above, since the electric motor and the wheel are directly connected via the input shaft, the intermediate shaft, and the drive shaft, when the driving force supply of the electric motor is cut off, such as during inertia traveling When the rotation of the wheel becomes faster than the rotation of the electric motor, the electric motor is rotated along with the rotation of the wheel, and the electric motor is loaded and damaged.

  On the other hand, in the power transmission device 1 described in Japanese Patent Laid-Open No. 2001-287550 (Patent Document 1), a technique is described in which a multi-plate intermittent clutch 5 is interposed between the outer shaft 37 and the inner shaft 39. ing. According to this technique, the intermittent clutch 5 can disconnect the connection between the outer shaft 37 and the inner shaft 38, that is, the connection between the electric motor 2129 and the wheel, so that the electric motor 2129 can rotate the wheel. It is possible to prevent the electric motor 2129 from being loaded by preventing it from being accompanied.

  The multi-plate intermittent clutch 5 is configured to include a plurality of plates. When the plates come into contact with each other, the driving force is transmitted by the frictional force between the plates, and the plates are separated from each other. The driving force is cut off when a gap is formed between the plates.

JP 2001-287550 A (see FIG. 1)

  However, since oil is interposed between the plates of the intermittent clutch 5 mainly for the purpose of cooling, even when the plates are separated from each other and the driving force is cut off, the viscosity of the oil causes the gap between the plates. Therefore, a so-called drag in which the driving force is transmitted occurs. As a result, there is a problem in that the driving force cannot be reliably interrupted, and the electric motor 2129 rotates along with the rotation of the wheel, and a load is applied to the electric motor 2129.

  The present invention has been made in order to solve the above-described problems, and provides a power transmission device capable of preventing the electric motor from rotating with the rotation of the wheel and applying a load to the electric motor. It is an object.

  In order to achieve this object, a power transmission device according to claim 1 includes an input shaft to which a driving force of an electric motor is input, an intermediate shaft that is connected to the input shaft and transmits the driving force of the electric motor, A differential device that distributes the driving force transmitted by the intermediate shaft to the wheel side; and a clutch that is provided on the intermediate shaft so that the driving force transmitted to the differential device can be connected and disconnected. The clutch includes an inner ring member having a substantially polygonal cross section, a roller disposed on each outer peripheral side surface of the inner ring member, a retainer that holds the roller, a retainer, and an inner ring member. The retainer is switched between an outer ring member that externally fits the roller, a neutral position where a gap is formed between the outer ring member and the roller, and a driving position where the outer ring member and the roller are in contact with each other. It is constructed and a that switching device, the outer ring member is connected to the differential gear side.

  According to a second aspect of the present invention, the power transmission device according to the first aspect includes a gear that meshes with the differential device, and the gear is joined to one axial end surface of the outer ring member.

  A power transmission device according to a third aspect is the power transmission device according to the second aspect, wherein the gear is joined to the outer ring member by welding or brazing.

  A power transmission device according to a fourth aspect of the present invention is the power transmission device according to any one of the first to third aspects, wherein the intermediate shaft is constituted by one and the outer ring member is directly connected to the differential device. .

  According to the power transmission device of the first aspect, when the driving force of the electric motor is input to the input shaft, the driving force is transmitted from the input shaft to the differential device and distributed to the wheel side. A clutch provided on the intermediate shaft transmits or interrupts the driving force between the differential device and the intermediate shaft.

  This clutch forms a gap between the roller and the outer ring member when the retainer is positioned at the neutral position by the switching device, and disconnects the connection between the inner ring member and the outer ring member, i.e., the intermediate shaft and the differential device. The driving force transmitted between the two is cut off. On the other hand, when the retainer is positioned at the driving position by the switching device, the roller and the outer ring member come into contact with each other, and the inner ring member and the outer ring member are connected via the roller, that is, driven between the intermediate shaft and the differential device. Transmit power.

  When the driving force is switched from cutoff to transmission between the intermediate shaft and the differential device, the rollers are engaged with each other while being in line contact with the outer ring member, so that the plates are in surface contact with each other with slippage. Compared with the multi-plate clutch, the frictional heat generated upon contact can be suppressed, and the amount of oil used can be reduced accordingly. As a result, the amount of oil interposed between the roller and the outer ring member can be extremely reduced. Therefore, even when the clutch is in the disengaged state, the drag generated by the viscosity of the oil can be suppressed, so that the electric motor is prevented from being accompanied by the rotation of the wheel and the electric motor is prevented from being loaded. There is an effect that can be.

  Further, according to the present invention, since the outer ring member of the clutch is connected to the differential device side, when the clutch cuts off the driving force, the rotation of the wheel is transmitted to the outer ring member to rotate the outer ring member. Can be made. Here, when the inner ring member and the differential device side are connected, when the clutch interrupts the driving force, the rotation of the wheel is transmitted to the inner ring member, and the inner ring member rotates. The rotation of the inner ring member causes the rollers disposed on the respective outer peripheral side surfaces of the inner ring member to rotate integrally with the inner ring member, so that centrifugal force due to the rotation is applied to the roller and moves to the outer ring member side. Will come into contact. As a result, the drag that transmits the driving force occurs due to the contact between the roller and the outer ring member, and the driving force cannot be reliably interrupted.

On the other hand, according to the present invention, as described above, the clutch is configured such that the outer ring member is connected to the differential device side, so that when the clutch cuts off the driving force, the rotation of the wheel is performed. The outer ring member can be rotated without transmitting to the inner ring member. Thereby, it is possible to prevent the centrifugal force from being applied to the roller and to prevent the roller and the outer ring member from coming into contact with each other. Therefore, it is possible to prevent the occurrence of drag due to the contact between the roller and the outer ring member. As a result, there is an effect that the electric motor can be prevented from rotating with the rotation of the wheel.
According to the present invention, the clutch is disposed on the intermediate shaft. Here, when the clutch is arranged on the input shaft, the input shaft rotates at a higher speed than the intermediate shaft, and therefore it is necessary to provide a clutch having a high allowable rotational speed. On the other hand, when the clutch is disposed on the drive shaft connected to the differential device, the drive force of the drive shaft is larger than the drive force of the intermediate shaft, and therefore it is necessary to provide a clutch that can withstand a large drive force.

  On the other hand, according to the present invention, since the clutch is disposed on the intermediate shaft, it is not necessary to provide a clutch having a high permissible rotational speed or a clutch that can withstand a large driving force. Since it can be used, there is an effect that the cost for the clutch can be reduced, and the manufacturing cost of the entire power transmission device can be reduced accordingly.

  According to the power transmission device according to claim 2, in addition to the effect of the power transmission device according to claim 1, the gear meshing with the differential device is joined to one end surface in the axial direction of the outer ring member. Compared with the gear joined to the outer peripheral surface, the outer diameter of the gear can be reduced. Here, when the gear is joined to the outer peripheral surface of the outer ring member, the outer diameter dimension of the differential case of the differential device must be made larger than the outer diameter dimension of the gear in order to amplify the driving torque. The entire device becomes larger.

  On the other hand, as described above, the gear in the power transmission device of the present invention is joined to the axial end surface of the outer ring member, and therefore compared to the case where the gear is joined to the outer peripheral surface of the outer ring member. The outer diameter can be reduced. As a result, compared with the case where the gear is joined to the outer peripheral surface of the outer ring member, the differential device can be made smaller, and the size of the entire power transmission device can be reduced accordingly.

  According to the power transmission device according to claim 3, in addition to the effect of the power transmission device according to claim 2, the gear is joined to the outer ring member by welding or brazing. Compared with the case where it is connected to the outer ring member, the connecting portion between the gear and the outer ring member can be reduced in size. That is, when the gear and the outer ring member are connected by spline fitting, the spline of the gear and the outer ring member must be enlarged in order to ensure the contact area of the spline, and accordingly, the gear and the outer ring member The connecting part is enlarged. In addition, when the gear and the outer ring member are connected by bolting, a part for drilling a screw hole must be provided in the gear and the outer ring member, and the connection part between the gear and the outer ring member is correspondingly provided. Increase in size. Further, the connecting portion between the gear and the outer ring member is enlarged by the amount that the bolt screwed into the gear and the outer ring member protrudes from the screw hole.

  On the other hand, in the present invention, since the gear is joined to the outer ring member by welding or brazing, the connecting portion between the gear and the outer ring member is compared with the case where the gear is connected by spline fitting or bolt fastening. There is an effect that the entire power transmission device can be reduced in size.

  According to the power transmission device of the fourth aspect, in addition to the effect of the power transmission device according to any one of the first to third aspects, the intermediate shaft is constituted by one and the outer ring member is directly connected to the differential device. Has been.

  Here, in the case where the intermediate shaft is composed of two or more, the weight of the entire power transmission device increases as the intermediate shaft increases. Furthermore, as the intermediate shaft increases, the material cost increases and the manufacturing cost of the power transmission device increases. On the other hand, in the present invention, since the intermediate shaft is constituted by one, it is possible to suppress an increase in weight due to an increase in the intermediate shaft and suppress an increase in material cost, and accordingly, the weight of the power transmission device and There is an effect that an increase in manufacturing cost can be suppressed.

  On the other hand, when there are zero intermediate shafts, that is, when the input shaft and the differential device are directly connected, the drive torque of the electric motor cannot be sufficiently amplified, and the drive for running the vehicle is not possible. I cannot secure enough power. On the other hand, in the present invention, since the intermediate shaft is constituted by one, the intermediate shaft has an effect of amplifying the driving torque of the electric motor and ensuring the driving force for running the vehicle. .

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of the power transmission device 1 of the present embodiment. In FIG. 1, the illustration of one drive shaft 6 is omitted, and the illustration of the axial length of the other drive shaft 6 (length in the left-right direction in FIG. 1) is omitted.

  First, the overall configuration of the power transmission device 1 will be described with reference to FIG. The power transmission device 1 is mounted on an electric vehicle using an electric motor (not shown) as a drive source, transmits the driving force of the electric motor to a drive shaft 6 described later, and wheels (see FIG. (Not shown) for rotating the vehicle.

  The power transmission device 1 includes an input shaft 2 to which a driving force of an electric motor is input, an intermediate shaft 3 coupled to the input shaft 2, a two-way clutch 4 externally fitted to the intermediate shaft 3, and The input shaft 2, the intermediate shaft 3, the two-way clutch 4, and the differential device 5 are housed in a casing 7.

  The input shaft 2 is a shaft-like member that is connected to an output shaft (not shown) of the electric motor and receives the driving force of the electric motor, and is supported in the casing 7 by bearings 81 and 82. An oil seal 83 that prevents oil leakage to the outside is provided on one end side (left side in FIG. 1) of the input shaft 2. Further, a connecting member 21 for connecting to the output shaft of the electric motor is fastened and fixed to one end side of the input shaft 2 with a nut so that rotation input through the output shaft can be transmitted to the electric motor. Yes. The input shaft 2 has an output gear 22 that meshes with an input gear 31 of the intermediate shaft 3 described later on the outer peripheral surface on the other end side (right side in FIG. 1).

  The intermediate shaft 3 is a hollow shaft-shaped member that is engaged with and coupled to the output gear 22 of the input shaft 2 to amplify the driving force input from the input shaft 2. It is pivotally supported inside. The intermediate shaft 3 is formed in a hollow shape, and the input gear 31, the output gear 32, and the two-way clutch 4 are cooled by the hollow portion, and the bearing 84 is lubricated. Further, the intermediate shaft 3 is formed with an input gear 31 that meshes with the output gear 22 of the input shaft 2 on the outer peripheral surface on the other end side (right side in FIG. 1), and can be rotated following the rotation of the input shaft 2. It is configured. The input gear 31 has an outer diameter dimension set to be larger than an outer diameter dimension of the output gear 22 of the input shaft 2, and amplifies the driving force input from the input shaft 2.

  The two-way clutch 4 is a device for transmitting or interrupting the driving force in both the forward and reverse rotation directions, and is externally fitted at the approximate center of the intermediate shaft 3. Here, when the two-way clutch 4 is disposed on the input shaft 2, the input shaft 2 rotates at a higher speed than the intermediate shaft 3, and therefore it is necessary to provide a two-way clutch having a high permissible rotational speed. On the other hand, when the 2-way clutch 4 is disposed on the drive shaft 6, the drive force of the drive shaft 6 is greater than that of the intermediate shaft 3, so it is necessary to provide a 2-way clutch that can withstand a large drive force.

  On the other hand, in the power transmission device 1 of the present embodiment, since the two-way clutch 4 is disposed on the intermediate shaft 3, a two-way clutch having a high permissible rotational speed or a two-way clutch that can withstand a large driving force is provided. Is no longer necessary. That is, since a general two-way clutch can be used, the cost of the two-way clutch 4 can be reduced, and the manufacturing cost of the entire power transmission device 1 can be reduced accordingly.

  An output gear 32 is welded to one axial end surface (left side surface in FIG. 1) of the outer ring member 44 described later. Details of the 2-way clutch 4 will be described later (see FIGS. 2 and 3).

  The output gear 32 is a gear for meshing with an input gear 56 (to be described later) of the differential device 5, and has an inner diameter supported by the intermediate shaft 3 by a bearing 32a. Thereby, compared with the case where the output gear 32 is joined to the outer peripheral surface of the outer ring member 44, the outer diameter of the output gear 32 can be reduced. As a result, it is possible to reduce the outer diameter of an input gear 56 (described later) that meshes with the output gear 32 to amplify the driving force, and accordingly, the power transmission device 1 as a whole can be downsized.

  Further, since the output gear 32 is joined to the outer ring member 44 by welding, the output gear 32 and the outer ring member 44 are compared with the case where the output gear 32 is connected to the outer ring member 44 by spline fitting or bolt tightening. A connection part can be reduced in size. That is, when the output gear 32 and the outer ring member 44 are connected by spline fitting, the spline of the output gear 32 and the outer ring member 44 must be increased in order to secure the spline contact area. The connecting portion between the output gear 32 and the outer ring member 44 is increased in size. Further, when the output gear 32 and the outer ring member 44 are coupled by bolting, the output gear 32 and the outer ring member 44 must be provided with a portion for drilling a screw hole. The connecting portion between the outer ring member 44 and the outer ring member 44 is enlarged. Further, the connecting portion between the output gear 32 and the outer ring member 44 is increased in size by the amount of the bolt screwed into the output gear 32 and the outer ring member 44 protruding from the screw hole.

  On the other hand, in the power transmission device 1 of the present embodiment, the output gear 32 and the outer ring are compared with the case where the output gear 32 is welded to the outer ring member 44 and is connected by spline fitting or bolt fastening. The connecting portion with the member 44 can be reduced in size, and accordingly, the entire power transmission device 1 can be reduced in size. In this embodiment, the output gear 32 and the outer ring member 44 are connected by welding, but the output gear 32 and the outer ring member 44 may be connected by brazing.

  The differential device 5 is a differential device for canceling the rotational difference between the left and right drive wheels 6, and includes a pinion shaft 51 fixed to the differential case 55, a pair of pinions 52 supported on the pinion shaft 51, and A pair of side gears 53 meshing with the pinion 52 and an axle shaft 54 fitted to the side gear 53 are provided. The pinion shaft 51, the pinion 52, the side gear 53, and the axle shaft 54 are accommodated in a differential case 55. ing.

  The differential case 55 is pivotally supported in the casing 7 by bearings 86 and 87, and oil seals 88 and 89 for preventing oil leakage to the outside are provided at the front ends of the side gears 53. The differential case 55 is provided with a projecting portion 55a that projects in a flange shape in a direction perpendicular to the axial direction (the vertical direction in FIG. 1), and an input gear 56 that meshes with the output gear 32 is provided in the projecting portion 55a. It is fastened with bolts.

  Thus, when the output gear 32 rotates, the differential case 55 and the pinion shaft 51 rotate following the rotation of the output gear 32, and the rotation of the pinion shaft 51 is transferred to the left and right side gears 53 via the pinion 52. The axle shaft 54 is rotated by being transmitted. Further, when a drive resistance difference occurs between the left and right axle shafts 54, such as when turning or traveling on a rough road, the pinion 52 rotates and each axle shaft 54 rotates differentially. Note that the outer diameter of the input gear 56 is set to be larger than the outer diameter of the output gear 32, and the driving force input from the output gear 32 is amplified.

  Next, details of the 2-way clutch 4 will be described with reference to FIGS. 2 and 3. FIG. 2 is a sectional view of the 2-way clutch 4. 3A is a cross-sectional view of the 2-way clutch 4 taken along the line IIIa-IIIa in FIG. 2, and FIG. 3B is a cross-sectional view of the 2-way clutch 4 in which the retainer 43 is located at the driving position. .

  In FIG. 2, the axial lengths of the intermediate shaft 3, the output gear 32, and the input gear 56 (the length in the left-right direction in FIG. 2) are not shown. Further, in FIG. 3, the illustration of the external fitting member 94 is omitted for easy understanding.

  As described above, the two-way clutch 4 is a device for transmitting or interrupting the driving force in both the forward rotation direction and the reverse rotation direction. As shown in FIGS. 3, an inner ring member 41 that fits outside, a roller 42 that is rotatably arranged on each outer peripheral side surface of the inner ring member 41, a cage 43 that holds the roller 42, the cage 43, the roller 42, and the inner ring member 41 is mainly provided with an outer ring member 44 that is fitted on the outer ring member 41, and an electromagnetic control unit 9 that is disposed on the other axial end side (right side in FIG. 2) of the outer ring member 44.

  As shown in FIGS. 2 and 3, the inner ring member 41 is a cylindrical member having a substantially polygonal cross section, is spline-fitted to the intermediate shaft 3, and rotates integrally with the hollow shaft 3. Further, a substantially circular recess 41a is formed in the end surface of the inner ring member 41 on the other end side in the axial direction (the right side in FIG. 2 and the front side in FIG. 3).

  A ring portion 45a of the switch spring 45 is fitted to the inner periphery of the recess 41a, and a pair of hooks 45b projecting radially outward (upward in FIGS. 2 and 3) from both ends of the ring portion 45a are formed in the recess 41a. It engages with a notch (not shown) of the retainer 43 through a notch 41a1 on the peripheral wall. The cage 43 is held at a neutral position where a gap is formed between the roller 42 and the inner peripheral surface of the outer ring member 44 by the spring force in the circumferential direction of the hook 45b.

  As shown in FIGS. 2 and 3, the roller 42 is a columnar member disposed on each outer peripheral side surface of the inner ring member 41 and is fitted into a fitting hole (not shown) formed in the cage 43. Thus, it is configured to be capable of rotating and revolving integrally with the cage 43.

  2 and 3, the retainer 43 is a retaining member that is disposed on the outer peripheral side of the inner ring member 41 and retains the roller 42. A pair of retainers 43 is provided on the end surface on the other axial end side (right side in FIG. 1). The non-rotating piece 43a is projected. This detent piece 43a engages with a first engagement hole 91a of an armature 91, which will be described later, and rotates the retainer 43 integrally with the armature 91.

  As shown in FIGS. 2 and 3, the outer ring member 44 is a cylindrical member that externally fits the inner ring member 41, the roller 42, and the retainer 43 via the bearing 101. ) Is provided with an electromagnetic control unit 9 which will be described later. In addition, as described above, the output gear 32 is welded to the end surface of one end side in the axial direction (left side in FIG. 2) of the outer ring member 44.

  As shown in FIG. 2, the electromagnetic control unit 9 is provided at the end of the outer ring member 44 on the other end side in the axial direction (right side in FIG. 2), and includes an armature 91 that engages with the retainer 43 and the armature thereof. 91 mainly includes a rotor 92 disposed opposite to the other axial end side surface (right side surface in FIG. 2), and an electromagnetic coil 93 disposed on the other axial end side of the rotor 92. .

  As shown in FIG. 2, the armature 91 has two first engagement holes 91a, and a pair of detent pieces 43a are inserted into the respective engagement holes 91a. 43, and is configured to be movable in the axial direction (left-right direction in FIG. 2). The armature 91 has a second engagement hole 91b, and is biased in a direction away from the rotor 92 (left side in FIG. 2) by a separation spring 91c interposed between the armature 91 and the inner ring member. 41 is engaged with a convex portion 41b projecting from the end portion.

  The rotor 92 is a member made of a magnetic material, is connected to the outer fitting member 94, is prevented from rotating with respect to the outer ring member 44 via the outer fitting member 94, and is positioned in the axial direction.

  The electromagnetic coil 93 is a device for exciting a magnetomotive force by energization, and is supported on the intermediate shaft 3 by a bearing 102. Further, the electromagnetic coil 93 is prevented from rotating with respect to the casing 7 and is positioned in the axial direction.

  Here, when the energization to the electromagnetic coil 93 is in a cut-off state, as shown in FIG. 2, the armature 91 is urged toward the inner ring member 41 side (left side in FIG. 2) by the separation spring 91c, and is urged. The second engagement hole 91 b of the armature 91 engages with the convex portion 41 b of the inner ring member 41. As a result, the armature 91 rotates integrally with the inner ring member 41, and the retainer 43 that is prevented from rotating by the armature 91 rotates together with the inner ring member 41. As a result, as shown in FIG. 3A, the roller 42 is held at the neutral position, and interrupts the driving force transmitted between the intermediate shaft 3 and the differential device 5 (see FIG. 1).

  On the other hand, when the electromagnetic coil 93 is energized, the armature 91 is attracted to the rotor 92 and moves to the rotor 92 side (right side in FIG. 2), and the engagement between the second engagement hole 91b of the armature 91 and the convex portion 41b of the inner ring member 41 is achieved. The match is released. As a result, the armature 91 rotates independently of the inner ring member 41 and rotates integrally with the rotor 92. That is, the armature 91 rotates integrally with the outer ring member 44 via the rotor 92 and the outer fitting member 94. Further, the retainer 43 that is prevented from rotating by the armature 91 rotates integrally with the outer ring member 44. As a result, when a rotational difference occurs between the outer ring member 44 and the inner ring member 41, the roller 42 is formed between the inner ring member 41 and the outer ring member 44 as shown in FIG. The driving force is transmitted between the intermediate shaft 3 and the differential device 5 at a driving position that bites into the wedge-shaped space.

As described above, according to the two-way clutch 4 used in the power transmission device 1 of the present embodiment, when the driving force is switched from cutoff to transmission between the intermediate shaft 3 and the differential device 5,
Since the roller 42 is instantaneously engaged while being in line contact with the outer ring member 44, friction heat generated at the time of contact can be suppressed as compared with a multi-plate clutch in which the plates are in surface contact with each other. Therefore, the amount of oil to be used can be reduced. As a result, the amount of oil interposed between the roller 42 and the outer ring member 44 can be extremely reduced. Therefore, when the roller 42 is positioned at the neutral position, it is possible to prevent the electric motor from being accompanied by the rotation of the wheel due to the viscosity of the oil, and to prevent the electric motor from being loaded.

  2, since the outer ring member 44 is connected to the output gear 32, the rotation of the wheel is transmitted to the outer ring member 44 when the two-way clutch 4 cuts off the driving force. 44 can be rotated. Here, in the case where the inner ring member 41 is connected to the output gear 32, when the two-way clutch 4 cuts off the driving force, the rotation of the wheel is transmitted to the inner ring member 41, and the inner ring member 41 rotates. The rotation of the inner ring member 41 causes the roller 42 to rotate integrally with the inner ring member 41, so that centrifugal force due to the rotation is applied to the roller 42, so that the roller 42 is on the outer ring member 44 side (FIG. 3A) ) And the roller 42 and the outer ring member 44 come into contact with each other. As a result, drag between the driving force transmitted by the roller 42 and the outer ring member 44 occurs, and the driving force cannot be reliably interrupted.

  On the other hand, according to the power transmission device 1 of the present embodiment, since the outer ring member 44 of the 2-way clutch 4 is connected to the output gear 32 as described above, the 2-way clutch 4 generates driving force. When shut off, the outer ring member 44 can be rotated without transmitting the rotation of the wheel to the inner ring member 41. Thereby, it is possible to prevent the centrifugal force from being applied to the roller 42 and to prevent the roller 42 and the outer ring member 44 from coming into contact with each other, thereby preventing the occurrence of dragging due to the contact between the roller 42 and the outer ring member 44. be able to. As a result, it is possible to prevent the electric motor from rotating along with the rotation of the wheel and to prevent the electric motor from being loaded.

  The “electric motor” described in claim 1 corresponds to a driving source that is driven by electricity supplied from a battery or the like to rotate the input shaft 2. The “wheel” described in claim 1 corresponds to a member that rolls on the road surface by rotating integrally with the drive shaft 6 and causes the vehicle to travel.

  Further, as shown in FIG. 3A, the “neutral position” described in claim 1 is such that the roller 42 is positioned approximately at the center of each outer peripheral side surface of the inner ring member 41, and the inner periphery of the roller 42 and the outer ring member 44. This corresponds to the position where a gap is formed between the surface.

  The “drive position” described in claim 1 corresponds to a position where the roller 42 bites into a wedge-shaped space formed between the inner ring member 41 and the outer ring member 44 as shown in FIG. However, as shown in FIG. 3B, the drive position is not limited to the case where the phase of the roller 42 is shifted from the neutral position counterclockwise (counterclockwise in FIG. 3B), and the roller 42 is in the neutral position. This also applies to the case where the phase is displaced clockwise from the clockwise direction (the clockwise direction in FIG. 3B).

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, in the present embodiment, the intermediate shaft 3 is configured by one, but is not necessarily limited thereto, and the intermediate shaft 3 may be configured by two or more. It may be configured by zero, that is, the input shaft 2 and the differential device 5 may be directly connected.

  However, it is desirable that the intermediate shaft 3 is constituted by one. When the intermediate shaft 3 is composed of two or more, the weight of the entire power transmission device 1 increases as the intermediate shaft 3 increases, and the manufacturing cost of the power transmission device 1 increases due to an increase in material cost. Moreover, when the intermediate shaft 3 is composed of zero, the driving force of the electric motor cannot be sufficiently amplified. On the other hand, in this embodiment, since the intermediate shaft 3 is composed of one, it is possible to suppress an increase in weight and manufacturing cost of the power transmission device 1 while sufficiently amplifying the driving force of the electric motor.

  Note that “the outer ring member is connected to the differential device side” in claim 1 means that the outer ring member 44 is arranged on the differential device 5 or the differential device 5 side when a plurality of intermediate shafts 3 are arranged. The outer ring member 44 is rotated without transmitting the rotation of the wheel to the inner ring member 41.

  In the present embodiment, the two-way clutch 4 is configured such that the electromagnetic coil 93 moves the armature 91 in the axial direction (left-right direction in FIG. 2) to switch the driving direction, but is not necessarily limited thereto. Instead, a lever operation type in which the drive direction is arbitrarily switched by operating a lever capable of switching the phase of the cage 43 with respect to the inner ring member 41 may be used.

  In this embodiment, the output gear 32 is connected to the drive shaft 6 via the differential device 5, but an input gear is formed on the outer periphery of the drive shaft 6 and is configured to be directly connected to the drive shaft 6. May be.

It is sectional drawing of the power transmission device of this embodiment. It is sectional drawing of a 2 way clutch. (A) is sectional drawing of the 2-way clutch in the IIIa-IIIa line | wire of FIG. 2, (b) is sectional drawing of the 2-way clutch in which a holder | retainer is located in a drive position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power transmission device 2 Input shaft 3 Intermediate shaft 4 2-way clutch (clutch)
5 Differential device 9 Electromagnetic controller (switching device)
32 Output gear (gear)
41 Inner ring member 42 Roller 43 Cage 44 Outer ring member

Claims (4)

An input shaft to which the driving force of the electric motor is input, an intermediate shaft connected to the input shaft and transmitting the driving force of the electric motor, and a differential device that distributes the driving force transmitted by the intermediate shaft to the wheel side A power transmission device including a clutch provided on the intermediate shaft so as to be able to connect and disconnect the driving force transmitted to the differential device, and amplifying the driving force of the electric motor,
The clutch includes an inner ring member having a substantially polygonal cross section, a roller disposed on each outer peripheral side surface of the inner ring member, a cage that holds the roller, and an outer ring that externally fits the cage, the inner ring member, and the roller. A member, a neutral position where a gap is formed between the outer ring member and the roller, and a switching device that switches the retainer between a driving position where the outer ring member and the roller are in contact with each other.
The power transmission device, wherein the outer ring member is connected to the differential device side. Comprising a gear meshing with the differential device;
The power transmission device according to claim 1, wherein the gear is joined to one axial end surface of the outer ring member.   The power transmission device according to claim 2, wherein the gear is joined to the outer ring member by welding or brazing.   4. The power transmission device according to claim 1, wherein the intermediate shaft is constituted by one and the outer ring member is directly connected to the differential device. 5.

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