JP2019199209A - Vehicular power transmission device - Google Patents

Abstract

To provide a vehicular power transmission device capable of preventing occurrence of backlash noise during stop and at low speed of a vehicle, and preventing deterioration of power transmission efficiency due to drag resistance at intermediate and high speed of the vehicle.SOLUTION: In a vehicular power transmission device P, a brake mechanism 100 is configured by providing a return spring (energizing means)103 that pivotally supports a centrifugal weight 102 rotatably and energizes the centrifugal weight 102 toward an inner ring 5A of a bearing 5 fixed to the radial inner side of the centrifugal weight in a gear 31a. The brake mechanism 100 causes the centrifugal weight 102 to abut on the inner ring 5A of the bearing 5 when rotating speed of the output gear 31a is a set value or smaller, and rotates the centrifugal weight 102 by centrifugal force applied to the centrifugal weight 102 to separate it from the inner ring 5A of the bearing 5 when rotating speed of the output gear 31a exceeds the set value.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a vehicular power transmission device that transmits a driving force from an engine to left and right driving wheels via a gear or the like provided in a driving force transmission path.

  A vehicle having an engine as a driving source is equipped with a vehicle power transmission device that transmits driving force to left and right driving wheels via a gear provided in a transmission path of driving force output from the engine ( For example, see Patent Document 1).

  By the way, in such a vehicle power transmission device, there is a possibility that a backlash noise may be generated on the meshing tooth surface of the gear and another gear meshing with the gear due to fluctuations in engine rotation when the vehicle is stopped or at a low speed.

  Therefore, a rubber seal type bearing is used as a bearing for supporting the gear, and the generation of backlash noise is suppressed by braking the rotation of the gear by the sliding resistance of the rubber seal.

  Further, Patent Document 2 proposes a celestial gear device for suppressing the occurrence of backlash noise. In this gear unit, a sub gear is rotatably mounted on a shoulder portion of a primary gear fixed on a crankshaft, one end of a spring mounted on the shoulder portion of the primary gear is locked to the shoulder portion, and the other end of the spring is Is inserted into the sub gear and locked to a centrifugal weight arranged in parallel with the sub gear. The centrifugal weight receives centrifugal force and moves radially outward in the middle and high speed rotation range. As the ends move together, it is changed so as to weaken the ceramic load on the sub gear.

Japanese Patent No. 5489954 Japanese Patent No. 4558909

  However, in a configuration using a rubber seal type bearing, sliding resistance always acts on the bearing (including the middle / high speed rotation range), and in the CERASI GEAR device proposed in Patent Document 2, the pressing load is always applied to the tooth surface of the CERACY gear. Therefore, there is a problem that drag torque increases in the middle / high speed rotation region and power transmission efficiency is lowered.

  The present invention has been made in view of the above problems, and its object is to prevent the occurrence of backlash noise when the vehicle is stopped and when the vehicle is running at a low speed, and to reduce the power transmission efficiency due to drag resistance when the vehicle is at a middle or high speed. An object of the present invention is to provide a vehicular power transmission device that can prevent the above.

  In order to achieve the above object, the present invention transfers the driving force to the left and right driving wheels (47) via a gear (31a) provided in the transmission path of the driving force output from the engine (50) as a driving source. A vehicle power transmission device (P) for transmitting, wherein the gear (31a) is pivotally supported by a centrifugal weight (102) that rotates in a plane orthogonal to the rotation center axis thereof, and The brake mechanism (100) is configured by providing an urging means for urging the centrifugal weight (102) toward the fixing member (5A) fixed inward in the radial direction. The brake mechanism (100) When the rotational speed of the gear (31a) is equal to or lower than a set value, the centrifugal weight (102) urged by the urging means is brought into contact with the fixing member, and the gear (31a) When the rotation speed exceeds the set value, Serial rotates the centrifugal weights (102) by the centrifugal force acting on the centrifugal weight (102) and wherein the disengaging it from the fixing member.

  According to the vehicle power transmission device of the present invention, the brake mechanism including the centrifugal weight and the urging means for urging the centrifugal weight is provided in the gear, and the rotation speed of the gear is set when the vehicle is stopped and at a low speed. In the following cases, since the centrifugal weight urged by the urging means is brought into contact with the fixed member, braking is applied to the rotation of the gear by the sliding resistance (friction resistance) generated between the two, The backlash existing between the tooth surfaces of the gear and the other gear meshing with the gear becomes zero, and the occurrence of backlash noise caused by engine rotation fluctuations when the vehicle is stopped and at low speeds is prevented.

  In addition, when the rotational speed of the gear exceeds the set value at the middle / high speed of the vehicle, the centrifugal weight is rotated by the centrifugal force acting on the centrifugal weight and is detached from the fixing member. The drag torque that accompanies the sliding contact becomes zero, and the reduction in power transmission efficiency is prevented.

  In the present invention, the fixing member is an inner ring (5A) of the bearing (5) that rotatably supports the gear (31a), and is axially attached to the bearing (5) of the gear (31a). You may arrange | position the said brake mechanism (100) in the space (S) formed between one opposing side surface and the said bearing (5).

  In the present invention, the gear (31a) is a bearing different from the bearing (5) at one end (1a) in the axial direction of the engine shaft (1) rotated by the driving force from the engine (50). It is good also as what is supported so that relative rotation is possible by (6).

  In the present invention, a plurality of the centrifugal weights (102) and the urging means constituting the brake mechanism (100) may be arranged in the circumferential direction.

  In the present invention, the biasing means may be constituted by a return spring (103) that is contracted between the gear (31a) and the centrifugal weight (102) in the radial direction.

  According to the present invention, it is possible to prevent the occurrence of backlash noise when the vehicle is stopped and at a low speed, and to prevent a decrease in power transmission efficiency due to drag resistance at the middle and high speeds of the vehicle.

It is sectional drawing of the principal part of the power transmission device for vehicles concerning this invention. It is a skeleton figure of the power transmission device for vehicles concerning the present invention. It is a figure for showing arrangement relation of an engine driving force transmission gear train and a motor driving force transmission gear train, and is a figure showing typically a meshing state of each gear seen from the axial direction. It is the A section enlarged detail drawing of FIG. It is the B section enlarged detail drawing of FIG. It is CC sectional view taken on the line of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Configuration of vehicle power transmission device]
1 is a cross-sectional view of a main part of a vehicle power transmission device according to the present invention, FIG. 2 is a skeleton diagram of the vehicle power transmission device, and FIG. 3 is an arrangement relationship between an engine driving force transmission gear train and a motor driving force transmission gear train. FIG. 4 is a diagram schematically showing the meshing state of each gear as viewed from the axial direction, and FIG. 4 is an enlarged detail view of part A in FIG.

  The vehicle power transmission device P according to the present embodiment is mounted on a hybrid vehicle (not shown), and includes an engine 50 (shown only in FIG. 2) and a motor 70 as drive sources. In the vehicle power transmission device P, as shown in FIG. 1, an engine shaft 1, a generator shaft 2, and an idler shaft 3 that are arranged in parallel to each other are accommodated in a case 52.

  The case 52 includes a plurality of first cases 52a, second cases 52b, and third cases 52c that are sequentially arranged from the engine 50 side (right side in FIG. 1) along the axial direction (left-right direction in FIG. 1). The two bolts 54 (only one is shown in FIG. 1) are connected to each other. The first case 52 a is fixed to the housing 53 that houses the flywheel 55.

  By the way, the engine shaft 1 is arranged coaxially with the crankshaft (output shaft) 51 of the engine 50, and the driving force output from the engine 50 to the crankshaft 51 is transmitted to the engine shaft via the flywheel 55. 1 is transmitted. An output gear 11a constituting a generator driving gear train 10 to be described later is provided at the central portion of the engine shaft 1 in the axial direction. Here, as shown in FIGS. 1 and 4, the output gear 11 a is integrally formed on the outer periphery of the engine shaft 1, and the end surface on the crankshaft 51 side (right side in FIG. 1) is a housing 53 by a bearing 12. Is rotatably supported.

  Further, as shown in FIG. 1, an engine driving force transmission gear train is disposed radially outward of an end portion 1a (see FIG. 4) on the opposite side (left side in FIG. 1) of the engine shaft 1 to the crankshaft 51 side. An output gear 31 a constituting 30 is provided. As shown in FIGS. 1 and 4, the output gear 31 a is supported on the end 1 a of the engine shaft 1 by a bearing 6 so as to be relatively rotatable. In order to connect the engine shaft 1 and the output gear 31a in an detachable manner between the output gear 11a and the output gear 31a on the engine shaft 1 in the axial direction (left and right direction in FIGS. 1 and 2). The clutch 80 is provided.

  The clutch 80 is a multi-plate friction clutch, and, as shown in detail in FIG. 4, the large-diameter bottomed cylindrical clutch drum 85 fixed to the outer periphery of the engine shaft 1 by spline fitting. A small-diameter, generally cylindrical clutch hub 87 integrally projecting in the axial direction from the end surface of the output gear 31a on the crankshaft 51 side (right side in FIG. 4), and a clutch drum 85 and a clutch hub 87 in the axial direction. A plurality of ring-plate-like clutch disks 81 and clutch plates 82 alternately stacked along the axial direction between them, and a clutch that urges these clutch disks 81 and clutch plates 82 toward the stopper 89 in the axial direction And a piston 83.

  The plurality of clutch disks 81 have their outer peripheral ends held by a clutch drum 85 and can move slightly in the axial direction within the clutch drum 85. Further, the inner peripheral ends of the plurality of clutch plates 82 are held by the clutch hub 87, and can be slightly moved in the axial direction on the outer peripheral side of the clutch hub 87.

  The clutch drum 85 includes a wall portion 85a extending radially outward from the outer peripheral surface of the engine shaft 1 and a side opposite to the crankshaft 51 along the axial direction from the outer peripheral end of the wall portion 85a (the left side in FIG. 4). ) And a substantially cylindrical tubular portion 85b extending to the bottom, and the whole is formed in a bottomed tubular shape. A hydraulic oil chamber 90 is formed between the wall 85 a of the clutch drum 85 and the clutch piston 83 in the axial direction. The hydraulic oil chamber 90 is configured to be supplied with hydraulic oil through an oil passage 1 b that penetrates in the radial direction from the axis of the engine shaft 1. Here, the clutch piston 83 is urged in the direction away from the clutch disk 81 and the clutch plate 82 (right side in FIG. 4) by the urging force of the spring 88 installed on the side opposite to the hydraulic oil chamber 90. When the pressure in the hydraulic oil chamber 90 exceeds a predetermined value, the clutch piston 83 moves toward the clutch disc 81 and the clutch plate 82 against the urging force of the spring 88.

  On the other hand, in the output gear 31 a integrally formed with the clutch hub 87, the end surface 32 on the inner diameter side provided at a position facing the end 1 a of the engine shaft 1 is relatively rotated by the bearing 6 to the end 1 a of the engine shaft 1. The end face 33 on the inner diameter side provided at a position adjacent to the end face 32 in the axial direction (position adjacent to the side opposite to the crankshaft 51) is supported by the bearing 5 on the outer periphery of the flange portion 52d of the case 52. It is supported so as to be rotatable relative to the surface.

  On the other hand, the generator shaft 2 is configured as an inner / outer double shaft by an inner peripheral shaft 2a and an outer peripheral shaft 2b disposed coaxially and relatively rotatably on the outer peripheral side of the inner peripheral shaft 2a. As shown in FIG. 1, the end of the inner peripheral shaft 2a on the crankshaft 51 side (the right end in FIG. 1) is rotatably supported by the housing 53 by a bearing 61. A cylindrical member 2c is fixed to an end portion (left end portion in FIG. 1) opposite to the crankshaft 51. The cylindrical member 2c is rotatably supported by the third case 52c by a bearing 62, and a generator 60 is attached to the cylindrical member 2c. Here, the generator 60 includes a rotor 60a fixed to the cylindrical member 2c, and a stator 60b fixed to the second case 52b and disposed opposite to the outer peripheral side of the rotor 60a.

  Further, an input gear 11b that meshes with the output gear 11a fixed on the engine shaft 1 is located in the vicinity of the end on the crankshaft 51 side (the right end in FIGS. 1 and 2) of the inner peripheral shaft 2a of the generator shaft 2. These output gear 11a and input gear 11b constitute a generator driving gear train 10 for transmitting the driving force of the engine shaft 1 to the inner peripheral shaft 2a.

  When the driving force of the engine shaft 1 is transmitted to the inner peripheral shaft 2a of the generator shaft 2 via the generator driving gear train 10, the inner peripheral shaft 2a rotates and the cylinder fixed to the inner peripheral shaft 2a. And the rotor 60a of the generator 60 fixed to the cylindrical member 2c rotate. Therefore, the generator 60 is driven by the driving force of the engine 1, and the driving force of the engine 1 is converted into electric power by the generator 60.

  An output gear 21a that meshes with an input gear 21b fixed on the idler shaft 3 is located near the end of the outer peripheral shaft 2b of the generator shaft 2 on the crankshaft 51 side (the right end in FIGS. 1 and 2). A motor 70 is attached to the end of the outer peripheral shaft 2b opposite to the crankshaft 51 (the left end in FIGS. 1 and 2). Here, the motor 70 includes a rotor 70a fixed to the outer peripheral shaft 2b and a stator 70b fixed to the first case 52a and disposed opposite to the outer peripheral side of the rotor 70a. The outer peripheral shaft 2b is rotatably supported in the first case 52a by a bearing 71 (see FIG. 1) at a portion between the motor 70 and the output gear 21a in the axial direction, and is opposite to the crankshaft 51. The end portion (the left end portion in FIG. 1) is rotatably supported by the second case 52 b by a bearing 72.

  By the way, the motor driving force for transmitting the driving force of the outer peripheral shaft 2 b to the idler shaft 3 by the output gear 21 a fixed on the outer peripheral shaft 2 b of the generator shaft 2 and the input gear 21 b fixed on the idler shaft 3. A transmission gear train 20 is configured. Therefore, when the outer peripheral shaft 2 b of the generator shaft 2 is rotationally driven by the driving force of the motor 70, the rotation is transmitted to the idler shaft 3 via the motor driving force transmission gear train 20. As shown in FIG. 1, the end of the idler shaft 3 on the crankshaft 51 side (the right end in FIG. 1) is rotatably supported by a housing 53 by a bearing 57, and is opposite to the crankshaft 51. The end portion (left end portion in FIG. 1) is rotatably supported by the first case 52 a by a bearing 58.

  As shown in FIG. 1, the idler shaft 3 has an output gear 41a meshing with an input gear 41b attached to a differential case 45a and an engine shaft 1 on the crankshaft 51 side (right side in FIG. 1). An input gear 21b that meshes with the output gear 31a and the output gear 21a on the outer peripheral shaft 2b of the generator shaft 2 is provided.

  Here, the output gear 31 a on the engine shaft 1 and the input gear 21 b on the idler shaft 3 constitute an engine driving force transmission gear train 30 for transmitting the driving force of the engine shaft 1 to the idler shaft 3. The output gear 41a on the idler shaft 3 and the input gear 41b on the differential case 45a constitute a final gear train 40 for transmitting the driving force of the idler shaft 3 to the differential mechanism 45.

  Here, the positional relationship between the motor driving force transmission gear train 20 and the engine driving force transmission gear train 30 will be described with reference to FIG.

  As shown in FIG. 3, in the vehicle power transmission device P according to the present embodiment, the output gear 31a fixed on the engine shaft 1 and the output gear 21a fixed on the outer peripheral shaft 2b of the generator shaft 2 are Both mesh with an input gear 21b fixed on the idler shaft 3. Thus, in this embodiment, since the output gear 31a and the output gear 21a are meshed with the same input gear 21b on the idler shaft 3, the engine driving force transmission gear train 30 and the motor driving force transmission gear train 20 Thus, the input gear 21b on the idler shaft 3 is shared. Therefore, as shown in FIGS. 1 and 2, the engine driving force transmission gear train 30 and the motor driving force transmission gear 20 can be arranged at the same position in the axial direction, and the width of the vehicle power transmission device P can be reduced. The size can be reduced to reduce the size, and the number of parts can be reduced to reduce weight and cost.

  By the way, as will be described later, when the engine 50 is driven and the clutch 80 is turned on (connected), the driving force of the engine 50 passes through the engine power driving force transmission gear train 30 and the left and right driving wheels 47 (FIG. 2). As described above, the backlash noise is generated on the meshing tooth surfaces of the output gear 31a and the input gear 21b due to the rotational fluctuation of the engine 50 when the vehicle is running at low speed.

  Therefore, in the vehicle power transmission device P according to the present embodiment, the output gear 31a is provided with a brake mechanism 100 for preventing the occurrence of backlash noise at the time of low speed of the vehicle. Here, details of the configuration of the brake mechanism 100 will be described below with reference to FIGS. 5 and 6.

  5 is an enlarged detailed view of a portion B in FIG. 4, and FIG. 6 is a cross-sectional view taken along the line CC in FIG. A plurality of centrifugal weights 102 (only one is shown in FIGS. 5 and 6) pivotally supported so as to be rotatable (in a plane orthogonal to the rotation axis center of the output shaft 31a), and each centrifugal weight It includes a return spring 103 that is a biasing means that biases 102 inward in the radial direction (obliquely downward in FIG. 6).

  More specifically, a ring-shaped concave groove 31a1 is formed over the entire circumference on the side surface of the output gear 31a facing the bearing 5 (left side in FIG. 5), and the concave portion 31a1 and the bearing 5 The plurality of centrifugal weights 102 and the plurality of return springs 103 are accommodated in the formed space S. Here, as described above, each centrifugal weight 102 is pivotally supported at one end (the left end in FIG. 6) by the support shaft 101 so as to be vertically rotatable on the side surface facing the bearing 5 of the output gear 31a. In order to reduce the rotational friction of the centrifugal weight 102, a ring-shaped washer 104 inserted through the support shaft 101 is interposed between the centrifugal weight 102 and the side surface of the output gear 31a.

  Incidentally, the bearing (ball bearing) 5 that rotatably supports the output gear 31a with respect to the case 52 has a plurality of balls (steel balls) 5C and each ball 5C fixed in the circumferential direction between the inner ring 5A and the outer ring 5B. However, as shown in FIG. 5, the outer ring portion of the inner ring 5 </ b> A of the bearing 5 has a ring-like convex portion projecting horizontally toward the space S. 5a is integrally formed. In the present embodiment, the inner ring 5A of the bearing 5 constitutes a fixed member fixed inward in the radial direction of the centrifugal weight 102, and the rotational speed of the output gear 31a is equal to or less than a set value as will be described later. In this case, the distal end of the centrifugal weight 102 urged by the return spring 103 comes into contact with the convex portion 5a of the inner ring 5A that is a fixing member.

  The return spring 103 is contracted between the step portion 31b of the output gear 31a and the centrifugal weight 102, and the centrifugal weight 102 is disposed at the tip (an end portion on the opposite side to the side supported by the support shaft 101). (Right end portion in FIG. 6) is biased in the direction pressed against the inner ring 5A of the bearing 5. Each return spring 103 is engaged with a groove 31b1 formed by cutting out a part of the step 31b of the output gear 31a, and the other end is in the middle of the centrifugal weight 102 in the longitudinal direction. It is in contact with the upper surface of the part. In the present embodiment, a plurality of centrifugal weights 102 and a plurality of return springs 103 for biasing them are arranged at an equal angular pitch in the circumferential direction, but the number of these centrifugal weights 102 and return springs 103 is arbitrary. .

[Operation of vehicle power transmission device]
Next, the operation of the vehicle power transmission device P will be described.

  The vehicle power transmission device P according to the present embodiment transmits a driving force of the motor 70 to the left and right drive wheels 47 to drive the vehicle (hereinafter referred to as “first transmission path”). It has a power transmission path (hereinafter referred to as “second transmission path”) for driving the vehicle by transmitting the driving force of the engine 50 to the left and right drive wheels 47, and these two first and second The vehicle can be driven by selectively using the transmission path or using it in combination. Specifically, the first transmission path or the second transmission path is selectively used or both transmission paths are switched by ON / OFF (connection / disconnection) of a clutch 80 provided between the engine shaft 1 and the output gear 31a. You can switch the setting of whether or not to use.

  That is, in the clutch 80, by controlling the pressure in the hydraulic oil chamber 90, the clutch piston 83 is moved in the axial direction so as to abut or separate from the clutch disk 81 and the clutch plate 82. Specifically, when the pressure in the hydraulic oil chamber 90 is lowered to a predetermined value, the clutch piston 83 moves in the direction of the crankshaft 51 (rightward in FIG. 4) by the urging force of the spring 88. Then, the adjacent clutch disc 81 and the clutch plate 82 are separated from each other, and the clutch 80 is turned off (disconnected). When the clutch 80 is thus turned off (disconnected), the driving force of the engine shaft 1 is not transmitted to the engine driving force transmission gear train 30.

  In the above state, the driving force of the motor 70 is transmitted to the left and right driving wheels 47 through the first transmission path, and these driving wheels 47 are rotationally driven, whereby the vehicle travels. That is, the driving force of the engine 50 is input from the engine shaft 1 through the generator driving gear train 10 to the inner peripheral shaft 2a of the generator shaft 2, and the inner peripheral shaft 2a rotates. Then, since the rotor 60a of the generator 60 fixed to the inner peripheral shaft 2a rotates, the generator 60 generates power. The electric power generated by the generator 60 is stored in a storage battery (not shown), and the motor 70 is driven by the electric power stored in the storage battery.

  When the motor 70 is driven as described above, the outer shaft 2b of the generator shaft 2 is rotated by the driving force of the motor 70, and the rotation of the outer shaft 2b is caused by the motor driving force transmission gear train 20, the differential mechanism 45, and It is transmitted to the left and right drive wheels 47 via the differential shaft 46. Thus, a so-called series operation in which all of the driving force of the engine 50 is converted into electric power by the generator 60 and operated is possible.

  On the other hand, when the pressure in the hydraulic oil chamber 90 of the clutch 80 is higher than a predetermined value, the clutch piston 83 moves in the direction opposite to the crankshaft 51 (leftward in FIG. 4) against the urging force of the spring 88. . Then, the clutch piston 83 presses the clutch disc 81 and the clutch plate 82 and sandwiches them between the stopper 89. As a result, the clutch disk 81 and the clutch plate 82 are frictionally engaged, the clutch 80 is turned on (connected), and the output gear 31a is in a lockup state in which it is directly connected to the engine shaft 1.

  In the lockup state, the driving force of the engine 50 is transmitted to the left and right drive wheels 47 through the second transmission path, and the vehicle is caused to travel. That is, when the clutch 80 is turned on (connected), the driving force of the engine shaft 1 is transmitted to the left and right driving wheels 47 via the engine driving force transmission gear train 30 and the vehicle is caused to travel. That is, when the clutch 80 is turned on (connected), the driving force of the engine shaft 1 is transmitted to the idler shaft 3 through the output gear 31a and the input gear 21b of the engine driving force transmission gear train 30 that are engaged with each other. 3 is transmitted to the left and right drive wheels 47 via the final gear train 40, the differential mechanism 45 and the differential shaft 46. Here, since the inner peripheral shaft 2a of the engine shaft 1 and the generator shaft 2 is always connected via the generator drive gear train 10, the rotor 60a of the generator 60 rotates as the inner peripheral shaft 2a rotates. . Therefore, since the generator 60 can generate electric power, it is possible to perform parallel operation in which the motor 70 is rotated by the generated electric power. In addition, by performing zero torque control on the motor 70 and the generator 60, the drag loss can be minimized and the vehicle can be driven only by the engine 50.

  By the way, in the lockup state, the vehicle travels at a low speed in the process in which the driving force of the engine shaft 1 is transmitted to the idler shaft 3 through the output gear 31a and the input gear 21b of the engine driving force transmission gear train 30 that are engaged with each other. Therefore, when the rotational speed of the output gear 31a is less than or equal to a predetermined value, the radial outward centrifugal force acting on the centrifugal weight 102 rotating with the output gear 31a in the brake mechanism 100 is small, and the value is When it is smaller than the urging force of the return spring 103, as shown by a solid line in FIG. 6, the tip of the centrifugal weight 102 urged by the return spring 103 protrudes from the inner ring 5 </ b> A of the bearing 5. It contacts the outer periphery of 5a. In this way, when the centrifugal weight 102 abuts on the convex portion 5a protruding from the inner ring 5A of the bearing 5, braking is applied to the rotation of the output gear 31a by the sliding resistance (friction resistance) generated between the two. The backlash existing between the tooth surfaces of the output gear 31a and the input gear 21b meshing therewith becomes zero. For this reason, the occurrence of backlash noise (backlash noise on the meshing tooth surfaces of the output gear 31a and the input gear 21b) due to the rotational fluctuation of the engine 50 at low speed of the vehicle is prevented, and the vehicle power transmission device P can be silenced.

  When the rotational speed of the output gear 31a exceeds the set value because the vehicle traveling speed has increased, the radially outward centrifugal force acting on the centrifugal weight 102 that rotates together with the output gear 31a in the brake mechanism 100 is generated. As shown by a chain line in FIG. 6, the centrifugal weight 102 rotates upward about the support shaft 101 and protrudes from the inner ring 5 </ b> A of the bearing 5. Since it is separated from the portion 5a, the drag torque associated with the sliding contact between the centrifugal weight 102 and the convex portion 5a of the inner ring 5A of the bearing 5 becomes zero, and the reduction in power transmission efficiency is prevented.

  As described above, according to the vehicle power transmission device P according to the present embodiment, the generation of backlash noise at the time of low speed of the vehicle is prevented, and the power transmission efficiency is reduced by drag resistance at the time of middle and high speed of the vehicle. The effect that it can prevent is acquired.

  In the vehicle power transmission device P according to the present embodiment, since the output gear 31a is rotationally driven when the engine 50 is driven and the clutch 80 is ON (connected), the vehicle speed is low. In other vehicle power transmission devices in which the engine is driven even when the vehicle is stopped and the gear is driven to rotate by the driving force of the engine, By providing the brake mechanism, backlash noise can be prevented even when the vehicle is stopped.

  In the above embodiment, the inner ring 5A of the bearing 5 is used as a fixing member with which the centrifugal weight 102 of the brake mechanism 100 abuts at a low speed of the vehicle, but any other fixing member can be used. .

  In addition, the application of the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the technical idea described in the claims and the description and the drawings.

1 Engine shaft 1a End of engine shaft 2 Generator shaft 3 Idler shaft 5 Bearing 5A Bearing inner ring (fixed member)
5a Convex part of inner ring 6 Bearing (other bearings)
DESCRIPTION OF SYMBOLS 10 Generator drive gear train 20 Motor drive transmission gear train 21a Output gear 21b Input gear 30 Engine drive force transmission gear train 31a Output gear (gear)
40 Final gear train 50 Engine (drive source)
60 generator 70 motor 80 clutch 90 hydraulic oil chamber 100 brake mechanism 101 support shaft 102 centrifugal weight 103 return spring (biasing means)
P Vehicle power transmission device S Space

Claims (5)

A vehicle power transmission device that transmits a driving force to left and right driving wheels via a gear provided in a transmission path of a driving force output from an engine that is a driving source,
A centrifugal weight that rotates in a plane orthogonal to the rotation center axis is rotatably supported on the gear, and the centrifugal weight is directed to a fixing member that is fixed radially inward from the centrifugal weight. A brake mechanism is configured by providing a biasing means for biasing,
When the rotation speed of the gear is equal to or lower than a set value, the brake mechanism abuts the centrifugal weight biased by the biasing means on the fixed member, and the rotation speed of the gear decreases to a set value. If it exceeds, the centrifugal weight is rotated by a centrifugal force acting on the centrifugal weight, and the centrifugal weight is detached from the fixing member.   The fixing member is an inner ring of a bearing that rotatably supports the gear, and the brake mechanism is disposed in a space formed between a side surface facing the bearing of the gear in the axial direction and the bearing. The vehicle power transmission device according to claim 1, wherein the vehicle power transmission device is arranged.   The vehicle according to claim 2, wherein the gear is supported at one axial end portion of an engine shaft that is rotated by a driving force from the engine by a bearing different from the bearing so as to be relatively rotatable. Power transmission device.   The vehicle power transmission device according to any one of claims 1 to 3, wherein a plurality of the centrifugal weights and the urging means constituting the brake mechanism are arranged in a circumferential direction.   The vehicular power transmission device according to any one of claims 1 to 4, wherein the urging means is configured by a return spring that is compressed between the gear and the centrifugal weight in the radial direction.