JP2006342969A - Driving unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving unit capable of controlling membrane oscillation of cases for power output devices when the power output devices are oscillated. <P>SOLUTION: In this driving unit formed by integrating the power output device cases 4B, 4C on which the power output devices 7, 8, 24 are mounted, and an auxiliary device case 56 on which an auxiliary device 55 is mounted, specific gravity of a material of the auxiliary device case 56 is more than that of a material of the power output device cases 4B, 4C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drive unit in which a case for a power output device to which a power output device is attached and a case for an auxiliary device to which an auxiliary device is attached are integrated.

  2. Description of the Related Art Conventionally, a drive unit in which a power output device case to which a power output device is attached and an auxiliary device case to which an auxiliary device is attached is known as a drive unit described in Patent Document 1.

  This Patent Document 1 describes a hydraulic pressure generator (auxiliary device) and a power output device. The power output device includes an engine, a first motor, a second motor, a planetary gear, and the like, and the crankshaft of the engine and the carrier shaft are arranged concentrically. A hollow shaft is connected to the rotor of the second motor, and a carrier shaft is disposed inside the hollow shaft. The crankshaft, the first motor, the second motor, the carrier shaft, the hollow shaft, and the like are arranged inside a case (power output device case). The stators of the first motor and the second motor are attached to the case.

  On the other hand, a hydraulic pressure generator is provided outside the case, and the hydraulic pressure is generated by the rotary shaft having the larger rotational speed of the two rotary shafts. The two rotating shafts are connected to the hollow shaft and the carrier shaft. Furthermore, the casing (auxiliary device case) of the hydraulic pressure generator is integrated with the case. In the power output device described in Patent Document 1, by integrating the casing of the hydraulic pressure generator with the case, the hydraulic pressure generator is made into a large mass that vibrates integrally with the first motor. When the vibration generated by operating the engine is input to the hydraulic pressure generator, the damping effect can be increased. Note that Patent Document 2 and Patent Document 3 are known as other examples of the technique for suppressing the vibration of the casing.

JP 10-89446 A (paragraph number 0031 to paragraph number 0035, FIG. 5) Actual application No. 2-51967 microfilm (No. 4-1127) Japanese Utility Model Publication No. 6-51606

  By the way, when integrating the casing of the hydraulic pressure generator (auxiliary device) with the case as in the technique described in Patent Document 1, it is conceivable that the casing and the case are made of the same material. However, even in this case, there is a possibility that the membrane vibration of the case increases due to the vibration of the power output device.

  This invention is made against the background of the above circumstances, even when the case for the power output device to which the power output device is attached and the case for the auxiliary device to which the auxiliary device is attached, It aims at providing the drive unit which can suppress that the case for power output devices carries out a membrane vibration by the vibration of a power output device.

  In order to achieve the above object, the invention of claim 1 is a drive unit in which a case for a power output device to which a power output device is attached and a case for an auxiliary device to which an auxiliary device is attached are integrated in the drive unit. The specific gravity of the material constituting the auxiliary device case is set to be greater than the specific gravity of the material constituting the power output device case.

  The invention according to claim 2 is a drive unit in which a case for a power output device to which a power output device is attached and a case for an auxiliary device to which an auxiliary device is attached, wherein the power output device includes an electric motor. And a plurality of bearings for supporting the power output device by the power output device case are provided on both sides of the electric motor, and the position closest to the auxiliary device among the plurality of bearings. A load adjusting device is provided in which a load transmitted to a bearing attached to the bearing is set to be lower than a load transmitted to other bearings.

  According to a third aspect of the present invention, in addition to the configuration of the second aspect, the specific gravity of the material constituting the auxiliary device case is set larger than the specific gravity of the material constituting the power output device case. It is characterized by.

  As described above, according to the first aspect of the present invention, the specific gravity of the material constituting the auxiliary device case is set larger than the specific gravity of the material constituting the power output device case. Even when the case for power and the case for power output device are integrated, the mass constituted by the case for auxiliary equipment and the case for power output device becomes large. Therefore, even when the vibration of the power output device is transmitted to the case for the power output device, the membrane vibration of the case for the power output device can be suppressed using the case for the auxiliary device.

  According to the second aspect of the present invention, even when the accessory device case and the power output device case are integrated, the plurality of bearings are transmitted to the bearing attached at the position closest to the accessory device. The load is set to be lower than the load transmitted to the other bearings. Therefore, when the vibration of the power output device is transmitted to the power output device case via a plurality of bearings, the membrane vibration of the power output device case closest to the auxiliary device is suppressed. it can.

  According to the invention of claim 3, the same effects as those of the inventions of claims 1 and 2 can be obtained, and the membrane vibration of the case for the power output apparatus can be more reliably suppressed.

  Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is a skeleton diagram showing a power train of an FF (front engine front drive; front wheel drive in front of engine) type vehicle according to an embodiment of the present invention, and FIG. 2 is a partial sectional view of FIG.

  In FIG. 1, 1 is an engine, and the engine 1 has a crankshaft 2. The crankshaft 2 is arranged horizontally in the vehicle width direction. A flywheel 3 is formed at the end of the crankshaft 2.

  A hollow transaxle case 4 is attached to the outer wall of the engine 1. The transaxle case 4 has an engine side housing 4A, a case 4B, and a case cover 4C. These engine-side housing 4A, case 4B, and case cover 4C are made of a metal material such as aluminum or aluminum alloy. The engine 1 and the engine side housing 4A are fixed. Further, a case 4B is disposed between the engine side housing 4A and the case cover 4C. Furthermore, the engine side housing 4A and the case 4B are fixed. Furthermore, the case 4B has a cylindrical shape, and a case cover 4C is coupled and fixed to the opening end of the case 4B by a screw member (not shown) or the like.

  An input shaft 5, a first motor / generator 6, a power distribution mechanism 7, a transmission mechanism 8, and a second motor / generator 9 are provided in the interior G 1 of the transaxle case 4. The input shaft 5 rotates about the rotation axis A1. A clutch hub 10 is spline-fitted to an end of the input shaft 5 on the crankshaft 2 side.

  Further, a damper mechanism 12 that suppresses and absorbs torque fluctuation between the flywheel 3 and the input shaft 5 is provided. The first motor / generator 6 is disposed outside the input shaft 5, and the second motor / generator 9 is disposed farther from the engine 1 than the first motor / generator 6.

  That is, the first motor / generator 6 is disposed between the engine 1 and the second motor / generator 9. The first motor / generator 6 and the second motor / generator 9 have a function as a motor driven by supplying electric power (power running function) and a function as a generator that converts mechanical energy into electric energy (regeneration function). And combine. First, the first motor / generator 6 has a stator 13 fixed to the transaxle case 4 and a rotatable rotor 14.

  On the other hand, a hollow shaft 17 is attached to the outer periphery of the input shaft 5. And the input shaft 5 and the hollow shaft 17 are comprised so that relative rotation is possible. The rotor 14 is connected to the outer peripheral side of the hollow shaft 17. The power distribution mechanism 7 is provided between the first motor / generator 6 and the second motor / generator 9. The power distribution mechanism 7 has a so-called single pinion type planetary gear mechanism 7A. That is, the planetary gear mechanism 7 </ b> A includes a sun gear 18, a ring gear 19 disposed concentrically with the sun gear 18, and a carrier 21 that holds a pinion gear 20 that meshes with the sun gear 18 and the ring gear 19. The sun gear 18 and the hollow shaft 17 are connected, and the carrier 21 and the input shaft 5 are connected. The ring gear 19 is formed on the inner peripheral side of an annular member 22 disposed concentrically with the input shaft 5, and a counter drive gear 23 is formed on the outer peripheral side of the annular member 22.

  Further, a hollow shaft 24 is rotatably attached to the outer periphery of the input shaft 5, and the second motor / generator 9 is disposed on the outer peripheral side of the hollow shaft 24. The arrangement position of the second motor / generator 9 and the configuration of the second motor / generator 9 will be specifically described. A partition wall 4D extending toward the input shaft 5 side is formed on the inner surface of the case 4B. The second motor / generator 9 is disposed in a space surrounded by the case 4B, the partition wall 4D, and the case cover 4C.

  The second motor / generator 9 has a stator 25 fixed to the transaxle case 4 and a rotatable rotor 26. The rotor 26 and the hollow shaft 24 are connected so as to rotate integrally.

  The speed change mechanism 8 is disposed between the power distribution mechanism 7 and the second motor / generator 9 in the rotation axis direction. The speed change mechanism 8 has a so-called single pinion type planetary gear mechanism 8A. ing. That is, the planetary gear mechanism 8 </ b> A holds the sun gear 29, the ring gear 30 that is arranged concentrically with the sun gear 29 and formed on the inner periphery of the annular member 22, and the pinion gear 31 that meshes with the sun gear 29 and the ring gear 30. And a carrier 32. The sun gear 29 and the hollow shaft 24 are connected to rotate integrally.

  The sun gear 18, the ring gear 19, and the pinion gear 20 that constitute the power distribution mechanism 7 and the sun gear 29, the ring gear 30, and the pinion gear 31 that constitute the planetary gear mechanism 8A are all constituted by helical gears. The carrier 32 is fixed to the case 4B. Further, the annular member 22 is rotatably held by a bearing 33.

  The structure for supporting the hollow shaft 24 will be described with reference to FIG. The hollow shaft 24 is supported by bearings 35 and 36, and the bearings 35 and 36 are arranged at different positions in the rotation axis direction. The second motor / generator 9 is disposed between the bearing 35 and the bearing 36 in the rotation axis direction. The bearing 35 includes an inner ring 37 and an outer ring 38, and rolling elements 39 provided between the inner ring 37 and the outer ring 38. The inner ring 37 is fitted to the outer periphery of the hollow shaft 24, and the outer ring 38 is fitted to the mounting hole 40 of the partition wall 4D. An annular step 41 is formed on the outer periphery of the hollow shaft 24.

  Further, a snap ring 42 is attached to the outer periphery of the hollow shaft 24, and the snap ring 42 restricts the sun gear 29 from moving in the direction of the rotation axis in a direction away from the step portion 41. An inner ring 37 is disposed between the sun gear 29 and the step portion 41. Specifically, both end surfaces of the inner ring 37 in the direction of the rotation axis are in contact with the end surfaces of the step portion 41 and the sun gear 29. That is, the inner ring 37, the sun gear 29, and the hollow shaft 24 are positioned and fixed in the rotational axis direction. As described above, the rotor 26, the hollow shaft 24, the speed change mechanism 8, and the input shaft 5 of the second motor / generator 9 are disposed so as to be rotatable about the rotation axis A1.

  On the other hand, in the partition wall 4D, annular stepped portions 43 and snap rings 44 are provided on both sides of the mounting hole 40 in the rotation axis direction. An outer ring 38 is disposed between the stepped portion 43 and the snap ring 44. Specifically, both end surfaces of the outer ring 38 in the rotation axis direction are in contact with the stepped portion 43 and the snap ring 44. That is, the outer ring 38 and the partition 4D are positioned and fixed in the rotation axis direction. Thus, the bearing 35, the hollow shaft 24, and the partition 4D are positioned in the rotation axis direction.

  Next, the mounting structure of the bearing 36 will be described. Of the plurality of bearings 35, 36, the bearing 36 is disposed at a position closest to the oil pump 55 in the rotation axis direction. The case cover 4C has a plate shape or a film shape set to a predetermined thickness, and the case cover 4C is formed with a boss portion 53 extending in a direction intersecting the rotation axis A1. Yes. The bearing 36 includes an inner ring 45 and an outer ring 46, and rolling elements 47 provided between the inner ring 45 and the outer ring 46. The inner ring 45 is fitted and fixed to the outer periphery of the hollow shaft 24, and the outer ring 46 is disposed in the holding hole 48 of the boss portion 53.

  The outer ring 46 and the case cover 4C are relatively movable in the rotation axis direction, and the bearing 36 and the case cover 4C can be restricted from moving relative to each other in a direction perpendicular to the rotation axis. The outer diameter and the inner diameter of the holding hole 48 are set. Further, the case cover 4C is formed with a stepped portion 49, and in a state where one end surface 50 of the outer ring 46 and the stepped portion 49 are in contact with each other, the boss is more bossed than the other end surface 51 of the outer ring 46 in the rotation axis direction. The position of the end surface 52 in the rotation axis direction is set so that the end surface 52 of the portion 53 is closer to the bearing 35. Thus, the bearing 35 and the bearing 36 are arranged on both sides of the center (not shown) of the second motor / generator 9 in the rotation axis direction.

  The boss portion 53 is formed with a shaft hole 54 centered on the rotation axis A <b> 1, and a part of the input shaft 5 is disposed in the shaft hole 54. An oil pump 55 is provided at a position in the boss portion 53 that faces the outside G2 of the transaxle case 4. The oil pump 55 is driven by the torque of the input shaft 5. The oil pump cover 56 is fixed to the boss portion 53 at a position facing the outside G2 of the transaxle case 4. The oil pump cover 56 is fixed by a screw member (not shown) or the like, and the oil pump cover 56 is attached so as to cover the oil pump 55.

  An oil passage 57 is formed in the oil pump cover 56. The oil pump cover 56 is made of a metal material having a specific gravity greater than the specific gravity of the metal material constituting the case 4B and the case cover 4C. For example, the case 4B and the case cover 4C can be made of aluminum, and the oil pump cover 56 can be made of cast iron (iron-carbon alloy). In addition, the rotation axis A1 is arranged in the arrangement region of the oil pump cover 56 in a plane orthogonal to the rotation axis. In this way, the case cover 4C and the oil pump cover 56 are joined together to form a joined body E1.

  In the power train having the above configuration, torque output from the engine 1 is transmitted to the carrier 21 via the input shaft 5. The torque transmitted to the carrier 21 is transmitted to the front wheels (not shown) via the ring gear 19, the annular member 22, and the counter drive gear 23. Further, when the torque of the engine 1 is transmitted to the carrier 21, the first motor / generator 6 can function as a generator, and the generated electric power can be charged in a power storage device (not shown).

  Further, the second motor / generator 9 can be driven as an electric motor, and the power can be transmitted to the power distribution mechanism 7. When the power of the second motor / generator 9 is transmitted to the sun gear 29 of the transmission mechanism 8 via the hollow shaft 24, the carrier 32 acts as a reaction force element, the rotational speed of the sun gear 29 is reduced, and Power is transmitted in a direction in which the ring gear 30 is rotated in a direction opposite to the rotation direction of the sun gear 29.

  In this way, the power of the engine 1 and the power of the second motor / generator 9 are input to the power distribution mechanism 7 and combined, and the combined power passes through the counter drive gear 23 to the front wheels (not shown). Is transmitted to. Note that, by reducing the rotational speed of the second motor / generator 9 by the speed change mechanism 8, the torque of the second motor / generator 9 can be amplified and transmitted to the power distribution mechanism 7. The vehicle having the power train shown in FIG. 1 is a vehicle that can transmit the torque of at least one of the engine 1 or the second motor / generator 9 to the wheels, that is, a so-called hybrid vehicle.

  1 and 2, the bearings 35 and 36 that support the hollow shaft 24 have a function as radial bearings. By the way, each gear constituting the power distribution mechanism 7 and the transmission mechanism 8 is a helical gear. For this reason, a load (thrust load) in the rotation axis direction may act on the sun gear 29 during torque transmission. The load of the sun gear 29 is transmitted to the hollow shaft 24, and the hollow shaft 24 may vibrate in the rotation axis direction. When the hollow shaft 24 vibrates in the direction of the rotation axis, the vibration is transmitted to the case cover 4C via the bearing 36 to cause membrane vibration, and radiated sound may be generated.

  Here, a side member (not shown) is arranged on the side G2 of the transaxle case 4 and on the side of the case cover 4C, while on the inside G1 of the transaxle case 4, the side cover 4C A coil of the stator 25 of the second motor / generator 9 is arranged on the side. Therefore, it is difficult to employ a configuration in which a rib or the like is provided on the case cover 4C to increase rigidity and suppress vibration of the case cover 4C.

  In contrast, in this embodiment, when a load in the rotation axis direction, for example, a leftward load in FIG. 1 is transmitted to the sun gear 29, the load is transmitted to the partition 4D via the bearing 35 and the snap ring 44. Is done. On the other hand, when the rightward load in FIG. 1 is transmitted to the sun gear 29, the load is transmitted to the partition 4D via the snap ring 42, the hollow shaft 24, and the bearing 35.

  As described above, when the load in the rotation axis direction is transmitted to the sun gear 29, the load is transmitted to the partition wall 4 </ b> D through the bearing 35. In other words, the load is received by the partition 4D which is a built-in object of the transaxle case 4. In other words, the bearing 35 functions as a thrust bearing. Therefore, it is possible to suppress the generation of radiated sound due to vibration of the case cover 4C without enlarging the size of the case cover 4C in the rotation axis direction and without being restricted by the relative positional relationship between the case cover 4C and peripheral components.

  Further, the inner ring 45 of the bearing 36 is fixed to the hollow shaft 24, and the outer ring 46 of the bearing 36 and the case cover 4C are relatively movable in the rotation axis direction. That is, the bearing 36 does not have a function as a thrust bearing. For this reason, even if the hollow shaft 24 moves leftward in FIG. 1, the moving force is not transmitted to the case cover 4C, and the vibration of the case cover 4C can be more reliably suppressed. Here, since the end surface 52 of the boss portion 53 is disposed closer to the bearing 35 than the position of the end surface 51 of the bearing 36 in the rotational axis direction, the hollow shaft 24 and the bearing 36 are 1 and FIG. 2, even when moved integrally in the right direction, the center (not shown) of the rolling element 47 can be prevented from moving outside the holding hole 48, and the deterioration of the radial bearing function of the bearing 36 can be suppressed. it can.

  Furthermore, in this embodiment, the mass of the combined body E1 is made as large as possible by setting the specific gravity of the material constituting the oil pump cover 56 to be larger than the specific gravity of the material constituting the case cover 4C. ing. The natural frequency of the coupled body E1 can be adjusted to a natural frequency that makes it difficult for the coupled body E1 to resonate even when a load in the rotational axis direction is generated. Therefore, even when the load in the rotation axis direction acting on the sun gear 29 is transmitted to the case cover 4C, the generation of radiated sound due to the vibration of the case cover 4C can be suppressed. Further, the mass of the combined body E1 can be increased by using the oil pump cover 56 provided in advance.

  Thus, in this embodiment, when the case cover 4C is fixed to the case 4B, and the oil pump cover 56 is integrally fixed to the case cover 4C, the transmission mechanism 8 and the power distribution mechanism 7 vibrate. The oil pump cover 56 can suppress the membrane vibration of the case cover 4B transmitted to the case cover 4B.

  Here, the correspondence between the configuration of this embodiment and the configuration of the present invention will be described. The case 4B and the case cover 4C correspond to the case for the power output apparatus of the present invention, and the oil pump 55 is the present invention. The oil pump cover 56 corresponds to the auxiliary device case of the present invention, the bearings 35 and 36 correspond to a plurality of bearings of the present invention, and the bearing 36 of the present invention “ The bearing 35 corresponds to the “other bearing” of the present invention, the second motor / generator 9 corresponds to the electric motor of the present invention, The planetary gear mechanism 7A that constitutes the power distribution mechanism 7, the planetary gear mechanism 8A that constitutes the speed change mechanism 8, and the hollow shaft 24 correspond to the power output device of the present invention, and the bearings 35 and 36, the snap rings 42 and 44, and the like. Septum 4D, the hollow shaft 24 corresponds to the load adjusting apparatus of the present invention.

  In the embodiment shown in FIGS. 1 and 2, the power output device is arranged inside the case for the power output device. However, in the invention of claim 1, the power output device is located outside the case for the power output device. The present invention can also be applied to a drive unit having an arrangement. Further, the outer ring 46 of the bearing 36 is fitted and fixed to the boss portion 53, and the inner diameter and the outer diameter of the bearing 36 are set so that the inner ring 45 and the hollow shaft 24 of the bearing 36 slide, thereby functioning as a thrust bearing. Even if the configuration does not exhibit the above, the same effect as described above can be obtained. The present invention can also be applied to a configuration in which the rotation axis of the rotating member of the power output device is arranged in the front-rear direction of the vehicle.

  It is as follows if the characteristic structure disclosed by said Example is enumerated. That is, the case for the power output device includes a case 4B that houses the motor / generator 9, the power distribution mechanism 7, and the speed change mechanism 8, and a case cover 4C that is fixed so as to close the open end of the case 4B. The oil pump cover 56 is integrally fixed to the case cover 4C. Of the plurality of bearings 35, 36, the bearing 36 is attached to the case cover 4C, and the bearing 35 is attached to the case 4B. The load transmitted from the speed change mechanism 8 and the power distribution mechanism 7 to the hollow shaft 24 and the bearing 35 is a thrust load in the rotation axis direction. Further, the rotation axis means the rotation center of the rotating member of the power output apparatus.

It is a skeleton diagram of a hybrid vehicle to which the present invention is applied. It is sectional drawing which shows the principal part of FIG.

Explanation of symbols

  4B: Case, 4C: Case cover, 4D: Partition, 7: Power distribution mechanism, 7A: Planetary gear mechanism, 8: Transmission mechanism, 8A: Planetary gear mechanism, 9: Second motor / generator, 24: Hollow shaft, 29 ... Sun gear, 35, 36 ... Bearing, 42, 44 ... Snap ring, 55 ... Oil pump, 56 ... Oil pump cover.

Claims (3)

In the drive unit in which the case for the power output device to which the power output device is attached and the case for the auxiliary device to which the auxiliary device is attached are integrated,
The drive unit, wherein a specific gravity of a material constituting the auxiliary device case is set to be greater than a specific gravity of a material constituting the power output device case. In the drive unit in which the case for the power output device to which the power output device is attached and the case for the auxiliary device to which the auxiliary device is attached are integrated,
The power output device includes an electric motor, and on both sides of the electric motor, a plurality of bearings that support the power output device are provided by the power output device case. Among them, a load adjusting device is provided that sets so that the load transmitted to the bearing attached to the closest position to the auxiliary device is lower than the load transmitted to the other bearings. Drive unit.   3. The drive unit according to claim 2, wherein the specific gravity of the material constituting the auxiliary device case is set to be larger than the specific gravity of the material constituting the power output device case.

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