JP2013126846A - Transaxle of hybrid system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the assembling workability of a transaxle employing a multi-axial hybrid system in which two motor generators are connected to different rotation shafts, respectively.SOLUTION: The transaxle includes: an engine side housing 3 for fastening an engine 30; an extension housing 4 that forms, together with the engine side housing 3, a space to store a gear group 40 of a power transmission unit; a rear cover 5 which has a storing part 5a for storing first and second motor generators 10, 20 connected to rotation shafts different from each other, respectively, and is connected together with the first and the second motor generators 10, 20 to the extension housing 4; and a retaining member 6 retaining the first and the second motor generators 10, 20 as movable with respect to the rear cover 5 in the storing part 5a.

Description

  The present invention relates to a transaxle of a multi-shaft hybrid system in which two motors / generators are connected to different rotating shafts.

  Conventionally, in a transaxle of this type of hybrid system, a gear group of a power transmission unit and two motors / generators are accommodated in a transaxle case, and an engine and driving wheels are connected. The transaxle case is provided with an engine side housing, an extension housing, and a rear cover, arranged in that order from the engine side and bolted between adjacent ones. In this transaxle, a gear group of the transaxle is accommodated in a space formed by the engine side housing and the extension housing, and two motors / generators are accommodated in a space formed by the extension housing and the rear cover. In this transaxle, the engine (oil pan and engine block) is bolted to the engine side housing. For example, such a transaxle is disclosed in Patent Document 1 below.

JP 2010-139052 A

  By the way, the conventional transaxle case has a shape in which the rear cover is attached so as to close the opening of the housing portion after the two motor / generators are housed in the housing portion of the extension housing. On the other hand, the gear group of the transaxle is inserted into the bearing of the extension housing after being inserted into the bearing of the engine side housing. For this reason, conventionally, after the assembly of two such motors / generators is finished, the transaxle is manufactured by assembling them into the engine-side housing to which the gear group is attached. After that, the assembly of the hybrid system is completed by assembling the engine to the engine-side housing. Therefore, in the conventional transaxle, when the hybrid system is assembled, for example, positioning of each motor / generator with respect to each rotation shaft of the gear group, and with respect to each motor / generator of the rear cover where the oil pump is arranged. The assembly process such as positioning is complicated.

  Therefore, an object of the present invention is to provide a transaxle for a hybrid system that can improve the disadvantages of the conventional example and improve the assembly workability.

  In order to achieve the above object, the present invention connects an engine-side housing for fastening an engine, an extension housing that forms a space for storing a gear group of a power transmission unit together with the engine-side housing, and different rotating shafts. And a rear cover connected to the extension housing together with the motor / generator, and the motor / generator in the storage part with respect to the rear cover. And a holding member that is movably held.

  Here, the engine side housing is formed by fastening a first engine side housing integrated with an engine block of the engine and a second engine side housing integrated with an oil pan of the engine. It is desirable to be.

  In the transaxle of the hybrid system according to the present invention, each motor / generator is provided in the rear cover, and each motor / generator can be assembled to the rear cover in advance, so that each motor / generator can be easily positioned with respect to the rear cover. Thus, the assembly workability can be improved. In addition, since each motor / generator after the assembly is held by the rear cover and the holding member, the workability when assembling to the extension housing or the gear group is also improved.

FIG. 1 is a partial cross-sectional view showing an example of a transaxle of a hybrid system according to the present invention. FIG. 2 is a partial cross-sectional view showing a transaxle of a conventional hybrid system.

  Hereinafter, embodiments of a transaxle of a hybrid system according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments.

[Example]
An embodiment of a transaxle of a hybrid system according to the present invention will be described with reference to FIGS.

  Reference numeral 1 in FIG. 1 indicates a transaxle of the hybrid system in the present embodiment. The hybrid system of the present embodiment is a multi-shaft in which a first motor / generator (MG1) 10 and a second motor / generator (MG2) 20 are coupled to different rotating shafts (MG1 shaft 11 and MG2 shaft 21). The engine 30 is further provided as a power source. In this hybrid system, the first motor / generator 10, the second motor / generator 20, and the engine 30 are coupled to the gear group 40 of the transaxle 1 that is a power transmission unit. FIG. 1 shows a state where the transaxle case 2 is not fastened with bolts for convenience of later explanation.

  The gear group 40 includes a counter drive gear 41, a counter driven gear 42 that meshes with the counter drive gear 41, an MG2 reduction drive gear 43 that meshes with the counter driven gear 42, and a drive pinion gear 44 that is disposed concentrically with the counter driven gear 42. And a differential ring gear 45 that meshes with the drive pinion gear 44. Further, the gear group 40 includes a gear group housed in the case of the differential 46.

  First motor / generator 10 is coupled to counter drive gear 41 via MG1 shaft 11. Here, the MG1 shaft 11 is a hollow shaft, and supplies lubricating oil through its internal space. The lubricating oil is supplied by an oil pump 51 attached to the rear cover 5 described later.

  Further, the crankshaft 31 of the engine 30 is connected to the counter drive gear 41 via a damper device 52. The damper device 52 is for absorbing output fluctuations of the engine 30 and the like.

  The second motor / generator 20 is connected to the MG2 reduction drive gear 43 via the MG2 shaft 21.

  Here, the transaxle 1 includes a transaxle case 2 that houses the gear group 40 and the first and second motor / generators 10 and 20. The transaxle case 2 is roughly divided into an engine-side housing 3, an extension housing 4, and a rear cover 5, and arranged in that order from the engine side.

  The engine-side housing 3 includes a storage portion 3a for the damper device 52 on the engine 30 side. The engine-side housing 3 is fastened to the extension housing 4 to form a space closer to the first and second motor / generators 10 and 20 than the storage portion 3a. A gear group 40 of the transaxle 1 is accommodated in a space formed with the extension housing 4.

  The engine side housing 3 has a two-part structure composed of a first engine side housing 3A and a second engine side housing 3B. The first engine side housing 3 </ b> A is integrated with the engine block 32. On the other hand, the second engine side housing 3 </ b> B is integrated with the oil pan 33 of the engine 30. The integration refers to integral molding.

  In this case, the integrated product of the first engine side housing 3A and the engine block 32 and the integrated product of the second engine side housing 3B and the oil pan 33 are bolted. Here, the conventional transaxle 101 has a structure in which the engine block 132 and the oil pan 133 are bolted and the assembled engine 130 is bolted to the engine-side housing 103 (FIG. 2). Therefore, in the transaxle 1 of the present embodiment, the number of parts can be reduced as compared with the prior art, and the number of bolt fastening points can be reduced (that is, the mating surface of each part to be bolted can be reduced from two to one). it can. And in this transaxle 1, the number of the bolts to be used can also be reduced with the reduction in the number of parts and bolt fastening locations. Therefore, according to the transaxle 1, the assembly workability of the hybrid system is improved.

  In this hybrid system, the rotating shafts of the gear group 40 are inserted into bearings attached to the engine side housing 3 with the engine 30 side facing down and the engine side housing 3 facing up in the assembled structure. To do. Then, the operator places the extension housing 4 on the engine-side housing 3 while inserting the opposite side of each rotation shaft of the gear group 40 into the bearing, and fastens them with bolts.

  The extension housing 4 is fastened to the rear cover 5 to form a space on the first and second motor / generators 10 and 20 side. The first and second motor / generators 10 and 20 are accommodated in the space formed together with the rear cover 5.

  Here, the extension housing 4 of this embodiment has a shorter axial direction (for example, the axial direction of the rotation shaft of the gear group 40) than the conventional extension housing 104 shown in FIG. On the other hand, the rear cover 5 is longer in the axial direction than the conventional rear cover 105 so as to be housed so as to cover the first and second motor / generators 10 and 20.

  The rear cover 5 has a storage portion 5a for storing the first and second motor / generators 10 and 20 so as to cover them. The oil pump 51 described above is disposed in the storage portion 5a.

  The operator inserts the first motor / generator 10 into the bearing 61 attached to the oil pump cover 51a, and inserts the second motor / generator 20 into the bearing 63 attached to the storage portion 5a. That is, the operator can assemble the first and second motor / generators 10 and 20 to the rear cover 5 while visually checking the insertion portions of the bearings 61 and 63. On the other hand, conventionally, the rear cover 105 can be attached only after the first and second motor / generators 10 and 20 are attached to the extension housing 104 in which the gear group 140 is housed. Therefore, conventionally, the rear cover 105 cannot be attached to the first and second motor / generators 110 and 120 while visually observing the insertion portion of the bearing attached to the rear cover 105. Therefore, the transaxle 1 according to the present embodiment can be easily positioned between the rear cover 5 and the first and second motor / generators 10 and 20, and the assembling workability is improved.

  In the storage portion 5a in this state, only one of the MG1 shaft 11 and the MG2 shaft 21 is rotatably held by the bearings 61 and 63. For this reason, the transaxle 1 is provided with bearings 62 and 64 that rotatably hold the MG1 shaft 11 and the MG2 shaft 21 and stabilize the rotational operation thereof. The bearings 62 and 64 are attached to a holding member 6 that holds the first and second motor / generators 10 and 20 movably with respect to the rear cover 5 in the storage portion 5a.

  The holding member 6 covers the opening on the side of the extension housing 4 in the storage portion 5a, and is a plate-like member formed according to the shape of the opening. The operator stores the holding member 6 in the storage portion 5a while inserting the MG1 shaft 11 and the MG2 shaft 21 into the bearing 62 and the bearing 64, respectively.

  In this state, the first and second motor / generators 10 and 20 are in an operable state in which the MG1 shaft 11 and the MG2 shaft 21 protrude from the holding member 6 respectively. Therefore, in the transaxle 1, the first and second motor / generators 10 and 20 are inspected in the state where the first and second motor / generators 10 and 20 are confirmed while the first and second motor / generators 10 and 20 are housed in the rear cover 5. be able to. On the other hand, conventionally, the first and second motor / generators 110 and 120 cannot be inspected unless the final process is performed after the rear cover 105 is attached and before the engine is fastened. That is, in the transaxle 1 of the present embodiment, unlike the conventional case, the first and second motor / generators 10 and 20 can be pre-assembled to the rear cover 5, so The generators 10, 20 can be inspected in advance. Moreover, according to this transaxle 1, since the physique at the time of the test | inspection is smaller than before, the test | inspection apparatus can also be reduced in size.

  The operator connects the first motor / generator 10 and the second motor / generator 20 after the inspection to the counter drive gear 41 and the drive pinion gear 44, respectively, and fastens the extension housing 4 and the rear cover 5 with bolts. Here, the MG1 shaft 11 and the MG2 shaft 21 at the time of this assembly are already held by the bearings 61 and 63 of the rear cover 5 and the bearings 62 and 64 of the holding member 6, and there is almost no backlash other than the backlash of the bearings. Does not occur. Accordingly, the transaxle 1 is positioned when the MG1 shaft 11 and the MG2 shaft 21 are inserted into the counter drive gear 41 and the MG2 reduction drive gear 43, that is, the first and second motor / generators 10 and 20 are inserted. Positioning to the gear group 40 is easy. Therefore, in this transaxle 1, these assembling workability is also improved.

  As described above, according to the transaxle 1 of the present embodiment, the assembly workability of the transaxle 1 and the hybrid system can be improved.

DESCRIPTION OF SYMBOLS 1 Transaxle 2 Transaxle case 3 Engine side housing 3A 1st engine side housing 3B 2nd engine side housing 4 Extension housing 5 Rear cover 5a Storage part 6 Holding member 10 1st motor / generator 11 MG1 shaft 20 2nd motor / generator 21 MG2 shaft 30 Engine 32 Engine block 33 Oil pan 40 Gear group 51 Oil pump 51a Oil pump cover 61, 62, 63, 64 Bearing

Claims (2)

An engine side housing for fastening the engine;
An extension housing that forms a space in which the gear group of the power transmission unit is housed together with the engine-side housing;
A rear cover connected to the extension housing together with each motor / generator, the storage unit storing two motors / generators coupled to different rotating shafts;
A holding member for movably holding the motor / generator with respect to the rear cover in the storage portion;
A transaxle of a hybrid system characterized by comprising:   The engine-side housing is formed by fastening a first engine-side housing integrated with an engine block of the engine and a second engine-side housing integrated with an oil pan of the engine. The transaxle of the hybrid system according to claim 1.

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