JP2007126065A - Bearing device for motor rotary shaft in hybrid prime mover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid prime mover constituted by arranging the motor between an engine and a transmission and improving a bearing structure of a motor rotary shaft to shorten the whole length of the motor. <P>SOLUTION: An end part of the rotary shaft 24A protruding onto an engine side from a main body of a rotor 23 is received by a pilot bearing 26 provided in a central part of a flywheel 11, and an end part of a rotary shaft 24B protruding onto a transmission side from the main body of the rotor 23 is received by a main bearing 42 fixed in a front gear housing 41 on the transmission side. A spline 44 formed in a tip part of a main drive shaft 43 passing through a hole 30 provided in the rotary shaft 24B and a spline 31 formed in the hole 30 are mutually fitted so that the main bearing 42 serves also as a bearing of the main drive shaft 43. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor bearing structure in a hybrid prime mover having a structure in which a motor (electric motor) is disposed between an engine (internal combustion engine) and a transmission.

Patent Document 1 discloses a hybrid prime mover having a structure in which a motor is disposed between an engine and a transmission.
In this type of hybrid prime mover, the bearing structure of the motor rotating shaft is such that the rotating shaft protruding from the rotor body of the motor to the engine side and the transmission side is supported by a pair of dedicated bearings provided in the motor housing. It has become.

On the other hand, a pilot bearing for aligning the axis of the motor rotation shaft with the flywheel is provided on the engine side, and a bearing for bearing the main drive shaft of the transmission is separately provided on the transmission side.
JP 2004-114771 A

  In current small cars, there are many methods for driving the front wheels by the front engine as a model indicating the arrangement of the engine and the drive wheels. When this is hybridized, it is usually necessary to store the motor in the space where the torque converter or clutch is stored. However, if a motor that satisfies the required power is installed, the total length of the prime mover increases, and the small vehicle Layout constraints that make it difficult to install in a narrow engine room are a major issue.

  The present invention has been made paying attention to such a conventional problem, and aims to suppress an increase in the total length of the prime mover while attaching a motor having a necessary power by improving the bearing structure of the motor rotation shaft. And

For this reason, the present invention
In a hybrid prime mover having a structure in which an engine, a motor, and a transmission are main prime mover elements, and a motor is disposed between the engine and the transmission,
The engine-side end of the motor rotation shaft is supported by a bearing provided on the rotation member on the engine side, and the transmission-side end of the motor rotation shaft is used as a bearing for the rotation shaft on the transmission side. The bearing is also used as a side rotation shaft.

In this way, since the rotation shaft of the motor is supported by the bearing provided on the rotating member on the engine side and the bearing provided on the transmission side, the motor dedicated bearing can be omitted, so that the motor shaft direction can be omitted. Therefore, it is possible to avoid an increase in the total length of the prime mover while attaching a motor having a necessary power.
As will be described later, it is confirmed that the bearing strength of the motor can be sufficiently secured even if the function of the bearing is also used, and not only can the cost be simply reduced by reducing the number of bearings to the minimum necessary, The load applied to the weakly strong part of the prime mover due to a disturbance or the like can be reduced by reducing the restraint by the bearing, thereby improving the durability of the prime mover.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an overall schematic configuration of the embodiment.
The engine 1, the motor 2, and the transmission 3 are the main prime mover elements as a prime mover for traveling, and a hybrid prime mover in which the motor 2 is disposed between the engine 1 and the transmission 3 is used.

The engine 1 is connected to a flywheel 11 at an output shaft (crankshaft) end portion, and includes an electromagnetic clutch 25 between the flywheel 11 and the motor 2. Transmission / cutoff of the driving force to the motor 2 can be switched. The output of the transmission 3 is transmitted to the wheel 5 via the axle 4.
In such a basic system configuration, the rotating shaft of the motor 2 is not supported by the motor 2 alone, and both ends of the rotating shaft are provided on the flywheel 11 and the main drive shaft of the transmission 3 or on this. The bearing is configured to be supported by a main bearing 42 for bearings of similar rotating shafts.

FIG. 2 shows the details of the main part.
The motor 2 is housed and supported in a motor housing 21 that covers the outer periphery of the stator 22. An electromagnetic clutch 25 penetrates and is attached to a rotating shaft 24A that protrudes toward the engine side of the rotor 23 provided inside the stator 22, and a tip portion of the rotating shaft 24A is supported by a pilot bearing 26 provided on the flywheel 11. Has been.

The electromagnetic clutch 25 includes a coil storage case 25A, a rotating piece 25B, and a floating piece 25C in this order from the rotor 23 side. The coil storage case 25A is connected to a motor housing via a rotation preventing member 28 connected to the lower end. 21 is supported on the bottom wall.
The rotating piece 25B is key-coupled to the rotating shaft 24A of the motor 2 and rotates integrally. On the other hand, the floating piece 25 </ b> C is attached to the flywheel 11 so as to be integrally movable but movable in the axial direction by a predetermined amount.

  When the coil in the coil storage case 25A is energized, the rotating piece 25B is magnetized, and the floating piece 25C is attracted by the magnetic force, so that the torque of the engine 1 causes the flywheel 11 to move the floating piece 25C and the rotating piece 25B. Via the rotary shaft 24A of the motor 2. On the other hand, when the coil is not energized, the rotating piece 25B and the floating piece 25C are separated from each other, and transmission of engine torque to the motor 2 is interrupted.

  The rotary shaft 24A is supported by the bearing 27 in the coil storage case 25A. However, since the coil storage case 25A is supported by the non-rotating member 28 in a flexible structure, the bearing 27 is an electromagnetic clutch. 25 is not attached to the rotating shaft 24A of the motor 2 and is attached so as to rotate the rotating shaft 24 smoothly. The rotating shaft 24 of the motor 2 is not restricted and supported.

On the other hand, the rotating shaft 24B protruding to the transmission 3 side of the rotor 23 is connected to a main drive shaft (or attached to a hub at the center of the front gear housing 41 of the transmission fastened to the transmission side end surface of the motor housing 21). It is supported by a main bearing 42 for a similar rotating shaft.
The rotation shaft 24B is formed with a hole 30 that communicates with an oil cooling chamber 29 formed in the center of the rotor body and penetrates in the axial direction. The hole 30 has a small-diameter portion on the rotor body side and a large-diameter portion on the transmission side, and a spline 31 is formed on the inner peripheral surface of the small-diameter portion.

On the other hand, the main drive shaft 43 of the transmission 3 has a stepped end portion with a small diameter, and a spline 44 formed on the outer peripheral surface of the small diameter portion.
Then, the end portion of the main drive shaft 43 is inserted into the shaft hole 46 of the cylindrical shroud member 45 attached with the flange fastened to the hub, and the spline 44 on the outer periphery of the tip portion protruding from the shroud member 45 is connected to the rotating shaft. It is made to mate with the spline 31 of 24B. Thereby, the rotor 22 and the main drive shaft 43 rotate integrally.

  An annular gap 47 is provided between the inner peripheral surface of the large-diameter portion of the hole 30 and the outer peripheral surface of the shroud member 45, and the outer peripheral portion of the spline 31 forming portion of the rotating shaft 24 </ b> B has oil in the rotor body. A plurality of oil holes 48 are formed so as to communicate with the cooling chamber 29 and the annular gap 47. Similarly, a plurality of oil holes 49 are formed through the flange of the shroud member 45 so as to communicate the annular gap 47 and the internal space on the transmission side with respect to the front gear housing 41.

On the other hand, an oil passage 50 is formed along the central axis of the main drive shaft 43, and an oil hole (not shown) branched in a radial direction from the oil passage 49 is formed in the transmission-side internal space.
Further, an oil pump (not shown) that engages with the main drive shaft 43 and is driven to rotate is provided at a position close to the shroud member 45 in the front gear housing 41 so that the oil discharged from the oil pump is discharged. The oil hole 49, the annular gap 47, and the oil hole 48 are supplied to the oil cooling chamber 29 of the rotor body, and after cooling the rotor body, the transmission of the transmission is made via the oil passage 50 of the main drive shaft 43. It is supplied to the part to be lubricated and lubricated. Part of the oil that has passed through the oil hole 49 is also supplied to the main bearing 42 through the gap between the end surface of the rotating shaft 24 </ b> B and the flange back surface of the shroud member 44 to lubricate the main bearing 42.

  As described above, in the present invention, the rotating shafts 24A and 24B of the motor 2 (rotor 23) are not supported by the motor alone, but are substantially attached to the flywheel 11 which is a rotating member on the engine 1 side. And is also used as a main drive shaft 43 via a main bearing 42 on the transmission 3 side. The pilot bearing 26 and the main bearing 42 need to be strengthened with respect to the pilot bearing and the main bearing in the case where the conventional motor dedicated bearing is provided. However, as described later, the rotation shaft is less restricted. It was confirmed that the strength required for motor bearings could be secured by reducing the load.

This is compared with a conventional bearing structure in which the rotor rotating shaft is supported by two dedicated bearings (front and rear bearings) with a single motor.
Even in the conventional structure, the pilot bearing is necessary to prevent misalignment between the rotation center axis of the flywheel and the rotor rotation axis, and the main bearing on the transmission side is naturally necessary for bearing the main drive shaft and the like. It is. As described above, in the conventional structure, it is necessary to provide bearings for the engine, the motor, and the transmission, and to secure a space for mounting the bearings according to the number of bearings. Therefore, the shaft length of the motor or the hybrid prime mover has been increased. .

In addition, the conventional structure requires high accuracy in order to secure the straightness of the bearing.
That is, the pilot bearings, the front and rear bearings, the oil pump, the motor, and the rotation shafts of the transmission need high straightness. In particular, the straightness at the time of production can be maintained in a stationary / normal temperature state, but when the vehicle is splashed from the road surface during running, thermal distortion occurs, or when it receives an impact, it bends considerably.

  At this time, if the front and rear bearings in the motor that can withstand a large load are used in consideration of the stress on the pilot bearings, etc., the motor is dedicated to these motors when the transmission is deformed. Since the movement is restrained so as not to cause misalignment by the bearing, a great stress is applied to the pilot bearing on the engine side and the main bearing on the transmission side, and the bearings are damaged.

As a result, although the stress due to the vibration and rotational force generated by the operation of the motor itself is small, the derivative stress generated due to the thermal deformation of the prime mover becomes larger, resulting in damage. This is a problem peculiar to the type of hybrid prime mover in which the motor is sandwiched between the engine and the transmission.
There is also a problem that the structure before and after the rotor is complicated.

  In order to support the bearing, a structure having a certain degree of strength is required, and these shapes are considerably complicated and require a space. In particular, when setting a motor to be used for an FF type vehicle that drives front wheels by a front engine, the motor shaft must be extremely cut off. As described above, in the conventional structure having many bearings, it is necessary to shorten the rotor width, which results in lowering the output of the motor.

In addition, since the shape of the housing becomes complicated as the structure becomes complicated, there is a problem that the price of the casting for forming the housing becomes high and the processing cost is high.
On the other hand, the hybrid prime mover shown in the above embodiment can omit the dedicated bearings provided in the conventional motor alone, so that the following improvement effect can be obtained compared to the conventional bearing structure.

  As described above, the prime mover that has a long overall length due to the thermal influence and impact from the road surface is distorted. In the conventional structure with many bearings and many restraints, this restraint suffers and has weak points. However, in the bearing structure according to the present invention, by reducing the number of bearings attached, the distortion of the prime mover can be absorbed flexibly at the bearing portion, and the bearing can be prevented from being damaged.

Further, since there is no bearing dedicated to the motor, the corresponding space is vacant, the width of the rotor and the stator necessary for generating power can be expanded, and the essential condition of a powerful motor can be satisfied.
Since a motor-dedicated bearing and its supporting housing can be omitted, a casting having a complicated shape is not necessary. Accordingly, the number of processing steps can be greatly reduced, and the manufacturing cost can be greatly reduced.

  The pilot bearing 26 that also serves as the front bearing of the motor 2 is operated with both the engine 1 and the motor 2 for most of the usage time. On the other hand, since the outer race is fixed to the stationary housing, the main bearing 42 that also serves as the rear bearing of the motor 2 is always accompanied by relative motion and has a large load.

  As described above, since wet lubrication can be performed on the main bearing 42 with the oil in the transmission, it is possible to ensure durability.

The figure which shows the outline | summary structure of the whole system of embodiment. The figure which shows the principal part detail of embodiment same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Motor 3 Transmission 21 Motor housing 22 Stator 23 Rotor 24A Rotor rotating shaft (engine side)
24B Rotor rotation shaft (transmission side)
25 Electromagnetic clutch 26 Pilot bearing 30 hole 31 Rotating shaft spline 41 Front gear housing 42 Main bearing 43 Main drive shaft 44 Main drive shaft spline 47 Annular gap 48 Oil hole 49 Oil hole 50 Oil passage

Claims (6)

In a hybrid prime mover having a structure in which an engine, a motor, and a transmission are main prime mover elements, and a motor is disposed between the engine and the transmission,
The engine-side end of the motor rotation shaft is supported by a bearing provided on the rotation member on the engine side, and the transmission-side end of the motor rotation shaft is used as a bearing for the rotation shaft on the transmission side. A bearing device for a motor rotating shaft in a hybrid prime mover, wherein the bearing is used also as a side rotating shaft.   2. The bearing device for a motor rotation shaft in a hybrid prime mover according to claim 1, wherein the engine-side bearing is provided at a rotation center portion of a rotation member of the engine.   3. The bearing device for a motor rotation shaft in a hybrid prime mover according to claim 2, wherein the rotation member of the engine is a crankshaft or a flywheel.   4. The bearing device for a motor rotation shaft in a hybrid prime mover according to claim 1, wherein the transmission-side bearing is provided on a transmission-side fixing member.   5. The bearing device for a motor rotating shaft in a hybrid prime mover according to claim 4, wherein the bearing on the transmission side serves as a main drive shaft of the transmission or a similar rotating shaft.   6. The transmission-side end portion of the motor rotation shaft and the motor-side end portion of the transmission main drive shaft or similar rotation shaft are concentrically spline-coupled. Bearing device for motor rotation shaft in hybrid prime mover.