JP2009247087A - Rotating electrical machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce wear in a bearing and a housing caused by thrust force produced in the motor shaft in a rotating electrical machine with a speed reducer using a helical gear speed reducer. <P>SOLUTION: The rotating electrical machine includes: a stator 3; a rotor 4 attached to a helical gear comprising a speed reducing mechanism and rotatably provided on the stator 3 with a predetermined gap in-between; a first bearing that supports the shaft of the rotor 4 on the speed reducing mechanism side through a ball bearing 6a; and a second bearing that supports the shaft of the rotor 4 on the anti-speed reducing mechanism side in an enclosure through a grease-lubricated ball bearing 6b and has an insert material 18 between the grease-lubricated ball bearing 6b and the enclosure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine.

  There exists a rotary electric machine with a reduction gear as a rotary electric machine mounted in a hybrid vehicle (HEV). It is known that the gears of the speed reduction mechanism and the bearings on the speed reduction mechanism that supports the rotor shaft of the rotating electrical machine are lubricated with the lubricating oil sealed in the gear box, and the bearings on the anti-deceleration mechanism side are lubricated with grease. (For example, refer to Patent Document 1).

JP 2001-37158 A

  As a small gear for power transmission described in the prior art, a spur gear is generally used. When a spur gear is used, only a radial force is generated during power transmission.

  In general, it is preferable to use a helical gear as a small gear for noise reduction of the motor. However, when a helical gear is used, a force is generated in the thrust direction and the radial direction during power transmission. For the former force in the thrust direction, it is necessary to prevent the ball bearing that supports the rotor shaft on the reduction mechanism side from coming off, and the outer ring of the reduction mechanism side ball bearing is held by a stopper ring. However, due to the tolerance of the stopper ring assembly, a gap is created between the bearing and the stopper ring, and the rotor shaft and the grease-lubricated ball bearing on the side of the anti-deceleration mechanism fitted to it move in the thrust direction and move against the rear case. There is a concern that wear may occur between the grease lubricated ball bearings on the speed reduction mechanism side and the device may rattle.

  An object of the present invention is to provide a rotating electric machine with less backlash.

  The present invention provides a first bearing for supporting a shaft on the speed reduction mechanism side of a rotor via a ball bearing, a shaft on the side of the anti-deceleration mechanism side of the rotor supported on a housing via a grease lubricated ball bearing, and grease lubrication. And a second bearing provided with an insert material between the ball bearing and the housing.

  ADVANTAGE OF THE INVENTION According to this invention, a rotary electric machine with little shakiness can be provided.

  Embodiments of the present invention will be described below. The following embodiments relate to a rotating electric machine with a helical gear reducer particularly suitable for use in a hybrid vehicle.

  FIG. 1 is a side sectional view of a rotating electrical machine with a helical gear reducer according to an embodiment of the present invention. In the figure, the same reference numerals denote the same parts.

  The rotating electrical machine with a helical gear reducer shown in FIG. 1 generates a driving force as an electric motor when the vehicle is accelerated and assists engine power (not shown), and regenerates energy as a generator when the vehicle is decelerated. Then, a battery (not shown) is charged.

  The rotating electrical machine 1 includes a stator 3 that is fitted and fixed to the inner peripheral side of a motor housing 2 as a housing, a rotor 4 that is disposed inside the stator and is rotatably supported, and an anti-deceleration mechanism side of the motor housing 2. It has a rear case 9 as a case fixed with bolts, and a front case 11 as a case fixed with bolts to the reduction mechanism side of the motor housing 2. A resolver cover 10 is attached to the rear case 9. Here, the motor housing 2, the front case 11, and the rear case 9 are shown as separate housings, but one may also serve as the other.

  A rotor shaft 5 is fitted in the center of the rotor 4. The rotor shaft 5 is supported mainly by ball bearings 6 a and 6 b on both sides of the rotating electrical machine 1. Each of them forms a first bearing and a second bearing. Further, the needle bearing 8 in the overhang portion of the small gear 7 to be described later is arranged in an auxiliary manner so as to prevent the rotor shaft 5 from falling.

  A resolver 12 that detects the rotational positions of the rotor 4 and the rotor shaft 5 is disposed on the rotor shaft 5 between the rear case 9 and the resolver cover 10. The motor housing 2 is provided with an oil seal 15 a that prevents oil from entering from the speed reduction mechanism chamber 14 to the motor chamber 13.

  The reduction gear 17 is an output shaft 16 arranged in parallel to the rotor shaft 5 of the rotating electrical machine 1 and a helical gear small gear 7 that is a transmission mechanism for transmitting power between the rotor shaft 5 and the output shaft 16. The small gear 7 is fixed to the rotor shaft 5. The large gear 17 is supported by ball bearings 6c and 6d. An oil seal 15b that prevents oil from flowing out of the speed reduction mechanism chamber 14 to the outside is disposed outside the ball bearing 6d.

  The output shaft 16 is connected to a power combining mechanism with engine power (not shown) via a flange at the end of the output shaft. When the vehicle starts and accelerates, the driving force of the rotating electrical machine is amplified by the speed reducer 17, and the engine power (not shown) and the amplified motor driving force are combined to drive the vehicle. At the time of deceleration, the speed reducer 17 accelerates the rotation input through a flange from a power combining mechanism with engine power (not shown), and regenerates energy by the rotating electrical machine.

  Next, lubrication in a rotating electrical machine with a reduction gear will be described with reference to FIG.

  Oil accumulates at the bottom of the deceleration mechanism chamber 14, for example, at a position below the line indicated by the broken line Y in FIG. Note that the position of the broken line Y is the position of the upper surface of the oil when a normal amount of oil is sealed while the vehicle is stationary.

The oil accumulated in the bottom of the speed reduction mechanism chamber 14 is swept up when the rotating electric machine rotates, when the large gear 17 of the rotating speed reducer output shaft 16 rotates counterclockwise as seen from the output side. . The oil that was fried up
(A) Two ball bearings 6c and 6d for supporting the output shaft 16 and an oil seal 15b
(B) A ball bearing 6a of the motor housing portion for supporting the rotor shaft and a needle bearing 8 of the overhang portion of the small gear 7
(C) An oil seal 15a that prevents oil from entering the motor chamber 13 from the speed reduction mechanism chamber 12
Led to.

  Next, the mounting structure of the grease lubricated ball bearing on the side of the anti-deceleration mechanism in the rotary electric machine 1 with a speed reducer will be described.

  Details of the support of the rotor shaft 5 will be described with reference to FIG.

  The rotor shaft 5 is supported mainly by ball bearings 6 a and 6 b on both sides of the rotor shaft of the rotating electrical machine 1.

  The rotor shaft 5 and the ball bearing 6a are fixed in the axial direction, and the ball bearing 6a is held by the motor housing 2 and the stopper ring 19 and fixed in the axial direction.

  Due to the mounting tolerance of the stopper ring 19, a slight gap is generated between the bearing end and the stopper ring 19, and the amount of the gap is the amount of movement of the rotor shaft 5 in the axial direction.

  On the other hand, the grease-lubricated ball bearing 6b that supports the rear of the rotor shaft 5 is smaller in size than the ball bearing 6a on the speed reduction mechanism side and cannot receive a load in the thrust direction. The grease-lubricated ball bearing 6b and the rotor shaft 5 have an interference fit, the grease-lubricated ball bearing 6b and the rear case 9 have a clearance fit, and the rotor shaft 5 and the connected grease-lubricated ball bearing 6b have a thrust fit. You can move in the direction.

  Since the rotor shaft 5 and the connected grease lubricated ball bearing 6b move in the thrust direction, even if friction occurs between the grease lubricated ball bearing 6b and the rear case 9, the friction portion between the grease lubricated ball bearing 6b and the rear case 9 In addition, by mounting the gray cast iron insert 18 on the rear case 9, the graphite contained in the gray cast iron has a role as a lubricant, so that wear is reduced.

  Further, by attaching the insert material 18 of the tag tile cast iron material to the friction portion between the grease lubricated ball bearing 6b and the rear case 9, the graphite contained in the tag tile cast iron has a role as a lubricant, so that the wear is reduced. Reduced.

  Furthermore, the wear can be reduced by attaching a sintered metal insert 18 impregnated with a solid lubricant having a lubricating action, such as molybdenum disulfide, to the friction part between the grease lubricated ball bearing 6b and the rear case 9 to the rear case. The

  As described above, according to this embodiment, the grease lubricated ball bearing 6b and the rear case 9 are prevented from rattling by reducing the frictional wear caused by the thrust movement of the rotor shaft 5 generated by the helical gear. Therefore, it is possible to easily provide a rotating electric machine with a reduction gear that has a long life and high reliability as well as low noise.

1 is a side cross-sectional view of a rotating electrical machine according to an embodiment of the present invention. The detail drawing of the rotor shaft support structure of the said rotary electric machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 2 Motor housing 3 Stator 4 Rotor 5 Rotor shaft 6a, 6c, 6d Ball bearing 6b Grease lubrication ball bearing 7 Small gear 8 Needle bearing 9 Rear case 10 Resolver cover 11 Front case 12 Reduction mechanism chamber 13 Motor chamber 14 Reduction gear 15a , 15b Oil seal 16 Output shaft 17 Large gear 18 Insert material 19 Stopper ring

Claims (6)

A stator,
A rotor mounted on a helical gear constituting a speed reduction mechanism and provided rotatably with respect to the stator via a predetermined gap;
A first bearing that supports a shaft on the speed reduction mechanism side of the rotor via a ball bearing;
A second bearing having an insert member provided between the grease-lubricated ball bearing and the housing; and a shaft on the anti-deceleration mechanism side of the rotor supported on the housing via a grease-lubricated ball bearing;
Rotating electric machine having The rotating electrical machine according to claim 1,
The rotating electrical machine wherein the insert material is a gray cast iron material. The rotating electrical machine according to claim 1,
The rotary electric machine, wherein the insert material is a tag tile. The rotating electrical machine according to claim 1,
The rotary electric machine, wherein the insert material is a sintered metal. The rotating electrical machine according to claim 1,
The first bearing is a rotating electrical machine having a stopper ring that prevents axial movement of the ball bearing. The rotating electrical machine according to claim 1,
A rotating electrical machine in which the stator, the rotor, and the speed reduction mechanism are held in a common housing.

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