Motor, and electric power steering apparatus and vehicle equipped with the same

Abstract

A motor having a configuration that includes plural openings which are disposed in a circumferential direction on a case bottom surface and are pulled-out bus bar terminals, and is directly connected between a control board and bus bars by using a simple procedure, and to an electric power steering apparatus and a vehicle equipped with the motor. The outer periphery of the motor is enclosed in a case and wirings are implemented at an anti-load side. The motor has a configuration that includes plural openings which are provided in a circumferential direction on a case bottom surface at the anti-load side and allow bus bar terminals to protrude therefrom, and openings which have an almost same shape of the plural openings and are disposed at a predetermined interval in a similar shape are added as needed.

Claims

1. A motor that an outer periphery is enclosed in a case and wirings are implemented at an anti-load side, comprising: a configuration in which plural openings having an elliptical shape are provided in a circumferential direction on a case bottom surface at said anti-load side in a same interval, a part of said plural openings having the elliptical shape are provided for protruding bus bars of motor windings and others of said plural openings having the elliptical shape are provided for being utilized as threaded holes, said plural openings having the elliptical shape are a similar shape and are not contacted with said bus bars, plural protrusions are provided in a circumferential direction on an axial end inside of an outer periphery of an insulator, said insulator comprises plural notch sections which are cutouts disposed between said neighbor protrusions, said motor comprises a bus bar structure which is provided at one side of a motor stator and is opposed to an axial end inside of an outer periphery of an insulator, and engagement sections, which are provided on a circumferential side surface of said bus bar structure, are engaged with said notch sections, and an insulating cap or an insulating film to cover said case is provided to insulate between said case and said bus bars.

2. The motor according to claim 1, wherein said motor windings are a dual-system and said bus bars are connected to said dual-system motor windings.

3. The motor according to claim 2, wherein bus bar positions of said dual-system motor windings are arranged in diagonal positions with respect to a center and said openings are provided corresponding to said arrangement of said bus bars.

4. The motor according to claim 3, wherein a cylindrical recess coupled to a rotational position detecting means is provided on a bottom surface of said case, a number for said openings is a number which is added at least two or more to a number for said bus bars, and said at least two or more openings which are not used for said bus bars are utilized as threaded holes.

5. The motor according to claim 2, wherein bus bar positions of said dual-system motor windings are sequentially arranged in an order of a system and said openings are provided corresponding to said arrangement of said bus bars.

6. The motor according to claim 5, wherein a cylindrical recess coupled to a rotational position detecting means is provided on a bottom surface of said case, a number for said openings is a number which is added at least two or more to a number for said bus bars, and said at least two or more openings which are not used for said bus bars are utilized as threaded holes.

7. The motor according to claim 2, wherein a cylindrical recess coupled to a rotational position detecting means is provided on a bottom surface of said case, a number for said openings is a number which is added at least two or more to a number for said bus bars, and said at least two or more openings which are not used for said bus bars are utilized as threaded holes.

8. The motor according to claim 1, wherein threaded holes for being fixed to a rotational position sensor are provided on said insulating cap by tapping thereon.

9. An electric power steering apparatus that is driving-controlled by said motor according to claim 1, and applies an assist force to a steering system of a vehicle by means of a current command value calculated based on at least a steering torque.

10. A vehicle which is equipped with said electric power steering apparatus according to claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the accompanying drawings:

(2) FIG. 1 is a configuration diagram illustrating a general outline of an electric power steering apparatus;

(3) FIG. 2 is a diagram showing a coupling mechanism example of a motor of the electric power steering apparatus and a reduction section, and a connection example of the motor and a control unit (ECU);

(4) FIG. 3 is a plan view showing an example of a case bottom surface of an anti-load side;

(5) FIG. 4 is a perspective view showing a structure example of the motor according to the present invention;

(6) FIG. 5 is a perspective view showing a structure example (attaching a resolver stator) of the motor according to the present invention;

(7) FIG. 6 is an assembling elevation view of the motor according to the present invention, showing a state of attaching the resolver stator;

(8) FIG. 7 is a wiring diagram of dual-system windings of the motor;

(9) FIG. 8 is an exploded schematic perspective view showing a bus bar structure and a motor stator;

(10) FIG. 9 is an external structure diagram explaining an assembling state of the bus bar structure and the motor stator;

(11) FIG. 10 is a perspective view showing a structure example of the motor of which a yoke is covered with an insulating film; and

(12) FIG. 11 is a perspective view showing a structure example of the motor of which the yoke is covered with an insulating cap.

MODE FOR CARRYING OUT THE INVENTION

(13) An outer periphery of a motor according to the present invention is covered with a steel plate case. A wiring process and an assembling process of a configuration that wirings are performed by pulled-out bus bars to an anti-load side (an opposite side of an output shaft), are considered in the motor.

(14) In a case of disposing a control board to the anti-load side in the present invention, it has an effect that suppresses strain which is affected to a concentric degree of a bearing house in a process by disposing a plurality of similar holes in a circumferential direction at the same interval on the case bottom surface when the bus bars are penetrated by providing holes on the case. The plural holes can use not only to pull-out the bus bars which increase by using dual-system windings, but also to fix a resolver stator via screws. In order to need to keep insulating between wiring terminals and the bus bars connecting section and between the bus bars and the case, a cap-shape insulating resin so as to cover the bus bars is provided between a yoke and the bus bars. Alternatively, an insulating film is wound to the bus bars so as to cover the bus bars. Further, in a case of using the insulating cap, screw holes to fix the resolver stator can be disposed by provided taps on the insulating cap.

(15) The resolver stator may be directly fixed to the case by provided the taps on the case. When screw engagement allowance is not adequate in case of thin steel plate case or the like and a fixed force is inadequate, a countermeasure such as providing burring taps is performed. In this way, a similar effect is obtained.

(16) In the motor of the present invention, the motor has a configuration that the plural openings are disposed at the same interval with a similar shape in a circumferential direction on a case bottom surface at the anti-load side, and the motor bus bars are protruded from the openings and are wiring-connected to bus terminals of an ECU side. By symmetrically disposing the openings opposed to the steel plate case, the strain in a press punching processing is minimized, a freedom of the wiring layout is existed as well as a concentric degree to the motor is kept. When dual-system motor windings are used in order to improve a redundancy of the motor, the bus bars increase to three-phase six-wires. However, the countermeasure can sequentially be performed by disposing the openings at the same interval with a similar shape. Further, the openings which do not use to protrude the bus bars can be also used to fix the resolver stator via the screws.

(17) In addition, in order to insulate between the case and the bus bars, the insulating cap or the insulating film is provided. In the case of the insulating cap, a fixing mechanism of a rotational position sensor such as the resolver can be constructed by providing the taps on the case bottom surface.

(18) The motor structure of the present invention has been established in itself to the utmost. Since the case covers the motor bottom surface and the wirings are pulled-out to the anti-load side via the bus bars, the openings to protrude the bus bars can be disposed at the same interval with a similar shape in a circumferential direction on the case bottom surface, and the wirings can use short wirings in a case of disposing the control board to the anti-load side. Further, in order to maintain the accuracy of the concentric degree to the motor shaft in the press punching process, holes are made by 90 degree equally spaced (the shape of the openings, the same interval, and the similar shape). The plural openings are also used as the holes for passing through the screws to fix the resolver stator or the holes for fixing via the screws, except for the holes for pulling-out the bus bars which increase by using the dual-system windings.

(19) In the motor structure of the present invention, it is necessary to keep the insulating between winding terminals and the bus bars connecting section and between the bus bars and the case. Therefore, the insulating cap which is composed of the insulating resin is disposed between the case and the bus bars, or the insulating film is wound or layered to cover the bus bars. Consequently, it is possible to insulate between the case and the bus bar and between the case and the windings, and it is possible that the windings are surely pulled-out to the anti-load side of the motor. Further, in the case of using the insulating cap, the threaded holes to fix the resolver stator are provided on the insulating cap by engraving the taps on the surface of the insulating cap. The resolver stator is directly fixed to the insulating cap via the screws.

(20) Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiments, an example of the openings applied to the bus bars of three-phase dual-system windings is described, and it is possible to be applied to another motor types. The number of the openings, the shape of the openings, and the arrangement of the openings are appropriately changeable.

(21) FIG. 3 is a plan view of the case bottom surface 110 of the motor 100 according to the present invention, and FIG. 4 is a perspective view of the motor 100 according to the present invention. Eight rectangular openings 111 to 118 in the circumferential direction at the same interval are disposed on the case bottom surface 110 at the anti-load side by a press punching process or the like. Bus bars U1in, V1in, and W1in of a first system of the motor windings are protruded and pulled-out from the openings 111, 112, and 113, respectively. Bus bars U2in, V2in, and W2in of a second system of the motor windings are protruded and pulled-out from the openings 115, 116, and 117, respectively. The bus bars U1in, V1in, and W1in are a first coil of the bus bars of the dual-system winding motor, and the bus bars U2in, V2in, and W2in are a second coil of the bus bars of the dual-system winding motor. The bus bars U1in to W1in and the bus bars U2in to W2in are not contacted with the openings 111 to 113 and the openings 115 to 117 of the yoke 110, respectively.

(22) In the center portion of the case bottom surface 110, a cylindrical recess 120 is provided. The case which is provided with the recess 120 forms the case bottom surface 110. The dual-system bus bars U1in to W1in and U2in to W2in which are protruded from the openings 111 to 113 and 115 to 117 are wiring-connected to bus terminals of the ECU side.

(23) In FIGS. 3 and 4, although the openings 111 to 118 are the same shape, they may be the similar shape. Both ends of the openings 111 to 118 shown in FIGS. 3 and 4 respectively have round shapes. However, the round shapes may not be existed, and the shapes of the openings may be square or rectangular which is not contacted with the bus bars.

(24) In the case that the motor 100 is a brushless motor, it is required to detect a rotational position. Accordingly, as shown in FIGS. 5 and 6, the resolver stator 150 is inserted into the recess 120, and the resolver stator 150 is fastened and fixed to the motor 100 via the screws 151. At this time, unused openings 114 and 118 are used as fixing threaded holes. In FIG. 6, the rotor shaft 101 is protruded and a bearing 102 are provided in the recess 120.

(25) Next, the motor which has the dual-system windings is described as follows.

(26) In the motor with the dual-system windings, the coils of the stator are divided into two systems (U1 to W1 phases and U2 to W2 phases). When one system of the motor fails to operate, the other system can rotate a rotor, and the motor windings are shown in FIG. 7. That is, six first coils include two first U-phase coils 137Ua and 137Ub which are excited by a current of the first U-phase, two first V-phase coils 137Va and 137Vb which are excited by a current of the first V-phase, and two first W-phase coils 137Wa and 137Wb which are excited by a current of the first W-phase. The first U-phase coil 137Ub is connected in series to the first U-phase coil 137Ua, the first V-phase coil 137Vb is connected in series to the first V-phase coil 137Va, and the first W-phase coil 137Wb is connected in series to the first W-phase coil 137Wa. Winding directions to teeth of the first coils are the same direction, and wirings Lu1, Lv1, and Lw1 are connected by Y-connection (star connection) via the bus bars U1in, V1in, and W1in.

(27) Similarly, six second coils include two second U-phase coils 138Ua and 138Ub which are excited by a current of the second U-phase, two second V-phase coils 138Va and 138Vb which are excited by a current of the second V-phase, and two second W-phase coils 138Wa and 138Wb which are excited by a current of the second W-phase. The second U-phase coil 138Ub is connected in series to the second U-phase coil 138Ua, the second V-phase coil 138Vb is connected in series to the second V-phase coil 138Va, and the second W-phase coil 137Wb is connected in series to the second W-phase coil 137Wa. Winding directions to teeth of the second coils are the same direction, and wirings Lu2, Lv2, and Lw2 are connected by Y-connection (star connection) via the bus bars U2in, V2in, and W2in.

(28) FIG. 8 is an exploded schematic perspective view showing a bus bar structure 140 that the bus bars U1in, V1in, W1in, U2in, V2in, and W2in stand in perpendicular and a motor stator 145. FIG. 9 is a diagram explaining an assembling state of the bus bar structure 140 and the motor stator 145. As shown in FIG. 8, the bus bar structure 140 makes the bus bars U1in, V1in, W1in and U2in, V2in, W2in protrude upward for each three-phase input from one surface in an axial direction of a plate-type insulating member 141.

(29) The bus bar structure 140 is provided at one side of the motor stator 145, and is opposed to an axial end 148 inside of an outer periphery 147 of an insulator 146. Plural protrusions 148A are provided on the axial end 148 in the circumferential direction, and the axial end 148 has a plurality of notches 148B which are cutouts being pinched with the neighbor on protrusions 148A. The bus bar structure 140 is fixed and positioned shown in FIG. 9 by putting the protrusions 141A in the notches 148B.

(30) The above bus bars of the dual-system windings U1in, V1in, and W1in, and U2in, V2in, and W2in are protruded upward not so as to be contacted with the openings 111 to 113 and 115 to 117 which are disposed on the case bottom surface 110. Accordingly, it is necessary that the sizes of the openings 111 to 113 and 115 to 117 are larger than those of the bus bars U1in, V1in, and W1in, and U2in, V2in, and W2in for having a margin.

(31) In order to surely insulate between the bus bars U1in, V1in, and W1in, and U2in, V2in, and W2in and the yoke 110 such that the bus bars are not contact with the yoke 110, an insulating film 160 is wound or layered as shown in FIG. 10, or an insulating cap 170 which is composed of the insulating resin with a cap shape is disposed as shown in FIG. 11. In order to insulate between the case openings and the bus bars, in case of the insulating film 160, the insulating film is wound to the bus bar pull-out portion and in case of the insulating cap 170, the protrusions of the bus bars are also covered with the insulating cap.

(32) As well, in the case of the insulating cap 170, the threaded holes to fix the resolver stator can be provided by engraving the taps on the surfaces of the insulating cap 170.

EXPLANATION OF REFERENCE NUMERALS

(33) 1 handle 2 column shaft (steering shaft, handle shaft) 10 torque sensor 12 vehicle speed sensor 14 steering angle sensor 20 motor 21 output shaft 30 control unit (ECU) 40 CAN 100 motor (brushless motor) 110 case bottom surface 111118 opening 120 recess 140 bus bar structure 145 motor stator 150 resolver stator 160 insulating film 170 insulating cap