JP2015020513A - Electric power steering device and electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric power steering device and an electric motor to suppress a contact noise caused between a motor case end surface and a flange end surface when a force acts on a coupling part between a speed reducer and a motor in one direction.SOLUTION: An electric motor 10 having a cylindrical shape with an opening side, comprises a case flange 11b disposed on the opening side to expand an end face of the open side towards outside of the outer periphery; a motor case 11 incorporating a motor rotor 20; an input/output shaft 21 rotating in conjugation with the motor rotor 20, connected to a worm; and a flange member 12 fixed to the case flange 11b, allowing the input/output shaft 21 to extend through the motor case 11 to be exposed. The case flange 11b and the flange member 12 are fixed by case fixing mechanisms H1 at two or more fixing areas. Claw parts 40 are interposed at some positions different from the fixing areas including the case fixing mechanisms H1, between some portions of opposing faces of the case flange 11b and the flange member 12.

Description

  The present invention relates to an electric power steering device and an electric motor.

  For example, in Patent Document 1, a motor case that is formed in a cylindrical shape with one end opened and has a built-in motor rotating portion, and a substantially disk-shaped flange that is coupled so as to close the opening at one end of the motor case. An electric motor provided with a member and an electric power steering device are described.

JP 2005-212559 A

  By the way, the worm speed reduction mechanism of the electric power steering device described in Patent Document 1 described above uses a worm so that the worm moves in one direction (vertical direction) with the motor coupling portion side bearing as a fulcrum in order to suppress worm rattling noise. It is in contact with the wheel. Due to the movement of the worm, the same unidirectional (vertical) force is also applied to the coupling portion between the worm and the motor side, for example, spline fitting or coupling connection portion. For this reason, with the flange member as a fulcrum, a force is generated in the motor in conjunction with the movement of the worm in one direction (vertical direction) described above with respect to the rear side bearing in the motor. As described above, when the electric motor transmits the steering assist force to the steering shaft, the meshing reaction force between the worm and the worm wheel of the worm reduction mechanism swings to the motor rotor built in the motor case of the electric motor via the output shaft. It is transmitted as a turning force.

  In the technique disclosed in Patent Document 1, a motor case is fixed to a flange member, arranged symmetrically about the motor central axis between mounting case flanges, and the contact case flange is flush with the mounting case flange. Bulges outward at the end face of the opening and abuts against the flange member. Even if the motor case tries to fall with the case fixing mechanism of the two fixing regions as a fulcrum, the contact flange suppresses the falling behavior of the motor case. Therefore, since the falling behavior of the motor case is suppressed, the influence on the rotation operation of the motor rotor in the motor case is reduced.

  However, the technique disclosed in Patent Document 1 is desired to further suppress the falling behavior of the motor case. For example, when a force that shakes the motor case acts at a position where the fixing force of the motor case is the smallest, the gap between the flange member and the case flange changes, and the contact between the motor case end surface and the flange end surface occurs. there is a possibility. As a result, contact noise (abnormal noise) between the motor case end surface and the flange end surface may occur. To suppress the contact noise (abnormal noise) between the motor case end face and the flange end face, if the number of case fixing mechanisms between the motor case and the flange is increased to three or more, the number of parts increases and the space occupancy rate around the motor This increases the mountability and may lead to an increase in assembly man-hours.

  The present invention has been made in view of the above, and in the case where a force acts in one direction at the coupling portion between the reduction gear and the motor, the electric power steering capable of suppressing the contact noise between the motor case end surface and the flange end surface An object is to provide an apparatus and an electric motor.

  In order to solve the above-described problems and achieve the object, an electric power steering apparatus includes a steering column including a steering shaft to which a steering torque is transmitted, and a reduction gear including a worm that transmits a steering assist force to the steering shaft. An electric motor that rotates the worm, and the electric motor has a cylindrical shape with one end opened, and a case flange that is an end surface with an end on the opening side extended to the outside of the outer periphery. A built-in motor case, an input / output shaft that rotates in conjunction with the motor rotor, is connected to the worm coaxially with a rotating shaft, is fixed to the case flange, and the input / output shaft passes through the input / output shaft. A flange member exposed from the motor case, and the case flange and the flange member are small in number. Both are fixed by a case fixing mechanism in two fixing regions, and a part of the case flange is part of the opposing surface of the case flange and the flange member at a position different from the fixing region. A claw portion protruding toward the member is provided, and the claw portion is in contact with an inclined portion that is an outer peripheral edge of the flange member and has an inclination angle with respect to the facing surface.

  At the position where the claw is present, the distribution of the motor fixing force in the circumferential direction (radial) direction changes. As a result, the electric motor as a whole is tilted with the fixed points of the two fixed regions as fulcrums, and when the force that shakes the motor case acts at the position where the fixing force of the motor case is the smallest, the flange member and the case flange Even if the gap between them changes, the case flange and the flange member can continue to contact each other at a position where the claw portion is present. The flange member and the case flange can maintain a certain distance. For this reason, the electric power steering apparatus can suppress the possibility that the flange member and the case flange come into contact with each other without generating a case fixing mechanism and generate contact noise (abnormal noise). As a result, the electric power steering apparatus can reduce operating noise and give a comfortable steering feeling to the operator.

  Moreover, since the electric motor can reduce the part which expands the area of a case flange as a fixed area | region, it can suppress interference of the surrounding members of an electric motor. For this reason, the electric power steering apparatus can improve the mountability to the vehicle.

  In order to solve the above-described problems and achieve the object, an electric motor is an electric motor having an input / output shaft that rotates in conjunction with a motor rotor and is coaxially connected to a rotating shaft to a worm meshed with a worm wheel. A case flange that is a cylindrical shape with one end open and has an end on the opening side that is expanded to the outside of the outer periphery, and is fixed to the motor case including the motor rotor and the case flange. And a flange member that passes through the input / output shaft and is exposed from the motor case, and the case flange and the flange member are fixed by a case fixing mechanism in at least two fixing regions, and the fixing region At a position different from the case flange, a part of the case flange is located on a part of the facing surface of the case flange and the flange member. A claw portion protruding toward the flange member is provided, and the claw portion is an edge of the outer periphery of the flange member and is in contact with an inclined portion having an inclination angle with respect to the facing surface. It is characterized by that.

  At the position where the claw is present, the distribution of the motor fixing force in the radial direction changes. As a result, the electric motor as a whole is tilted with the fixed points of the two fixed regions as fulcrums, and when the force that shakes the motor case acts at the position where the fixing force of the motor case is the smallest, the flange member and the case flange Even if the gap between them changes, the case flange and the flange member can continue to contact each other at a position where the claw portion is present. The flange member and the case flange can maintain a certain distance. For this reason, even if an electric motor does not add a case fixing mechanism, a flange member and a case flange contact | abut, and it can suppress possibility that a contact noise (abnormal noise) will be generated. Moreover, since the electric motor can reduce the part which expands the area of a case flange as a fixed area | region, it can suppress interference of the surrounding members of an electric motor.

  As a desirable mode of the present invention, it is preferable that a part of the case flange has a bending angle with respect to the facing surface with a slit as a boundary.

  Thereby, a nail | claw part can exhibit elastic force like a leaf | plate spring. When the claw portion is compressed by the motor side surface of the flange member and the case flange, the flange member and the case flange act in a direction away from each other, and the flange member and the case flange can maintain a certain distance. As a result, even if the gap between the flange member and the case flange changes, the case flange and the flange member are kept in contact with each other at a position where the claw portion is located, so that the possibility of generating contact noise (abnormal noise) can be suppressed. .

  As a desirable aspect of the present invention, it is preferable that the claw portion is bent so that the bending angle is larger than the inclination angle. Thereby, a nail | claw part can exhibit elastic force like a leaf | plate spring.

  As a desirable aspect of the present invention, a plurality of the claw portions are provided, a first imaginary line connecting the fixed regions passes through the rotation axis in the same plane as the facing surface, and at least of the plurality of claw portions. It is preferable that the 2nd virtual line which connects a pair of nail | claw parts passes the said rotating shaft, and the said 1st virtual line and the said 2nd virtual line are orthogonal. Thereby, the effect which suppresses the behavior which the whole electric motor falls over the fixed point of two fixed area | regions as a fulcrum can be heightened.

  As a desirable aspect of the present invention, a plurality of the claws are provided in a range in which the case flange and the flange member overlap in a direction parallel to the rotation axis, and between the fixed regions. It is preferable that the parts are arranged. Thereby, the change of the clearance gap between a flange member and a case flange is suppressed, and a case flange and a flange member can contact | abut at a position with a nail | claw part.

  As a desirable aspect of the present invention, among the plurality of claw portions, the inclined portion with which the claw portion with a small distance to the fixed region abuts is more than the inclined portion with which the claw portion with a large distance to the fixed region abuts. It is preferable that the inclination angle is large. Thereby, the effect which suppresses the behavior which the whole electric motor falls over the fixed point of two fixed area | regions as a fulcrum can be heightened.

  As a desirable aspect of the present invention, when the inclination angle is constant, a claw portion having a large distance to the fixed region among the plurality of claw portions has a bending angle smaller than that of the claw portion having a small distance to the fixed region. Is preferably large. Thereby, the effect which suppresses the behavior which the whole electric motor falls over the fixed point of two fixed area | regions as a fulcrum can be heightened.

  As a desirable aspect of the present invention, it is preferable that the outer peripheral side end of the claw portion protrudes from the outer periphery of the case flange in a state before bending. Thereby, the area which a nail | claw part contact | abuts with an inclination part can be enlarged. As a result, when the motor side surface of the flange member and the case flange are compressed, the elastic force acting on the claw portion is increased, and the contact noise can be further suppressed.

  According to the present invention, it is possible to provide an electric power steering device and an electric motor that can suppress the contact noise between the end surface of the motor case and the end surface of the flange when a force acts in one direction at the coupling portion between the reduction gear and the motor. it can.

FIG. 1 is a configuration diagram of an electric power steering apparatus including the electric motor according to the first embodiment. FIG. 2 is an explanatory diagram schematically showing a steering force assist mechanism around the electric motor. FIG. 3 is an explanatory diagram schematically showing the internal structure of the steering force assist mechanism shown in FIG. FIG. 4 is an explanatory diagram illustrating an example of the electric motor and the speed reducer according to the first embodiment. FIG. 5 is a plan view schematically showing the position of the claw portion when viewed from the bottom side of the motor case of the electric motor according to the first embodiment. FIG. 6 is a side view schematically showing the structure of the claw portion shown in FIG. 4 when viewed from the outer peripheral side. FIG. 7 is a cross-sectional view schematically showing the claw portion according to Embodiment 1 cut in the circumferential direction. FIG. 8 is a cross-sectional view schematically showing a position other than the claw portion according to the first embodiment and cutting the facing surfaces of the case flange and the flange member in the circumferential direction. FIG. 9 is a plan view schematically showing the position of the claw portion as viewed from the bottom side of the motor case of the electric motor according to the second embodiment. FIG. 10 is a plan view schematically showing a claw portion before bending as seen from the bottom side of the motor case of the electric motor according to the third embodiment. FIG. 11 is a cross-sectional view schematically showing a claw portion according to Embodiment 3 cut in the circumferential direction.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

(Embodiment 1)
FIG. 1 is a configuration diagram of an electric power steering apparatus including the electric motor according to the first embodiment. FIG. 2 is an explanatory diagram schematically showing a steering force assist mechanism around the electric motor. FIG. 3 is an explanatory diagram schematically showing the internal structure of the steering force assist mechanism shown in FIG. FIG. 4 is an explanatory diagram illustrating an example of the electric motor and the speed reducer according to the first embodiment. 3 and 4 show a part of the structure partially in cross-section. An outline of an electric power steering apparatus 80 including the electric motor 10 will be described with reference to FIGS. 1 to 4.

<Electric power steering device>
The electric power steering device 80 includes a steering wheel 81, a steering shaft 82, a steering force assist mechanism 83, a universal joint 84, a lower shaft 85, a universal joint 86, in the order in which the force applied from the steering wheel is transmitted. A pinion shaft 87, a steering gear 88, and a tie rod 89 are provided. The electric power steering device 80 includes an ECU (Electronic Control Unit) 90 and a torque sensor 91a. The vehicle speed sensor 91b is provided in the vehicle and inputs a vehicle speed signal V to the ECU 90 by CAN (Controller Area Network) communication.

  The steering shaft 82 includes an input shaft 82a and an output shaft 82b. The input shaft 82a has one end connected to the steering wheel 81 and the other end connected to the steering force assist mechanism 83 via the torque sensor 91a. The output shaft 82 b has one end connected to the steering force assist mechanism 83 and the other end connected to the universal joint 84. In the present embodiment, the input shaft 82a and the output shaft 82b are made of a magnetic material such as iron.

  The lower shaft 85 has one end connected to the universal joint 84 and the other end connected to the universal joint 86. The pinion shaft 87 has one end connected to the universal joint 86 and the other end connected to the steering gear 88.

  Steering gear 88 includes a pinion 88a and a rack 88b. The pinion 88a is connected to the pinion shaft 87. The rack 88b meshes with the pinion 88a. The steering gear 88 is configured as a rack and pinion type. The steering gear 88 converts the rotational motion transmitted to the pinion 88a into a linear motion by the rack 88b. The tie rod 89 is connected to the rack 88b.

  The steering force assist mechanism 83 includes a speed reducer 92 and an electric motor (motor) 10. The electric motor 10 is described as an example of a so-called brushless motor, but may be an electric motor including a brush (slider) and a commutator (commutator). The reduction gear 92 is connected to the output shaft 82b. The electric motor 10 is an electric motor that is connected to the reduction gear 92 and generates auxiliary steering torque. In the electric power steering device 80, a steering column is constituted by the steering shaft 82, the torque sensor 91a, and the speed reducer 92. The electric motor 10 gives auxiliary steering torque to the output shaft 82b of the steering column. That is, the electric power steering apparatus 80 of this embodiment is a column assist system.

  In the column assist type electric power steering device 80, the distance between the operator and the electric motor 10 is relatively short, and the electric motor 10 is disposed near the driver's feet in the passenger compartment. The sound generated in the vicinity of the electric motor 10 may be amplified and affect the steering person. For this reason, in the electric power steering apparatus 80, suppressing the sound generated in the vicinity of the electric motor 10 contributes to a more comfortable assist operation.

  As shown in FIGS. 2 and 3, the steering force assist mechanism 83 of the electric power steering device 80 is a mechanism that supports each part such as the ECU 90 and the electric motor 10, and includes a steering column 51, an upper mounting bracket 52, and a lower mounting. Bracket 54. The steering column 51 includes an input shaft 82a rotatably. The steering column 51 has a double-tube structure composed of an inner tube and an outer tube that secures a predetermined collapse stroke by absorbing impact energy at the time of collapse at a connecting portion with the speed reducer 92.

  The upper mounting bracket 52 is disposed on the outer pipe of the steering column 51 and the upper side in the vertical direction of the speed reduction device 92. The upper mounting bracket 52 is attached to the vehicle body and supports the outer tube of the steering column 51 and the reduction gear 92. The upper mounting bracket 52 includes a mounting plate portion that is attached to a vehicle body side member (not shown), a rectangular frame-shaped support portion that is formed integrally with the mounting plate portion, and a tilt mechanism that supports the outer tube of the steering column 51. And. The tilt mechanism is formed on the rectangular frame-shaped support portion.

  The mounting plate portion of the upper mounting bracket 52 includes a pair of left and right capsules attached to the vehicle body side member, and a sliding plate portion fixed to these capsules by resin injection. The mounting plate portion is subjected to an impact force that moves the steering column 51 forward of the vehicle body in the event of a collision, whereby the sliding plate portion slides forward of the vehicle body with respect to the capsule and the resin injection is sheared. It is comprised so that it may become a collapse start load.

  By rotating the tilt lever 53 of the tilt mechanism, the support state is released. By this operation, the tilt position of the steering column 51 can be adjusted up and down around the pivot axis of the lower mounting bracket 54.

  The lower mounting bracket 54 is disposed on the lower side in the vertical direction of the outer tube of the steering column 51 and the speed reduction device 92. The lower mounting bracket 54 is attached to the vehicle body and supports the outer tube of the steering column 51 and the speed reduction device 92. The lower mounting bracket 54 is formed by a mounting plate portion that is attached to a vehicle body side member (not shown) and a pair of support plate portions that extend in parallel with a predetermined distance on the lower surface of the mounting plate portion. . The lower mounting bracket 54 is pivotally connected to a portion formed on the lower end side of the speed reduction device housing 93 of the speed reduction device 92, that is, the front side of the vehicle body, via a pivot shaft.

  The electric motor 10 is provided on a side surface of the reduction gear 92 (a surface parallel to the rotation axis of the steering shaft 82 and parallel to the vertical direction), and is fixed to the reduction gear housing 93 of the reduction gear 92.

  As shown in FIGS. 2 and 3, the steering shaft 82 includes an input shaft 82a, an output shaft 82b, and a connecting shaft (torsion bar) 82c that connects the input shaft 82a and the output shaft 82b. The steering shaft 82 transmits the rotation input to the input shaft 82a to the output shaft 82b via the connecting shaft 82c.

(Decelerator)
As shown in FIGS. 3 and 4, the speed reducer 92 is a worm speed reducer, and includes a speed reducer housing 93, a worm 94, a ball bearing 95a, a ball bearing 95b, a worm wheel 96, and a holder 97. Prepare.

  The worm 94 is coupled to the input / output shaft 21 of the electric motor 10 by a spline or an elastic coupling. The worm 94 is held in the speed reducer housing 93 so as to be rotatable by a ball bearing 95 a and a ball bearing 95 b held by the holder 97. The worm wheel 96 is rotatably held by the speed reducer housing 93. The worm teeth 94 a formed on a part of the worm 94 mesh with the worm wheel teeth 96 a formed on the worm wheel 96.

  The reduction gear housing 93 is called a reduction gear box, and is made by die-casting, for example, any one of materials having high thermal conductivity such as aluminum, aluminum alloy, magnesium and magnesium alloy.

  The rotational force of the electric motor 10 is transmitted to the worm wheel 96 through the worm 94 to rotate the worm wheel 96. The reduction gear 92 increases the torque of the electric motor 10 by the worm 94 and the worm wheel 96. Then, the reduction gear 92 gives an auxiliary steering torque to the output shaft 82b of the steering column shown in FIG. In order to suppress the rattling noise of the worm 94, the reduction gear 92 uses the motor coupling portion side bearing described later as a fulcrum so that the worm 94 moves in one direction, that is, the worm displacement direction FW shown in FIG. 96. Due to the movement of the worm wheel 96, the same unidirectional (vertical) force is also applied to the joint between the worm and the motor side, for example, spline fitting or elastic coupling. For this reason, with the flange member described later as a fulcrum, the electric motor 10 generates a force interlocking with the movement in the worm displacement direction FW described above with respect to the rear side bearing in the electric motor 10.

  The torque sensor 91a shown in FIG. 1 detects the driver's steering force transmitted to the input shaft 82a via the steering wheel 81 as a steering torque. The vehicle speed sensor 91b detects the traveling speed (vehicle speed) of the vehicle on which the electric power steering device 80 is mounted. The ECU 90 is electrically connected to the electric motor 10, the torque sensor 91a, and the vehicle speed sensor 91b.

(Control unit: ECU)
The ECU 90 controls the operation of the electric motor 10. Moreover, ECU90 acquires a signal from each of the torque sensor 91a and the vehicle speed sensor 91b. That is, the ECU 90 acquires the steering torque T from the torque sensor 91a, and acquires the vehicle speed signal V of the vehicle from the vehicle speed sensor 91b. The ECU 90 is supplied with electric power from a power source (for example, a vehicle-mounted battery) 99 with the ignition switch 98 being on. The ECU 90 calculates an assist steering command value of the assist command based on the steering torque T and the vehicle speed signal V. Then, the ECU 90 adjusts the power value X supplied to the electric motor 10 based on the calculated auxiliary steering command value. The ECU 90 acquires information on the induced voltage or information on the rotation of a rotor such as a resolver described later as the operation information Y from the electric motor 10.

  The steering force of the driver (driver) input to the steering wheel 81 is transmitted to the speed reduction device 92 of the steering force assist mechanism 83 via the input shaft 82a. At this time, the ECU 90 acquires the steering torque T input to the input shaft 82a from the torque sensor 91a, and acquires the vehicle speed signal V from the vehicle speed sensor 91b. The ECU 90 controls the operation of the electric motor 10. The auxiliary steering torque created by the electric motor 10 is transmitted to the speed reducer 92.

  The steering torque (including auxiliary steering torque) output via the output shaft 82 b is transmitted to the lower shaft 85 via the universal joint 84 and further transmitted to the pinion shaft 87 via the universal joint 86. The steering force transmitted to the pinion shaft 87 is transmitted to the tie rod 89 via the steering gear 88 to steer the steered wheels. Next, the electric motor 10 will be described.

<Electric motor>
The electric motor 10 which concerns on Embodiment 1 shown in FIG. 4 has shown the typical cross section at the time of cutting with the virtual cross section containing a rotating shaft. As shown in FIG. 4, the electric motor 10 includes a motor case 11, a rear side bearing 13, a resolver 14, a motor rotor 20, and a stator 30 as an electric motor stator.

  The electric motor 10 according to the first embodiment includes a cylindrical housing 11 a and a flange member 12. The flange member 12 is formed in a substantially disc shape and is attached to face the case flange 11b at the end of the cylindrical housing 11a so as to close one open end of the cylindrical housing 11a. The motor case 11 that is the housing of the electric motor 10 according to the first embodiment has a bottom portion at the end opposite to the cylindrical housing 11a and the flange member 12 so as to close the end. The bottom is formed integrally with the cylindrical housing 11a, for example. As a magnetic material forming the cylindrical housing 11a, for example, a general steel material such as SPCC (Steel Plate Cold Commercial), electromagnetic soft iron, or the like can be applied. Further, the flange member 12 plays a role of attaching the electric motor 10 to a desired device (the reduction gear 92 in the first embodiment).

  The rear side bearing 13 is provided inside the cylindrical housing 11a and at a substantially central portion of the bottom. The rear side bearing 13 rotatably supports one end of an input / output shaft 21 which is a part of the motor rotor 20 disposed inside the cylindrical housing 11a. Thereby, the input / output shaft 21 rotates around the rotation axis Zr. A front-side bearing (not shown) may be provided on the inner side of the cylindrical housing 11 a and at a substantially central portion of the flange member 12. The front side bearing rotatably supports the input / output shaft 21.

  The stator 30 is provided in a cylindrical shape so as to surround the motor rotor 20 inside the cylindrical housing 11a. The stator 30 is attached, for example, by being fitted to the inner peripheral surface 11d of the cylindrical housing 11a. The central axis of the stator 30 coincides with the rotation axis Zr of the motor rotor 20. The stator 30 includes a cylindrical stator core 31 and an excitation coil 37. In the stator 30, an exciting coil 37 is wound around the stator core 31. The electric motor 10 and the ECU 90 are electrically connected via a bus bar made of a metal plate member having electrical conductivity. The bus bar supplies power according to the control signal from the ECU 90 via the terminal block 15 that supplies the excitation coil 37 with power.

  The stator core 31 is formed of a magnetic material such as an electromagnetic steel plate, and includes a plurality of divided cores in which a plurality of core pieces formed in substantially the same shape are stacked and bundled in the direction of the rotation axis Zr. The plurality of divided cores are arranged side by side at equal intervals in the circumferential direction around the rotation axis Zr. Hereinafter, the circumferential direction around the rotation axis Zr is simply referred to as the circumferential direction. The stator core 31 is press-fitted into the cylindrical housing 11a, so that the stator 30 is provided in the cylindrical housing 11a in an annular state. The cylindrical housing 11a is formed by press working (deep drawing), and even if the stator core 31 is press-fitted into the cylindrical housing 11a, the thickness of the cylindrical housing 11a is suppressed so that distortion generated in the stator core 31 is suppressed. Is less than or equal to the thickness of the back yoke of the stator core 31, for example, the plate thickness is preferably 1 mm or more and 5 mm or less. The case flange 11b is formed by pressing (deep drawing) together with the cylindrical housing 11a, and the plate thickness is limited to 5 mm or less. For this reason, since the plate | board thickness is restricted, the case flange 11b has an upper limit in rigidity. Further, even if the case flange 11b is cut to increase the accuracy of the end surface portion, the gap between the flange member 12 and the case flange 11b is caused by processing stress generated when the stator core 31 is press-fitted into the cylindrical housing 11a. It can happen. This gap is, for example, about several tens of μm. The stator core 31 and the cylindrical housing 11a may be fixed by adhesion, shrink fitting, welding or the like in addition to press-fitting.

  The exciting coil 37 is a linear electric wire. The exciting coil 37 is concentratedly wound around the outer periphery of the stator core 31 via an exciting coil insulator 37a. With this configuration, the number of magnetic poles can be reduced, and the coil amount can be reduced because the coil ends are shortened compared to distributed winding. As a result, the cost can be reduced and the electric motor 10 can be made compact. The exciting coil 37 may be distributedly wound around a plurality of outer circumferences of the teeth of the split core. With this configuration, the number of magnetic poles is increased and the distribution of magnetic flux is stabilized, so that torque ripple can be suppressed. The exciting coil 37 may be toroidally wound around the outer periphery of the back yoke of the split core.

  The exciting coil insulator 37a is a member for insulating the exciting coil 37 and the stator core 31, and is formed of a heat resistant member. Thus, the stator 30 has a shape that can surround the motor rotor 20. That is, the stator core 31 is annularly arranged at a predetermined interval outside the rotor yoke 22 described later.

  The motor rotor 20 is provided inside the cylindrical housing 11a so that the motor rotor 20 can rotate around the rotation axis Zr with respect to the cylindrical housing 11a. The motor rotor 20 includes an input / output shaft 21, a rotor yoke 22, and a magnet 23. The input / output shaft 21 is formed in a cylindrical shape. The rotor yoke 22 is formed in a cylindrical shape. The rotor yoke 22 has an arcuate outer periphery.

  The rotor yoke 22 is manufactured by laminating thin plates such as electromagnetic steel plates and cold-rolled steel plates by means of adhesion, boss, caulking or the like. The rotor yoke 22 is sequentially stacked in the mold and discharged from the mold. The rotor yoke 22 is fixed to the input / output shaft 21 by press-fitting the input / output shaft 21 into, for example, a hollow portion thereof. The input / output shaft 21 and the rotor yoke 22 may be integrally formed.

  A plurality of magnets 23 are embedded in the outer periphery of the rotor yoke 22 along the circumferential direction. The magnet 23 is a permanent magnet, and S poles and N poles are alternately arranged at equal intervals in the circumferential direction of the rotor yoke 22.

  The resolver 14 detects the rotational position of the motor rotor 20 (input / output shaft 21). The resolver 14 includes a resolver rotor 14a and a resolver stator 14b. The resolver rotor 14a is attached to the circumferential surface of the input / output shaft 21, for example, by press fitting. The resolver stator 14b is disposed to face the resolver rotor 14a with a predetermined gap. The resolver stator 14b is formed of a magnetic material such as an electromagnetic steel plate, and a plurality of resolver stator cores in which a plurality of core pieces formed in substantially the same shape are stacked and bundled in the rotation axis Zr direction, and the resolver stator core is wound. A resolver coil, and a resolver insulator that insulates the resolver stator core from the resolver coil.

  The resolver rotor 14a has an annular rotor core formed of a magnetic material such as an electromagnetic steel plate. In the resolver rotor 14a, the inner diameter center of the rotor iron core coincides with the rotation axis Zr. The resolver rotor 14a changes the outer diameter of the rotor core so that the outer diameter center of the rotor core is decentered by a certain amount of eccentricity from the inner diameter center of the rotor core. When the rotor core rotates, the distance between the inner diameter of the resolver stator core of the resolver stator 14b at the predetermined position and the outer diameter of the rotor core changes. Thereby, the distance of the air gap between the outer diameter of the rotor core and the resolver stator core changes. As a result, the rotation of the rotor core changes the reluctance between the rotor core and the stator core. A resolver device that detects the rotational position using the change in reluctance between the resolver rotor 14a and the resolver stator 14b is called a variable reluctance resolver, and outputs a resolver signal whose current value changes in accordance with the change in reluctance. Is done. This resolver signal becomes the rotation information of the motor rotor 20 and the operation information Y (see FIG. 1) described above. The ECU 90 can calculate the rotation angle or the number of rotations of the motor rotor 20 from the resolver signal.

  The flange member 12 is formed by die-casting, for example, any one of materials having high thermal conductivity such as aluminum, aluminum alloy, magnesium and magnesium alloy. The flange member 12 may be formed of resin. The flange member 12 includes an inlay 12a that can be inserted inside the cylindrical housing 11a, and a shape protruding from the motor side facing surface 12b is annular in the circumferential direction. The inlay 12a is a positioning portion that regulates the positions of the flange member 12 and the cylindrical housing 11a by being inserted inside the cylindrical housing 11a. The inlays 12a may not be annular protrusions in the circumferential direction. For example, a plurality of inlays 12a may be scattered in the circumferential direction. When the plurality of inlays 12a are scattered in the circumferential direction, the inlays 12a are preferably arranged at equal intervals. With this structure, the force for regulating the positions of the flange member 12 and the cylindrical housing 11a can be made uniform.

  As described above, the electric motor 10 according to the first embodiment is attached to face the flange member 12 and the case flange 11b. As shown in FIG. 7, the case flange 11b extends so that the outer shape is widened so that the cylindrical housing 11a is as parallel as possible to the motor-side facing surface 12b of the flange member 12 via the tapered portion 11c. ing.

  Between the flange member 12 and the case flange 11b, there is a claw portion 40 formed by deforming the case flange 11b. FIG. 5 is a plan view schematically showing the position of the claw portion when viewed from the bottom side of the motor case of the electric motor according to the first embodiment. 4 corresponds to the position of the claw portion 40 shown in FIG.

  As shown in FIG. 5, the flange member 12 is fixed by the motor case 11 and the case fixing mechanism H1. The case fixing mechanism H1 is a fastening structure including, for example, a female screw of the flange member 12 that passes through the mounting hole of the case flange 11b and a male screw that is screwed and coupled to the female screw. The case fixing mechanism H1 only needs to be able to fix the case flange 11b and the flange member 12, and may be, for example, coupling coupling. The flange member 12 includes a gear box fixing mechanism H3 at a position that does not overlap with the case fixing mechanism H1. The gear box fixing mechanism H3 also has a fastening structure including a female screw provided in the speed reducer housing 93 and a male screw that is screwed and coupled to the female screw through an attachment hole that penetrates the flange member 12. The gear box fixing mechanism H3 may be coupled by coupling as long as the reduction gear housing 93 and the flange member 12 can be fixed.

  As shown in FIG. 5, the case fixing rigidity line L1 connecting the two first fixing regions fixed by the case fixing mechanism H1 and the rotation axis Zr has a strong fixing force for fixing the case flange 11b and the flange member 12. It becomes the 1st virtual line which acts. In the case fixing rigidity line L2 that passes through the rotation axis Zr and is orthogonal to the fixing rigidity line L1, the fixing force of the case fixing mechanism H1 tends not to act. As described above, the gap between the flange member 12 and the case flange 11b moves in the worm displacement direction FW shown in FIG. 2 so that the case flange 11b and the flange member 12 repeat contact and non-contact. There is a possibility that a contact noise (abnormal noise) is generated.

  For example, the case fixing rigidity line L1 connecting the two fixing regions fixed by the case fixing mechanism H1 and the rotation shaft and the worm displacement direction FW of the movement of the worm 94 are substantially orthogonal depending on the motor mounting position on the column. There is a possibility that the force that shakes the motor case is more greatly applied at the position where the fixing force of the motor case is the smallest. Therefore, the electric motor 10 according to the first embodiment suppresses the possibility of generating contact noise (abnormal noise) by interposing the claw portion 40 between the flange member 12 and the case flange 11b.

  FIG. 6 is a side view schematically showing the structure of the claw portion shown in FIG. 4 when viewed from the outer peripheral side. FIG. 7 is a cross-sectional view schematically showing the claw portion according to Embodiment 1 cut in the circumferential direction. FIG. 8 is a cross-sectional view schematically showing a position other than the claw portion according to the first embodiment and cutting the facing surfaces of the case flange and the flange member in the circumferential direction. As shown in FIGS. 6 and 7, the flange member 12 according to the first embodiment includes an inclined portion 12 c that is an outer peripheral edge and has an inclination angle α with respect to the motor-side facing surface 12 b (facing surface 11 f). Have. The inclined portion 12c according to the first embodiment has an inclination angle α so as to form a groove with respect to the motor-side facing surface 12b. The inclined portion 12c according to the first embodiment may be configured such that the outer peripheral edge of the flange member 12 is chamfered on the entire circumference or part thereof and has an inclination angle α.

  The slit CL is a notch provided in the middle of the case flange 11b from the outer peripheral side of the case flange 11b toward the rotation axis. The claw portion 40 is a part of the case flange 11b between the adjacent slits CL, and is a cut and raised plate spring 11e that protrudes from the back surface 11r toward the flange member 12 with respect to the facing surface 11f. In the claw portion 40, a part of the case flange 11b has a bending angle β with respect to the facing surface 11f with the slit CL as a boundary.

  As shown in FIG. 6, the claw portion 40 has a leaf spring 11e in the form of a tongue. The leaf spring 11e is bent from the back surface 11r side facing the flange member 12 to the flange member 12 side by bending the base portion of the leaf spring 11e along the folding line PL, and as shown in FIGS. 6 and 7, toward the flange member 12 side. Protruding. The claw portion 40 is bent so that the bending angle β before coming into contact with the inclined portion 12c is larger than the inclination angle α. For this reason, if the inclined part 12c of the flange member 12 and the leaf | plate spring 11e of the nail | claw part 40 contact | abut, an elastic force will act between the inclined part 12c of the flange member 12, and the nail | claw part 40 (leaf spring 11e).

  FIG. 8 is a cross-sectional view schematically showing a position other than the claw portion according to the first embodiment and cutting the facing surfaces of the case flange and the flange member in the circumferential direction. The claw portion 40 is only part of the entire circumference in the circumferential direction. For this reason, as shown in FIG. 8, at positions other than the claw portion 40 and the fixing region fixed by the two case fixing mechanisms H <b> 1 in the range where the case flange 11 b and the flange member 12 overlap in the direction parallel to the rotation axis Zr, The fixing force at which the case flange 11b and the flange member 12 are fixed is reduced as compared with the fixing region in which the case flange 11b and the flange member 12 are fixed by the two case fixing mechanisms H1.

  As shown in FIG. 5, when the claw portion 40 includes a case fixing rigidity line L2 and is cut along a virtual cross section including the rotation axis, the leaf spring 11e protrudes toward the flange member 12 with respect to the case flange 11b. The inclined portion 12c of the flange member 12 is pressed by an elastic force. Therefore, in the electric motor 10 according to the first embodiment, the claw portion 40 is interposed between the flange member 12 and the case flange 11b, and the inclined portion 12c of the flange member 12 and the claw portion 40 (plate spring 11e of the case flange 11b). ), And the possibility of generating contact noise (abnormal noise) even when the worm moves in the worm displacement direction FW shown in FIG. 2 is suppressed.

  Since the leaf spring 11e presses the flange member 12 with elastic force, it is desirable to chamfer the tip on the facing surface 11f side with the slit CL shown in FIG. Thereby, it can suppress that the leaf | plate spring 11e bites into the flange member 12. FIG. Alternatively, when the slit CL is formed by pressing the case flange 11b of the motor case 11, by pressing the press mold of the case flange 11b from the opposing surface 11f toward the back surface 11r, the end surface of the slit CL Burrs are more likely to occur on the back surface 11r side than the facing surface 11f. Thereby, the burr | flash of the leaf | plate spring 11e can suppress biting into the flange member 12. FIG.

  As shown in FIG. 8, the claw portion 40 is disposed in the gap between the flange member 12 and the case flange 11b, and the claw portion 40 is formed by a plate spring 11e having elasticity. When compressed by the motor-side facing surface 12b of the member 12 and the case flange 11b, the flange member 12 and the case flange 11b act in directions away from each other, and the flange member 12 and the case flange 11b maintain a certain distance. Can do. For this reason, even if the case fixing mechanism H2 shown in FIG. 7 is not added, the electric motor 10 according to the first embodiment continues to contact the flange member 12 and the leaf spring 11e of the case flange 11b. The possibility of generating abnormal noise) can be suppressed. As a result, the number of parts is suppressed, the occupation ratio of the space around the electric motor 10 is reduced, and the mountability of the electric power steering device 80 on the vehicle is improved. The electric power steering device 80 is reduced in assembly man-hours and is low in cost.

  As described above, the electric power steering device 80 according to the first embodiment includes the steering column 51 including the steering shaft 82 to which the steering torque is transmitted, and the speed reducing device 92 including the worm that transmits the steering assist force to the steering shaft 82. And an electric motor 10 that rotates the worm 94. The electric motor 10 according to the first embodiment has a cylindrical shape with one end opened, and includes a case flange 11b that is an end surface with an end on the opening side extended to the outside of the outer periphery, and includes a motor rotor 20. 11, an input / output shaft 21 that rotates in conjunction with the motor rotor 20 and is connected to the worm 94, and a flange member 12 that is fixed to the case flange 11 b and that the input / output shaft 21 passes through and is exposed from the motor case 11. It is equipped with. The case flange 11b and the flange member 12 are fixed by the case fixing mechanism H1 at the positions of at least two fixing regions, and the case flange 11b and the flange member 12 are at positions different from the fixing region where the case fixing mechanism H1 is located. The nail | claw part 40 is interposing in a part of opposing surface.

  At a position where the claw portion 40 is present, the distribution of the motor fixing force in the circumferential direction (radial direction) changes. As a result, the electric motor 10 as a whole is tilted with the fixing points of the two fixing regions as fulcrums, and when the force that shakes the motor case 11 is applied to the position where the fixing force of the motor case 11 is the smallest, the flange member 12 Even when the gap between the case flange 11b and the case flange 11b is changed, the case flange 11b and the flange member 12 are kept in contact with each other at a position where the claw portion 40 is located. It is possible to suppress the generation of contact noise (abnormal noise) repeatedly. For this reason, the electric power steering device 80 can suppress the possibility of generating contact noise (abnormal noise) without adding the case fixing mechanism H2.

  Moreover, since the electric motor 10 can reduce the location which expands the area of a case flange as a fixed area | region, it can suppress the interference of the members around the electric motor 10. For this reason, the electric power steering apparatus 80 can improve the mounting property to a vehicle.

  The claw portion 40 described above is a leaf spring that is cut and raised by the slit CL adjacent to the leaf spring 11e. As a result, when the leaf spring 11e is compressed by the motor-side facing surface 12b of the flange member 12 and the case flange 11b, the flange member 12 and the case flange 11b repel each other. As a result, even if the gap between the flange member 12 and the case flange 11b changes, the case flange 11b and the flange member 12 can continue to contact each other at a position where the claw portion 40 is present.

  As described above, the claw portion 40 is on the same plane as the case flange 11b, the fixed rigidity line L1, which is the first imaginary line connecting the fixed regions, passes through the rotation axis Zr, and the plurality of leaf springs 11e. Of these, it is preferable that the case fixed rigidity line L2, which is a second imaginary line connecting at least one pair of leaf springs 11e, passes through the rotation axis Zr, and the fixed rigidity line L1 and the case fixed rigidity line L2 are orthogonal to each other. Thereby, the effect which suppresses the behavior which the electric motor 10 whole falls down by using the fixed point of two fixed area | regions as a fulcrum can be heightened.

  The electric power steering device 80 obtains auxiliary steering torque by the electric motor 10 described above. The electric power steering device 80 can reduce abnormal noise around the electric motor 10. For this reason, the electric power steering device 80 can operate the vehicle in a state where the steering person suppresses the uncomfortable feeling. As a result, the electric power steering apparatus 80 can reduce operating noise and give a comfortable steering feeling to the operator.

(Embodiment 2)
FIG. 9 is a plan view schematically showing the position of the claw portion as viewed from the bottom side of the motor case of the electric motor according to the second embodiment. Note that the same components as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 9, a plurality of claw portions are in a range where the case flange 11b and the flange member 12 overlap in a direction parallel to the rotation axis Zr and between the fixing regions fixed by the two case fixing mechanisms H1. 40a, 40b and 40c are arranged. The claw portions 40a, 40b, and 40c have the same structure as the claw portion 40 described above. At the positions of the plurality of claw portions 40a, 40b, and 40c shown in FIG. 9, there is the inclined portion 12c of the flange member 12 described above.

  As shown in FIG. 9, a case fixed rigidity line L2 orthogonal to the fixed rigidity line L1 passes through the claw portion 40a and the rotation axis Zr.

  In the electric motor 10 according to the second embodiment, since the flange member 12 and the leaf spring 11e of the case flange 11b are kept in contact with each other, the possibility of generating contact noise (abnormal noise) can be suppressed. Regarding the distribution of the force with which the flange member 12 and the leaf spring 11e of the case flange 11b abut, the claw portions 40a, 40b and 40c according to the second embodiment have more leaf springs 11e than the claw portion 40 according to the first embodiment. For this reason, the claw portion 40 according to the second embodiment is more prone to the flange member when the leaf spring 11e is compressed by the motor side facing surface 12b of the flange member 12 and the case flange 11b than the claw portion 40 according to the first embodiment. The repulsive behavior can be adjusted such that the case 12 and the case flange 11b are separated from each other. As a result, the number of parts is suppressed, the occupation ratio of the space around the electric motor 10 is reduced, and the mountability of the electric power steering device 80 on the vehicle is improved. The electric power steering device 80 is reduced in assembly man-hours and is low in cost.

  It is preferable that the nail | claw part 40a which concerns on Embodiment 2 has a larger elastic force than the nail | claw parts 40b and 40c. Thereby, even if the behavior that the whole electric motor falls with the case fixing rigidity line L1 as a fulcrum occurs, the elastic force of the case fixing rigidity line L2 to which the fixing force of the case fixing mechanism H1 hardly acts can be increased.

  Comparing the claw portions 40a, 40b and 40c, the claw portions 40b and 40c have a small distance to the fixing region to which the case fixing mechanism H1 is fixed (near), and the claw portion 40a has a fixing region to which the case fixing mechanism H1 is fixed. The distance to is large (far). Therefore, the claw portions 40a and claw portions 40b and 40c are inclined portions where the claw portions 40b and 40c are in contact with the inclined portions 12a when the bending angle β before contact with the inclined portions 12c is constant. The inclination angle α is made larger than 12c. As a result, the claw portion 40a according to the second embodiment has a greater elastic force than the claw portions 40b and 40c. In the fixed rigidity line L2, the distance between the flange member 12 and the case flange 11b can be easily kept constant, and the electric motor 10 according to the second embodiment has a contact sound ( Noise) can be suppressed.

  Alternatively, when the inclination angle of the inclined portion 12c is constant, the claw portion 40a has a bending angle β before contacting the inclined portion 12c larger than the bending angle β before the claw portions 40b and 40c contact the inclined portion 12c. To do. As a result, the claw portion 40a according to the second embodiment has a greater elastic force than the claw portions 40b and 40c. In the fixed rigidity line L2, the distance between the flange member 12 and the case flange 11b can be easily kept constant, and the electric motor 10 according to the second embodiment has a contact sound ( Noise) can be suppressed.

(Embodiment 3)
FIG. 10 is a plan view schematically showing a claw portion before bending as seen from the bottom side of the motor case of the electric motor according to the third embodiment. FIG. 11 is a cross-sectional view schematically showing a claw portion according to Embodiment 3 cut in the circumferential direction. Note that the same components as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 10, a plurality of claws are in a range where the case flange 11b and the flange member 12 overlap in a direction parallel to the rotation axis Zr and between the fixing regions fixed by the two case fixing mechanisms H1. Forty plate springs 11eL are arranged.

  The leaf spring 11eL has the same structure as the leaf spring 11e described above. The claw portion 40 bends a part of the case flange 11b with respect to the above-described facing surface 11f with the slit CL as a boundary. The leaf spring 11eL of the claw portion 40 has an outer peripheral end 11ep protruding beyond the outer periphery 11s of the case flange 11b in a state before bending.

  The leaf spring 11eL bends the base of the leaf spring 11eL from the back surface 11r side of the surface facing the flange member 12 to the flange member 12 side, and protrudes toward the flange member 12 as shown in FIG. When the inclined portion 12c of the flange member 12 and the leaf spring 11eL of the claw portion 40 contact each other, an elastic force acts between the inclined portion 12c of the flange member 12 and the claw portion 40 (leaf spring 11eL). The leaf spring 11eL has a larger area in contact with the inclined portion 12c because the outer peripheral end 11ep protrudes from the outer periphery 11s of the case flange 11b in a state before bending. As a result, the claw portion 40 according to the third embodiment has a greater elastic force than the claw portion according to the first embodiment. And it becomes easy to keep the distance of the flange member 12 and the case flange 11b constant, and the electric motor 10 which concerns on Embodiment 3 suppresses contact noise (abnormal noise) rather than the electric motor 10 which concerns on Embodiment 1. FIG. be able to.

  As described above, the electric power steering device 80 of the present embodiment has been described by taking the column assist method as an example, but the electric motor 10 and the speed reducer 92 described above are also applied to the pinion assist method and the rack assist method. be able to. The electric motor 10 has been described as an example of the electric motor according to the present embodiment, and the case where the electric motor 10 is applied to a right-hand drive vehicle has been described. However, the present invention is not limited to this. 10 and the speed reducer 92 may be arranged on the right side of the plane symmetric with respect to the vertical plane passing through the central axis of the steering column.

DESCRIPTION OF SYMBOLS 10 Electric motor 11 Motor case 11a Tubular housing 11b Case flange 11c Tapered part 11d Inner peripheral surface 11e, 11eL Leaf spring 12 Flange member 12a Inner 12b Motor side opposing surface 12c Inclined part 13 Rear side bearing 14 Resolver 15 Terminal block 20 Motor rotor 21 I / O shaft 22 Rotor yoke 23 Magnet 30 Stator 31 Stator core 37 Excitation coil 37a Excitation coil insulator 40, 40a, 40b, 40c Claw portion 42 Rib 51 Steering column 52 Upper mounting bracket 54 Lower mounting bracket 80 Electric power steering device 81 Steering wheel 82 Steering Shaft 82a Input shaft 82b Output shaft 82c Connecting shaft 83 Steering force assist mechanism 84 Universal joint 85 Lower shaft DOO 86 universal joint 87 the pinion shaft 88 steering gear 88a pinion 88b rack 89 tie rod 90 ECU
91a Torque sensor 91b Vehicle speed sensor 92 Decelerator 93 Decelerator housing 94 Worm 94a Worm tooth 96 Worm wheel 97 Holder 98 Ignition switch FW Worm displacement direction H1 Case fixing mechanism H2 Case fixing mechanism H3 Gear box fixing mechanism L1 Case fixing rigidity line L2 Case Fixed rigidity line Zr Rotating shaft

Claims (16)

A steering column including a steering shaft to which steering torque is transmitted, a reduction gear including a worm that transmits a steering assist force to the steering shaft, and an electric motor that rotates the worm,
The electric motor is
A motor case having a cylindrical shape with one end open, a case flange that is an end face with the end on the opening side expanded to the outside of the outer periphery, and a motor rotor built-in;
An input / output shaft that rotates in conjunction with the motor rotor and is connected to the worm coaxially with a rotating shaft;
A flange member that is fixed to the case flange and that the input / output shaft passes through and is exposed from the motor case; and
The case flange and the flange member are fixed by a case fixing mechanism in at least two fixing regions,
At a position different from the fixed region, a part of the facing surface of the case flange and the flange member is provided with a claw portion in which a part of the case flange projects to the flange member side,
The electric power steering apparatus according to claim 1, wherein the claw portion is in contact with an inclined portion that is an outer peripheral edge of the flange member and has an inclination angle with respect to the facing surface.   2. The electric power steering apparatus according to claim 1, wherein a part of the case flange has a bending angle with respect to the facing surface with a slit as a boundary.   The electric power steering apparatus according to claim 2, wherein the claw portion is bent so that the bending angle is larger than the inclination angle. A plurality of the claw portions;
In the same plane as the facing surface, a first imaginary line that connects the fixed regions passes through the rotation axis, and a second imaginary line that connects at least a pair of claw parts among the plurality of claw parts is the rotation axis. 4. The electric power steering apparatus according to claim 1, wherein the first imaginary line and the second imaginary line are orthogonal to each other. A plurality of the claw portions;
5. The method according to claim 2, wherein the case flange and the flange member overlap each other in a direction parallel to the rotation axis, and a plurality of the claw portions are disposed between the fixed regions. The electric power steering device according to the item.   The inclined portion with which the claw portion with a small distance to the fixed region abuts among the plurality of claw portions has a larger inclination angle than the inclined portion with which the claw portion with a large distance to the fixed region abuts. The electric power steering device described in 1.   The claw portion having a large distance to the fixed region among the plurality of claw portions has a larger bending angle than the claw portion having a small distance to the fixed region, when the inclination angle is constant. The electric power steering apparatus as described.   The electric power steering device according to any one of claims 1 to 7, wherein an outer peripheral side end of the claw portion protrudes from an outer periphery of the case flange in a state before bending. An electric motor having an input / output shaft that rotates in conjunction with a motor rotor and is coaxially connected to a rotating shaft to a worm meshed with a worm wheel,
A motor case having a cylindrical shape with one end opened, a case flange that is an end surface with the end on the opening side extended to the outside of the outer periphery, and the motor rotor built therein;
A flange member that is fixed to the case flange and that the input / output shaft passes through and is exposed from the motor case; and
The case flange and the flange member are fixed by a case fixing mechanism in at least two fixing regions,
At a position different from the fixed region, a part of the facing surface of the case flange and the flange member is provided with a claw portion in which a part of the case flange projects to the flange member side,
The electric motor according to claim 1, wherein the claw portion is an edge of the outer periphery of the flange member and is in contact with an inclined portion having an inclination angle with respect to the facing surface.   10. The electric motor according to claim 9, wherein the claw portion has a bending angle with respect to the facing surface, with a part of the case flange having a slit as a boundary.   The electric motor according to claim 10, wherein the claw portion is bent so that the bending angle is larger than the inclination angle. A plurality of the claw portions;
In the same plane as the facing surface, a first imaginary line that connects the fixed regions passes through the rotation axis, and a second imaginary line that connects at least a pair of claw parts among the plurality of claw parts is the rotation axis. The electric motor according to claim 9, wherein the first imaginary line and the second imaginary line are orthogonal to each other. A plurality of the claw portions;
The range of the said case flange and the said flange member overlaps in the direction parallel to the said rotating shaft, The said some nail | claw part is arrange | positioned between the said fixed area | regions. The electric motor described in 1.   The electric motor according to claim 13, wherein a claw portion having a short distance to the fixed region among the plurality of claw portions has a larger inclination angle than a claw portion having a far distance to the fixed region.   The claw part with a large distance to the fixed area among the plurality of claw parts has a larger bending angle than a claw part with a small distance to the fixed area when the inclination angle is constant. Electric motor.   The electric motor according to any one of claims 9 to 15, wherein an outer peripheral side end of the claw portion protrudes from an outer periphery of the case flange in a state before bending.

Images