JP5099485B2 - Motor and electric power steering apparatus using the same - Google Patents

Description

  The present invention relates to a motor capable of suppressing generation of operating noise and an electric power steering apparatus using the motor.

  In addition to output performance, the motor is required to be particularly quiet depending on the application. For example, since a motor for an electric power steering device for a vehicle is disposed in the vehicle interior or in the vicinity of the vehicle interior, it is one of the problems to reduce the operation noise generated when assisting the steering force. Yes.

Specifically, for example, in consideration of assembly, a structure is adopted in which the output shaft of the rotor is press-fitted into the inner ring of the bearing and a gap for insertion is provided between the outer ring of the bearing and the bearing housing of the motor case. There is something. However, due to the movement of the worm in the radial direction in the speed reduction mechanism connected to the output end of the motor, a force that swings around the motor output shaft is generated, and the bearings arranged at both ends of the output shaft are uneven in the radial direction. Force may act. In such a case, particularly, the outer ring of the bearing on the side opposite to the output end of the motor may come into contact with the bearing housing to generate a hitting sound. As a countermeasure against this hitting sound, a groove is formed on the outer peripheral portion of the bearing over the entire circumference, and an O-ring is inserted into the groove, thereby holding the outer ring of the bearing in the bearing housing via the O-ring (for example, , Patent Documents 1 and 2), a cylindrical elastic body and an anti-vibration material disposed between a bearing housing and a bearing outer ring (for example, refer to Patent Document 3), and a bearing housing and a bearing outer ring. There is a method of applying grease in between.
JP 2000-166169 A JP 2005-188527 A Japanese Patent Laid-Open No. 11-252851

  However, if a groove is formed in the outer ring of the bearing as described above and an O-ring is inserted into this groove, it takes time and effort to form the outer ring groove of the bearing, which may increase the cost. . Also, in the case where a cylindrical elastic body or the like is disposed between the bearing housing and the outer ring of the bearing, the accuracy of the inner diameter dimension of the bearing housing must be increased if the eccentricity of the output shaft is to be suppressed. Cost may increase. Furthermore, in the method of applying grease between the bearing housing and the bearing outer ring, it is difficult to apply a certain amount of grease, which is troublesome and may increase the assembly cost.

  An object of this invention is to provide the motor which can suppress an operation sound, suppressing an increase in cost, and an electric power steering apparatus using the same.

  In order to achieve the above object, a motor of the present invention is a motor that supports an output shaft of a rotor by a bearing provided in a bearing housing of a motor case, and is spaced circumferentially at least at an inner peripheral portion of the bearing housing. A plurality of grooves are provided, and an outer ring of the bearing is brought into contact with an inner side of an elastic support portion fitted in each of the grooves to support the bearing.

  With such a configuration, it is possible to support the bearing by fitting an elastic support portion to each of the plurality of grooves on the inner peripheral portion of the bearing housing and bringing the outer ring of the bearing into contact with the inside of the elastic support portion. In such a case, it is possible to suppress the eccentricity of the shaft by a plurality of elastic support portions and suppress the operation noise. Further, for example, the shape and material of the elastic support portion can be arbitrarily selected for each motor as compared with the method of providing an O-ring on the bearing, which is advantageous in that the delivery time can be shortened and the cost can be reduced. . In addition, in the case of a structure having a plurality of elastic support portions as described above, it becomes easy to assemble the outer ring of the bearing to the bearing housing of the motor case, so that the operation noise is suppressed while suppressing an increase in cost by improving workability. Can do. In addition, since the eccentricity of the output shaft can be absorbed by a plurality of elastic support portions that support the bearing, it is not necessary to increase the precision of the inner diameter processing of the bearing housing, and the cost can also be reduced in this respect.

  In addition, an elastic member formed by projecting a plurality of elastic support portions at intervals in the circumferential direction on the inner peripheral portion of the annular ring-shaped portion is provided, and the bearing housing includes a ring arrangement in which the ring-shaped portion is disposed. The provided portion may be provided on the outer peripheral outer side or in the radial thickness, and a groove may be provided penetrating from the ring disposing portion to the inner peripheral inner side. In this case, the elastic member has a structure in which a plurality of elastic support portions are held in the ring-shaped portion, and the work of assembling the elastic member while aligning the positions of the elastic support portions in the grooves of the bearing housing is facilitated. According to this, the assembly workability can be further improved, and the assembly cost can be further reduced.

  Further, the bearing housing has an outer surface opening that opens at the outer surface position of the motor case on one side in the axial direction, and the elastic member is formed with a lid portion that closes one side in the axial direction of the ring-shaped portion, The lid may close the outer surface opening. With this configuration, the bottom of the housing also serves as the opening and the lid of the motor housing, and it is not necessary to close the outer surface opening of the bearing housing with a separate lid member. Can be reduced.

  Moreover, the some elastic support part may be provided separately. By adopting such a configuration, it becomes possible to select the shape and material of the elastic support portion for each groove according to the direction in which the force is applied, and a higher operating noise suppression effect can be obtained.

  Moreover, the inscribed circle diameter in the arrangement | positioning state to the groove | channel of a some elastic support part may be set smaller than the internal diameter of a bearing housing. By adopting such a configuration, the outer ring of the bearing can be reliably supported by the plurality of elastic support portions, and the operation noise suppression effect can be obtained with certainty.

  Since the electric power steering apparatus of the present invention includes the above-described motor, the electric power steering apparatus itself is an apparatus that is excellent in quietness and low in cost.

  ADVANTAGE OF THE INVENTION According to this invention, the motor which can suppress an operation noise, suppressing an increase in cost, and an electric power steering apparatus using the same can be provided.

  Embodiments of a motor and an electric power steering apparatus using the motor according to the present invention will be described below with reference to the drawings.

(First embodiment)
First, a first embodiment of a motor and an electric power steering apparatus using the motor according to the present invention will be described with reference to FIGS. 1 to 3 and FIG. 10.

  FIG. 10 shows a column-type electric power steering apparatus 10, where 11 is a steering shaft, 12 is a housing of the steering shaft 11, 20 is a rack and pinion type motion conversion mechanism, and 30 is a worm reduction mechanism. These constitute a vehicle steering system. Reference numeral 13 denotes a power assist electric motor that applies steering assist torque to the steering system, and reference numeral 40 denotes a torque sensor.

  The steering shaft 11 includes a steering input shaft (input shaft) 11a and a steering output shaft (output shaft) 11b, and is supported inside the housing 12 so as to be rotatable around an axis. The housing 12 is fixed to a predetermined position in the vehicle interior in a state where the lower portion is inclined forward. A steering wheel (not shown) is fixed to the upper end of the steering input shaft 11a, and rotates in synchronization with the steering wheel.

  Further, the steering input shaft 11a and the steering output shaft 11b are connected via a torsion bar of the torque sensor 40, and the steering torque transmitted from the steering wheel to the steering output shaft 11b via the steering input shaft 11a is torque sensor 40. The output of the motor 13 is controlled based on the detected steering torque.

  The rack-and-pinion type motion conversion mechanism 20 is disposed substantially horizontally in the engine room at the front of the vehicle with the longitudinal direction being, for example, the left-right direction of the vehicle, and a rack shaft 21 that is movable in the axial direction, Are provided with a pinion shaft 22 having a tooth portion that is supported obliquely with respect to the tooth portion of the rack shaft 21, and a cylindrical case 23 that supports the rack shaft 21 and the pinion shaft 22. A front wheel is attached to a knuckle (not shown) provided on both ends of the rack shaft 21 of the rack and pinion type motion conversion mechanism 20.

  The pinion shaft 22 and the lower end of the steering output shaft 11 b are connected by two universal joints 15 and 16 and a connecting member 17. A worm reduction mechanism 30 is disposed at an intermediate position in the axial direction of the steering output shaft 11b, and the steering assist torque is applied from the motor 13 to the steering output shaft 11b, which is a vehicle steering system, via the worm reduction mechanism 30. Power to give is given. Although not shown, the worm speed reduction mechanism 30 includes a worm wheel that rotates integrally with the steering output unit 11b, and a worm that meshes with the worm wheel in a direction orthogonal to the worm wheel. Are connected coaxially and integrally rotatable.

  Next, the motor 13 will be described. As shown in FIG. 2, the motor 13 includes a case body 50 made of a substantially bottomed cylindrical casting and a substantially annular flange 51 attached to the opening side of the case body 50. Is configured.

  The case main body 50 has a cylindrical body portion 53 along the motor axial direction, and a bottom portion 54 that closes one side of the body portion 53 in the motor axial direction.

  At the center of the bottom 54 of the case body 50, a bearing housing 58 is formed on the opening side so as to protrude into a bottomed cylinder. A bearing 59 on the rear side is provided inside the bearing housing 58.

  A stator core 61 is fixed to the inner peripheral surface of the body 53 of the case body 50, and a coil 63 is wound around the stator core 61 via an insulator 62. A terminal block 65 for connecting a power harness 64 for power feeding to the flange 51 side of the stator core 61 is fixed to the inner peripheral surface of the body portion 53 of the case body 50.

  The flange 51 is fitted to the opening side of the motor case 50, and a bearing holding recess 66 is formed at the center position opposite to the motor case 50 so as to be recessed toward the motor case 50. A bearing 67 on the front side is held in the bearing holding recess 66, and the output shaft 71 of the rotor 70 can be rotated by the bearing 67 and the bearing 59 provided in the bearing housing 58 of the motor case 52 described above. Supported by

  The rotor 70 includes an output shaft 71, a rotor core 72 that fixes the output shaft 71 at the center position, and a magnet 73 that is fixed to the outer peripheral surface of the rotor core 72. The rotor 70 has an output shaft 71 protruding outward from the flange 51, and a connecting member 74 for connecting the worm of the worm speed reduction mechanism 30 shown in FIG. ing.

  A resolver rotor 75 is fixed to the output shaft 71 of the rotor 70 at a position inside the flange 51. And the resolver stator 76 is being fixed to the terminal block 65 mentioned above in the state facing this resolver rotor 75. FIG. The resolver stator 76 detects the rotational position of the rotor 70 by detecting the rotational position of the resolver rotor 75.

  As shown in FIG. 3, the bearing housing 58 has a cylindrical wall portion 78 along the motor axial direction and a bottom portion 79 that closes the opposite side of the wall portion 78 from the rotor 70. A plurality of grooves 80 are formed in the inner peripheral portion of the portion 78 at predetermined equal intervals in the circumferential direction. Each of these grooves 80 is formed along the axial direction of the bearing housing 58 and with a constant width in the circumferential direction so as to pass from the position on the bottom 79 side to the opening side. It penetrates.

  An elastic member 83 is attached to the bearing housing 58. The elastic member 83 has a plurality of elastic support portions 82 projecting from the inner peripheral portion of the annular ring-shaped portion 81 at predetermined intervals in the circumferential direction. . The elastic member 83 is integrally formed from an elastic material such as synthetic rubber, and each of the plurality of elastic support portions 82 protrudes radially inward from the ring-shaped portion 81 and extends along the axial direction of the ring-shaped portion 81. The ring-shaped portion 81 has a constant width in the circumferential direction. In this elastic member 83, the ring-shaped portion 81 is fitted to the outer peripheral surface of the cylindrical wall portion 78, and at this time, the plurality of grooves 80 penetrating from the outer peripheral surface to the inner peripheral inner side are elastically supported one-on-one. The portion 82 is fitted to the bearing housing 58. The outer periphery of the wall portion 78 is a ring disposing portion 84 in which a ring-shaped portion 81 is disposed, and a plurality of grooves 80 penetrate from the ring disposing portion 84 to the inner periphery of the wall portion 78. ing.

  As described above, in the elastic member 83 attached to the bearing housing 58, all the elastic support portions 82 protrude inward from the inner peripheral surface of the wall portion 78. In other words, the inscribed circle diameter in a state where the plurality of elastic support portions 82 are disposed in the groove 80 is set smaller than the inner diameter of the bearing housing 58. Here, the inscribed circle diameter is set smaller than the outer diameter of the bearing 59.

  The bearing 59 includes an inner ring 85 arranged in an annular shape on the radially inner side, an outer ring 86 arranged in an annular shape on the radially outer side, an outer ring raceway surface of the outer ring 86, and an inner ring raceway surface of the inner ring 85. And a plurality of spherical rolling elements 87 disposed between the two. Here, in consideration of assembly, the output shaft 71 of the rotor 70 is press-fitted into the inner ring 85 of the bearing 59, and a gap for insertion is provided between the outer ring 86 of the bearing 59 and the bearing housing 58 of the motor case 52. Is formed.

  Then, the bearing 59 in which the output shaft 71 is press-fitted is inserted inside the bearing housing 58. At this time, a plurality of elastic support portions of the elastic member 83 attached to the bearing housing 58 are inserted into the bearing 59. 82 is fitted inside. As a result, the outer ring 86 is brought into contact with the inside of the plurality of elastic support portions 82 to support the bearing 59. The plurality of elastic support portions 82 are pushed outward in the radial direction by the outer ring 86 due to the difference in diameter. However, the ring-shaped portion 81 is fitted into the bearing housing 58 to be elastic. The size, material, and the like of each part of the elastic member 83 are set so that the movement of the support part 82 in the radial direction is restricted and the diameter difference is absorbed by elastic deformation of the elastic support part 82.

  According to the motor 13 described above, the elastic support portion 82 is fitted into each of the plurality of grooves 80 on the inner peripheral portion of the bearing housing 58, and the outer ring 86 of the bearing 59 is brought into contact with the inside of the elastic support portion 82. Since the bearing 59 is supported, the operation noise of the motor 13 can be suppressed. That is, as described above, when the structure in which the output shaft 71 is press-fitted into the inner ring 85 and a gap for insertion is provided between the outer ring 86 and the bearing housing 58 is adopted, the worm speed reduction mechanism 30 connected to the output shaft 71 As a result, a non-uniform force is generated in the radial direction on the output shaft 71, and the outer ring 86 of the bearing 59 and the bearing housing 58 may come into contact with each other to generate a hitting sound. The operating noise that is included can be reduced by the elastic support portion 82.

  Further, in order to support the bearing 59 by fitting the elastic support portion 82 to each of the plurality of grooves 80 on the inner peripheral portion of the bearing housing 58 and bringing the outer ring 86 of the bearing 59 into contact with the inside of the elastic support portion 82, Since the shape of the elastic support portion 82 can be held by the groove 80, the bearing 59 can be accurately inserted easily. Therefore, an increase in cost can be suppressed by improving workability.

Further, the shape, material, and the like of the elastic member 83 including the elastic support portion 82 can be selected for each motor 13, and a higher operating noise suppression effect can be obtained.
In addition, since the eccentricity of the bearing housing 58 can be absorbed by supporting the bearing 59 with the plurality of elastic support portions 82, it is not necessary to increase the precision of the inner diameter processing of the bearing housing 58, and this can also reduce the cost. .

  In addition, since the elastic member 83 is configured to hold the plurality of elastic support portions 82 on the ring-shaped portion 81, the elastic member 83 is fitted to each groove 80 of the bearing housing 58 while adjusting the phase of the elastic support portion 82. If it does, the elastic support part 82 can be fitted to each groove | channel 80 at once. Therefore, the assembling workability is improved and the assembling cost can be further reduced.

  In addition, since the inscribed circle diameter in the state in which the plurality of elastic support portions 82 are disposed in the grooves 80 is set smaller than the inner diameter of the bearing housing 58, the outer ring 86 of the bearing 59 is connected to the plurality of elastic support portions 82. Therefore, it is possible to reliably support the operation sound, and it is possible to reliably obtain an operation noise suppressing effect.

  Therefore, the electric power steering apparatus 10 including the motor 13 described above is also an apparatus that is excellent in quietness and low in cost.

(Second Embodiment)
A second embodiment of a motor and an electric power steering apparatus using the motor according to the present invention will be described below mainly with reference to FIG. 4 with a focus on differences from the first embodiment. In the second embodiment, the support structure of the bearing 59 provided on the output shaft 71 of the motor 13 is different.

  In the second embodiment, a groove 80A is formed in the wall portion 78, which is substantially the same as the groove 80 of the first embodiment, but is different in that a notch portion 88A extending on both sides in the circumferential direction is formed at the radially inner end portion. Has been.

  Further, in the second embodiment, the elastic support portion 82A is substantially the same as the elastic support portion 82 of the first embodiment, and is different in that a protrusion 89A protruding on both sides in the circumferential direction is provided at the radially inner end portion. Is formed on the elastic member 83. When the elastic member 83 is attached to the bearing housing 58, the elastic support portion 82A is fitted into the groove 80A while the projection 89A is locked to the notch 88A. In this manner, the outer ring 86 of the bearing 59 is brought into contact with the inner side of the plurality of elastic support portions 82A that are fitted in the plurality of grooves 80A of the bearing housing 58 and project inwardly, and the bearing 59 is moved by the elastic member 83. To support.

  According to the second embodiment, the inner end portion of the elastic support portion 82A into the groove 80A can be fitted into the groove 80A by engaging the elastic support portion 82A with the groove 80A while locking the protrusion portion 89A with the notch portion 88A. Can be surely regulated.

(Third embodiment)
A third embodiment of the motor and the electric power steering apparatus using the motor according to the present invention will be described below mainly with reference to FIG. 5 focusing on the differences from the second embodiment. In the third embodiment, the support structure of the bearing 59 provided on the output shaft 71 of the motor 13 is different.

  In the third embodiment, a plurality of elastic support portions 82B that are substantially the same as the elastic support portions 82A of the second embodiment and that are different from each other are used.

  Similarly to the second embodiment, the outer ring 86 of the bearing 59 is brought into contact with the inner side of the plurality of elastic support portions 82B that are fitted into the plurality of grooves 80A of the bearing housing 58 and project inwardly. Support.

  According to such 3rd Embodiment, since it is set as the structure which provides the some elastic support part 82B separately, according to the direction where a force is added, etc., the one where a larger applied force is hardened etc. The shape, material, and the like of 82B can be selected for each groove 80A, and a higher operating noise suppression effect can be obtained.

(Fourth embodiment)
A motor according to a fourth embodiment of the present invention and an electric power steering apparatus using the motor according to the present invention will be described below with reference mainly to FIG. 6, focusing on the differences from the second and third embodiments. Also in the fourth embodiment, the support structure of the bearing 59 provided on the output shaft 71 of the motor 13 is different.

  In the fourth embodiment, the groove portion 80C is substantially the same as the groove portion 80A of the second embodiment, except that the groove portion 80C is different from the inner peripheral surface of the wall portion 78 to the intermediate thickness portion in the radial direction. Is formed. That is, the groove 80C does not penetrate the wall portion 78 in the radial direction. The plurality of grooves 80C are fitted with individual elastic support portions 82B having substantially the same structure as that of the third embodiment and having different thicknesses.

  Similarly to the third embodiment, the outer ring 86 of the bearing 59 is brought into contact with the inner side of the plurality of elastic support portions 82C that are fitted in the plurality of grooves 80C of the bearing housing 58 and project inwardly. Support.

  According to the fourth embodiment as described above, the bottom of the groove 80C can also restrict the intrusion of the elastic support portion 82B into the groove 80C.

(Fifth embodiment)
A motor according to a fifth embodiment of the present invention and an electric power steering apparatus using the motor according to the present invention will be described below with reference mainly to FIG. 7, focusing on differences from the first and fourth embodiments. Also in the fifth embodiment, the support structure of the bearing 59 provided on the output shaft 71 of the motor 13 is different.

  In the fifth embodiment, the groove portion 80D is substantially the same as the groove portion 80 of the first embodiment except that the groove portion 80D is different from the inner peripheral surface of the wall portion 78 to the intermediate thickness portion in the radial direction. Is formed. That is, the groove 80D does not penetrate the wall 78 in the radial direction. An annular circumferential groove 91D is formed at the intermediate portion of the wall portion 78 in the radial direction so as to connect the bottoms of the grooves 80D.

  An elastic member 83 having a structure similar to that of the first embodiment and having different sizes is attached to the bearing housing 58. In the elastic member 83, the ring-shaped portion 81 is fitted into the annular circumferential groove 91D, and at this time, the elastic support portions 82 are in one-to-one correspondence with the plurality of grooves 80D penetrating from the circumferential groove 91D to the inner periphery. Are fitted to the bearing housing 58. In this case, the circumferential groove 91 </ b> D serves as a ring disposing portion where the ring-shaped portion 81 is disposed.

  As in the first and fourth embodiments, the outer ring 86 of the bearing 59 is brought into contact with the inside of the plurality of elastic support portions 82 that are fitted in the plurality of grooves 80D of the bearing housing 58 and project inward. The bearing 59 is supported.

(Sixth embodiment)
A motor according to a sixth embodiment of the present invention and an electric power steering apparatus using the motor according to the present invention will be described below with reference mainly to FIGS. 8 and 9 focusing on differences from the first and second embodiments. . Also in the sixth embodiment, the support structure of the bearing 59 provided on the output shaft 71 of the motor 13 is different.

  In the sixth embodiment, a bearing housing 58E is formed on the case body 50, which is substantially the same as the bearing housing 58 of the first embodiment, but differs in that it protrudes from the bottom 54 of the case body 50 to the side opposite to the flange 51. Has been. The bearing housing 58E has a bottomless cylindrical shape that opens in a protruding direction from the bottom portion 54, and an opening on one side in the axial direction of the wall portion 78 becomes an outer surface opening portion 92E that opens at the outer surface position of the motor case 50. ing. In the sixth embodiment, the case body 50 is also different in that it is formed of sheet metal, and thus the radial thickness of the wall portion 78 is thin.

  As shown in FIG. 9, the sixth embodiment has substantially the same structure as the elastic member 83 of the second embodiment, the size of each part is different, and the ring-shaped part 81 is closed on one side in the axial direction. An elastic member 83E made of an integrally molded elastic material, which is different in that a lid portion 93E is formed, is attached. In the elastic member 83E, the ring-shaped portion 81 is fitted to the outer peripheral surface of the cylindrical wall portion 78, and the elastic support portions 82A are fitted to the plurality of grooves 80 penetrating from the outer peripheral surface to the inner peripheral side. In this case, the protrusion 89A of the elastic support portion 82A is locked to the inner peripheral surface of the wall portion 78, and the lid portion 93E is an outer surface opening portion 92E of the bearing housing 58E. Occlude. In this case as well, the outer periphery of the wall 78 is the ring disposing portion 84 where the ring-shaped portion 81 is disposed.

  Similarly to the second embodiment, the outer ring 86 of the bearing 59 is brought into contact with the inner side of the elastic support portion 82A that is fitted into each of the plurality of grooves 80 of the bearing housing 58E and protrudes inward, thereby supporting the bearing 59. To do.

  According to the sixth embodiment described above, it is not necessary to close the outer surface opening 92E of the bearing housing 58E with a separate lid member, so that the component cost and assembly cost can be further reduced.

It is a perspective view which shows the example of an internal structure of the motor which concerns on this invention. It is a whole sectional view showing a 1st embodiment of the motor. The principal part of 1st Embodiment of the motor is shown, (a) is an axial orthogonal sectional view near the bearing housing, and (b) is a III-III sectional view of (a). It is an axial orthogonal cross section of the bearing housing vicinity which shows the principal part of 2nd Embodiment of the motor. The principal part of 3rd Embodiment of the motor is shown, (a) is an axial orthogonal sectional view near the bearing housing, and (b) is a VV sectional view of (a). It is an axis orthogonal sectional view near the bearing housing showing the important section of a 4th embodiment of the motor. The principal part of 5th Embodiment of the motor is shown, (a) is an axial orthogonal sectional view near the bearing housing, and (b) is a VII-VII sectional view of (a). It is a whole sectional view showing a 6th embodiment of the motor. The principal part of 6th Embodiment of the motor is shown, (a) is an axial orthogonal sectional view near the bearing housing, and (b) is an IX-IX sectional view of (a). 1 is a front view showing an example of a motor according to the present invention and an electric power steering device using the motor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Electric power steering device, 13 ... Motor, 52 ... Motor case, 58, 58E ... Bearing housing, 59 ... Bearing, 70 ... Rotor, 71 ... Output shaft, 80, 80A, 80C, 80D ... Groove, 81 ... Ring shape Part, 82, 82A, 82B, 82C ... elastic support part, 83, 83E ... elastic member, 84 ... ring arrangement part, 86 ... outer ring, 91D ... circumferential groove (ring arrangement part), 92E ... outer surface opening part, 93E ... the lid.

Claims (2)

In the motor that supports the output shaft of the rotor by a bearing provided in the bearing housing of the motor case,
Wherein the inner periphery of the bearing housing at intervals in the circumferential direction a plurality of grooves, the contacting the outer ring of the bearing in the elastic support portion of the inner mated elastic member for each of these grooves supporting the bearing Is a configuration to
The groove is provided in a radial thickness of the bearing housing ;
A plurality of the elastic support portions are individually provided,
An inscribed circle diameter in a state where the plurality of elastic support portions are disposed in the groove is set smaller than an inner diameter of the bearing housing;
In addition, the motor is characterized in that protrusions projecting on both sides in the circumferential direction are provided at the radially inner end portion of the elastic support portion .   An electric power steering apparatus that applies a steering assist torque to a steering system of a vehicle by the motor according to claim 1.

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