JP2017007587A - Electric power steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent inclination of a nut due to a tensile force of a belt without enlarging and complicating a device in an electric power steering device having a pulley belt mechanism and a ball screw mechanism.SOLUTION: An electric power steering device comprises: a ball screw mechanism for converting a rotational motion of a nut 3 into an axial motion of a rack shaft 8; a belt 6 for transmitting drive power of a motor to the nut 3; a bearing 4 for rotatably supporting the nut 3 at one end side of the nut 3 in an axial direction; and a reaction force generation mechanism for generating a reaction force against a tensile force of the belt 6 which is directly or indirectly applied to the nut 3. The reaction force generation mechanism generates moment in an opposite direction from moment due to the tensile force of the belt 6 that rotates around the bearing. An inclined surface 17 is provided on an inner peripheral side of a housing 1.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electric power steering apparatus.

  The electric power steering device is a device for assisting a driver's steering force with a motor and changing the traveling direction of the vehicle. As one type, a belt-driven electric power steering device has been proposed in which a motor axis and a rack shaft are arranged in parallel and the power of the motor is transmitted by a belt and a ball screw (for example, Patent Documents 1 and 2). .

  In the electric power steering apparatus described in Patent Documents 1 and 2, the rotation of the output shaft of the electric motor is decelerated through a reduction mechanism including a pulley and belt mechanism, and then a ball screw mechanism arranged coaxially with the rack shaft is provided. It is converted into the axial movement of the rack shaft.

JP 2004-314770 A JP 2013-194901 A

  In the electric power steering device described in Patent Document 1, the belt wound around the driving pulley and the driven pulley is rotatable around the nut constituting the ball screw and the nut as viewed from the direction perpendicular to the axis of the rack shaft. It is arranged at a position that is offset from the center of gravity of the bearing that supports it.

  For this reason, as shown in FIG. 9, the tension of the belt 6 becomes a moment centering on the bearing, and the nut 3 is tilted with respect to the rack shaft 8. Such an inclination between the nut 3 and the rack shaft 8 gives a biased load to the ball 12, and decreases the efficiency of the ball screw and increases the ball rolling sound generated when the ball rolls on the screw surface.

  Further, in the electric power steering device described in Patent Document 2, in order not to generate a rotational moment around the nut shaft, the driven pulley and the bearing that rotatably supports the nut extend along a direction perpendicular to the axis of the rack shaft. Are arranged at the same position. For this reason, the apparatus is increased in size and complexity.

  An object of the present invention is to suppress an inclination of a nut with respect to a rack shaft caused by belt tension in an electric power steering apparatus having a pulley / belt mechanism and a ball screw mechanism without causing an increase in size and complexity of the apparatus. is there.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. As an example, in an electric power steering apparatus including a ball screw mechanism that converts the rotational movement of a nut into an axial movement of a rack shaft, and a belt that transmits a driving force of a motor to the nut, the nut is directly applied to the nut. Alternatively, a reaction force generation mechanism that generates a reaction force that counteracts the tension of the belt acting indirectly is provided.

  According to the present invention, in the belt-driven electric power steering device that transmits the power of the motor by the belt and the ball screw, the relative angle between the nut and the rack shaft is reduced, and the ball load of the ball screw mechanism is made uniform. Can do. Therefore, it is possible to provide an electric power steering apparatus that has a small and simple structure, but has a high efficiency of the ball screw and a small ball rolling sound generated when the ball rolls on the thread surface.

Sectional drawing of the electric power steering apparatus which concerns on the 1st Embodiment of this invention Sectional drawing of the electric power steering apparatus which concerns on the 2nd Embodiment of this invention. Sectional drawing of the electric power steering apparatus which concerns on the 3rd Embodiment of this invention. Sectional drawing of the electric power steering apparatus which concerns on the 4th Embodiment of this invention. Sectional drawing of the electric power steering device which concerns on the 5th Embodiment of this invention Sectional drawing of the electric power steering device which concerns on the 6th Embodiment of this invention Sectional drawing seen from the AA cross section of Fig.6 (a) Sectional drawing of the electric power steering device which concerns on the 7th Embodiment of this invention Sectional drawing of the electric power steering apparatus which concerns on the 8th Embodiment of this invention. Sectional drawing seen from the BB cross section of Fig.8 (a) Sectional view of a conventional electric power steering device

  Hereinafter, an embodiment of a power conversion device according to the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is described about the same element and the overlapping description is abbreviate | omitted.

  First, the problem to be solved by the present invention will be described in detail with reference to FIG. FIG. 9 is a cross-sectional view of a main part showing the structure of a conventional electric power steering apparatus.

  The electric power steering apparatus applies an assist force to the driver's steering force by transmitting the driving force of the motor to the rack shaft 8 via a speed reduction mechanism including a pulley / belt mechanism. A motor (not shown) is provided with a cylindrical driving pulley on the output shaft. The driving pulley is fixed so as to rotate integrally with the output shaft of the motor.

  The electric power steering apparatus includes a ball screw mechanism including a rack shaft 8, a nut 3, and a ball 12. The rack shaft 8 is disposed in parallel with the output shaft of the motor. On the outer periphery of the rack shaft 8, a male screw groove is formed in a spiral shape. A female thread groove is formed in a spiral shape on the inner periphery of the nut 3. A plurality of balls 12 are provided between the male thread groove of the rack shaft 8 and the female thread groove of the nut 3. The ball screw mechanism converts the rotational motion of the nut 3 into the linear motion of the rack shaft 8.

  A cylindrical driven pulley 7 is provided on the outer periphery of the nut 3. The driven pulley 7 is fixed to the nut 3 so as to be coaxial with the nut 3. A belt 6 is wound around the driving pulley and the driven pulley 7. The belt 6 transmits the power of the motor to the nut 3 and rotates the nut 3. A bearing that rotatably supports the nut 3 is provided on the outer periphery of the nut 3. In FIG. 9, the outer peripheral surface of the nut 3 is formed as a bearing inner race. The bearing includes a bearing ball 4 and a bearing outer race 2. The bearing outer race 2 is fixed to the inner periphery of the housing 1.

  As shown in FIG. 9, the nut 3 has one end in the axial direction receiving radial tension by the belt 6, while the other end in the axial direction is rotatably supported by the bearing by the bearing. Since the tension of the belt 6 becomes a moment around the bearing as a rotation center, the nut 3 acts to incline the rack 3 with respect to the rack shaft 8. In FIG. 9, the moment due to the belt tension is a moment acting in a counterclockwise direction with respect to the nut 3. A reference numeral 11 in the drawing indicates a relative angle difference between a nut shaft direction 9 that is an axial direction of the nut 3 and a rack shaft direction 10 that is an axial direction of the rack shaft 8. In the figure, for the sake of explanation, the angle 11 is shown with emphasis over the actual value.

  When an angle difference 11 exists between the nut axis direction 9 and the rack axis direction 10 as shown in FIG. 9, a load is applied to the ball screw ball indicated by reference numeral 13 among the ball screw balls 12. The ball screw ball 13 that receives a load is a ball screw ball that is positioned on the opposite side of the driving pulley at the axial end on the side where the nut 3 receives tension by the belt 6 among the circulating ball screw balls 12. . Further, the ball screw ball located on the side where the driving pulley is disposed at the other end of the nut 3 also becomes the ball screw ball 13 that receives the load.

  When the ball screw ball 13 receiving such a load rolls on the rolling surfaces of the rack shaft 8 and the nut 3, noise is generated. Further, such a biased load of the ball screw ball 12 may cause a decrease in efficiency and durability of the ball screw.

  In view of such a problem, each embodiment of the present invention described below reduces the angular difference between the nut shaft direction 9 and the rack shaft direction 10 as much as possible against the tension applied to the nut 3 by the belt 6. It was devised as a basic idea to make the structure to be. The embodiment of the present invention will be described in order with reference to FIGS.

(First embodiment)
FIG. 1 is a cross-sectional view of a main part showing the configuration of the electric power steering apparatus according to the first embodiment. The electric power steering device of this embodiment is provided with a shim 14 on the outer peripheral side of the outer race 2 of the bearing as a reaction force generating mechanism for reducing the maximum inclination angle of the nut 3.

  The bearing outer race 2 according to the present embodiment is inclined with respect to a direction 15 perpendicular to the rack axial direction 10 by a shim 14. When the direction in which the driving pulley is disposed with respect to the driven pulley 7 is defined as the upward direction, the shim 14 is the upward direction of the nut 3, and the belt 6 is disposed with respect to the bearing outer race 2. It is arrange | positioned on the opposite side to the side made. The bearing outer radial direction 5, which is the radial direction of the bearing outer race 2, is inclined clockwise with respect to the nut radial direction 15.

  The shim 14 that functions as a reaction force generating mechanism in the present embodiment is a mechanism that generates a moment in a direction opposite to the moment caused by the tension of the belt 6 centering on the bearing, and the outer race 2 of the bearing is moved against the inner race. This is a mechanism for generating a tilting force.

  As described above, the relative angular difference 16 is formed between the bearing outer peripheral radial direction 5 and the nut radial direction 15, so that a clockwise moment due to the deformation of the bearing ball 4 is generated on the nut 3. . Due to this clockwise moment, the counterclockwise moment due to the tension of the belt 6 is canceled, and the maximum inclination angle of the nut 3 is reduced. Therefore, in the electric power steering apparatus according to the present embodiment, the load applied to the ball screw ball 12 that rolls during steering can be made uniform, and the ball screw rolling noise can be reduced.

  Note that the configuration of the shim 14 in the present embodiment is not limited to this. For example, an annular shim 14 having a different axial thickness in the circumferential direction is prepared. It is good also as a structure arrange | positioned in a direction. Moreover, you may provide the shim 14 in the outer periphery of the outer side of the radial direction of the outer race 2. FIG. In short, it is only necessary to generate a force that inclines the outer race 2 of the bearing with respect to the inner race.

(Second Embodiment)
FIG. 2 is a cross-sectional view of a main part showing the configuration of the electric power steering apparatus according to the second embodiment. The electric power steering apparatus of the present embodiment is provided with an inclined surface 17 on the inner peripheral side of the housing 1 as a reaction force generating mechanism that reduces the maximum inclination angle of the nut 3.

  The bearing outer race 2 according to the present embodiment is inclined with respect to a direction 15 perpendicular to the rack axial direction 10 by an inclined surface 17 formed on the inner peripheral side of the housing 1. The inclined surface 17 here is an inner peripheral surface on the housing 1 side corresponding to the outer peripheral surface of the outer race 2 of the bearing provided inclined with respect to the nut 3 which is the inner race of the bearing.

  In this embodiment, the inclined surface 17 that functions as a reaction force generating mechanism is a mechanism that generates a moment in a direction opposite to the moment caused by the tension of the belt 6 with the bearing as the rotation center, and the outer race 2 of the bearing is used as the inner race. It is a mechanism that generates a force for tilting.

  As described above, the relative angular difference 16 is formed between the bearing outer peripheral radial direction 5 and the nut radial direction 15, so that a clockwise moment due to the deformation of the bearing ball 4 is generated on the nut 3. . Due to this clockwise moment, the counterclockwise moment due to the tension of the belt 6 is canceled, and the maximum inclination angle of the nut 3 is reduced. Therefore, in the electric power steering apparatus according to the present embodiment, the load applied to the ball screw ball 12 that rolls during steering can be made uniform, and the ball screw rolling noise can be reduced.

  In the present embodiment, it is not necessary to provide a shim or the like separately in order to provide the relative angle difference 16 between the bearing outer circumferential direction 5 and the nut radial direction 15. Therefore, a desired effect can be obtained without increasing the number of parts.

(Third embodiment)
FIG. 3 is a cross-sectional view of the main part showing the configuration of the electric power steering apparatus according to the third embodiment. The electric power steering apparatus of the present embodiment is provided with an elastic body 18 on the outer peripheral side of the outer race 2 of the bearing as a reaction force generating mechanism for reducing the maximum inclination angle of the nut.

  The bearing outer race 2 according to the present embodiment is urged by the elastic body 18 so that a moment is applied clockwise in FIG. In the present embodiment, when the direction in which the driving pulley is disposed with respect to the driven pulley 7 is defined as the upward direction, the elastic body 18 has a belt relative to the outer race 2 in the upward direction from the nut 3. It is arrange | positioned on the opposite side to the side by which 6 is arrange | positioned. The elastic body 18 is disposed on the side where the belt 6 is disposed with respect to the outer race 2 in a lower direction than the nut 3.

  The elastic body 18 functioning as a reaction force generating mechanism in the present embodiment is a mechanism that generates a moment in a direction opposite to the moment caused by the tension of the belt 6 centering on the bearing, and the outer race 2 of the bearing is used as the inner race. It is a mechanism that generates a force for tilting.

  The clockwise moment generated by the elastic body 18 around the nut 3 is offset by the counterclockwise moment generated by the tension of the belt 6. Therefore, in the electric power steering apparatus according to the present embodiment, the load applied to the ball screw ball 12 that rolls during steering can be made uniform, and the ball screw rolling noise can be reduced.

  Moreover, in this embodiment, since a bearing is elastically supported, the vibration transmitted to the housing 1 can be suppressed and the sound vibration reduction effect can be obtained.

(Fourth embodiment)
FIG. 4 is a cross-sectional view of a main part showing the configuration of the electric power steering apparatus according to the fourth embodiment. The electric power steering apparatus according to the present embodiment is provided with a second bearing that rotatably holds the other end of the nut 3 as a reaction force generation mechanism that reduces the maximum inclination angle of the nut 3.

  The second bearing according to the present embodiment includes an inner race integrally provided on the other end side of the nut 3, a belt-side bearing outer race 19, and a belt-side bearing ball 20. The belt-side bearing outer race 19 is held on the inner peripheral side of the housing 1 similarly to the bearing outer race 2. In the nut 3, an inner race formed on one end side contacts the bearing ball 4, and an inner race formed on the other end side contacts the belt-side bearing ball 20.

  In the present embodiment, the second bearing functioning as a reaction force generating mechanism is centered on the bearing disposed on one end side of the nut 3 by the reaction force of the second bearing disposed on the other end side of the nut 3. The mechanism generates a moment in the opposite direction to the moment due to the tension of the belt 6.

  Thus, since the second bearing is also provided on the other end side of the nut 3, the moment due to the tension of the belt 6 is offset by the moment due to the reaction force of the bearing, and the maximum inclination angle of the nut 3 is reduced. . Therefore, in the electric power steering apparatus according to the present embodiment, the load applied to the ball screw ball 12 that rolls during steering can be made uniform, and the ball screw rolling noise can be reduced. In the present embodiment, since the reaction force generation mechanism is provided on the belt side, the tension of the belt 6 can be counteracted even with a small force.

(Fifth embodiment)
FIG. 5 is a cross-sectional view of a principal part showing the configuration of the electric power steering apparatus according to the fifth embodiment. The electric power steering apparatus of the present embodiment is provided with a biasing means that biases the other end side of the nut 3 in a direction opposite to the tension of the belt 6 as a reaction force generating mechanism that reduces the maximum inclination angle of the nut 3. Is.

  As the biasing means according to the present embodiment, an elastic body 21 is provided on the opposite side to the bearing outer race 2 with the belt 6 interposed therebetween. The elastic body 21 has one end fixed to the inner peripheral side of the housing 1 and the other end pressed against the sliding portion 22. The sliding portion 22 is disposed between the elastic body 21 and the outer periphery of the nut 3. The elastic body 21 presses the nut 3 through the sliding portion 22 to be rotatable. The elastic body 21 and the sliding portion 22 are arranged on the same side as the side on which the driving pulley is arranged with respect to the nut 3.

  The urging means functioning as a reaction force generating mechanism in this embodiment is arranged on one end side of the nut 3 by urging the other end side of the nut 3 in the direction opposite to the tension of the belt 6 by the urging means. This is a mechanism that generates a moment in the opposite direction to the moment caused by the tension of the belt 6 with the bearing as the center of rotation.

  Thus, since the urging means is provided on the other end side of the nut 3, the moment due to the tension of the belt 6 is offset by the moment due to the urging force of the urging means, and the maximum inclination angle of the nut 3 is reduced. . Therefore, in the electric power steering apparatus according to the present embodiment, the load applied to the ball screw ball 12 that rolls during steering can be made uniform, and the ball screw rolling noise can be reduced. In the present embodiment, since the reaction force generation mechanism is provided on the belt side, the tension of the belt 6 can be counteracted even with a small force.

  In the present embodiment, the elastic body 21 as the biasing means in FIG. 5 is arranged above the nut 3 and the elastic body 21 pushes the nut 3 downward. The method of providing is not limited to this. The biasing means may be arranged below the nut 3 and the biasing means may pull the nut 3 downward.

(Sixth embodiment)
FIG. 6A is a cross-sectional view of a main part showing the configuration of the electric power steering apparatus according to the sixth embodiment. The electric power steering apparatus of the present embodiment is provided with a rack retainer 24 that generates a biasing force in a direction in which the rack shaft 8 is inclined as a mechanism for inclining the rack shaft 8.

  The electric power steering apparatus according to the present embodiment includes a pinion 23 that transmits a steering force by a driver to the rack shaft 8, and a rack retainer 24 that holds the rack shaft 8. A feature of the electric power steering apparatus according to the present embodiment is that the rack retainer 24 also serves as a mechanism for inclining the rack shaft 8. Here, in FIG. 6A, the axial direction of the rack shaft 8 is defined as the x-axis direction, and the directions orthogonal to the x-axis direction are defined as the y-axis direction and the z-axis direction.

  FIG.6 (b) is sectional drawing in the AA cross section of Fig.6 (a). The rack retainer 24 includes a retainer sliding portion 25 that contacts the rack shaft 8 and a compression spring 26 that presses the retainer sliding portion 25 toward the rack shaft 8. In the drawing, the axial direction of the pinion 23 is arranged in the z-axis direction. The direction in which the rack retainer 24 according to the present embodiment urges the rack shaft 8 is in contact with the pinion axial direction 27 that is the axial direction of the pinion 23. Thereby, the rack retainer 24 urges the rack shaft 8 in the negative y-axis direction and urges the rack shaft 8 in the negative z-axis direction.

  As can be seen from FIG. 6A, the rack retainer 24 of this embodiment generates a counterclockwise moment about the bearing supporting the nut 3 on the rack shaft 8. As a result, the rack shaft 8 is inclined counterclockwise with respect to the axial direction of the bearing outer race 2.

  Therefore, the nut 3 has an inclination angle due to the moment due to the tension of the belt 6 centering on the bearing, but the rack shaft 8 is inclined along the inclination angle of the nut 3. Thereby, the electric power steering apparatus according to the present embodiment can equalize the load applied to the ball screw ball 12 that rolls during steering, and can reduce ball screw rolling noise.

(Seventh embodiment)
FIG. 7 is an essential part cross-sectional view showing the configuration of the electric power steering apparatus according to the seventh embodiment. The electric power steering apparatus according to the present embodiment is provided with a rack retainer 24 disposed at a position where the rack shaft 8 is regulated to be inclined as a mechanism for tilting the rack shaft 8.

  The electric power steering apparatus according to the present embodiment includes a pinion 23 that transmits a steering force by a driver to the rack shaft 8, and a rack retainer 24 that holds the rack shaft 8. The rack retainer 24 is arranged so as to give the rack shaft 8 an inclination angle 32 with respect to the axial direction 31 of the bearing outer race 2.

  Thus, in the electric power steering apparatus according to the present embodiment, the nut 3 has an inclination angle due to the moment due to the tension of the belt 6 centering on the bearing, but the position of the retainer 24 is offset. The rack shaft 8 is inclined along the inclination angle of the nut 3. Thereby, the electric power steering apparatus according to the present embodiment can equalize the load applied to the ball screw ball 12 that rolls during steering, and can reduce ball screw rolling noise.

  In the electric power steering apparatus according to the present embodiment, the rack retainer 24 is used as a member for restricting the rack shaft 8 to be inclined. However, the rack shaft 8 is inclined by another member without using the rack retainer 24. It is good also as restricting to the state which carried out. In this case, although the number of parts for regulating the position of the rack shaft 8 increases, the load applied to the ball screw ball 12 is made uniform, so that the ball screw rolling noise can be reduced.

(Eighth embodiment)
FIG. 8A is a cross-sectional view of a main part showing the configuration of the electric power steering apparatus according to the eighth embodiment. In the electric power steering apparatus of the present embodiment, the nut 3 and the driven pulley 7 are provided so that the axial direction of the driven pulley can be inclined with respect to the axial direction of the nut.

  FIG.8 (b) is sectional drawing in the BB cross section of Fig.8 (a). The nut 3 and the driven pulley 7 are engaged via a spline engaging portion 30. Thereby, generation | occurrence | production of the relative angle of the radial direction of the nut 3 and the driven side 7 pulley is permitted, and transmission of the rotational force from the driven side pulley 7 to the nut 3 can be permitted. Therefore, the driven pulley 7 has an inclination angle due to the moment due to the tension of the belt 6 centering on the bearing, but the generation of the inclination angle between the nut 3 and the rack shaft 8 can be suppressed. In the electric power steering apparatus according to the present embodiment, the load applied to the ball screw ball 12 that rolls during steering is made uniform, and the ball screw rolling noise can be reduced.

  The first to eighth embodiments described above can be implemented in appropriate combination. For example, the shim 14 is provided on the outer peripheral side of the outer race 2 of the bearing as a reaction force generating mechanism, and the rack shaft 8 is inclined by the rack retainer 24, so that the angular difference between the nut shaft direction 9 and the rack shaft direction 10 is achieved. It is good also as a structure which reduces.

1: Housing 2: Bearing outer race 3: Nut 4: Bearing ball 5: Bearing outer circumferential direction 6: Belt 7: Driven pulley 8: Rack shaft 9: Nut shaft direction 10: Rack shaft direction 11: Nut and rack shaft direction Relative angle difference 12: Ball screw Ball 13: Ball screw ball 14 receiving load: Shim 15: Nut radial direction 16: Relative angular difference between bearing outer periphery and nut radial direction 17: Inclined surface 18 on housing inner periphery side: Elastic body 19: Belt-side bearing outer race 20: Belt-side bearing ball 21: Belt-side elastic body 22: Sliding member 23: Pinion 24: Rack retainer 25: Rack retainer sliding portion 26: Rack retainer compression spring 27: Pinion shaft Direction 28: Retainer shaft direction 29: Relative angle difference between pinion and retainer shaft direction 30: Nut Spline engagement portion 31 of the rack shaft: bearing outer race axis 32: bearing outer race and the rack shaft direction of the relative angle difference 35: tension direction of the belt

Claims (19)

A ball screw mechanism that converts the rotational movement of the nut into the axial movement of the rack shaft;
In an electric power steering apparatus comprising a belt for transmitting a driving force of a motor to the nut,
An electric power steering apparatus comprising a reaction force generation mechanism that generates a reaction force that opposes the tension of the belt that directly or indirectly acts on the nut. The electric power steering according to claim 1, wherein
A bearing that rotatably supports the nut on one end side in the axial direction of the nut;
The electric power steering device according to claim 1, wherein the reaction force generation mechanism is a mechanism that generates a moment in a direction opposite to a moment caused by a tension of the belt with the bearing as a rotation center. The electric power steering according to claim 2,
The electric power steering device according to claim 1, wherein the reaction force generation mechanism is a mechanism that generates a force that inclines the outer race of the bearing with respect to the inner race. In the electric power steering according to claim 3,
The electric power steering apparatus, wherein the reaction force generation mechanism is a shim provided on an outer peripheral side of the outer race. In the electric power steering according to claim 3,
A housing for holding the outer race of the bearing on the inner peripheral side;
The electric power steering apparatus, wherein the reaction force generation mechanism is an inclined surface formed on an inner peripheral side of the housing. In the electric power steering according to claim 3,
The electric power steering apparatus, wherein the reaction force generation mechanism is an elastic body provided on an outer peripheral side of the outer race. The electric power steering according to claim 2,
The reaction force generation mechanism is configured to generate a moment in the reverse direction on the other end side of the nut, which is opposite to the one end side on the side where the bearing is disposed, across the belt. Electric power steering device. The electric power steering according to claim 7,
The electric power steering device, wherein the reaction force generation mechanism is a second bearing that rotatably holds the other end side of the nut. The electric power steering according to claim 7,
The electric power steering apparatus according to claim 1, wherein the reaction force generation mechanism is a biasing unit that biases the other end side of the nut to a side opposite to a tension of the belt. The electric power steering according to claim 9,
The electric power steering apparatus, wherein the reaction force generation mechanism is a mechanism that pulls the nut. The electric power steering according to claim 9,
The electric power steering apparatus, wherein the reaction force generation mechanism is a mechanism that pushes the nut. A ball screw mechanism that converts the rotational movement of the nut into the axial movement of the rack shaft;
A belt for transmitting the driving force of the motor to the nut;
In an electric power steering device comprising a bearing that rotatably supports the nut at one end side in the axial direction of the nut,
An electric power steering apparatus comprising a mechanism for inclining the rack shaft in the same direction as the direction in which the axial direction of the nut is inclined with respect to the outer race axial direction of the bearing. The electric power steering according to claim 12,
The electric power steering apparatus according to claim 1, wherein the mechanism for inclining the rack shaft is a rack retainer that supports the rack shaft. The electric power steering according to claim 13,
The electric power steering apparatus according to claim 1, wherein the rack retainer generates a biasing force in a direction in which the rack shaft is inclined. The electric power steering according to claim 13,
The electric power steering apparatus, wherein the rack retainer is disposed at a position that regulates the rack shaft to be inclined. The electric power steering according to claim 12,
The mechanism for inclining the rack shaft is a mechanism provided separately from a rack retainer that supports the rack shaft. A ball screw mechanism that converts the rotational movement of the nut into the axial movement of the rack shaft;
A belt for transmitting the driving force of the motor to the nut;
In an electric power steering device comprising a bearing that rotatably supports the nut at one end side in the axial direction of the nut,
Providing a reaction force generating mechanism for generating a reaction force against the tension of the belt acting directly or indirectly on the nut;
An electric power steering apparatus comprising a mechanism for inclining the rack shaft in the same direction as the direction in which the axial direction of the nut is inclined with respect to the outer race axial direction of the bearing. A ball screw mechanism that converts the rotational movement of the nut into the axial movement of the rack shaft;
A driven pulley attached to the outer periphery of the nut;
In an electric power steering apparatus comprising: a belt that transmits a driving force of a motor to the nut via the driven pulley.
The driven pulley is attached to the nut so that a rotational force is transmitted to the nut and the axial direction of the driven pulley can be inclined with respect to the axial direction of the nut. Power steering device. The electric power steering according to claim 18,
The electric power steering apparatus, wherein the nut and the driven pulley are engaged by a spline.

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