JPH0710568U - Electromagnetic clutch - Google Patents

Abstract

(57) [Summary] [Arrangement] The armature 25 facing the rotor connected to one of the driving side rotating member and the driven side rotating member is an inner peripheral member connected to the other of the driving side rotating member and the driven side rotating member. Outer peripheral member 34 connected to 32 via a clutch spring 33
Have. Due to the electromagnetic force, the outer peripheral member 34 is axially displaced with respect to the inner peripheral member 32 against the elastic force of the clutch spring 33 and pressed against the rotor 22. The outer peripheral member 3
4, the magnitude of the elastic force of the clutch spring acting in the axial direction is not uniform in the circumferential direction. [Effect] It is possible to prevent a loud clutch connection noise from being generated.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electromagnetic clutch used for transmitting rotational power.

[0002]

[Prior art]

 A rotor connected to one of the drive-side rotating member and the driven-side rotating member, and an armature facing the rotor are provided, and the armature is an inner peripheral member connected to the other of the drive-side rotating member and the driven-side rotating member. And an outer peripheral member connected to the inner peripheral member via a clutch spring, the electromagnetic force displaces the outer peripheral member axially with respect to the inner peripheral member against the elastic force of the clutch spring. An electromagnetic clutch that is pressed against the rotor by a conventional method has been used.

FIG. 5 shows an example of a conventional structure of the armature 101, which has a ring-shaped inner peripheral member 102, a disc-shaped clutch spring 103, and a ring-shaped outer peripheral member 104. A spline 102a for connecting to the rotating member is formed on the inner circumference of the inner peripheral member 102. The clutch spring 103 has a plurality of openings 103a, is connected to the inner peripheral member 102 by a plurality of rivets 105, and is fitted to a plurality of protrusions 104a protruding from the outer peripheral member 104. By crimping, the clutch spring 103 is connected to the outer peripheral member 104. The openings 103a of the clutch spring 103 have the same area and are equidistant from the center of rotation and are equally spaced along the circumferential direction. The rivets 105 are equidistant from the center of rotation. The protrusions 104a are arranged at equal intervals along the circumferential direction, and the protrusions 104a are arranged at equal distances from the center of rotation, and are arranged at equal intervals along the circumferential direction.

Further, Japanese Patent Publication No. 63-44972 discloses that an armature is composed of a plurality of ring-shaped members arranged concentrically and a clutch spring connecting the ring-shaped members, and the elastic force of the clutch spring is An electromagnetic clutch has been proposed in which the ring-shaped members are changed in the radial direction, and each ring-shaped member is axially displaced by the electromagnetic force against the elastic force of the clutch spring and sequentially pressed against the rotor.

[0005]

[Problems to be solved by the device]

 In the electromagnetic clutch equipped with the armature shown in FIG. 5, when an electromagnetic force is applied, the entire outer peripheral member 104 is pressed against the rotor at one time, and a large clutch engagement noise is generated. For example, when an electromagnetic clutch is used to connect and disconnect the rotational power of a motor for generating a steering assist force of an electric power steering device, the vehicle speed is ensured in order to ensure the stability of steering during high speed traveling and the high responsiveness of steering during low speed traveling. Since the electromagnetic clutch is engaged and disengaged depending on the situation, the clutch engagement noise that occurs every time the vehicle speed changes becomes a problem.

In the conventional example in which a plurality of concentric ring-shaped members are sequentially pressed against the rotor by an electromagnetic force, it is possible to prevent a rapid increase in the transmission torque, but each ring-shaped member is temporarily Since it is pressed against the rotor, a large clutch connection noise may occur, and the number of ring-shaped members increases, which complicates the structure.

An object of the present invention is to provide an electromagnetic clutch that can solve the above-mentioned problems of the prior art.

[0008]

[Means for Solving the Problems]

 The present invention comprises a rotor connected to one of a driving side rotating member and a driven side rotating member, and an armature facing the rotor, the armature being provided on the other side of the driving side rotating member and the driven side rotating member. It has an inner peripheral member to be connected and an outer peripheral member connected to the inner peripheral member via a clutch vane, and the outer peripheral member is axially supported by the electromagnetic force against the inner peripheral member against the elastic force of the clutch spring. In an electromagnetic clutch that is displaced in the direction and pressed against the rotor, the magnitude of the elastic force of the clutch spring that acts on the outer peripheral member along the axial direction is uneven in the circumferential direction.

[0009]

[Action]

 According to the structure of the present invention, when the outer peripheral member of the armature is axially displaced against the inner peripheral member against the elastic force of the clutch by the electromagnetic force and pressed against the rotor, the outer peripheral member is axially moved along the axial direction. Since the magnitude of the acting elastic force is non-uniform in the circumferential direction, the outer peripheral member is sequentially pressed against the rotor from the portion where the acting elastic force is small.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

A motor 2 with an electromagnetic clutch 1 shown in FIG. 2 is used as a steering assist force generation source of an electric power steering device, and is a motor shaft (driving side) supported by a motor yoke 3 via bearings 4 and 5. (Rotating member) 6, an armature coil 7 provided on the outer periphery of the motor shaft 6, a ferrite magnet 8 attached to the inner periphery of the motor yoke 3, and a rectifier 9 provided on the outer periphery of the motor shaft 6. And a pair of brushes 12 held by the brush holder 10 attached to the motor yoke 3 and pressed against the commutator 9 by the spring 11.

The electromagnetic clutch 1 rotates together with the clutch yoke 20 attached to the motor housing 3 a of the motor yoke 3, the electromagnetic coil 21 attached to the clutch yoke 20, and the outer periphery of the motor shaft 6. The annular rotor 22 is fitted with serrations, and the armature 25 is fitted to the outer periphery of the tip of the motor shaft 6 through a bearing 23 so as to be relatively rotated and faces the annular lining 22a of the rotor 22. The rotor 22 is sandwiched between the two bearings 4 and 23 to prevent the rotor 22 from moving in the axial direction with respect to the motor shaft 6.

As shown in FIG. 1, the armature 25 has a ring-shaped inner peripheral member 32, a disc-shaped clutch spring 33, and a ring-shaped outer peripheral member 34. The inner peripheral member 32 The output shaft (driven side rotating member) 26 is spline-fitted into the spline hole 32a formed in the central boss portion so as to rotate together. From the output shaft 26, the steering assist force of the electric power steering device is taken out. The clutch spring 33 has three openings 33a, 33b, 33c and is connected to the inner peripheral member 32 by three rivets 35a, 35b, 35c, and three protrusions 34a, 34b protruding from the outer peripheral member 34. , 34c, and the protrusions 34a, 34b, 34c are caulked after the fitting, so that the clutch spring 33 is connected to the outer peripheral member 34. The respective rivets 35a, 35b, 35c are arranged at equal distances from the center of rotation and equally spaced along the circumferential direction, and the respective protrusions 34a, 34b, 34c are arranged at equal distances from the center of rotation and in the circumferential direction. Are evenly spaced along. As a result, the outer peripheral member 34 of the armature 25 resists the elastic force of the clutch spring 33 by the electromagnetic force generated by energizing the electromagnetic coil 21, and the outer peripheral member 34 in the axial direction (see FIG. In the right direction), the rotor 22 is pressed against the lining 22a of the rotor 22, and the rotation of the motor shaft 6 is transmitted to the output shaft 26. Further, when the electromagnetic force is released, the outer peripheral member 34 is displaced in the other axial direction away from the rotor 22 by the elastic force of the clutch spring 33.

The magnitude of the elastic force of the clutch spring 33 acting on the outer peripheral member 34 along the axial direction is nonuniform in the circumferential direction. That is, the opening areas of the three openings 33a, 33b, 33c of the clutch spring 33 are different from each other, and their radial inner peripheral edges 33a ', 33b', 33c 'are at equal distances from the center of rotation and along the circumferential direction. Are arranged at equal intervals, and the radial opening widths Wa, Wb, and Wc are gradually reduced toward one side in the circumferential direction (direction of arrow A in FIG. 1), and the first opening having the largest opening area is provided. A second opening 33b having the second largest opening area is arranged adjacent to one side in the circumferential direction of 33a, and a second opening 33b having the smallest opening area is adjacent to the second opening 33b having the second largest opening area. The opening 33c is arranged. As a result, the spring constant of the clutch spring 33 becomes the smallest at a position in the vicinity of the edge 33a ″ on the other side in the circumferential direction of the first opening 33a, and gradually increases from that position in the circumferential direction. The magnitude of the elastic force of the clutch spring 33 acting on the shaft 34 along the axial direction gradually changes along the circumferential direction.

According to the above configuration, when the outer peripheral member 34 of the armature 25 is axially displaced with respect to the inner peripheral member 32 against the elastic force of the clutch spring 33 by the electromagnetic force and is pressed against the lining 22a of the rotor 22, Since the magnitude of the elastic force acting on the outer peripheral member 34 along the axial direction gradually changes along the circumferential direction, the outer peripheral member 34 is sequentially arranged along the circumferential direction from a portion having a small elastic force to be used. It is pressed against the lining 22a of the rotor 22, which prevents a loud clutch engagement noise from being generated.

The present invention is not limited to the above embodiment. For example, as shown in FIG. 3, it is assumed that the openings 33a, 33b, 33c of the clutch spring 33 have equal opening areas, are equidistant from the center of rotation, and are equally spaced along the circumferential direction. The distances Da, Db, Dc from the center of rotation of the three rivets 35a, 35b, 35c connecting the clutch spring 33 to the inner peripheral member 32 may be different from each other. As a result, the magnitude of the elastic force acting on the outer peripheral member 34 along the axial direction becomes minimum near the rivet 35b closest to the rotation center, and becomes maximum near the rivet 35a farthest from the rotation center. Since there is a gradual change along the circumferential direction between the circumferential directions, the same effect as that of the above-described embodiment is obtained. Others are the same as the above-described embodiment and have the same structure. Further, the distances from the center of rotation of the three protrusions 34a, 34b, 34c that connect the clutch spring 33 to the outer peripheral member 34 may be different from each other. The point is that the elastic force acting on the outer peripheral member along the axial direction. The size of can be made non-uniform along the circumference. Further, the inner peripheral member of the armature may be connected to the driving side rotating member and the rotor may be connected to the driven side rotating member. Further, in the above embodiment, the present invention is applied to the electromagnetic clutch for connecting / disconnecting the output of the power steering device, but the present invention can be applied to any electromagnetic clutch.

The facing surface 12 a of the brush 12 of the motor 2 facing the commutator 9 is separated from the commutator 9 toward one side of the motor shaft 6 in the axial direction. As shown, a plurality of grooves 12b are formed along the axial direction and the radial direction of the motor shaft 6. The end of each groove 12b opens on the surface intersecting the facing surface 12a of the brush 12. As a result, the abrasion powder 40 generated by the contact between the brush 12 and the commutator 9 is shown in the groove 12b by the rotation of the commutator 9 shown in (1) of FIG. It is possible to prevent the contact failure between the brush 12 and the commutator 9 due to the abrasion powder 40 being caught between the opposing surfaces of the brush 12 and the commutator 9. Further, the plurality of grooves 12b have a heat dissipation effect and can prevent heat generation and seizure caused by the contact between the brush 12 and the commutator 9. The facing surface 12a of the brush 12 may be in surface contact with the commutator 9 by being along the axial direction of the motor shaft 6.

[0018]

[Effect of device]

 According to the electromagnetic clutch of the present invention, since the outer peripheral member of the armature is not pressed against the rotor at one time when the clutch is engaged, a large clutch engagement noise can be prevented.

[Brief description of drawings]

FIG. 1 is a front view of an armature of an electromagnetic clutch according to an embodiment of the present invention.

FIG. 2 is a sectional view of a motor with an electromagnetic clutch according to an embodiment of the present invention.

FIG. 3 is a front view of an armature of an electromagnetic clutch according to a modified example of the present invention.

FIG. 4 is a front view of the motor brush (1) and a side view of the motor brush (2).

FIG. 5 is a front view of an armature of a conventional electromagnetic clutch.

[Explanation of symbols]

 6 Motor shaft (driving side rotating member) 22 Rotor 25 Armature 26 Output shaft (driven side rotating member) 32 Inner peripheral member 33 Clutch spring 34 Outer peripheral member

Claims (1)

[Scope of utility model registration request] 1. A rotor connected to one of a drive-side rotating member and a driven-side rotating member, and an armature facing the rotor, the armature being connected to the other of the drive-side rotating member and the driven-side rotating member. And an outer peripheral member connected to the inner peripheral member via a clutch spring. The electromagnetic force causes the outer peripheral member to resist the elastic force of the clutch spring in the axial direction with respect to the inner peripheral member. An electromagnetic clutch, wherein the elastic force of the clutch spring acting on the outer peripheral member along the axial direction is non-uniform in the circumferential direction, in the electromagnetic clutch which is displaced to the front and is pressed against the rotor.