JPH0550162U - Non-excitation actuated electromagnetic clutch - Google Patents

Abstract

(57) [Summary] [Purpose] The operating spring is incorporated by effectively utilizing the internal space of the non-excitation actuated electromagnetic clutch. [Structure] A disc spring 11 as an actuating spring is incorporated outside a fixed frame 2a of a device 2 by using a bearing abutting portion 7g side surface of a rotor 7 and an armature 8 side surface as spring seats. Since the armature 8 is pressed against the clutch plate 10 by the spring force of the disc spring 11, the rotation of the rotor 7 is caused by the device 2
Is transmitted to the rotating shaft 2b.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a non-excitation actuated electromagnetic clutch.

[Prior Art]

 A typical non-excitation actuated electromagnetic clutch is the "clutch device" disclosed in Japanese Patent Laid-Open No. 59-83840. The publication proposes a non-excitation actuated electromagnetic clutch that transmits the rotation of the engine to a power steering pump, which is a device for automobiles, and cuts off the rotation transmission.

A non-excitation actuated electromagnetic clutch is a field core fixed to a pump fixing frame and having an electromagnetic coil installed therein, an annular groove into which the field core is fitted, and an outer circumference on which a belt is stretched. Belt groove of the rotor, which is rotatably supported on the pump shaft through a bearing, and an armature which is arranged to face the outer side of the disk portion where the circular arc slit of the rotor is formed. And a clutch plate mounted on the pump shaft while the friction plate fixed to this armature comes in contact with and separates from each other, and between the plurality of recesses formed in the disc part of the rotor and the armature, rotation transmission is performed. A plurality of actuating springs consisting of compression coil springs are provided, which also serve as a buffer member that absorbs the torsional impact force and a guide member that displaces the armature relative to the rotor only in the axial direction. There is.

In the non-excitation actuated electromagnetic clutch having such a structure, the belt is stretched around the belt groove of the rotor and the crank pulley of the engine, and the rotor rotates when the engine is started. It is transmitted to the pump shaft via the operating spring, the armature, the friction plate fixed to the armature, and the clutch plate. If the armature is magnetically attracted to the rotor against the spring force of the actuating spring by energizing the electromagnetic coil, the friction plate fixed to the armature will be separated from the clutch plate, so that the rotation transmission to the pump shaft will be transmitted. Is cut off.

[0004]

[Problems to be solved by the device]

 Regarding the previously proposed non-excitation actuated electromagnetic clutch, the applicant considered a prototype design, but a design failure occurred because a compression coil spring was selected as the actuating spring. In other words, in the conventional non-excitation actuated electromagnetic clutch, the compression coil spring is used not only as an actuating member but also as a cushioning member and a guide member, and the rotor and the armature, which are spring seats of this compression coil spring, are used. The depth of the recess is increased.

Therefore, since the outer diameter side of the disc portion of the rotor is thick and the space of the annular groove into which the field core is fitted is narrow, the number of coil turns of the electromagnetic coil is also increased in this structure. The magnetic force that magnetically attracts the armature to the rotor is reduced. In addition, since the spring force of the compression coil spring is designed to be smaller than this magnetic force, it became clear that the rated torque of the non-excitation actuated electromagnetic clutch does not meet the requirements of equipment manufacturers.

In view of the above problems, the present invention provides a non-excitation actuated electromagnetic clutch that can effectively utilize the internal space of the non-excitation actuated electromagnetic clutch to obtain a sufficient rated torque. With the goal.

[Means for Solving the Problems]

 In order to achieve such an object, the applicant has noticed that a disc spring is selected as an actuating spring and incorporated in the non-excitation actuated electromagnetic clutch.

Then, the non-excitation actuated electromagnetic clutch is fixed to the fixed frame of the device and the field core in which the electromagnetic coil is installed, the annular groove into which the field core is fitted, and the belt are stretched. The outer peripheral belt groove is formed, and the rotor is rotatably supported via a bearing on the cylindrical fixed frame of the equipment or the rotating shaft of the equipment, and the rotor is disposed so as to face the disc portion of the rotor. On the other hand, a structure is provided that includes an armature that is displaceable only in the axial direction, and a clutch plate that is arranged to face the rotor disk part through this armature and that is mounted on the rotating shaft of the equipment. The side face of the abutment part of the bearing outer ring protruding from the inner cylinder part and the side face on the inner diameter side of the armature are used as spring seats in the cylindrical fixed frame of the equipment or in the annular space formed outside the rotation axis of the equipment. A disc spring is provided.

[0008]

[Action]

 In the non-excitation type electromagnetic clutch, the armature is pressed against the clutch plate by the spring force of the disc spring and these members are frictionally engaged, so the rotation of the rotor is transmitted to the rotating shaft of the equipment via the armature and clutch plate. Transmitted. When the armature is magnetically attracted to the rotor against the spring force of the disc spring, the armature is separated from the clutch plate and the rotation transmission to the rotary shaft is cut off.

[0009]

【Example】

 1 and 2 show an embodiment of a non-excitation actuated electromagnetic clutch of the present invention. FIG. 1 is a sectional view of only an upper half portion, and FIG. 2 is a partial side view of FIG. The non-excitation actuated electromagnetic clutch shown in these drawings was developed as a device to be mounted on automobile equipment as in the past. Hereinafter, description will be given with reference to the drawings.

In the non-excitation actuated electromagnetic clutch 1, a field core 5 having an electromagnetic coil 4 therein is fixed to a side surface of an automobile device 2 through a mounting flange 3. A rotor 7 is rotatably supported on a cylindrical fixed frame 2 a of the device 2 via a bearing 6. The rotor 7 is composed of an annular member having an approximately U-shaped cross section having an annular groove 7a in which the field core 5 is fitted, and an inner cylindrical portion 7b into which the outer ring 6a of the bearing 6 is press-fitted and a belt groove 7c on the outer periphery. It has a shape having an outer cylindrical portion 7d formed, and a disk portion 7e that connects the inner cylindrical portion 7b and each end portion of the outer cylindrical portion 7d. Reference numeral 7f is an arcuate slit for magnetic flux detouring, which is pressed on the disc portion 7e.

In the method of press-fitting and fixing the bearing 6 to the rotor 7 having such a shape, the bearing 6 is press-fitted inside the inner cylindrical portion 7 b of the rotor 7, and the end portion of the outer ring 6 a of the bearing 6 is fixed to the inner cylindrical portion 7 b. After abutting against the abutting portion 7g provided on the inner side of the bearing 6, the opposite end of the outer ring 6a of the bearing 6 is prevented from coming off by the plastically worked caulking piece 7h of the inner cylindrical portion 7b. On the other hand, the rotor 7 is formed with an annular protruding portion 7i at the outermost diameter portion of the disk portion 7e, and a groove 7j is formed at a position where the protruding portion 7i is divided into four equal parts in the circumferential direction. There is.

A disc-shaped armature 8 is arranged in front of the disc portion 7e of the rotor 7 with a predetermined gap therebetween, and the armature 8 has an inner diameter dimension that is larger than the inner diameter dimension of the rotor 7. Along with the reduction in size, a protrusion 8a is formed on the outer periphery to engage with the groove 7j of the rotor 7. With such a structure, the armature 8 can be displaced relative to the rotor 7 only in the axial direction.

A clutch plate 10 made of a non-magnetic material, which is key-fitted and prevented from coming off with a screw 9, is attached to the rotary shaft 2b of the device 2, and the armature 8 is attached to the disc portion 7e of the rotor 7. Are arranged opposite to each other. Reference numeral 11 is a disc spring as an actuating spring, and four disc springs 11 are combined in series and arranged in a space outside the cylindrical fixing frame 2a of the device 2. The outer diameter end of the disc spring 11 on the bearing 6 side is provided with the side surface of the abutting portion 7g of the rotor 7 as a spring seat, and the outer diameter end of the disc spring 11 on the opposite side springs the side surface of the armature 8. It is arranged as a seat.

In the non-excitation actuated electromagnetic clutch 1 having such a structure, the belt is stretched around the crank pulley of the engine and the rotor 7, and the rotor 7 rotates when the engine is started. The rotation of the rotor 7 is transmitted to the rotating shaft 2b of the device 2 by the force. When the electromagnetic coil 4 is energized and the armature 8 is magnetically attracted to the rotor 7 against the spring force of the disc spring 11, the rotation transmission to the rotary shaft 2b of the device 2 is cut off.

Here, in the non-excitation actuated electromagnetic clutch 1 of the present invention, the clearance between the rotor 7 and the armature 8 is about 0.5 mm, and the disc spring 11 increases the load with respect to this displacement amount. No, it is set and incorporated in the constant load area in the so-called nonlinear spring characteristics. Therefore, there is no delay in the release of the armature due to the increase in spring load due to the linear spring characteristic of the compression coil spring, and stable operation characteristics can be obtained.

In the above description, an example is shown in which the rotor 7 of the non-excitation actuated electromagnetic clutch 1 is supported on the cylindrical fixed frame 2a of the device 2, but this absorbs the belt tension by the fixed frame 2a. If the load due to the belt tension is light, the rotor 7 may be supported on the rotating shaft 2b of the device 2 via the bearing 6. Further, the groove 7j is formed in the rotor 7 as a guide portion of the armature 8, but a design is adopted in which a plurality of pins are driven into the rotor 7 and the pins are inserted into the through holes formed in the armature 8. It can be changed.

[0017]

[Effect of the device]

 As described above, in the present invention, the actuating spring of the non-excitation actuated electromagnetic clutch is a disc spring, and the spring seat of this disc spring is the side of the rotor bearing abutment part and the side of the armature. A disc spring could be placed outside the frame and the rotating shaft of the equipment, and the internal space of the non-excitation actuated electromagnetic clutch could be effectively utilized. Therefore, the space in the annular groove of the rotor is not reduced, in other words, the coil storage space of the field core is not reduced, and the rated torque required by the equipment manufacturer is satisfied without increasing the size of the device. I was able to do it.

Further, since the amount of deflection of the disc spring is designed and used in the constant load region in the non-linear spring characteristic, the operation characteristic of the non-excitation type electromagnetic clutch is good and the reliability of quality is improved. Was done.

[Brief description of drawings]

FIG. 1 is an upper half sectional view of a non-excitation actuated electromagnetic clutch.

FIG. 2 is a partial side view of FIG.

[Explanation of symbols]

 4 Electromagnetic coil 5 Field core 6 Bearing 7 Rotor 8 Armature 10 Clutch plate 11 Disc spring

Claims (1)

[Scope of utility model registration request] 1. A field core fixed to a stationary frame of a device, in which an electromagnetic coil is provided, an annular groove into which the field core is fitted, and a belt groove on an outer circumference on which a belt is stretched are formed. A rotor rotatably supported on a cylindrical fixed frame of a device or a rotating shaft of a device via a bearing, and a disc portion of the rotor that is disposed so as to face the rotor and is displaceable only in the axial direction with respect to the rotor. An armature and a clutch plate, which is disposed so as to face the disc portion of the rotor via the armature and is attached to the rotating shaft of the equipment, and the protrusion of the bearing outer ring protruding from the inner cylindrical portion of the rotor. A disc spring is arranged in a cylindrical fixed frame of the device or in an annular space formed outside the rotation axis of the device, with the side surface of the contact portion and the side surface on the inner diameter side of the armature as spring seats. Non-excitation actuated electromagnetic clutch.