JPH0215730B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic clutch installed in a compressor or the like, and particularly to an improvement in the axial fixing structure of a bearing fitted in a center hole of a rotor.

[Prior Art] Generally, an electromagnetic clutch installed in an automobile compressor has a yoke in which an excitation coil is fixed to the outer surface of the compressor frame, and a part of this yoke is loosely fitted. A rotor having a substantially U-shaped cross section is supported on a cylindrical portion integrally formed with the machine frame via a bearing so as to freely rotate; The main component is an armature that is movable only in the axial direction with respect to the tip of the rotating shaft of the compressor that protrudes from the rotor. The armature is magnetically attracted to the rotor's friction surface by the magnetic attraction force of the excitation coil, which is generated by directly connecting the engine and rotating it, and controlling the electric circuit between the excitation coil and battery power source on and off. to drive the compressor.

In addition, as a structure for fixing the bearing of such an electromagnetic clutch in the center hole of the rotor, the peripheral wall of the center hole of the rotor is pressed out from the friction surface side, so that the bearing protrudes into the center hole of the rotor. Forms a bearing abutment. It is known that the outer ring of the bearing is press-fitted into the center hole of the rotor until it comes into contact with this abutting part, and the end surface of the outer ring of the bearing opposite to the abutting part is fixed with a snap spring to prevent it from coming off.
Since the structure is formed by plastic flow of the material through press working, resource saving effects can be obtained (see Japanese Utility Model Publication No. 58-36900).

On the other hand, as a fixing structure for such a bearing, the circumferential wall of the center hole of the rotor is cut and raised by press working from the friction surface side to a predetermined position in the axial direction, and the inward protrusion of the cut and raised material is inserted into the protrusion of the bearing. It is also known that the abutment part is used to fix the bearing so that it does not come off in the same way as described above, and this fixing structure can also achieve a resource saving effect. (Refer to Utility Model Application Publication No. 57-16631).

[Problems to be Solved by the Invention] However, for example, if the axial dimension from the center of the bottom of the belt groove provided on the outer peripheral surface of the rotor to the friction surface of the rotor is long, the tension of the belt stretched in this belt groove becomes The bearing, which is subjected to a bending moment, must also be designed so that its center is approximately the same in the axial direction as the center of the bottom of the belt groove, so that the bending moment applied to the bearing is small.

Therefore, with the abutment part obtained by pressing the peripheral wall of the rotor's center hole from the friction surface side, it is not possible to increase the axial dimension between the abutment part and the friction surface, and this processing method is cannot be adopted. Also,
The abutment part is not simply press-cut, but the peripheral wall of the center hole of the rotor is cut and raised from the friction surface side to a predetermined position in the axial direction by press processing, and the cut-and-raised dimension is long and the plastic fluidity of the material is high. In terms of production technology, press processing itself is difficult and processing defects are likely to occur.

In addition, assembly work involves press-fitting a bearing into the center hole of the rotor by press working, bringing the outer ring of the bearing into contact with the abutting part of the peripheral wall of the center hole, and caulking and fixing the opposite side of the outer ring by press working in the same manner. Therefore, the pressing force from the press acts on the cut and raised abutting portion. Therefore, the amount of plastically flowing material in the peripheral wall of the rotor must be increased to a certain extent, and the design must be such that the abutment part does not break due to the pressing force of the press.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic clutch that can prevent defects such as machining defects and defective defects in press working of the abutting portion of a bearing and reduce loss due to defects.

[Means for Solving the Problem] In order to achieve such an object, the present invention includes a yoke in which an excitation coil is installed, and a part of the yoke that is loosely fitted onto a fixed member or a rotating member. The rotor has a substantially U-shaped cross section and is supported through a bearing so that it can freely rotate, and an armature that faces the friction surface of the rotor at a predetermined distance. In an electromagnetic clutch that is brought into contact with an abutting part consisting of an inward protrusion pressed into the peripheral wall of the center hole,
The rotor is composed of at least two members, and an inner cylindrical member having a hole serving as a center hole of the rotor,
It is characterized in that the abutment portion is formed by pressing into the center hole from the outside in the radial direction toward the inside.

[Operation] In the electromagnetic clutch, the armature is magnetically attracted to the friction surface of the rotor by the magnetic attraction force of the excitation coil, so that the rotor and armature rotate together. Further, the outer ring of the bearing press-fitted into the center hole of the rotor is firmly fixed by the caulking protrusion and the abutting part consisting of an inward protrusion formed on the peripheral wall of the inner cylindrical part of the rotor.

[Embodiment] FIG. 1 is a longitudinal sectional side view showing a first embodiment of an electromagnetic clutch according to the present invention.
is mounted, for example, on the machine frame 2 of a compressor as an auxiliary machine for an automobile. Reference numeral 3 denotes a yoke having an excitation coil 4 installed therein, and is fixed to the side surface of the machine frame 2 with screws via a mounting plate. Reference numeral 5 denotes a rotor which is supported on the cylindrical portion 2a of the machine frame 2 via a bearing 6 so that it can freely rotate with a part of the yoke 3 loosely fitted therein. An annular member having an L-shaped cross section and consisting of a disc member 5b whose front face is a friction surface 5d, and the disc member 5.
It is formed into an annular member having a substantially U-shaped cross section, and is formed on the outside of b with an outer cylindrical member 5c which is electron beam welded, for example. In addition, the code 7 is the disk member 5
b is a circular arc-shaped slit which is press punched, and reference numeral 8 is a belt groove in which a V-belt (not shown) is stretched. Reference numeral 9 denotes an armature that faces the friction surface 5d of the rotor 5 at a predetermined distance. It is supported by the rotary shaft 10 and is movable only in the axial direction with respect to the rotating shaft 10.

In the electromagnetic clutch 1 having such a structure, since the rotor 5 is rotated via the V-belt when the automobile engine is started, the excitation coil 4 is rotated.
The armature 9 is magnetically attracted to the friction surface 5d of the rotor 5 by the magnetic attraction force of the magnetic flux generated by energization. Power is then transmitted to a rotary shaft 10 of a compressor that is integrally connected to this armature 9. Furthermore, when the excitation coil 4 is de-energized, the armature 9 is moved by the leaf spring 12 to the friction surface 5 of the rotor 5.
Since it is spaced apart from d, the transmission of power to the rotating shaft 10 side is cut off.

Next, a structure for fixing the bearing 6 in the axial direction according to the present invention will be explained.

The inner cylindrical portion 5a of the rotor 5 is formed with an abutting portion 14 consisting of an inward protrusion pushed out from the outside in the radial direction into the center hole 13 of the rotor 5 by pressing with a flat head punch. ,
The outer ring 6a of the bearing 6 is press-fitted into the center hole 13 of the rotor 5, and one end of the outer ring 6a is brought into contact with the abutment part 14, and the other end of the outer ring 6a is pressed by the caulking projection 15 of the rotor 5. The bearing 6 is firmly fixed in the center hole 13 of the rotor 5 by being fixed so as not to come off. In addition, the rotor 5
The extrusion dimension of the abutment part 14 into the center hole 13 is small with respect to the radial wall thickness dimension of the inner cylindrical member 5a, and the abutment part 14 from the friction surface 5d of the rotor 5 is small.
This is a very small dimension compared to the previous axial dimension. Furthermore, the abutting portion 14 is connected to the inner cylindrical portion 5a.
It is formed at intervals on the same circumference, for example, at angular positions divided into 3 or 6 equal parts in the circumferential direction, and the amount of plastic flow of the material is small and the mechanical strength of the plastically deformed part is low. can be sufficiently secured.

FIG. 2 is a longitudinal sectional side view showing a second embodiment of the electromagnetic clutch according to the present invention. This electromagnetic clutch 1
6 is different from the electromagnetic clutch 1 shown in FIG. 1 in that the abutting part 14 is formed by pressing with a flat head punch, but is formed by pressing with an acute angle punch, except for the cross-sectional shape of the abutting part 17. The other structure is the same as the electromagnetic clutch 1.

In addition, in the above explanation, the electromagnetic clutches 1,
Although a structure in which 16 rotors 5 are supported on a cylindrical portion 2a formed in a compressor frame 2 via bearings 6 so as to be freely rotatable has been disclosed, it is also possible to support them on a rotating member such as a rotating shaft of a compressor, for example. It may also be a structure. Also,
A caulking protrusion 1 is provided on the rotor 5 to prevent the bearing 6 from coming off.
5 has been disclosed, however, a structure for fixing the bearing 6 to prevent it from coming off using a snap spring or the like may also be used.

[Effect] As described above, in the present invention, the rotor has at least two
The inner cylindrical member has a hole that becomes the center hole of the rotor, and has an abutment part that is pushed out from the outside in the radial direction into the center hole by press working, and the abutment part and the rotor Since the outer ring of the bearing is firmly fixed in the center hole of the rotor using caulking protrusions, etc., there may be problems with machining of the abutment part during press working, or when the bearing is press-fitted into the center hole of the rotor. It is possible to prevent defects in the abutting part caused by the outer ring being hit, as well as defects in the abutting part caused by the pressing force due to caulking on the side of the bearing outer ring opposite to the abutting part, thereby reducing defects in the production process. Loss is reduced and it is economical.

It also prevents damage to the abutting part due to external loads such as vibrations from the engine of a car or while driving.
We can provide electromagnetic clutches with high quality and reliability.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing a first embodiment of an electromagnetic clutch according to the present invention, and FIG. 2 is a longitudinal sectional side view showing a second embodiment of an electromagnetic clutch according to the invention. In the drawings, 1, 16...electromagnetic clutch, 3
... Yoke, 4 ... Excitation coil, 5 ... Rotor,
5a...Inner cylindrical member, 5d...Friction surface, 6...
Bearing, 6a... Outer ring, 9... Armature, 1
4, 17...Abutment part.

Claims (1)

[Claims] 1. A yoke in which an excitation coil is installed, a rotor having a substantially U-shaped cross section supported on a stationary member or a rotating member through a bearing so that it can freely rotate with a part of the yoke loosely fitted therein; and an armature facing the friction surface at a predetermined distance, one end of the outer ring of the bearing abuts against an abutting part consisting of an inward protrusion press-formed on the peripheral wall of the center hole of the rotor. In the electromagnetic clutch,
The rotor is composed of at least two members, and the abutment portion is formed by press working on an inner cylindrical member having a hole that becomes the center hole of the rotor, and is pushed out from the outside in the radial direction into the center hole. An electromagnetic clutch characterized by: