JPH023707A - Electromagnetic clutch - Google Patents

Abstract

PURPOSE:To prevent the cut trouble in a butt part and improve economic efficiency and reliability by forming a projecting part towards the inside from the outside onto an inside cylindrical member having a hole for the center hole of a rotor constituted of at least two members, through pressing work. CONSTITUTION:A rotor 5 is constituted of an inside cylindrical member 5a, disc member 5b and an outside cylindrical member 5c. Onto the inside cylindrical member 5a, a butt part 14 is extrusion-formed into the center hole 13 of the rotor 5 towards the inside from the outside in the radial direction through the pressing work by a flat head punch. One edge of the outer race 6a of a bearing 6 is butted onto the butt part 14, and the other edge is fixed, suppressing slip-off, by a caulking projection 15. Therefore, the cut trouble of the butt part 14 can be prevented, and productivity and reliability can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electromagnetic clutch installed in a compressor, etc.
The present invention relates to an improvement in the axial fixation structure of a bearing fitted into the center hole of a rotor.

[Prior Art] Generally, an electromagnetic clutch installed in an automobile compressor is
A yoke that houses an excitation coil is fixed to the outer surface of the compressor frame, and a part of the yoke is loosely fitted onto a cylindrical part integrally formed with the machine frame so as to be freely rotatable via a bearing. A supported rotor having a generally U-shaped cross section faces the friction surface of the rotor with a predetermined gap in the axial direction, and is movable only in the axial direction relative to the tip of the rotating shaft of the compressor protruding from the cylindrical portion. The main component is the arranged armature,
This rotor is directly connected to the engine and rotated at all times by a belt stretched through a belt groove provided on the outer circumference of the rotor.
Connect the electric circuit between the excitation coil and the battery power supply to 0N-
By the magnetic attraction force of the excitation coil generated by OFF control.

The armature is magnetically attracted to the friction surface of the rotor 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, by pressing the peripheral wall of the center hole of the rotor from the friction surface side, 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 ring to prevent removal.
Since the structure is processed by plastic flow of the material by press working, it is possible to obtain a resource saving effect.
(See Publication No. 900).

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 bearing is fixed as a stopper in the same way as above, and this fixing structure can also save resources (Utility Model Application No. 57-166).
(See Publication No. 31).

[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 bearing, which receives a bending moment due to the tension of the belt stretched in the belt groove, must also be designed so that its center is substantially the same as the center of the bottom of the belt groove in the axial direction, so that the bending moment applied to the bearing is reduced.

Therefore, in the abutting part where the circumferential wall of the center hole of the rotor is pressed from the friction surface side, it is not possible to increase the axial dimension between the abutting part and the friction surface, and such a processing method cannot be adopted. In addition, it is not simply a press process, but the abutment part where the circumferential 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, the cut and raised dimensions are long and the plasticity of the material If the flow rate is large, pressing itself is difficult in terms of production technology, 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 designed so that the abutment part does not break due to the pressing force of the press.

An object of the present invention is to provide an electromagnetic clutch that can prevent processing defects, chipping defects, etc., and reduce defective losses in press working of the abutting portion of such a bearing.

[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 with a predetermined gap therebetween, and one end of the outer ring of the bearing is located at the center of the rotor. In an electromagnetic clutch that is brought into contact with an abutting part consisting of an inward protrusion press-worked on a peripheral wall of a 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 is provided. The abutting 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 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 abutting part and the clamping protrusion, which are inwardly directed protrusions formed on the peripheral wall of the inner cylindrical part of the rotor.

[Embodiment] FIG. 1 is a vertical side view showing a first embodiment of an electromagnetic clutch according to the present invention. This electromagnetic clutch 1 is mounted on, for example, a machine frame 2 of a compressor as an automobile auxiliary machine. ing. Reference numeral 3 denotes a yoke that holds an excitation coil 4 inside, and is fixed to the side surface of the machine frame 2 by screwing through a 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 a substantially U-shaped cross section, consisting of a circular member 5b having a friction surface 5d on the front, and an outer cylindrical member 5c, for example, electron beam welded to the outside of the disc member 5b. It is formed in a member. In addition, the code|symbol 7 is a circular arc-shaped slit which was press punched in the disc member 5b, and the code|symbol 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 with a predetermined gap therebetween.
is supported via a leaf spring 12, and is movable only in the axial direction with respect to the rotating shaft 10.

The electromagnetic clutch 1 having such a structure is connected to the rotor 5 through the V-belt when the automobile engine is started.
As the armature 9 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 energizing the excitation coil 4. Power is then transmitted to a rotary shaft 10 of a compressor that is integrally connected to this armature 9. Further, when the excitation coil 4 is de-energized, the armature 9 is separated from the friction surface 5d of the rotor 5 by the leaf spring 12, so that the transmission of power to the rotating shaft 10 is interrupted.

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 pressed from the outside in the radial direction to the inside by a flat head punch.
A butting part 14 consisting of an inward protrusion pushed out into the center hole 13 of the bearing 6 is formed, and the outer ring 6a of the bearing 6 is connected to the rotor 5.
This outer ring 6a is press-fitted into the center hole 13 of the outer ring 6a.
one end of the outer ring 6 is brought into contact with the abutting portion 14, and
The bearing 6 is firmly fixed in the center hole 13 of the rotor 5 by fixing the other end of the rotor 5 with the caulking projection 15 of the rotor 5 so that it cannot be removed. Note that the extrusion dimension of the abutting portion 14 into the center hole 13 is small relative to the radial wall thickness dimension of the inner cylindrical member 5a of the rotor 5, and the friction surface 5 of the rotor 5 is small.
This dimension is very small compared to the axial dimension from d to the abutting portion 14. Further, the abutting portions 14 are formed at intervals on the same circumference of the inner cylindrical portion 5a at angular positions divided into 1, for example, 3 equally spaced or 6 equally spaced in the circumferential direction. The amount of plastic flow is small and the mechanical strength of the plastically deformed part can be ensured sufficiently.

FIG. 2 is a longitudinal sectional side view showing a second embodiment of the electromagnetic clutch according to the present invention. This electromagnetic clutch 16 is different from the electromagnetic clutch 1 shown in FIG. 1 in that the abutment part 14 is formed by press work using a flat head punch, whereas it is formed by press work using an acute angle punch.
The other structure is the same as the electromagnetic clutch 1 except for the cross-sectional shape.

In the above description, a structure is disclosed in which the rotor 5 of the electromagnetic clutch 16 is supported on the cylindrical portion 2a formed in the frame 2 of the compressor so as to freely rotate via the bearing 6. It may also be supported on a rotating member such as a shaft.

Although the caulking protrusion 15 is disclosed on the rotor 5 to prevent the bearing 6 from being removed, a fixing structure may be used to prevent the bearing 6 from being removed using a snap ring or the like.

[Effect] As described above, in the present invention, the rotor is composed of at least two members, and the inner cylindrical member having the hole that becomes the center hole of the rotor is extruded from the outside in the radial direction inward into the center hole by press working. The outer ring of the bearing is firmly fixed in the center hole of the rotor by this abutment and the caulking protrusion of the rotor. When the bearing is press-fitted into the center hole of the rotor, the outer ring of this bearing is hit and the abutment part is damaged, and the abutment part is damaged.Also, the outer ring of the bearing is damaged by the pressing force caused by caulking on the side opposite to the abutment part. It is possible to prevent damage to the contact portion, reduce losses due to defects in the production process, and is economical.

Furthermore, it is possible to prevent damage to the abutting portion due to external loads such as vibrations from the engine of a car or the like while driving, and to provide an electromagnetic clutch with high reliability in terms of quality.

[Brief explanation of the drawing]

FIG. 1 is a vertical side view showing a first embodiment of the electromagnetic clutch according to the present invention, and FIG. 2 is a longitudinal side view showing a second embodiment of the electromagnetic clutch according to the present invention.
FIG. 3 is a vertical side view showing an example. In the drawing. 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, 14.17...
Abutment part. Patent applicant Ogura Clutch Co., Ltd.

Claims (1)

[Claims] a yoke in which an excitation coil is installed; a rotor having a substantially U-shaped cross section and supported on a fixed member or a rotating member via a bearing so as to be freely rotatable with a part of the yoke loosely fitted therein;
and an armature that faces the friction surface of the rotor with a predetermined gap therebetween, and one end of the outer ring of the bearing comes into contact with 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 that is in contact, 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 is pressed into the center hole from the outside in the radial direction toward the inside. An electromagnetic clutch characterized in that the abutting portion is formed.