JPS6238022Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvements in the cover and hub flange structure of a coil spring in an electromagnetic spring clutch.

A conventional electromagnetic spring clutch will be described with reference to FIGS. 1 and 2. In the figure, 1 is a driven device, such as a compressor for a car cooler, 1a is its main shaft, 10 is a cylindrical protrusion that includes the main shaft 1a and projects in the axial direction, and 20 is rotated by a rotational drive source. It has a pulley part 21, a friction surface part (friction surface) 22 provided at one end in the axial direction, and a flange part 22a protruding in the axial direction from the inner diameter end thereof, and is rotatably supported on the cylindrical projection 10. 37 is a core portion containing an excitation coil 31 fixed stationary in a space within the clutch rotor 20; 40 is a friction surface 22 of the clutch rotor 20;
a ring-shaped suction plate placed oppositely with a predetermined gap,
50 is a clutch hub fixed to the end of the main shaft 1a, 60 is wound around the outer peripheral surface of the flange portion 22a, and one end 61 is connected to the suction plate 40 at the other end 62.
The hub flange 51 formed thickly on the hub 50
70 is a spring cover attached to the hub flange 51 so as to cover the outer peripheral edge of the coil spring 60 and the suction plate 40, and 80 is a recess on the side of the suction plate 40 in contact with the spring cover 70. A permanent magnet is embedded and fixed at 41 to attract the suction plate 40 to the spring cover 70, and 90 is a bolt for attaching the spring cover 70 to the hub flange 51.

In this configuration, when an excitation current is applied to the excitation coil 31, a magnetic flux φ as shown by an arrow in the figure
A flow of
The clutch rotor 20 and the suction plate 40 are rotated simultaneously, and then the coil spring 60 is tightened around the flange 22a to connect the flange 22a and the hub 50, and the clutch rotor 20 is attached to the main shaft 1a. The rotational motion of is transmitted.

In such a conventional electromagnetic spring clutch, a notch 5 is provided in order to lock the other end 62 of the coil spring 60 to the outer periphery 51a of the hub flange 51.
2, but the coil spring 6
In order to prevent the 0 from moving inward in the axial direction, the notch 5 is formed so as to leave a portion of the inner part of the outer periphery 51a in the axial direction.
2 must be provided. However, this method does not allow press punching and has to be carried out by milling using an end mill or the like, which has the drawback of requiring a long processing time. Also,
The outer periphery 51a of the hub flange 51 requires a notch 52 in which the other end 62 of the coil spring 60 is locked and a space for the part around which the coil spring 60 is wound, so the hub flange 51 must be thick. This increases the weight and cost of the electromagnetic spring clutch. Furthermore, since the hub flange 51 is formed thick as described above, the heads 91 of the bolts 90 for attaching the spring cover 70 to the hub flange 51 protrude outward in the axial direction, and the axial width W ₁ increases. This also led to the need for larger electromagnetic spring clutches.

In view of the above-mentioned drawbacks, the present invention provides a cover that covers the coil spring and a hub flange extending radially outward of the hub to lock the other end of the coil spring and to rotate the coil spring around the main axis. A recessed part extending in the circumferential direction and recessed inward in the axial direction of the main shaft is provided, the hub flange is formed thin, and the recessed part is attached to the thin part via bolts. The purpose of this is to shorten the machining time for the cover and hub flange, and to make the electromagnetic spring clutch lighter and smaller. The drawings will be explained below.

3 and 4 show an embodiment of the present invention, and the same components as those of the conventional example are denoted by the same reference numerals. That is, in the figure, 1 is a driven device, such as a compressor for a car cooler, 1a is its main shaft, 10 is a cylindrical protrusion that includes the main shaft 1a and projects in the axial direction, and 20 is a driven device that is rotated by a rotational drive source. The pulley portion 21 is formed by the pulley portion 21, a friction surface portion (friction surface) 22 provided at one end in the axial direction, a flange portion 22a protruding from the inner diameter end portion in the axial direction, and the pulley portion 21 and the friction surface 22. It consists of a non-magnetic ring 23 provided in an internal space. The inner diameter portion of the non-magnetic ring 23 is joined to a bearing 11 fitted on the outer periphery of the cylindrical projection 10, whereby the clutch rotor 20 is rotatably supported on the cylindrical projection 10. 30 is a core portion that is stationary and fixed in the space within the clutch rotor 20 and includes an excitation coil 31; 40 is a friction surface 22 of the clutch rotor 20;
This is a ring-shaped suction plate that is placed opposite the holder with a predetermined gap. A permanent magnet 80 is embedded and fixed in a recess 41 on the side in contact with a spring cover 110, which will be described later, to attract the attraction plate 40 to the spring cover 110.

A coil spring 100 is wound around the outer peripheral surface of the flange portion 22a, and one end 101 is engaged with the suction plate 40, and the other end 102 is engaged with the spring cover 110. 110
is a spring cover (hereinafter simply referred to as the cover) of the coil spring 100. The cover 110 also includes an annular protrusion 11 that extends circumferentially outward about the main shaft 1a and protrudes outward in the axial direction.
1 is provided. In addition, the main shaft 1 of the annular protrusion 111
A depressed portion 1 is provided on the a side by being depressed inward in the axial direction.
12 are formed. Reference numeral 120 indicates three bolt holes provided in the depressed portion 112 at predetermined intervals. 130 is the other end 10 of the coil spring 100
2 is a locking portion of the cover 110 to which the cover 110 is locked, and is provided so as to penetrate through the inner circumferential surface of the annular protrusion 111 and a part of the recessed portion 112. 140 is a clutch hub fixed to the end of the main shaft 1a. 1
Reference numeral 50 denotes a hub flange extending radially outward from one end of the hub 140, and its wall thickness is formed to be thin enough to allow the coil spring 100 to be wound around it. 160 is a bolt hole of the flange 150 into which a bolt 170 is screwed;
It is provided at a position corresponding to the bolt hole 120 of No. 0. Numeral 170 is a bolt that fastens the cover 110 and the flange 150 of the hub 140 through the bolt hole 120 of the recessed portion 112 and the bolt hole 160 of the flange 150.

In the above configuration, when an excitation current is applied to the excitation coil 31, a flow of magnetic flux φ occurs as shown by the arrow in the figure, and the suction plate 40 is attracted to the friction surface 22 of the clutch rotor 20, so that the clutch The rotor 20 and the suction plate 40 rotate simultaneously, and then the cover 110 locks the other end 102 of the coil spring 100 with rotational movement by tightening the coil spring 100 around the flange 22a.
The power is transmitted to the hub 140 and the main shaft 1a.

According to the embodiment described above, the other end 102 of the coil spring 100 is engaged with the engaging portion 130 of the cover 110, so that the hub flange 150
The other end 10 of the coil spring 100 is made thicker.
Therefore, it is not necessary to provide the notch 52 for engaging the retainer 2.
In addition, unlike the case where the notch 52 is provided in the flange portion 51 of the hub 50, there is no need to cut the notch 52 so as to leave a portion of the outer periphery 51a of the flange 51 on the axially inner side.
0 can be formed. Furthermore, the cover 11
Since the bolts 170 that fasten the flange 150 of the bearing 100 and the hub 140 are attached to the thin flange 150 and to the recessed portions 112 that are recessed axially inward, the axial width _W2 can be reduced.

As explained above, according to the present invention, the other end of the coil spring is locked to the cover that covers the coil spring and the hub flange extending radially outward of the hub, and The hub flange is formed with a thin wall, and the recessed portion is attached to the thin wall with bolts, so that the coil spring can be used in addition to the coil spring. The locking part that locks the end can be formed in a short time by press punching, and since the locking part is not provided on the hub flange, the hub flange can be made thinner and lighter. , and it is possible to reduce costs. Furthermore, since the recessed part of the cover that is recessed inward in the axial direction of the cover is attached to the thin hub flange via bolts, the head of the bolt fits into the recessed part, making it possible to reduce the width in the axial direction. This makes it possible to downsize the electromagnetic spring clutch.

[Brief explanation of drawings]

The drawings are for explaining the present invention. Figures 1 and 2 show an example of a conventional electromagnetic spring clutch. Figure 1 is a sectional view of the clutch, and Figure 2 is a partially cutaway perspective view showing the main parts. 3 and 4 show an electromagnetic spring clutch according to the present invention, FIG. 3 is a sectional view thereof, and FIG. 4 is a partially cutaway perspective view showing the main parts thereof. In the figure, 1a... Main shaft, 10... Cylindrical protrusion, 20
...Clutch rotor, 30...Core part, 40...
Suction plate, 50... Hub, 60, 100... Coil spring, 70, 110... Spring cover, 112... Recessed part, 120, 160... Bolt hole, 130... Locking part, 140... Hub, 15
0...Flange, 170...Bolt.

Claims (1)

[Scope of utility model registration request] A clutch rotor that is rotationally driven by a rotational drive source and has a flange protruding in the axial direction from the inner diameter end of a friction surface provided at one end of the clutch rotor in the axial direction, and a coil wound on the outer peripheral surface of the flange. A suction plate with one end of the spring locked is included in the magnetic circuit of an excitation coil disposed in the clutch rotor, and by energizing the excitation coil, the suction plate is attracted and joined to the friction surface, and the coil spring In an electromagnetic spring clutch that connects a hub and a flange portion of a main shaft of a driven device by tightening, a cover that covers the coil spring and the hub flange extending radially outward of the hub includes: providing a recessed portion that locks the other end of the coil spring, extends in the circumferential direction around the main shaft, and is recessed inward in the axial direction of the main shaft; further, the hub flange is formed thin;
An electromagnetic spring clutch characterized in that the recessed portion is attached to the thin walled portion via a bolt.