JPS6242182Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of an electromagnetic coupling device, and aims to reduce the weight and manufacture it at low cost.

First, the structure of the conventional device will be explained with reference to FIG. In FIG. 1, 1 is a machine frame such as a compressor, 2 is a plate fixed to the machine frame 1 with bolts (not shown), 3 is an annular stator fixed to this plate 2 by welding, etc., and 4 is a resin 5
excitation coil fixed by 6, rotor 6a
7 is an annular groove for blocking magnetism, 7 is a bearing fitted into the cylindrical portion 1a of the machine frame 1, 8 is a pulley integrated with the rotor 6 by welding, etc. A belt 17 from a drive source that does not operate is fitted. Reference numeral 9 indicates an armature disposed opposite to the rotor 6 through a gap g and supported by a leaf spring 10. Reference numeral 11 indicates a boss fixed to the rotating shaft 12 via a key 13. Reference numerals 14 and 15 connect the leaf spring 10 to the armature 9 and A rivet 16 fixed to the boss 11 is a bush for controlling the position of the armature 9, and the leaf spring 10 and the bush 16
are set up at several locations around the area.

The operation of the structure described above will be explained next. First, when the excitation coil 4 is deenergized, the rotor 6 and the pulley 8 continue to rotate together as a unit by the drive source, but the armature 9 is rotated by the leaf spring 1.
0, it is in contact with the bush 16, and the rotor 6
are opposed to each other with a gap g interposed therebetween. Therefore, the rotating shaft 12 is stopped and the compressor 1 does not rotate. Next, when the exciting coil 4 is energized, a magnetic flux Φ is generated as shown by the dotted line in the figure, and the armature 9 is attracted and adhered to the rotor 6 against the elastic force of the leaf spring 10, and the rotational force is transferred to the plate. 10 springs, 1 boss
1 to the rotating shaft 12.

Among the structures and operations described above, as shown in the present structure, the one in which the pitch diameter of the pulley groove 8a is reduced can increase the rotation of the compressor, thereby increasing the cooling capacity. Therefore, the compressor can be made smaller to that extent, contributing to compactness and weight reduction. However, the electromagnetic coupling device as a whole is expensive. That is, since the pulley groove 8a is considerably smaller and deeper than the outer diameter of the pulley 8, it takes a lot of time to machine the pulley groove 8a. This becomes expensive and has a poor material yield, and furthermore, the length of the magnetic path of the magnetic flux Φ becomes even slightly longer, and the diameter of the wire of the exciting coil 4 must be increased accordingly to increase the magnetomotive force. Ta. Therefore, the weight becomes relatively heavy and the cost increases, resulting in little merit from an overall perspective.

This idea was made in consideration of the above points,
An embodiment of this invention will be described below with reference to FIG. 18 is a pulley, 18a is its pulley groove, 18
b is a collar portion to be welded to the rotor 6, and the pulley 18 is set smaller than the outer diameter of the rotor 6 and larger than the outer annular groove 6a.

The rest of the structure is the same as that shown in FIG. 1, so the explanation will be omitted.

In the above structure, the operation is the same as the conventional one, but in the present invention, the collar portion 18b of the pulley 18
Since it is set smaller than the outer diameter of the rotor 6, the depth of the pulley groove 18a is only the depth necessary for the belt 17, the machining work is greatly reduced, and the yield of material is also improved. Therefore, the overall weight can be reduced and the device can be manufactured at low cost.Furthermore, the length of the magnetic path can be slightly shortened, and the size of the excitation coil 4 can also be reduced. Note that the size of the friction surface of the rotor 6 has not been changed at all, so the size of the transmitted torque is not affected in any way.

As described above, according to the present invention, the outer diameter of the pulley 18 is set smaller than the outer diameter of the rotor and larger than the outer annular groove for magnetic shielding, so weight reduction can be achieved without affecting torque in any way. It has the advantage of being easy to use and can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a conventional electromagnetic coupling device, and FIG. 2 is a partial sectional view showing an embodiment of this invention. In the figure, 3 is a stator, 4 is an excitation coil, 6 is a rotor, 6a is an annular groove, 9 is an armature, 17 is a belt, 18 is a pulley, 18a is a pulley groove, and 18b is a collar. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A rotor having a friction surface, an armature having an outer diameter equal to the outer diameter of the rotor and movably disposed in the axial direction via a gap, an excitation device for bringing the rotor and armature into pressure contact, and a counter armature of the rotor. In a device equipped with a power transmission pulley that is fixed to the side and forms part of the magnetic path, the outer diameter of the collar of the pulley is smaller than the outer diameter of the rotor and larger than the magnetic cutoff annular groove of the rotor. An electromagnetic coupling device characterized by: