JPH0439472Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is an automatic air gap adjustment device for electromagnetic clutches and brakes. This invention relates to an automatic gap adjustment device for always adjusting the gap between the plate and the plate.

(Prior art and problems) When the armature of an electromagnetic clutch/brake is released, the gap between the armature and the friction plate of the rotor field is always maintained at a constant value (for example, 0.5 mm), and the armature suction time by coil excitation is always kept constant. It is necessary to keep it. This is because as the number of times the electromagnetic clutch/brake engages and brakes increases, the friction surface wears out and the gap widens.The armature suction time due to coil excitation becomes longer, slowing down the engagement/braking operation, and further widens the gap. This is because if the coil becomes worn out, even if the coil is energized, the attraction force will not be applied to the armature, resulting in a failure in which connection and braking will not occur, so it is necessary to prevent this.

Figures 2 and 3 show the first and second automatic air gap adjustment devices for electromagnetic clutches and brakes described in the specification of Japanese Patent Application No. 61-266589 and Japanese Patent Application Laid-open No. 120921/1983 by the present inventor. This is a second embodiment,
The electromagnetic clutch/brake was published in 1983-13143.
Since the structure is substantially the same as that described in the specification of Japanese Patent Application No. 61-266589 except for the automatic gap adjusting device, the automatic gap adjusting device will be mainly described.

First, the first embodiment shown in FIGS. 2A and 2B is constructed as follows.

The automatic air gap adjustment device in the electromagnetic clutch/brake is driven by a plurality of leaf springs having one end fixed to the hub and the other end fixed to the armature. is fixed to the hub 13 via
A sliding ring 14 is press-fitted into a plurality of through holes provided in the peripheral portion of the hub 13 so as to have a predetermined gripping force, and the rear end portion on the side opposite to the armature protrudes by a predetermined amount. The drive pin 15 has a threaded portion at its tip for fixing the armature 11 and the leaf spring 12, and a flange portion at its rear end, the intermediate shaft portion of which is inserted into the sliding ring 14.

Reference numeral 16 denotes an elastic member such as a disc spring or a wave spring, which is interposed in the axial gap between the end face of the sliding ring 14 and the flange portion of the drive pin 15 so as to be compressible in the axial direction. When the armature is released, the axial gap G3 between the end face of the sliding ring 14 and the flange portion of the drive pin 15 is the axial gap G3 between the armature 11 and the friction plate 17 of the rotor field, as shown in FIG. 2A. The gap G4 is set equal to the sum of L and the axial length l of the elastic member 16, such as a disc spring, when compressed.

The operation of the automatic air gap adjusting device having such a structure is as follows.

When the armature is attracted at the initial stage of use, as shown in FIG. 2B, the armature 11 is attracted to the friction plate 17 and the gap G4 becomes zero, and the flange of the drive pin 15 also moves to the right and slides. An elastic member 16 such as a disc spring is attached to the ring 14.
is pressed, and the gap G3 becomes l. Regarding the effect when the friction surface is worn, the sliding ring 14
By sliding the inner surface of the through hole No. 3 in the armature direction by the amount of wear on the friction surface, the gap between the friction surfaces is always kept constant.

However, in the case of this first embodiment, a disc spring or a wave spring is used as the elastic member 16 which mainly has an armature release function, but the clutch/brake
When it is ON, it is completely flattened and the spring 16
The stress generated within the spring is extremely high, and the spring itself is likely to suffer fatigue failure due to frequent attachment and detachment. Furthermore, when the clutch/brake is turned on, the sliding ring 14 is moved through the leaf spring 12 due to frictional vibrations, load fluctuations, etc.
Since slight repeated slippage occurs between the end face of the drive pin 15 and the flange portion of the drive pin 15, the spring 16 is easily worn out, causing a change in the axial gap between the armature and the friction plate of the rotor field, which also causes problems in the durability of the spring. Become.

Next, since the second embodiment shown in FIGS. 3A and 3B shows different parts from the electromagnetic clutch/brake shown in FIGS. 2A and 2B, the different parts will be described.

Reference numeral 18 denotes an elastic member such as a coil spring or rubber, which is interposed in the axial gap between the stepped portion provided at the end portion of the sliding ring 19 on the side opposite to the armature and the flange portion of the drive pin 20. Then, the axial gap G5 between the end face of the sliding ring 19 and the flange portion of the drive pin 20 when the armature is released.
is armature 1, as shown in Figure 3A.
1 and the friction plate 17 of the rotor field is set equal to the axial gap G6=L.

The operation of the automatic air gap adjusting device having such a structure is as follows.

When the armature is attracted at the initial stage of use, as shown in FIG. 3B, the armature 11 is attracted to the friction plate 17 and the gap G6 becomes zero, and the flange of the drive pin 20 also slides to the right to close the gap. G5 becomes 0. Regarding the effect when the friction surface is worn, the sliding ring 19 slides on the inner surface of the through hole of the hub 13 in the direction of the armature by the amount of wear on the friction surface, so that the gap on the friction surface is always kept constant. It is.

However, in the case of this second embodiment, the sliding ring 1
No. 9 has a stepped portion at the rear end, making it difficult to press, and requiring machining, resulting in high costs. In addition, coil springs or rubber are used as elastic members, but due to the structure, the axial length when free is not long enough, and the rate of deflection is extremely large, so the clutch/brake is turned on and off.
For example, if the spring is set when ON, the pressurization will be small when OFF, and the armature will easily chatter back and forth due to rotational vibration when idling, which is not desirable in terms of the function of the automatic air gap adjustment device. There is.

Similarly, the assembled length of the elastic member 18 is limited to a short length, and the wire diameter and number of turns of the spring are also limited, making it difficult to design and select the spring 18 freely. Furthermore, since the elastic member 18 is exposed to the outside, it is easily deformed by external force, and especially during high-speed rotation, the spring swells in the radial direction due to centrifugal force, causing problems such as impeding normal operation.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention changes the shape of the sliding ring and forms a thin plate with an inward flange at the front end of the cylindrical body. In addition, the mounting position of the elastic member has been changed, and the elastic member is interposed between the inward flange of the front end of the sliding ring and the flange of the drive pin. This allows a long coil spring elastic member to be stored.

(Embodiment) Hereinafter, an embodiment of an automatic air gap adjustment device for an electromagnetic clutch/brake according to the present invention will be described with reference to FIGS. 1A, B, and C.

The electromagnetic clutch/brake shown in Figure 1 has substantially the same construction as the one described in the specification of Japanese Patent Application No. 61-266589 shown in Figures 2 and 3, except for the automatic gap adjustment device. Therefore, I will explain the differences between them.

The automatic air gap adjustment device in the electromagnetic clutch/brake is driven by a plurality of leaf springs with one end fixed to the hub and the other end fixed to the armature, as shown in Fig. 1A and B. The armature 1 is fixed to the hub 3 via a plurality of, for example, three leaf springs 2, and the sliding ring 4 is press-fitted into a plurality of through holes provided around the hub 3 so as to have a predetermined gripping force. The rear end on the side opposite to the armature is made to protrude by a predetermined amount. Sliding ring 4
As for the shape of , as shown in Figure 1C,
An inward flange 4a is formed at the front end of the cylindrical body. Also, a hub 3 is attached to the body of the sliding ring 4.
A slit 4b may be provided in the axial direction so that it can be press-fitted with a predetermined gripping force into a through hole provided in the. The drive pin 5 has a threaded portion at its tip for fixing the armature 1 and the leaf spring 2, and has a flange portion at its rear end having an outer diameter larger than the inner diameter of the sliding ring 4, and its intermediate shaft portion is connected to the sliding ring. 4 is inserted.

Reference numeral 6 denotes an elastic member, which is a coil spring in this embodiment, and is compressible in the axial direction within the axial gap between the inward flange formed at the front end of the sliding ring 4 and the flange of the drive pin 5. It has been intervened. The axial gap G1 between the rear end surface of the sliding ring 4 and the flange portion of the drive pin 5 when the armature is released is the axial gap G1 between the armature 1 and the friction plate 7 of the rotor field, as shown in FIG. 1A. The directional gap G2 is set equal to l.

The deflection load of the elastic member such as the coil spring is set so that the following relationship is satisfied: suction force of the armature > hub press-fit holding force of the sliding ring > leaf spring deflection load + deflection load of the elastic member.

The operation of the automatic air gap adjusting device having such a structure is as follows.

When the armature is attracted at the initial stage of use, as shown in FIG. 1B, the armature 1 is attracted to the friction plate 7 and the gap G2 becomes zero, and the flange of the drive pin 5 also moves to the right to close the gap G1.
also becomes 0. Regarding the effect when the friction surface is worn, the sliding ring 4 slides on the inner surface of the through hole of the hub 3 in the direction of the armature by the amount of wear on the friction surface, so that the gap on the friction surface is always kept constant. It is.

(Effects of the invention) Since the automatic air gap adjustment device for electromagnetic clutches and brakes according to the invention is configured as described above, (1) By changing the shape of the sliding ring, it can be made into a press, and this component can be manufactured at low cost. This reduces manufacturing costs.

(2) Furthermore, since it is possible to store an elastic member in the space between the sliding ring and the drive pin, the sliding ring serves as a protective cover, making it less susceptible to external forces, centrifugal force, etc. Since the overall length of the elastic member can be made sufficiently long, it is possible to freely select the wire diameter and number of turns, making it possible to select the optimal release force, and the deflection rate of the elastic member when ON and OFF can be kept small. It becomes possible to realize an automatic gap adjustment device for electromagnetic clutches and brakes that exhibits stable performance with little change in release force and is highly durable.

[Brief explanation of drawings]

FIG. 1A is a partial cross-sectional side view of an embodiment of the automatic air gap adjustment device for an electromagnetic clutch/brake according to the present invention when the armature is released; FIG. 1B is a partial cross-sectional side view of FIG. 1A when the armature is attracted; 1
Figure C is a perspective view of the sliding ring in Figures 1A and B, and Figure 2A is a cross section of the first embodiment of the automatic air gap adjustment device in an electromagnetic clutch/brake disclosed in Japanese Patent Application No. 61-266589 when the armature is released. 2B is a cross-sectional side view of the armature in FIG. 2A when it is attracted, and FIG. 3A is the armature of the second embodiment of the automatic air gap adjustment device in an electromagnetic clutch and brake disclosed in Japanese Patent Application No. 61-266589. FIG. 3B is a partially sectional side view of the armature shown in FIG. 3A when it is attracted. 1... Armature, 2... Leaf spring, 3... Hub, 4... Sliding ring, 4a... Inward flange, 4b... Slit, 5... Drive pin, 6...
Elastic member, 7... Friction plate, 11... Armature, 12... Leaf spring, 13... Hub, 14... Sliding ring, 15... Drive pin, 16... Elastic member, 17... Friction plate, 18...Elastic member, 19...
...Sliding ring, 20...Drive pin.

Claims (1)

[Claims for Utility Model Registration] (1) In an electromagnetic clutch/brake driven by a leaf spring whose one end is fixed to a hub and the other end is fixed to an armature, an inward flange is formed at the front end of the cylindrical body. Several sliding rings are press-fitted into several through holes provided at the periphery of the hub, each with a predetermined gripping force, so that the rear end protrudes by a predetermined amount, and the armature and the A shaft portion of a drive pin having means for fixing the leaf spring and having a flange portion at the rear end is inserted into the sliding ring, and the inward flange at the front end of the sliding ring and the flange portion of the driving pin are connected to each other. An axially compressible elastic member is interposed in the axial gap of the armature, and when the armature is released, the axial gap between the rear end surface of the sliding ring and the flange of the drive pin is in contact with the armature. An automatic gap adjustment device for an electromagnetic clutch/brake, characterized in that the gap is set equal to the axial gap between a rotor field and a friction plate. (2) Utility Model Registration The automatic gap adjustment device for an electromagnetic clutch/brake according to claim 1, wherein the elastic member is a coil spring.