JPS595234Y2 - Automatic air gap adjustment device for electromagnetic clutches and brakes - Google Patents

Description

[Detailed description of the invention] This invention is a so-called leaf spring type electromagnetic clutch or an electromagnetic brake armature in which the plate supporting the armature has both the function of returning the armature and the function of a power transmission member. This invention relates to a device for automatically adjusting the air gap between the opposite magnetic pole surfaces.

In the case of this type of leaf spring type electromagnetic clutch or brake,
It has the advantage that there is no buckling like when splines or pins are used to connect the power of the armature, and there is no noise caused by buckling. The disadvantage is that there is a problem with the magnetic gap adjustment mechanism.

First, let us explain about the conventional device shown in Fig. 1. In the figure, 1 is a rotor connected to a drive shaft (not shown) on the drive side, and the outer circumference is connected to other parts by a non-magnetic ring 2. The inner and outer magnetic pole portions are configured with the non-magnetic material ring 2 as a boundary.

Reference numeral 3 denotes an electromagnet having an electromagnetic coil 4 whose magnetic pole portion faces the rotor 1 across a magnetic gap.

Reference numeral 5 denotes a mounting plate for preventing rotation of the electromagnet 3, and fixes the electromagnet to a suitable fixing part (not shown).

6 is a return leaf spring 8 attached to the armature hub 7 which is the driven side.
The armature is attached via the armature and faces the magnetic pole face of the rotor 1 on one side with a magnetic gap g1 in between.

Reference numeral 9 is a sliding pin that also serves as a connecting bolt between the armature 6 and the leaf spring 8, and is attached horizontally to the back surface of the armature.

10 is a bushing press-fitted into the sliding pin 9, which allows the pin 9 to slide relative to the bushing based on the attraction movement caused by the electromagnetic attraction force of the armature 6, but due to the impact force when the armature is released. has a holding force against the sliding pin to restrain its sliding movement.

In addition, there are locking pieces 1 formed on the hub 7 on both sides of the bushing 10.
1 and 12 are facing each other, and usually one side of the bushing 10 is in contact with one of the locking pieces 11, and the other locking piece 1
A gap g2 is made to exist between the other side of the bushing 2 and the bushing, and this gap g2 and the magnetic gap g1 are set equal to each other.

When used as a clutch in the above configuration, when current is supplied to the electromagnetic coil 4, it comes out from one magnetic pole of the electromagnet 3, passes through the outer circumference of the rotor 1, the armature 6, and the inner circumference of the rotor in order, and then passes through the electromagnet. A magnetic flux is generated that returns to the other magnetic pole of 3, and the armature 6 receives the electromagnetic attractive force from the leaf spring 8.
is attracted toward the magnetic pole surface of the rotor 1 against the force of the rotor, and is brought into pressure contact with the transmission friction surface formed on the rotor. It is transmitted to the driven side load (not shown), and when the power supply to the electromagnetic coil 4 is cut off, the electromagnetic attractive force disappears, so the armature 6 is returned to the original position shown by the force of the leaf spring 8, and the power is transmitted. is blocked.

In the above case, when the transmission friction surface is worn and the magnetic gap g1 between the armature 6 and the magnetic pole surface of the rotor 1 becomes large,
When the armature 6 is attracted, the bush 10 on the pin 9 that is moved together with it abuts the locking piece 12, and a gap corresponding to the above wear amount exists between the armature 6 and the rotor 1. The holding force of the bushing against the pin is set so that the electromagnetic attraction force against the armature at this time exceeds the sliding load of the bushing 10 against the pin 9. Therefore, in the suction process of the armature 6, which is subsequently attracted, the pin 9 Only the bushing 10 is forced to slide inside the bushing while leaving the bushing 10, and as a result, the bushing 10 is moved relative to the tip (leftward in the drawing) on the pin 9 by the amount of wear mentioned above. It will be.

When the clutch is released, the armature is released and moved until the other side of the bushing 10 hits the other locking piece 11 and its movement is suppressed.

That is, the holding force of the bushing against the pin is set so that the bushing 10 and the pin 9 do not move relative to each other due to the impact force of the armature release at this time.

Therefore, the armature 6 assumes a position with an initially set air gap g1 between it and the magnetic pole surface of the rotor 1, and the air gap is eventually adjusted.

Such an operation is repeated each time the clutch is engaged or released depending on the wear of the transmission friction surface, and the gap g1 is automatically adjusted. However, in the conventional configuration, the magnetic gap g1 is not automatically adjusted. However, the amount of deflection of the leaf spring 8 changes each time it is adjusted and gradually increases, causing changes in characteristics such as suction and release time of the armature.

That is, the suction time of the armature becomes longer and the release time becomes shorter.

The present invention is intended to solve such problems, and the embodiments shown in FIGS. 2 to 5 will be described below.

The drawings show only the improved parts and are shown in Figure 13.
is an intermediate plate attached to the inner surface of the armature hub 7 via a retaining leaf spring 14, and the armature 6 is attached to this intermediate plate.
is attached via a leaf spring 15 for return.

Reference numeral 16 denotes a locking pin having a threaded portion for coupling the armature 6 and the leaf spring 15, which is coupled to each other by a threaded portion, and has a flange portion 17 at the head.

An axial gap g2 exists between one side surface of the flange portion 17 of the locking pin 16 and the locking piece 18 formed on the hub 7 to face this, and the length of this gap is the length between the armature 6 and the rotor 1. is set equal to the magnetic gap g1 of the friction surface.

Reference numeral 19 denotes a sliding pin installed laterally in the intermediate plate 13, into which the bushing 20 held in the recess of the hub 7 is press-fitted.

One embodiment of the present invention is constructed as described above, and the basic function of the present invention as a clutch or brake is the same as that of the above-mentioned conventional one, so the explanation thereof will be omitted, but the transmission between the armature 6 and the rotor 1 will be explained below. When the friction surface is worn, when the locking pin 16 is moved integrally with the armature 6 by suction movement due to power supply to the electromagnetic coil, the gap g1 between the armature 6 and the rotor 1, the flange portion 17 of the pin 16, and the intermediate plate are removed. Since the gaps g2 between the 13 locking pieces 18 are set equal, the intermediate plate 13 is moved in the same direction as the armature by the flange portion 17 of the pin 16 by an amount corresponding to the wear of the transmission friction surface. It happens.

Then, due to the movement of this intermediate plate, the sliding pin 19
is moved by sliding inside the bushing against the holding force of the bushing 20.

That is, in order to enable this sliding movement, the electromagnetic attraction force at this time is related to the holding force due to press fitting of the bushing 20 to the locking pin 19.

Next, when the power supply to the electromagnetic coil is cut off and the armature 6 is released, the armature is released and moved by the force of the return leaf spring 15 until it collides with the intermediate plate 13 and its movement is suppressed.

As described above, the intermediate plate 13 is displaced toward the rotor 1 by the amount of wear on the transmission friction surface during the armature suction movement process, and depending on the impact force on the intermediate plate 13 when the armature is released, Since the holding force of the bushing against the sliding pin is set so that the sliding pin 19 does not slide inside the bushing 20, the armature 6 has been moved back by the originally set gap of 21 minutes, and the This means that the gap g1 has been adjusted.

FIGS. 4 and 5 show another embodiment, except that this embodiment is characterized in that each of the leaf springs corresponding to the holding leaf spring 14 and the return leaf spring 15 is formed into an arc shape. Since there is no difference in structure and operation from the above embodiment, the same or corresponding parts as in the above embodiment will be given the same reference numerals, and the explanation thereof will be omitted.

In this way, this invention does not require that the gap adjustment mechanism consisting of a sliding pin and a bushing press-fitted into the sliding pin be provided directly on the armature, but rather on an intermediate plate that is supported by a retaining leaf spring on the armature hub. The armature is supported by this intermediate plate via a return leaf spring, and a locking pin is provided on this armature, and the intermediate plate is moved to follow the movement corresponding to the wear of the transmission friction surface of the armature, and The posture of the plate after the above-mentioned follow-up movement is maintained by a holding plate spring, and each time the armature is repeatedly engaged and released according to the wear of the transmission friction surface, the magnetic gap of the armature is adjusted and held constant. Of course, as a result, the gap adjustment is performed by moving the intermediate plate due to the deflection of the holding leaf spring, so the conditions for the return leaf spring that directly supports the armature are such that regardless of the gap adjustment. It will always remain as it was originally, so that the engagement and release characteristics of the armature remain unchanged, and its operating characteristics remain constant throughout the life of the clutch or brake.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the upper half of a conventional device, Figures 2 and 3 are cross-sectional views of the upper half of an embodiment of the present invention, Figure 2 shows the device when it is released, and Figure 3 shows the device when released. The time of combination is shown respectively. 4 and 5 are a front view and a sectional view taken along line AA' in FIG. 4, respectively, showing another embodiment of the present invention. 6... Armature, 7... Armature hub, 13... Intermediate plate, 14...
Holding leaf spring, 15... Returning leaf spring, 16.
...Locking pin, 19...Sliding pin, 20
...Butshu.

Claims (1)

[Scope of utility model registration request] An intermediate plate attached to the armature hub via a retaining leaf spring, an armature attached to this intermediate plate via a return leaf spring, and an armature connected to this armature that corresponds to the wear of the transmission friction surface. A locking pin that suppresses relative movement with respect to the intermediate plate, a sliding pin connected to the intermediate plate, and a holding force that is press-fitted into the sliding pin and held by the armature hub, and due to the press-fitting to the sliding pin. is equipped with a bush set to be larger than the impact force when the armature is released, and the intermediate plate is held by a holding leaf spring so that only the moving bone corresponding to the wear of the transmission friction surface of the armature is displaced. An automatic air gap adjustment device for electromagnetic clutches and brakes featuring: