JPS5912428Y2 - Friction type electromagnetic coupling device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in the connecting surface of a friction type electromagnetic coupling device.

First, a conventional device of this kind will be explained with reference to FIG.

In FIG. 1, 1 is an annular stator, 2 is an excitation coil fixed to this stator, 3 is a holder for fixing the stator 1 from the outside, and 4 is a holder installed in the center hole of the stator 1. The stator 1 is rotatably supported by the stator 1 via a bearing 5.

Reference numeral 6 denotes an annular connecting plate made of low carbon steel fixed to the drive shaft 4, and has an outer connecting surface 6a serving as a magnetic flux path from the excitation coil 2, and an inner connecting surface 6b. It has an annular hole 6C for.

7 is a non-magnetic friction plate 7a fixed to the rotor 6 so as to be flush with the connecting surfaces 6a and 6b; 8 is a friction surface of the friction plate; 8 is coaxial with the drive shaft 4; The arranged driven shaft 9 is an armature made of low carbon steel, which has a friction surface facing each of the connecting surfaces 6a, 6b and the friction surface 7a in the axial direction with a gap g therebetween, and is equipped with a spring 1o. It is connected to the driven shaft 8 through the drive shaft 8.

Next, the operation of this conventional device will be explained.

That is, first, when the excitation coil 2 is deenergized, the armature 9 is attracted to the right by the spring 10, and each connecting surface 6a
, 6b friction surface 7a and the friction surface of the armature 9 are opposed to each other with a gap g interposed therebetween.

In this state, no power is transmitted from the drive shaft 4 to the driven shaft 8.

Next, when the excitation coil 2 is energized, a magnetic flux passes through the magnetic path shown by the dotted line in FIG. Mabōmen 7
a and the friction surface of the armature 9 come into contact, and power is transmitted from the drive shaft 4 to the driven shaft 8.

In such a structure and operation, considering the structure of the connecting surface, in order to construct a magnetic path, the friction surfaces of the connecting plate 6 and the armature 9 are generally made of low carbon steel, which is a homogeneous material. .

In addition, this structure has connection surfaces 6a, 6b and friction surface 7a.
are provided so that they are on the same plane, and these are the amateur 9
When connected to the friction surface of the material, the entire surface is bonded.

However, after machining each structure or part, when assembling it and starting to use it as a product, the connecting surfaces 6a, 6b and the friction surface 7
It is extremely difficult and practically impossible to bring a into contact with the friction surface of the armature 9 over the entire surface.

This is because, as is generally said, no matter how precisely the parts are machined, due to manufacturing errors, only a few points on the entire surface will come into contact.

In this case, when the friction plate 7 and the friction surface of the armature 9 are joined, there is no problem because they are made of different materials, but when the connecting surfaces 6a, 6b and the friction surface of the armature 9 are joined, it is of the same material. Since it is a material and the contact area is small, the surface pressure is high, causing an abnormal temperature rise in that area and causing seizure.

Therefore, even if the current to the excitation coil 2 is cut off, the friction surface of the armature 9 does not separate from the connecting surfaces 6a, 6b, making it impossible to satisfy the function of the connecting device.

This phenomenon becomes noticeable when an overexciting current is applied to increase responsiveness.

This invention was devised in view of the above-mentioned circumstances and provides the following excellent friction type electromagnetic coupling device.

An embodiment of this invention shown in FIG. 2 will be described below.

In FIG. 2, reference numeral 11 denotes a connecting plate fixed to the rotating shaft 4, each having a tapered connecting surface 11 a that expands toward the end surface.
, 11b.

11C is an annular hole for magnetic shielding.

In the structure constructed as described above, first of all, the friction plate 7 and the armature 9 are attracted to each other by the urging force of the excitation coil 2 and are connected to each other.

At this time, despite the first connection operation, only the friction surfaces of the friction plate 7 and the armature 9 are connected, so no matter how poor the machining accuracy of each connection surface of the friction plate 7 and the armature 9 is,
Even if the surface pressure between them becomes high, seizure will not occur at all because they are made of different materials.

After that, as the connection is repeated, each connecting surface of the friction plate 7 and the armature 9 wears out, and the friction surface of the armature 9 comes to be joined to the entire surface of the friction plate 7, and then the connecting surfaces 11a, 1
The friction surfaces of l b and armature gradually come into contact.

Therefore, when the connecting surfaces 11 a, 11 b, which are made of the same material, come into contact with the armature 9, the friction surface of the armature 9 is in contact with the entire surface of the friction plate 7, so the surface pressure is low, and the connecting surface Since 11a and llb are inclined,
Since the friction surfaces of the armatures 9 gradually come into contact with each other, the surface pressure on these surfaces does not increase, and the connecting surfaces 11 a
, 11b and the friction surface of the armature 9 can be completely prevented from seizing.

Further, since the connecting surfaces 11a and 11b of the connecting plate 11 are inclined, manufacturing is easy, and the magnetic resistance can be made small enough to have no effect on the connecting operation.

In addition, in the above description, each connection surface 11a, 11 of the connection plate 11
Although the case where b is slanted is shown as an example, as another embodiment,
An armature 9 that can come into contact with each connecting surface 11a, 11b
Even if the friction surface is inclined, the same effect as in the above embodiment can be obtained.

Furthermore, in the above description, the shape of the inclined portion is exemplified as an inclined portion that expands toward the outer circumferential end or the inner circumferential end.
As shown in FIG. 3, a similar effect can be obtained by forming an inclined portion that expands in the direction of the friction plate 7 from the outer peripheral end or the inner peripheral end.

In this case as well, it goes without saying that the same effect can be achieved even if it is applied to the amateur 9 side.

Incidentally, it goes without saying that the processing of the inclined portions 11a, 1lb of the connecting surfaces must be carried out within a range that does not affect the connection performance.

Further, in the above description, the application to an electromagnetic clutch has been exemplified, but it goes without saying that the invention can also be applied to an electromagnetic brake.

As described above, this invention consists of a connecting plate made of a magnetic material and having an inner connecting surface and an outer connecting surface, a friction plate made of a non-magnetic material attached between the inner and outer connecting surfaces of this connecting plate, and a It has a friction surface that faces the plate and the inner and outer connecting surfaces,
An armature made of the same magnetic material as the connecting plate; when energized, at least the armature and the connecting plate form a closed magnetic path, and the friction plate, the inner and outer connecting surfaces, and the friction surface of the armature are brought into pressure contact with each other, and the connecting plate and an excitation coil for connecting the armature, the inner and outer connecting surfaces of the connecting plate are arranged such that the inner and outer connecting surfaces of the connecting plate are non-parallel to the friction surface of the armature that faces these inner and outer connecting surfaces. At least one of the surface and the friction surface of the armature is inclined, and the friction surface of the armature that faces the friction plate and the friction plate is wider than the gap between the inner and outer connecting surfaces of the connecting plate and the friction surface of the armature. Since the gap between the connecting plate and the armature is made small, the connecting surface of the connecting plate and the joint part of the armature are almost in a non-contact state for a predetermined period from the time of initial connection, which reduces the surface pressure when connecting the connecting plate and the armature. It can be made smaller and eliminates the conventional problem of the armature not being able to move away from the connecting surface of the connecting plate even if the current of the excitation coil is cut off.This prevents seizure between the connecting surface of the connecting plate and the armature and ensures reliable connecting operation. It also has the advantage that it can be manufactured simply and at low cost without increasing the size of the device.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional device, FIG. 2 is a sectional view showing one embodiment of this invention, and FIG. 3 is a sectional view showing another embodiment of this invention. In the figure, 1 is a stator, 2 is an excitation coil, 7 is a friction plate, 9 is an armature, 11 is a connecting plate, and 11 a and 11 b are connecting surfaces. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A connecting plate made of a magnetic material and having an inner connecting surface and an outer connecting surface, a friction plate 1 made of a non-magnetic material attached to the IJ of the slotted surface, and a friction plate C and the above-mentioned inner and outer connecting plates. The friction surface facing the surface is broken and the armature made of the same magnetic material as the connecting plate is formed to form a closed magnetic path between at least the armature and the connecting plate 1 when energized. and a magnetic coil that connects the connecting plate and the armature by press-contacting a friction surface of the armature with a friction surface of the armature, the inner and outer connecting surfaces of the connecting plate and the friction surface of the armature that opposes these inner and outer connecting surfaces. At least one of the inner and outer connecting surfaces of the connecting plate and the friction surface of the armature is inclined so that the inner and outer connecting surfaces of the connecting plate and the friction surface of the armature are non-parallel. A friction type electromagnetic coupling device characterized in that the gap between the friction plate and the friction surface of the doki armature facing the friction plate is smaller than the gap.