JPS5813145Y2 - Multi-plate electromagnetic coupling device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of a multi-plate electromagnetic coupling device having a large number of friction plates.

FIG. 1 shows a conventional device of this type.

In the figure, 1 is a stator with a built-in coil 2, 3 is an inner driver supported on the stator 1 via a bearing 4.5, and 3a and 3b are lubrication holes formed on the inner driver 3. A oil supply hole, 3C is a spline tooth formed on the outer periphery of the inner driver 3, 6.7 is a rotor, 8 is a non-magnetic ring for magnetic cutoff, and the inner driver 3,
The rotor 6.7 and the non-magnetic ring 8 are fixed to each other.

Reference numeral 9 denotes an outer friction plate which is fitted into a convex portion 10a formed on the outer driver 10 and is movable in the axial direction.

Reference numeral 11 denotes an inner friction plate which is arranged alternately with the outer friction plate 9 and has spline teeth 11a that fit into the spline teeth 3C of the inner driver 3 and is movable in the axial direction; 12 is a spline provided on the inner driver 3; An armature 1 having spline teeth 12a fitted with teeth 3c and capable of sliding in the axial direction
3 is C that prevents this amateur 12 from moving beyond a certain level.
Type retaining ring, 14 is C for fixing bearing 4.5
15 is a driven shaft fitted to the inner driver 3; 15a is an upper hole formed in this driven shaft 15; 15b is a retaining ring;
is a communication hole formed in the driven shaft 15 to communicate with this upper hole 15a, and each oil supply hole 3a, 3b of the inner driver 3 is used to supply oil to the inner friction plate 11, outer friction plate 9, and bearing 4.5. is connected to.

In the multi-plate electromagnetic coupling device configured as above,
Next, the operation will be explained in detail.

Here, the outer driver 10 is connected to a prime mover (not shown), and the inner driver 3 is connected to a load (not shown) via a driven shaft 15.

Now, when the outer driver 10 is rotating, the coil 2
When energized, a magnetic flux Φ is generated in the magnetic path shown by the broken line, so the armature 12 is attracted to the outer friction plate 9 and the inner friction plate 11 to be pressed against the rotor 6.7, and therefore the inner driver 3 and the outer driver 10 are connected, so the torque is transmitted to the inner driver 3.

By the way, during this connection operation, each friction plate 9, 11, armature 12, and rotor 6, 7 generate a considerable amount of heat due to slipping, and this heat may accelerate wear. In order to eliminate this problem, , upper hole 1 of driven shaft 15
A lubricant such as oil is supplied from 5a through the communication hole 15b and further through the oil supply hole 3a to remove heat generated in the connecting portion and to minimize wear.

Also, lubricating oil is simultaneously supplied to the bearings 4 and 5 through the oil supply hole 3b.

On the other hand, when the excitation to the coil 2 is cut off, the outer friction plate 9 and the inner friction plate 11 are separated due to the spring action of each friction plate 9 and 11, so that no torque is transmitted.

Now, considering the structure of the conventional device, when the coil 2 is excited, a magnetic flux Φ is generated, and it is clear that the driven shaft 15 is also magnetized to some extent by this magnetic flux Φ.

When this coupling device is used, for example, to change the main axis of a machine tool, the magnetization of the driven shaft 15 will also magnetize the chuck coupled to this shaft 15.
This causes chips to adhere to the workpiece, chuck, etc.

Therefore, machining becomes difficult, the workpiece is damaged, and the work becomes very long in order to remove chips.

In order to avoid this, it is possible to arrange an inner driver 3 made of a non-magnetic material on the inner side to which the rotor 6 and bearings 4.5 are fixed, and to design it so that the influence of the magnetic flux Φ is minimized. Also, when considering the spline tooth 30 portion of the inner driver 3, it is also important to design it by forming it from a non-magnetic material so that the magnetic flux Φ does not flow toward the inner driver 3.

This is because if the spline teeth 3c are magnetic, the magnetic flux Φ
Flows through the armature 12 to the spline teeth 3c, making it difficult for the armature 12 to slide in the axial direction, making it impossible to obtain the desired performance or causing malfunction.

Taking all of the above into account, the inner driver 3 must be made of a non-magnetic material, for example stainless steel.

However, the inner driver 3, which has a very important function in the coupling device such as transmitting torque and supporting the rotor 6゜7, the inner friction plate 11, and the armature 12, and has a high weight ratio, is made of stainless steel. If so, the cost of stainless steel is high, and since the material itself is sticky, it takes a lot of time to process, and the life of the tool used for forming is extremely short (and the efficiency of machining work is reduced). Therefore, it has the fatal disadvantage that the cost of both materials and processing is high, and the device itself is expensive.

Furthermore, regarding the machining of the spline teeth 3c, since it is necessary to form only a small part of the outer circumference of the inner driver 3, it is necessary to process one tooth at a time using a hobbing machine or the like, which is also the same as mentioned above. Together, these factors are one of the causes of high costs.

This invention provides an excellent multi-plate electromagnetic coupling device that can eliminate the above-mentioned drawbacks.

That is, one embodiment of this invention shown in FIG. 2 will be described. Reference numeral 16 denotes a cylindrical inner driver fitted to the driven shaft 15, and is made of a magnetic material.

1T is fitted onto the driven shaft 15, and has an inner friction plate 1 on the outer periphery.
1. A spline boss having spline teeth 17a into which the armature 12 is fitted, made of a non-magnetic material such as stainless steel, and integrally fixed to the axial end of the inner driver 16 by brazing or the like.

16a and 17b are oil supply holes for lubrication formed in the inner driver 16 and spline boss 17, respectively; 18 is integrally fixed to the axial end of the spline boss 17 by brazing or the like, and is different from the inner driver 16; The rotors are opposed to each other with a dog-shaped annular gap 19 in the radial direction, and are also integrated with the ring 8.

Incidentally, this annular gap 19 is set to be significantly larger than the minute annular gap 20 between the rotor 18 and the stator 1, and its magnetic resistance becomes an extremely large value.

Here, to explain in detail the features of the embodiment of the present invention, first of all, as mentioned above, the simplest means of solving the conventional internal defects is to form the inside driver from a non-magnetic material. However, if we take this one step further and consider the former, the problem is which part should be formed with the minimum necessary amount of non-magnetic material in order to solve the above-mentioned drawbacks, and from this point of view, the magnetic flux Only the sliding portion of the armature 12 that constitutes the passage Φ needs to be made of non-magnetic material.

That is, in the embodiment of the present invention, only the spline boss 11 is made of stainless steel, which is a non-magnetic material, and the inner driver 16, which is not originally necessary, is made of a magnetic material that is easy to form and is inexpensive. In order to prevent current flow, an annular gap 19 is formed between the inner driver 16 and the rotor 18, which is larger than the micro gap 20 of the flow path for the magnetic flux Φ, thereby increasing the magnetic resistance. is an important feature.

Therefore, since a dog-shaped annular gap 19 is formed between the rotor 18 and the inner driver 16, the magnetic flux Φ passing through the rotor 18 will not flow even if the inner driver 16 is made of a magnetic material. Therefore, the driven shaft 15 is not magnetized (the drawbacks of the conventional example are definitely solved).

Another important factor in this is that the spline boss 17 is made of a non-magnetic material.

This is because the magnetic circuit of the armature 12, spline boss 17, inner driver 16, and rotor 18 is no longer configured.

On the other hand, considering performance, since the spline boss 17 is a non-magnetic material, the magnetic flux Φ does not flow from the armature 12 to the spline boss 17, but instead passes through each friction plate 9, 11 and flows to the rotor 18. As a result, the armature 12 slides smoothly, so that stable operation can be obtained without causing any malfunction.

Furthermore, since the oil supply hole 16b can be formed very easily by having an opening in the end face of the inner driver 16, the drilling efficiency can be improved without damaging the drill.

Furthermore, when machining the spline teeth 17a of the spline boss 17, there is no need to insert the bearing 4.5 as in the conventional method, and since the spline tooth 17a is cylindrical, many sheets can be stacked and processed at once. As a result, machining efficiency can be greatly improved.

In this embodiment, the rotor 18 and the inner driver 1
Although the explanation was given by providing a gap 19 between the driven shaft 15
In applications where the magnetization of the rotor is not a problem, even if the rotor 18 and the inner driver 16 are integrated, it is possible to achieve a wide field reduction.

Furthermore, although only the starting device has been described, it goes without saying that the same effect can be obtained by fixing one of the devices and using it as a braking device.

As described above, according to the present invention, only the spline boss is made of a non-magnetic material such as stainless steel, and the inner driver is made of a magnetic material, thereby greatly improving the machining efficiency of the spline boss and the inner driver. In addition, since expensive non-magnetic material only needs to be used for a portion of the material, material costs can be greatly reduced.

Furthermore, spline bosses can be processed in multiple layers at once, which has a very large effect in reducing the cost of the entire device.

Moreover, the armature can be slid smoothly and the connection operation can be stable.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional example, and FIG. 2 is a sectional view showing an embodiment according to the present invention. In the figure, 1 is a stator, 2 is a coil, 9 is an outer friction plate, 10
1 is an outer driver, 11 is an inner friction plate, 12 is an armature, 15 is a driven shaft, 16 is an inner driver, 17 is a spline boss, 18 is a rotor, and 19.20 is an annular gap. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] an inner driver made of a magnetic material that is fitted onto the rotating shaft; a spline boss made of a non-magnetic material that has spline teeth on the outer periphery; a spline boss that is fitted onto the rotating shaft along the axial direction of the inner driver; a rotor fixed to the inner driver or fixed to face the inner driver through a gap, an inner friction plate fitted to the spline teeth, an outer driver, and fitted to the outer driver in alternating arrangement with the inner friction plate. an armature fitted to the spline teeth so as to be located on one side of each friction plate; A multi-plate electromagnetic coupling device comprising an electromagnetic device that attracts the armature toward the rotor and presses the friction plates together.