JPH09250540A - Bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the abrasion of a sliding friction surface, etc., by generating a magnetic field in the vicinity of the sliding friction surface, between the inner and outer rings of a bearing and a rolling element, in a bearing device wherein at least one side of a spindle and a roller bearing is composed of magnetic material. SOLUTION: In a cross roller bearing CB, plural rollers 3, arranged between inner and outer rings 1 and 2, are all magnetized in an axial direction as shown in a figure, and in this case in the inner and outer rings 1 and 2, at least one side is constituted of magnetic material. Since, this constitution makes a magnetic field, generated from the rollers 3 themselves, act on a sliding friction surface, between the inner ring 1 and the rollers 3, the abrasion of these sliding friction surfaces can be reduced. That is, acting mangetism on a sliding surface makes adsorbing gas, oxygen in particular, lively, to generate an oxide coat. Interposing the oxide coat in a sliding surface reduces the contact and agglutination of mating neo-surfaces, to refine abrasion powder, thereby reducing abrasion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device which is used for a circuit breaker, an elevator, an escalator, a robot, etc., and which comprises a shaft-rolling bearing, a shaft and a sleeve, and a shaft and a bearing.

[0002]

2. Description of the Related Art Conventionally, as an example of this type of bearing device,
There are some whose shafts are rotatably supported by ball bearings. In such a structure, the sliding friction surface between the ball and the inner ring and the sliding friction surface between the ball and the outer ring are worn by rotating the shaft for a predetermined period. Therefore, the operation accuracy of the device is reduced and the durability is reduced.
For this reason, conventionally, for example, when performing maintenance on the device, the device is replaced with a new one.

[0003]

However, it is troublesome to replace the bearing, and at the time of replacement, it is necessary to stop the operation of various devices, which causes trouble to the user. For these reasons, the development of bearings with little wear is strongly desired.

The object of the present invention is to satisfy such a demand, and a sliding friction surface between a rolling element and an inner ring of a bearing and a rolling element and an outer ring, or a sliding friction surface between a shaft and a sleeve, etc. The object of the present invention is to provide a bearing device capable of significantly reducing the wear of the bearing.

[0005]

To achieve the above object, the invention according to claim 1 comprises a shaft and a rolling bearing rotatably supporting the shaft, and at least the shaft and the rolling bearing. In a bearing device, one of which is made of a magnetic material, magnetic field generating means for applying a magnetic field to the sliding friction surface is provided in the vicinity of the sliding friction surface between the inner ring and the outer ring of the bearing and the rolling element existing therebetween. The bearing device is characterized in that

In order to achieve the above object, in the invention according to claim 2, the magnetic field generating means is either a magnetized member of the rolling element itself or a magnet arranged in the vicinity of the bearing. The bearing device according to claim 1.

In order to achieve the above object, the invention according to claim 3 comprises a shaft and a sleeve rotatably supporting the shaft, and at least one of the shaft and the sleeve is made of a magnetic material. The bearing device is characterized in that magnetic field generating means for applying a magnetic field to the sliding friction surface is provided in the vicinity of the sliding friction surface between the shaft and the sleeve.

In order to achieve the above object, the invention according to claim 4 is characterized in that the magnetic field generating means is a member in which the shaft itself is magnetized or the sleeve itself is magnetized. The bearing device according to claim 3, wherein the bearing device is one of a magnet arranged near the shaft and the sleeve.

In order to achieve the above object, the invention according to claim 5 comprises a shaft and a bearing movably supporting the shaft in a predetermined direction, and at least one of the shaft and the bearing is made of a magnetic material. In the configured bearing device, magnetic field generating means for applying a magnetic field to the sliding friction surface is provided near the sliding friction surface between the shaft and the bearing.

In order to achieve the above object, the invention according to claim 6 is characterized in that the magnetic field generating means is a member in which the shaft itself is magnetized or the bearing itself is magnetized. The bearing device according to claim 5, wherein the bearing device is one of a magnet arranged near the shaft and the bearing.

According to the invention according to any one of claims 1 to 6, the magnetic field acts on the sliding friction surfaces of the inner ring and the outer ring of the rolling bearing, the shaft and the sleeve, and the shaft and the bearing. Less wear

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a partial cross-sectional view of a cross roller barening CB showing a first embodiment of the present invention.
A plurality of rollers 3 arranged between the inner ring 1 and the outer ring 2.
Are all magnetized in the axial direction as shown in the figure. In this case, at least one of the inner ring 1 and the outer ring 2 is made of a magnetic material.

1 (a) and 1 (b) are sectional views taken at the positions of the adjacent rollers 3 of the cross roller bearing CB. With this configuration, the magnetic field generated from the roller 3 itself causes the inner ring 1, the roller 3, and the outer ring 2 to rotate.
Since it acts on the sliding friction surface of the roller 3, wear of the sliding friction surface is reduced.

It is clear from the principle and experimental results described below that such effects can be obtained. This will be described. First, the principle of magnetic wear reduction will be described with reference to FIG. When magnetism is applied to the sliding surface, adsorption of gas, especially adsorption of oxygen becomes active, and an oxide film is formed. It has been confirmed that, by interposing this oxide film on the sliding surface, the newly formed surfaces are less contacted and adhered to each other, and the abrasion powder is miniaturized to reduce the abrasion. The effect depends on the chemical composition or magnetic properties of the sliding material. That is, since the reaction to oxygen and the sensitivity to the environment such as temperature are different depending on the material (or the chemical component contained in the material), the effect is different for each material. A transition metal having holes in the electron orbit or a ferromagnetic material containing a transition metal as a main component, such as a steel material, is in a chemically non-equilibrium state, and is in a state where it is easily bonded to other elements. It is said that when a sliding body made of such a material is acted upon by magnetism, the binding (ionic bond or covalent bond) action with other elements is activated, oxygen adsorption is promoted, and thereby wear is reduced.

When magnetism is applied to the ferromagnetic material, an attractive force proportional to the square of the magnetic flux density is generated. When the suction force increases, the frictional force between the sliding surfaces also increases. Next, a test apparatus used for confirming the above-mentioned principle (magnetic friction / wear characteristics) will be described with reference to FIG.

FIG. 3A shows a pin-on-disk type testing device 20 using an electromagnetic coil, in which a rotary shaft 21 is vertically rotatably arranged, and an upper end portion of the rotary shaft 21 is an electric motor (M). It is configured so that the rotational force from 22 is transmitted. A rotating plate 23 having a pin test piece insertion hole is inserted into the lower end of the rotating shaft 21, and the rotating plate 23 is rotated by the two nuts 24 screwed to the lower end of the rotating shaft 21.
It is detachably supported by. On the outer peripheral side of the rotary shaft 21, a cylindrical test piece support is supported by a fixed portion (not shown), which is a cylindrical member 25 made of a magnetic material and can be attached to and detached from the lower end of the cylindrical member 25 by a bolt and a nut. And a circular ring-shaped pressing plate 26 made of a magnetic material. Between the cylindrical member 25 and the holding plate 26, as shown in FIG.
A disc test piece 27 made of a material described later having a circular ring shape shown in (b) is sandwiched, and a pin test made of the material shown below shown in FIG. 4 (a) is inserted into a pin test piece insertion hole of the rotary plate 23. The lower end of the piece 28 is inserted, and the pin test piece 2
A predetermined load is applied to the lower surface of the disk test piece 27 at the upper end of 8, and the pin test piece 28 slides on the lower surface of the disk test piece 27 as the rotary plate 23 rotates. . Then, the cylindrical member 25 and the holding plate 26
A cylindrical electromagnetic coil 29 is disposed on the outer peripheral side of the disk test piece 27 and the pin test piece 28, and a magnetic field having a desired magnetic flux density is applied to the sliding surface of the disk test piece 27 and the pin test piece 28. It can be applied. Also, pin test piece 2
On the outer peripheral side of 8, a disk test piece 27 and a pin test piece 28
A search coil 31 for measuring the magnetic flux density applied to the sliding surface of is disposed.

FIG. 3B shows a pin-on-disk type testing device 30 using a permanent magnet, which is different from FIG. 3A in that the electromagnetic coil 29 is not provided but a predetermined magnetic field is applied. A permanent magnet 32 that is generated and a return yoke 33 that forms a magnetic circuit of the magnetic flux generated from the permanent magnet 32 are arranged.

The test conditions for the test using the above-described test apparatus are as follows. Sliding speed is 10 (cm /
s), the load is 20 (N) or 100 (N), and the surface pressure is 1.
0 (N / mm ² ) or 10 (N / mm ² )
The temperature is room temperature, the type of magnetic field is either AC (50 HZ) or DC, or a permanent magnet, and the magnetic flux density is 0 to 100 (mT).

FIG. 5A shows the relationship between the wear characteristics (sliding distance 1 (m) and wear amount w (mg) of the pin test piece made of hard steel wire (SWRH60A) under the above test conditions. FIG. 5 (b) is a wear characteristic diagram (a diagram showing a relationship between a sliding distance 1 (m) and a wear amount w (mg)) for a disk test piece made of spheroidal graphite cast iron (FCD700).

In the characteristic diagram of FIG. 5, B = less wear
When the wear characteristics of 40, 60, 80, 100 (mT) are expanded, it becomes as shown in FIG. As is clear from this figure, the wear amount greatly changes when the sliding distance 1 is 100 to 200 (mm). In this figure, it is possible to define the wear of a region with a large amount of wear as “severe wear” and the wear of a region with less wear as “mild wear”.
This is because the application of a magnetic field promotes gas adsorption and accelerates the transition from severe wear to mild wear.

FIG. 7 is a diagram showing the relationship between the magnetic flux density and the wear amount ratio (specific wear amount). As is clear from this figure, the magnetic flux density is 0 between the magnetic flux density of 40 to 100 (mT). 1/2 compared with the case of rope material (hard steel wire rod SWRH69A),
It is about 1/100 for sheave material (spheroidal graphite cast iron FCD700).

FIG. 8 shows a cross-sectional profile of the disk test piece (FCD700) after the test, in which a load of 100 is applied.
(N) and when the magnetic flux density B = 40 to 100 (mT),
It can be seen that the wear is less than that of B = 0, 20 (mT).

Further, the relationship between the magnetic flux density and the frictional force ratio is as shown in FIG. 9, and since the frictional force increases, the slippage becomes smaller. In the above-described embodiment, as the magnetic field generating means,
Although the case where the permanent magnet 11 is used has been described, the same operation can be performed even when an electromagnetic coil is used instead of the permanent magnet 11. In the device using the permanent magnet 11,
Although it has the following advantages, it has a drawback that the magnetic flux density cannot be finely changed.

<Advantages of device using permanent magnet 11> (1) No power supply required (2) Simple and inexpensive structure (3) Permanent magnet even if wire rope and main sheave are large and complicated in shape 11 is relatively easy to arrange (4) It is easy to create a local magnetic field (5) Can be used even during a power failure In a device that uses an electromagnetic coil, the magnetic flux density can be changed finely, and it is easy to make the entire magnetic field condition because of the cylindrical shape. Has the advantage.

<Modifications> The characteristic diagrams (FIGS. 5 to 8) described in the above-mentioned embodiments are not limited to the representative examples of the examples, and the same tendency is exhibited even if other materials are used. Therefore, the attachment of the figure and its description are omitted.

In the above-mentioned embodiment, the case where an oxide magnet having a residual magnetic flux density of 100 mT is used as the permanent magnet has been taken as an example, but the present invention is not limited to this, and the residual magnetic flux density is 0.5 with a metal magnet. ˜1.45 T, rare earth magnets of 0.
65 to 1.20 T, an oxide magnet having a residual magnetic flux density of 0.20 to 0.45 T, and a bonded magnet having a residual magnetic flux density of 0.065 to 0.90 T. Good.

[Second Embodiment] FIG. 10 is a cross-sectional view of essential parts when a known cross roller bearing is applied to a robot arm. A recess 4 for supporting the inner ring side CB1 of the cross roller bearing CB is provided at the upper end of the robot base.
a is formed, and the inner ring side CB1 is fixed by a ring-shaped fixing member 4b. Cross roller bearing C
The outer ring side CB2 of B is a ring-shaped bearing retainer 5
It is fixed to the robot arm 5 via a and 5b.
The robot arm 5 has a base portion so as to cover an upper end of the base 4 of the robot, and an arm (not shown) extends in a predetermined direction from the base portion. An outer peripheral end (N side in the drawing) of a ring-shaped magnetic body 6 is fixed to the lower part of the bearing retainer 5b, and this inner peripheral end (S side in the drawing) faces the upper end of the base 4 of the robot via a gap. It is arranged as follows. Although the outer peripheral end is fixed in the figure, the same applies to the case where the inner peripheral end is fixed.

[Third Embodiment] FIG. 11 shows an annular electromagnet 7 disposed between the split rings of the cross roller bearing CB described above.

[Fourth Embodiment] FIG. 12 shows a ball bearing BB which is an example of a known rolling bearing in which an annular electromagnet 8 is arranged. It is arranged on the end side of.

[Fifth Embodiment] FIG. 13 shows an inner ring 9 and an outer ring 10 of a bearing bracket of a known ball bearing BB, which are magnetized as shown in FIG.

[Sixth Embodiment] FIG. 14 shows a shaft 11 and a sleeve 12 which is inserted into a hole of a fixing member 13 and rotatably supports the shaft 11. At least one of the shaft 11 and the sleeve 12 is magnetic. In the bearing device made of a material, the sleeve 12 is magnetized in the axial direction as shown in the figure.

[Seventh Embodiment] FIG. 15 shows a cylindrical sleeve 14 used in a bearing device similar to that shown in FIG. 14, magnetized in the circumferential direction as shown in the drawing.

[Eighth Embodiment] FIG. 16 shows a bearing device as shown in FIG. 14 in which the shaft 11 is magnetized so as to be divided into two parts in the longitudinal direction (axial direction). Apart from this, axis 1
You may make it attach a permanent magnet to the end part of 1.

[Ninth Embodiment] FIG. 17 shows a sleeve 14
In the case where the shaft 11 is rotatably supported, the permanent magnet 15 is arranged in close proximity to the sleeve 14 and the end of the shaft 11 in the axial direction.

[Tenth Embodiment] In FIG. 18, the permanent magnet 15 is not provided as in FIG. 17, but the end 11a of the shaft 11 is magnetized as shown in FIG.

[Eleventh Embodiment] FIG. 19 includes a shaft (first member) 16 and a bearing (second member) 17 that supports the shaft 16 so as to be movable in the axial direction. In a bearing device in which at least one of them is made of a magnetic material, the shaft 16 itself is magnetized as shown in the figure. 19 (a) is a front view thereof, and FIG. 19 (b) is a perspective view thereof.

[Twelfth Embodiment] FIG. 20, similarly to FIG. 19, is composed of a shaft (first member) 16 and a bearing (second member) 17, and a permanent magnet 18 is arranged close to them. It was set up. It goes without saying that the second to twelfth embodiments described above can obtain the same operational effects as the first embodiment described above.

[0038]

According to the present invention described above, the sliding friction surface between the rolling element and the inner ring of the bearing and the rolling element and the outer ring, or
It is possible to provide a bearing device that can significantly reduce the wear of the sliding friction surface between the shaft and the sleeve.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a first embodiment of a bearing device according to the present invention.

FIG. 2 is a diagram for explaining the principle of the embodiment of FIG.

FIG. 3 is a diagram showing a schematic configuration of a test apparatus for testing a test piece based on the principle of FIG.

FIG. 4 is a diagram showing the test piece of FIG.

FIG. 5 is a wear characteristic diagram for explaining the effect of magnetic flux density on wear characteristics tested by the test apparatus of FIG. 3;

FIG. 6 is a partially enlarged characteristic diagram of the wear characteristic diagram of FIG.

7 is a characteristic diagram showing the relationship between the magnetic flux density and the wear amount ratio tested by the test apparatus of FIG.

FIG. 8 is a diagram showing a cross-sectional profile of a test piece after the test performed by the test apparatus of FIG.

FIG. 9 is a view showing magnetic-frictional force characteristics for explaining the operation and effect of the embodiment of FIG. 1;

FIG. 10 is a view for explaining a second embodiment of the bearing device according to the present invention.

FIG. 11 is a view for explaining a third embodiment of the bearing device according to the present invention.

FIG. 12 is a view for explaining the fourth embodiment of the bearing device according to the present invention.

FIG. 13 is a view for explaining the fifth embodiment of the bearing device according to the present invention.

FIG. 14 is a view for explaining the sixth embodiment of the bearing device according to the present invention.

FIG. 15 is a view for explaining the seventh embodiment of the bearing device according to the present invention.

FIG. 16 is a view for explaining an eighth embodiment of the bearing device according to the present invention.

FIG. 17 is a view for explaining the ninth embodiment of the bearing device according to the present invention.

FIG. 18 is a view for explaining the tenth embodiment of the bearing device according to the present invention.

FIG. 19 is a view for explaining the eleventh embodiment of the bearing device according to the present invention.

FIG. 20 is a view for explaining a twelfth embodiment of the bearing device according to the present invention.

[Explanation of symbols]

 1 ... Inner ring, 2 ... Outer ring, 3 ... Roller, CB ... Cross roller bearing, 6,7,8,15,18 ... Permanent magnet, 9 ... Inner ring, 10 ... Outer ring, 11 ... Axis, 12 ... Sleeve, 14 ... Sleeve , 16 ... Shaft (first member), 17 ... Bearing (second member).

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Suyo Mizuno No. 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Corporation Fuchu factory inside

Claims (6)

[Claims] 1. A bearing device comprising a shaft and a rolling bearing rotatably supporting the shaft, wherein at least one of the shaft and the rolling bearing is made of a magnetic material, wherein an inner ring and an outer ring of the bearing are provided. A bearing device characterized in that a magnetic field generating means for applying a magnetic field to the sliding friction surface is provided in the vicinity of the sliding friction surface between the rolling elements existing between them. 2. The bearing device according to claim 1, wherein the magnetic field generating means is either a magnetized member of the rolling element itself or a magnet arranged in the vicinity of the bearing. 3. A bearing device comprising a shaft and a sleeve rotatably supporting the shaft, wherein at least one of the shaft and the sleeve is made of a magnetic material, wherein a sliding friction surface between the shaft and the sleeve. A bearing device characterized in that magnetic field generating means for applying a magnetic field to the sliding friction surface is provided in the vicinity thereof. 4. The magnetic field generating means uses the shaft itself as a magnetized member, or the sleeve itself as a magnetized member, or a magnet disposed near the shaft and the sleeve. The bearing device according to claim 3, which is any one of them. 5. A bearing device comprising a shaft and a bearing for movably supporting the shaft in a predetermined direction, and at least one of the shaft and the bearing is made of a magnetic material. A bearing device characterized in that a magnetic field generating means for applying a magnetic field to the sliding friction surface is provided in the vicinity of the sliding friction surface. 6. The magnetic field generating means includes a magnetized member for the shaft itself, a magnetized member for the bearing itself, or a magnet arranged near the shaft and the bearing. The bearing device according to claim 5, which is any one of them.