JPS63167125A - Rolling bearing - Google Patents

Abstract

PURPOSE:To improve rotary torque and the vibration characteristic while to decrease a noise, by using a metal lubricant which melts being placed in a liquid phase condition at a predetermined temperature. CONSTITUTION:A ball bearing is equipped with an inner ring 2, outer ring 3, cage 4 and balls 5. The ball hearing 1 uses a metal lubricant which is placed in a liquid phase condition in a temperature during operation. It is preferable for the lubricant to use as the material Ga or a Ga alloy with a melting point of 25 deg.C or less. The inner ring 2 and the outer ring 3 are equipped with recessed raceway surfaces 2a, 3a of the same curvature to the ball 5, and the ball 5, turnably held in a pocket 4a of the cage 4, exists interposing between these raceway surfaces. The lubricant in a liquid phase condition acts in a clearance h3 between the outer ring 3 and the cage 4 during operation. The cage 4 provides in its internal peripheral and peripheral surfaces plural spiral grooves 6a-6d to be engraved. These grooves generate pressures P1-P4, and the metal lubricant is prevented from its outflow to the outside.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a rolling bearing that uses a metal lubricant that melts at a predetermined temperature and becomes a liquid phase, in which the external surface of the metal lubricant is removed during operation. This invention relates to a rolling bearing improved to prevent leakage.

<Prior Art> Conventionally, fluid lubricants such as grease or solid lubricants such as soft metals are known as lubricants used in rolling bearings.

Fluid lubricants tend to leak out of the bearing in small amounts during operation, and have high vapor pressure, so they cannot be used in rolling bearings used in high-cleanliness environments, such as in vacuum equipment.

For this reason, there is a tendency to use solid lubricants in rolling bearings used in the above environment.

However, in -i, rolling bearings using solid lubricant are
Compared to rolling bearings that use fluid lubricants, they have poor rotational torque and vibration characteristics, are louder, and have the problem of shortening the lifespan of rolling bearings because the solid lubricant tends to peel off during rotation. .

Further, since minute abrasion powder due to the peeling may come out of the bearing, it is not optimal for use in a highly clean environment.

Therefore, the inventor of the present invention considered using a metal lubricant, which melts into a liquid phase at a predetermined temperature (temperature during operation) in a rolling bearing, as an alternative to the solid lubricant.

Rolling bearings using metal lubricants have superior properties compared to rolling bearings using solid lubricants, and are said to have the same or better properties than rolling bearings using fluid lubricants. Results are being obtained. For example, the vapor pressure is lower than that of fluid lubricants. Moreover, like a rolling bearing that uses a fluid lubricant, it has a relatively long life.

<Problems to be Solved by the Invention> However, when using the above metal lubricant, there are the following problems.

-C, one of the outer ring and the inner ring rotates, and the other is fixed. Since the rolling elements rotate following the rotating side, the liquid phase metal lubricant in the gap between the cage and the stationary side receives pressure from the center side in the width direction where the rolling elements are present to both sides. There is a risk that this metal lubricant may flow out from the gap to the outside, albeit in a small amount, and therefore, as in the case of a rolling bearing using a fluid lubricant, it cannot be used in a highly clean environment.

The present invention was devised in view of these circumstances, and an object of the present invention is to provide a rolling bearing that has excellent properties, has a long life, and can be used in a highly clean RK environment.

<Means for Solving the Problems> In order to achieve the above objects, the present invention has the following configuration.

That is, the rolling bearing according to the present invention uses a metal lubricant that melts into a liquid phase at a predetermined temperature, and the cage forms a minute gap with the fixed side of the inner ring and the outer ring. The fixed side of the inner ring and the outer ring and the retainer are formed to be inclined with respect to the rotating direction on one of the facing surfaces, and the width changes as the retainer rotates. It is equipped with a plurality of grooves that generate pressure on the metal lubricant in a liquid phase from both sides of the direction toward the center.

Effect〉 The effects of the configuration of the present invention are as follows.

Because it uses a metal lubricant that melts into a liquid phase at a certain temperature, it has superior properties and a longer lifespan compared to rolling bearings that use solid lubricants, as explained in the <Prior Technology> section. Moreover, when compared with the various characteristics of a rolling bearing using a fluid lubricant, it is equivalent to or better than that of a rolling bearing.

In addition, the grooves formed at an angle with respect to the rotational direction on one of the facing surfaces of the stationary side of the inner ring and the outer ring and the cage provide metal lubrication in the minute gap where this inclined groove faces. This creates pressure on the agent from both sides in the width direction toward the center, and this pressure counteracts the pressure generated from the center in the width direction toward both sides as the rolling elements rotate, so the metal in the liquid phase The lubricant is prevented from flowing out from the minute gap and is held in the minute gap.

<Example> Hereinafter, each example of the present invention will be described in detail based on the drawings.

1 to 3 show a first embodiment of the present invention.

The deep groove ball bearing 1 shown in FIGS. 1 and 2 has an inner ring of 2 degrees and an outer ring of 3 degrees. It includes a cage 4 and balls 5 as rolling elements.

This deep groove ball bearing l uses a metal lubricant that becomes liquid at the temperature during operation. As this metal lubricant, Ga or Ga alloy having a melting point of 25° C. or lower is preferable. In this case, inner ring 2. The outer end 3 and the ball 5 are Q
It is desirable to use a material that has corrosion resistance against a or Ga alloy. Specifically, for example, ceramics, W, Mo
Alternatively, an alloy of W and MO can be considered. These constitute the inner ring 2, outer ring 3, and balls 5, or the inner ring 2. It is optional whether the outer ring 3 and balls 5 are coated.

The inner ring 2 and the outer ring 3 are provided with concave raceway surfaces 2a and 3a having the same curvature as the balls 5. These raceway surfaces 2a, 3a
Each of these bearings is shallower than that of a normal deep groove ball bearing. Between the raceway surface 2a and the raceway surface 3a,
A ball 5 rotatably held in a pocket 4a of the retainer 4 is interposed. An extremely small gap h1 exists between the ball 5 and each raceway surface 2a, 3a.

A gap h2 is formed between the outer peripheral surfaces 2b and 2c on both sides of the raceway surface 2a of the inner ring 2 and the inner peripheral surface 4b of the retainer 4.

A gap is also formed between the inner peripheral surfaces 3b and 3c on both sides of the raceway surface 3a of the outer ring 3 and the outer peripheral surface 4c of the retainer 4.

The inner surface of the pocket 4a of the retainer 4 has a partial arc shape with the same curvature as the balls 5, and a minute gap is formed between the pocket 4a and the balls 5.

Ideally, the gap h is set to the same size as the gap h1, and ideally the gap h4 is set smaller than the gap h1.

The inner ring 2 and the outer ring 3 rotate relative to each other. In this embodiment, the inner ring 2 is rotated and the outer ring 3 is fixed. As the inner ring 2 rotates, the cage 4 follows. During operation, the metal lubricant in liquid phase in the gap h3 between the outer ring 3 and the retainer 4 is filled with liquid that moves from the center side in the width direction to both sides due to the rotation and revolution of the balls 5. A pressure P1 is created. On the other hand, a pressure P which is slightly lower than the pressure P described above is also generated in the metal lubricant in the gap h2 between the inner ring 2 and the retainer 4.

In this embodiment, the inner peripheral surface 4b of the cage 4 has a plurality of spiral grooves 6a, 6b, and the outer peripheral surface 4C of the cage 4 has a plurality of spiral grooves 6c.

6d is engraved on each.

The spiral groove 6a faces the outer peripheral surface 2b of the inner ring 2, the spiral groove 6b faces the outer peripheral surface 2C of the inner ring 2, the spiral groove 6C faces the inner peripheral surface 3b of the outer ring 3, and the spiral groove 6d faces the outer peripheral surface 2C of the outer ring 3. They respectively face the inner circumferential surface 3C.

As shown in FIG. 2, each of the spiral grooves 6a to 6d is formed to be inclined with respect to the rotation direction. The outer ends of each of the spiral grooves 6a to 6d are located on the lower side in the rotation direction on both sides in the width direction, and the center portion is located on the upper side in the rotation direction A on the center side in the width direction. There is. In addition, for convenience of drawing, FIG. 2 shows the spiral grooves 6a to 6a.
Since the number 6d is written as small, it does not correspond to the number of spiral grooves 6a to 6d in FIG.

The spiral groove 6a and the spiral groove 6b are continuous at their respective central portions and are configured in a ry shape, and
The spiral groove 6C and the spiral groove 6d are also continuous at their respective central portions and are configured in a ry shape. However, in the portion of the retainer 4 where the pocket 4a is located, the spiral grooves 6a, 6b and the spiral grooves 6c, 5d are not continuous.

During rotation, as shown in FIG. 3, when the retainer 4 rotates in the direction indicated by the arrow, each of the spirals p6a to 6d spreads over a width of the metal lubricant in the liquid phase state existing in the gaps h. Pressure P3. directed from both sides of the direction (both ends in the width direction of the inner ring 2 and the outer ring 3 and retainer 4) toward the center (the raceway surfaces 2a and 3a sides of the inner ring 2 and outer ring 3). P4 occurs.

Since the relative rotational speed of the cage 4 with respect to the inner ring 2 and the outer ring 3 is different between this pressure P and pressure P4, P,>P4
It becomes a relationship.

Then, this pressure P3 is added to the pressure P1 mentioned above, and the pressure P3 is added to the pressure P1 described above.
4 are respectively antagonistic to the pressure P2 described above, and due to this antagonistic action, the metal lubricant in the liquid phase is prevented from flowing out to the outside of the bearing in the gaps, h, and is retained therein.

Figure 4 shows a second embodiment of the invention. In this figure, the same reference numerals as in FIG. 1 refer to the same parts or corresponding parts.

In this embodiment, the depths of the raceway surface 2a of the inner ring 2 and the raceway surface 3a of the outer ring 3 are set deeper than those of a normal deep groove ball bearing.

In this case, the pocket 4a of the retainer 4 is configured in a cylindrical shape, but the retainer 4 is thin and the pocket 4a is blurred.
Since the pressure generated by the spiral grooves 6a to 6d is difficult to escape into the gap between the pocket 4a and the ball 5, the inner surface 4d of the pocket 4a does not have to have the same curvature as the ball 5 as in the first embodiment. do not have.

In addition, in each of the above embodiments, each spiral groove 6a to 6
d is formed on the inner circumferential surface 4b and outer circumferential surface 4c of the retainer 4, but the present invention is not limited to this,
For example, each spiral groove 6a to 6d is formed on the outer peripheral surface 2b of the inner ring 2.
, 2c and the inner circumferential surfaces 3b, 3c of the outer ring 3.

When a spiral groove is formed in the inner ring 2 or the outer ring 3, the end of the spiral groove must be placed on the upper side in the rotational direction with respect to the center thereof.

Further, the spiral grooves 6a to 6d are not limited to those configured so as to be continuous in a "■" shape, but the present invention also includes those arranged alternately as shown in FIG. 5, for example.

Furthermore, although the groove according to the present invention is described as a spiral groove in each of the above embodiments, the present invention is not limited to this, and may be a spiral groove.

In addition, the present invention is not only applicable to deep groove ball bearings, but can of course be applied to various rolling bearings.

<Effect of the invention> According to the present invention, the following effects are achieved.

Since it uses a metal lubricant that melts into a liquid phase at a certain temperature, it not only has a longer lifespan than rolling bearings that use fluid lubricants such as grease, but also has a longer lifespan.
Excellent rotational torque and vibration characteristics, as well as low noise. Also, the surrounding environment will not be polluted by other clans' atmospheric pressure.

Furthermore, during operation, a plurality of grooves inclined with respect to the rotation direction can generate pressure from both sides in the width direction toward the center, which counteracts the pressure generated from the center side in the width direction toward both sides. Due to the antagonistic action of this pressure, the metal lubricant in a liquid phase can be held in the minute gaps between the inner ring and the retainer and between the outer ring and the retainer.

In this manner, it is possible to prevent the metal lubricant from flowing out during operation, so that it can be used in a highly clean environment.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a longitudinal cross-sectional view of a deep groove ball bearing, FIG. 2 is a perspective view of a cage, and FIG. 3 is a pressure generated by a spiral groove. FIG. Further, FIG. 4 is a diagram corresponding to FIG. 1 according to a second embodiment of the present invention. FIG. 5 is an explanatory diagram showing another example of the groove arrangement according to the present invention. 1... Deep groove ball bearing (rolling bearing) 2... Inner ring 3... Outer ring 4... Cage 5... Balls (rolling elements) 6a to 6d... Spiral groove A... Rotation direction.

Claims (6)

[Claims] (1) In a rolling bearing using a metal lubricant that melts into a liquid phase at a predetermined temperature, the retainer faces the stationary side of the inner ring and outer ring with a small gap formed therein, and One of the facing surfaces of the fixed side of the inner ring and outer ring and the cage is formed in a state that is inclined with respect to the rotation direction, and as the cage rotates, it is formed from both sides in the width direction to the center side. A rolling bearing characterized in that it is provided with a plurality of grooves that generate pressure toward a metal lubricant in a liquid phase. (2) Claim (1) wherein the groove is formed in the cage, and both outer ends of the groove are located on the downstream side in the rotational direction of the cage with respect to the center portion. Rolling bearings listed. (3) The groove is formed on the fixed side of the inner ring and the outer ring, and both outer ends of the groove are located on the upper side in the rotational direction of the retainer than the center part. Rolling bearings described in scope item (1). (4) Claim No. 1, wherein the metal lubricant is made of Ga or a Ga alloy, and the inner ring, outer ring, and rolling elements are made of a material that is corrosion resistant to the Ga or Ga alloy. The rolling bearing according to any one of items 1 to 3. (5) The inner ring, outer ring and rolling elements are made of the Ga or G
The rolling bearing according to any one of claims (1) to (3), wherein the rolling bearing is coated with a material that has corrosion resistance against the a-alloy. (6) Either claim (4) or (5), wherein the material having corrosion resistance against a metal lubricant made of Ga or Ga alloy is W, Mo, or an alloy thereof. The rolling bearing described in item 1.