JP4924174B2 - Method for producing ceramic spherical body for rolling support device, and rolling support device having rolling elements obtained by this method - Google Patents

Description

The present invention relates to a method for producing a ceramic spherical body and a rolling support device having rolling elements obtained by this method.
In the present invention, the rolling support device includes a first member and a second member having raceway surfaces that are arranged to face each other, and a plurality of rolling elements that are rotatably arranged between the raceway surfaces of both members. , A device in which one of the first member and the second member moves relative to the other by rolling the rolling element, specifically, a rolling bearing (ball bearing, roller bearing, etc.), a ball screw , Linear guide, ball spline, linear ball bearing, etc.

In the machine tool spindle bearing, as described in Patent Document 1 below, the dmn value (the average dimension dm of the inner diameter and the outer diameter of the bearing ≈ the diameter of the pitch circle of the rolling element (unit: mm), There is a demand for sufficiently extending the life under high-speed rotation where the rotation speed n (unit: min ⁻¹ ) is 1.4 million or more.
On the other hand, since semiconductor devices, liquid crystal panels, hard disks, etc. are washed with various chemicals in the manufacturing process, the rolling support device incorporated in the device used in the manufacturing process can operate well in a corrosive environment. Required. Also, lubricants such as lubricating oil and grease cannot be used because they may scatter and cause contamination.

Rolling bearings that can be used in corrosive environments include a ceramic outer ring manufactured by atmospheric sintering and a corrosion-resistant rolling bearing with a ceramic inner ring manufactured by gas pressure sintering or HIP ( Patent Document 2), an inner ring, an outer ring, a rolling bearing whose rolling elements are made of silicon carbide (see Patent Document 3), and the like are known.
In addition, with the recent widespread use of inverter motors in home air conditioners and vacuum cleaners, it is a low-cost method to prevent rolling bearings for inverter motors from being damaged by leakage current from inverter motors. There is also an increasing demand for prevention.

  In Patent Document 4 below, as a method for toughening the surface of a ceramic product, the hardness is not less than 500 in terms of Hv (Vickers hardness), and not more than a value obtained by adding 50 to Hv of the target ceramic product, A method of forming a linear dislocation structure uniformly distributed on the surface of a ceramic product is described using an injection material (shot) having an average particle size of 0.1 μm to 200 μm and a surface made of fine particles having convex curved surfaces. ing.

  In Patent Document 5 below, a bottom disc that is rotated at a constant speed by a motor, a cylindrical side wall that stands up around the disc, and a lid that closes the top opening of the cylindrical side wall. The inner surface of the bottom disc and the inner surface of the cylindrical side wall are both coated with abrasive grains to form an abrasive surface, and a hose adapter is provided in the center of the lid. A spherical material forming apparatus for a brittle material, characterized in that a vacuum nozzle for sucking out the material can be connected is described.

Further, in Patent Document 6 below, a revolving rotary arm that rotates around a revolving shaft that is rotated by a driving force and a revolving rotary arm that is inclined from the vertical to the revolving shaft side are supported by the revolving rotary arm in a freely rotatable manner. And the outer peripheral surface of the mill pot which is fixedly disposed above the revolving rotary arm over the entire circumference around the revolving shaft and revolves as the revolving rotary arm rotates. There is described a planetary ball mill having an outer peripheral pot holder that causes the mill pot to rotate.
JP 2005-163893 A JP-A-8-121488 Japanese Patent Laid-Open No. 10-82426 JP 2004-136372 A JP 2006-35334 A JP 2006-43578 A

The first problem of the present invention is to provide a rolling support device such as a rolling bearing that can sufficiently extend its life even under high-speed rotation with a dmn value of 1.4 million or more or in a corrosive environment where a lubricant cannot be used. is there.
The second object of the present invention is to prevent the rolling bearing for the inverter motor from being damaged by the leakage current from the inverter motor in a low cost method.

  In order to solve the above-mentioned problems, the present invention provides a plurality of the same ceramic spherical bodies in a mill pot of a planetary ball mill. A ball mill step of causing the spherical bodies to collide with each other by applying a centrifugal force accompanying the force and rotation, and causing the spherical bodies to collide with the inner wall of the mill pot and introducing residual stress to the surface of the spherical bodies; A method for producing a ceramic spherical body is provided.

The method of the present invention can be applied to ceramic spherical bodies made of silicon nitride, alumina, silicon carbide, zirconia or the like. In addition, the present invention can be applied to ceramic spherical bodies having various compositions and properties such as those containing additives such as sintering aids and those produced through a HIP treatment step.
The residual stress introduced into the surface of the spherical body is in the range of −2000 to −70 MPa (“−” means compressive residual stress. Therefore, the absolute value of compressive residual stress is 70 to 2000 MPa) (breakage) The toughness value is preferably 12 MPa · √m or more). Moreover, it is preferable that residual stress is introduced into the spherical body at a depth exceeding 20 μm from the surface in the ball mill process. Residual stress can be measured by X-ray diffraction. The fracture toughness value can be measured from the indentation and crack size by a hardness tester.

In the method of the present invention, it is preferable to perform finish polishing after the ball mill step. As a result, the toughness, wear resistance, and dimensional accuracy are improved when the spherical surface becomes rough or the roundness is reduced by performing the above-mentioned ball mill process on the ceramic spherical body. And a ceramic spherical body having excellent seizure resistance.
The compressive residual stress existing on the surface of the ceramic spherical body after the finish polishing step is preferably more than 100 MPa in absolute value, more preferably 250 MPa or more, further preferably 500 MPa or more, and 800 MPa. The above is most preferable. In terms of fracture toughness value, it preferably exceeds 5 MPa · √m, more preferably 6 MPa · √m or more, further preferably 8 MPa · √m or more, and 10 MPa · √m or more. Most preferred.

  The result of comparing the method of the present invention and the method of Patent Document 4 is a graph showing the relationship between the depth from the surface of the obtained ceramic spherical body and the fracture toughness value (value correlated with the residual stress value). These are collectively shown in FIG. No. 1 in the graph of FIG. 1 is a result obtained by the method of the present invention obtained under the conditions shown in the later-described embodiment, and No. 2 is a result of Patent Document 4 obtained under the conditions shown in the later-described embodiment. This is the result of the method.

  From this graph, it can be seen that in the method of the present invention, residual stress is introduced to a depth of about 20 μm from the surface in the ball mill process, and in the method of Patent Document 4, the residual stress is introduced to a depth of about 10 μm from the surface. . As described above, according to the method of the present invention, the residual stress is introduced deeper on the surface of the ceramic spherical body than the method of Patent Document 4, so that it is made of ceramics having superior wear resistance and seizure resistance. A spherical body can be obtained. Even when the surface is polished to a depth of 3 μm from the surface by finish polishing, the fracture toughness value of the surface obtained is higher than the fracture toughness value of the surface obtained by the method of Patent Document 4.

  Thus, according to the method of the present invention, when the ceramic spherical body after the ball mill process is post-processed, the amount of the surface layer portion that can be removed by post-processing while maintaining a high fracture toughness value of the surface is large. Sufficient post-processing can be performed to obtain the required dimensional accuracy. That is, post-processing is not limited to one-step processing, and can be two-step or three-step or more multi-step processing.

  In addition, since the ball mill process of the method of the present invention is basically a collision between the same ceramic spherical bodies (that is, those having the same material and hardness), the surface damage can be reduced. Therefore, the change in the surface roughness and dimensional accuracy of the ceramic spherical body can be reduced before and after the ball mill process, and in this case, post-processing such as a finish polishing process can be minimized.

The ball mill process of the method of this invention can be performed using the planetary ball mill of patent document 6, for example. Examples of the mill pot include those made of stainless steel and provided with a lining material made of menor, alumina, zirconia, chrome steel, or silicon nitride. The lining material of the mill pot is preferably the same material as the ceramic spherical body to be treated.
The hardness of the inner wall of the mill pot is preferably equal to or higher than the hardness of the ceramic spherical body to be treated, and specifically, it is preferably Vickers hardness (Hv) of 1000 or more.

The surface roughness of the inner wall of the mill pot is preferably equal to or finer than the initial roughness of the ceramic spheres to be processed, irrespective of the presence or absence of the lining material, and specifically, the average roughness (Ra) is 0. A range of 0005 μm to 3.2 μm is preferable.
The operating conditions of the planetary ball mill are: revolution speed: 300 rpm to 1000 rpm (more preferably 500 rpm to 700 rpm), rotation speed: 600 rpm to 2000 rpm (more preferably 1000 rpm to 1400 rpm), and rotation time: 1 hour to 8 hours Time or less (more preferably 3 hours or more and 5 hours or less) is preferable.

  Moreover, it is preferable that the quantity of the ceramic spherical bodies put into the mill pot is 50% or more and 90% or less of the closest packing quantity (the quantity that enters when the mill pot is filled most densely). When the amount is less than 50% of the closest packing amount, the impact energy is large, so that the processing time of the ball mill process can be shortened. However, since the movement of the ceramic spherical body in the pot becomes too intense, it is difficult to obtain a uniform surface. If it exceeds 90% of the closest packing amount, the range of movement of the ceramic spherical body in the pot becomes small and the number of collisions increases, but the collision energy becomes small and the processing takes time. By setting it to 50% or more and 90% or less of the close-packed filling amount, the number of collisions and the collision energy can be balanced and processed effectively. A more preferable range is 70% or more and 90% or less of the closest packing amount.

  In the ball mill step of the method of the present invention, basically, residual stress is introduced into the ceramic spherical body using the collision energy between the ceramic spherical bodies. Therefore, if the ceramic spherical body is too small, the residual stress is reduced. It is difficult to introduce. Therefore, the diameter of a suitable ceramic spherical body is 0.3 mm or more, more preferably 0.8 mm or more, further preferably 2 mm or more, and the upper limit is determined by the inner volume of the mill pot, but is usually about 50 mm. It is.

Further, if the ball mill process of the method of the present invention is performed on a ceramic spherical body having a surface roughness exceeding 3.2 μmRa in average roughness (Ra), the ceramic spherical body may be cracked or chipped at the time of collision. Increases nature. Therefore, it is preferable to perform the ball mill process after setting the average roughness (Ra) of the ceramic spherical body to 3.2 μmRa or less.
The finish polishing process of the method of the present invention can be performed using the sphere forming apparatus described in Patent Document 5. Moreover, it can also carry out by general methods, such as processing with a ball lapping machine and barrel processing.

  Furthermore, in the method of the present invention, the very small debris generated by collision between spherical bodies or collision of spherical bodies with the inner wall of the mill pot exists in the mill pot and participates in the collision. You can think of it as high. Therefore, it is preferable to put fine powder of the same hardness as the ball or harder (preferably Hv1000 or more) from the beginning in the mill pot.

  It is also possible to control the collision energy by simultaneously interposing spheres having a diameter smaller or larger than the diameter of the ceramic spheres to be processed or spheres having different hardnesses. It is. By controlling the collision energy, it is considered that the processing time, the residual stress to be introduced, the dimensional accuracy after the processing, and the like can be controlled. Therefore, it is preferable that a sphere having a diameter smaller than or larger than that of the ceramic sphere to be processed or a sphere having a different hardness is placed in the mill pot from the beginning.

In the method of the present invention, residual stress is introduced into the ceramic spherical body using a planetary ball mill, but as a stirring device for introducing the residual stress into the ceramic spherical body, a normal ball mill, an attritor, a vibrating ball mill, A rolling mill or the like can also be used. Attritors that can be used include “Attritor D type” manufactured by Mitsui Mining Co., Ltd.
Furthermore, in the present invention, the ceramic spherical body is described. However, if it is made of ceramic and has a shape capable of imparting collision energy uniformly in the ball mill, a device such as a ball mill pot, pot By improving the filling method, etc., it can be applied to shapes other than spherical bodies.

  In addition, the ball mill process of the method of the present invention is basically performed at room temperature and normal pressure and under normal atmosphere, but if necessary, treatment at high temperature and low temperature, pressurizing the inside of the mill pot, It is possible to reduce the pressure or to fill the mill pot with an inert gas. It is also possible to put so-called coating simultaneously with the introduction of residual stress by putting lubricating oil, soft metal powder, solid lubricating powder or the like into the mill pot. In this case, if an oil film or the like is formed on the ceramic spherical body, the impact energy will be affected. Therefore, the hardness, viscosity, amount, etc. of the lubricating oil, soft metal powder, solid lubricating powder, etc. to be put into the mill pot, ball mill operating conditions, etc. In consideration of the above, it is preferable to control the collision energy between the ceramic spherical bodies.

  The present invention also includes at least a first member and a second member having raceway surfaces arranged to face each other, and a plurality of rolling elements arranged to be freely rollable between the raceway surfaces of both members, In the rolling support device in which one of the first member and the second member moves relative to the other by rolling the rolling element, the rolling element is a ceramic spherical body, and is obtained by the method of the present invention. The present invention provides a rolling support device characterized in that residual stress is introduced into the.

Since the rolling support device of the present invention includes the ceramic rolling element obtained by the method of the present invention, the rolling support device includes the ceramic rolling element whose surface is toughened by the method of Patent Document 4. However, the service life is prolonged under high-speed rotation with a dmn value of 1.4 million or more and in a corrosive environment where a lubricant cannot be used.
The ceramic spherical body obtained by the method of the present invention has less variation in the residual stress value at each part of the surface of one spherical body as compared with that obtained by processing such as shot blasting. In addition, there is less variation in residual stress value and dimensional accuracy between the ceramic spheres filled in the same pot as compared with the case of processing such as shot blasting. Another feature is that differences between pots hardly occur under the same processing conditions.

  Therefore, the difference between the residual stress value and the dimensional accuracy between the obtained ceramic spherical bodies can be reduced even before the final polishing step as well as those after the final polishing step. For this reason, especially when applied to a rolling support device having a large number of rolling elements, a highly accurate rolling support device can be obtained. Specifically, it is suitable for a rolling support device having 10 or more rolling elements.

  In addition, when using a ceramic spherical body as a rolling element of a rolling bearing, the surface roughness is preferably set to Ra 0.1 μm or less. And when desired surface roughness is obtained only by the ball mill process of the method of the present invention, finish polishing can be omitted. If rolling bearings require severe performance and conditions such as low dust generation, high load, low noise, and high-speed rotation, finish polishing should be performed to make the surface roughness Ra 0.010 μm or less. Is preferable, and Ra is 0.008 μm or less.

The present invention also provides a rolling bearing for an inverter motor of an air conditioner obtained by the method of the present invention and having, as a rolling element, an alumina spherical body in which residual stress is uniformly introduced on the surface.
The alumina spherical body obtained by the method of the present invention, in which residual stress is uniformly introduced on the surface, has excellent fracture toughness and good dimensional accuracy. Excellent torque performance and durability. Alumina is less expensive than silicon nitride. Therefore, according to the rolling bearing for an inverter motor of the present invention, it is possible to prevent damage due to a leakage current from the inverter motor while using a low-cost alumina spherical body as a rolling element.

According to the method of the present invention, a ceramic spherical body having superior toughness, wear resistance, and seizure resistance than the method of Patent Document 4 can be obtained.
The rolling support device of the present invention has a long life under high-speed rotation with a dmn value of 1.4 million or more or in a corrosive environment where a lubricant cannot be used.
Moreover, according to the rolling bearing for inverter motors of the present invention, it is possible to prevent damage due to leakage current from the inverter motor by a low cost method.

Hereinafter, embodiments of the present invention will be described.
[First Embodiment]
FIG. 2 is a partial longitudinal sectional view showing a structure of a rolling bearing which is an embodiment of the rolling support device of the present invention.
This rolling bearing is a deep groove ball bearing having an identification number of 6000 (inner diameter 10 mm, outer diameter 26 mm, width 8 mm, ball diameter 4.762 mm), an inner ring (first member) 1 having a raceway surface 1a on the outer peripheral surface, An outer ring (second member) 2 having a raceway surface 2a opposite to the raceway surface 1a on the inner peripheral surface, a plurality of balls (rolling elements) 3 disposed between the raceway surfaces 1a and 2a in a freely rolling manner, And a cage 4 that holds 3.

For the inner ring 1 and the outer ring 2, a material made of SUS440C was processed into a predetermined shape and subjected to normal heat treatment.
In No. 1, after processing a silicon nitride material of Hv1500 into a spherical shape having a diameter of 4.768 mm and a surface roughness (Ra) of 0.008 μm, a ball mill process was performed by the following method, and then a ball lapping machine Was used for final polishing. This was used as ball 3. The surface roughness (Ra) of the balls 3 was 0.008 μm, the same as before the ball mill process. The surface roughness (Ra) before final polishing was 0.013 μm, which was 0.005 μm rougher than that before the ball mill process.

<Ball mill process conditions>
Apparatus used: “Planet type ball mill P-5” manufactured by Fritsch. The mill pot has a total volume of 45 milliliters (cc) and is made of chrome steel.
Amount of silicon nitride spheres placed in the mill pot: 50% by volume of the closest packed amount of the mill pot
Revolution speed: 500rpm
Rotation speed: 1000rpm
Rotation time: 3 hours

  In No. 2, a silicon nitride material of Hv1500 was processed into a spherical shape having a diameter of 4.762 mm and the surface roughness (Ra) was adjusted to 0.008 μm, then the hardness was Hv1500, the average particle size was 150 μm, and the specific gravity Was used as a shot, and shot blasting was performed under the conditions of a projection pressure: 0.5 MPa, a projection speed: 50 m / s, a projection amount: 400 g / min, and a projection time: 10 s. This was used as ball 3. The surface roughness (Ra) of the balls 3 was 0.016 μm, 0.008 μm rougher than that before shot blasting.

In No. 3, an Hv1500 silicon nitride material processed into a spherical shape having a diameter of 4.762 mm and a surface roughness (Ra) of 0.008 μm was used as the ball 3 as it was.
The surface roughness was measured using a plate-shaped test piece made of silicon nitride of Hv1500 and having a thickness of 10 mm × 10 mm and a thickness of 5 mm. That is, in No. 1, the surface of this test piece was subjected to the ball mill process and polishing by the same method as the method for No. 1 ball 3 described above. In No. 2, the surface of this test piece was subjected to shot blasting by the same method as the method for No. 2 ball 3 described above. In No. 3, this test piece was used as it was.

Further, when the fracture toughness values were measured using test pieces corresponding to the balls 3 of No. 1 to No. 1-3, No. 1 was 15 MPa · √m, No. 2 was 11 MPa · √m, No. 3 was 6 MPa · √m.
In addition, FIG. 1 is a graph which shows the result of having measured the fracture toughness value in each depth position from the surface of a test piece about No. 1 and 2. FIG. In FIG. 1, the fracture toughness value of the surface of the No. 1 test piece is 15.3 MPa · √m. However, as the ball 3, 3 μm is removed from the surface after the ball mill process by finish polishing. The fracture toughness value of the surface of No. 1 ball 3 is 15.0 MPa · √m.

The rolling bearing shown in FIG. 2 was assembled using the balls 3 of the obtained sample Nos. 1 to 3, the inner ring 1 and the outer ring 3 and the cage 4 made of fluororesin. Then, each assembled rolling bearing was subjected to a bearing rotation tester manufactured by Nippon Seiko Co., Ltd. as shown in FIG. 3 to examine the durability in a state where it was immersed in a corrosive liquid.
This testing machine includes a shaft 11 for attaching an inner ring of a test bearing 10 to a tip end portion 11a, and a housing 12 for inserting an outer ring. A plate 13 is fixed to the outer periphery of the housing 12, and a vibrometer 14 is attached to the plate 13. One end of the wire 15 is fixed to the side of the outer periphery of the housing 12 opposite to the plate 13. A weight 16 for applying a radial load to the test bearing 10 is attached to the other end of the wire 15.

In this testing machine, an arm 31 is fixed to a table 30 on which the container 20 is placed, and a pulley 32 is mounted thereon. The test bearing 10 is installed in the container 20 in a state of being attached between the shaft 11 and the housing 12. In this state, the wire 15 is suspended from the side of the table 31 via the pulley 32. Water W is contained in the container 20.
Further, as a rotating device for the shaft 11, a rotating device 110 including a motor 111, a spindle 112, and a coupling joint 113 is provided.

  Using this testing machine, a rotation test was performed under the following conditions, and the bearing life was measured based on the vibration value. That is, the vibration generated in the bearing was constantly measured during the rotation test, and when the vibration value became three times or more of the initial value, the test was stopped, and the total number of rotations up to that time was regarded as the life. All rolling bearings were not lubricated with grease and lubricating oil.

<Rotational test conditions>
Atmospheric temperature: Normal temperature Radial load: 9N
Rotational speed: 3000min ^-1
Then, in order to compare the durability (rotational life) of each test bearing, a relative value was calculated when the life of the rolling bearing of sample No. 3 was set to “1”. As a result, the relative value of the life is “10” in No. 1 using the ball 3 produced by the method corresponding to the embodiment of the present invention, and No. using the ball 3 produced by the method of Patent Document 4. .2 was "3".
Thus, the rolling bearing using the No. 1 ball 3 corresponding to the embodiment of the present invention has a significantly longer life in a corrosive environment than the rolling bearing using No. 2 and 3. Become.

[Second Embodiment]
FIG. 4 is a partial longitudinal sectional view showing the structure of a rolling bearing which is an embodiment of the rolling support device of the present invention.
This rolling bearing is an angular ball bearing (inner diameter 70 mm, outer diameter 100 mm, width 20 mm, ball diameter 8.73 mm) having an identification number 70BNR10T, an inner ring (first member) 1 having a raceway surface 1a on the outer peripheral surface, An outer ring (second member) 2 having a raceway surface 2a opposite to the raceway surface 1a on the inner peripheral surface, a plurality of balls (rolling elements) 3 disposed between the raceway surfaces 1a and 2a in a freely rolling manner, 3, and a seal 5.
The inner ring 1 and the outer ring 2 produced by the same method as the first embodiment except that balls of No. 1 to 3 produced by the same method as the first embodiment and SHX material were used, and a cage 4 made of phenol resin Was used to assemble the rolling bearing shown in FIG.

Then, each assembled rolling bearing was subjected to a test for examining seizure resistance in oil-air lubrication using a test machine shown in FIG. This testing machine has a rotating shaft 22 driven by a belt 21, and the rolling bearing shown in FIG. 4 is attached as a test bearing 24 between the rotating shaft 22 and the housing 23. A support bearing 25 is attached to the end of the rotating shaft 22 opposite to the belt 21. Moreover, the flow path 26 which goes to the bearing space of each test bearing 24 is provided, and the connector of an oil air introduction tube is attached to the inlet 26a. Further, a thermocouple 27 for measuring the temperature of the outer ring of the test bearing 24 is provided.
Using this test machine, a rotation test was performed under the following conditions while changing the rotation speed, and after 2 hours, it was examined how much the temperature of the outer ring of the test bearing 24 rose from before the test. The result is shown in the graph of FIG.

<Rotational test conditions>
Ambient temperature: normal temperature Axial load: 200N
Rotation ^{speed: 5000min -1, 10000min -1, 15000min} -1, 20000min -1, 25000min -1, 30000min -1
Lubricating oil supplied as oil air: VG22 (mineral oil)
Oil / air supply rate: 0.2ml / min

  As can be seen from the graph of FIG. 6, the outer ring of No. 1 using the ball 3 manufactured by the method corresponding to the embodiment of the present invention is more than the No. 2 using the ball 3 manufactured by the method of Patent Document 4. Temperature rise value was small. Therefore, in No. 1 using the ball 3 produced by the method corresponding to the embodiment of the present invention, the seizure resistance by oil-air lubrication is higher than No. 2 using the ball 3 produced by the method of Patent Document 4. Excellent in properties.

Further, in No. 1 using the ball 3 produced by the method corresponding to the example of the present invention, the rotation speed was 30000 min ⁻¹ (corresponding to a dmn value of 250,000) and the outer ring temperature rise value was 25 ° C. On the other hand, in No. 2 using the ball 3 produced by the method of Patent Document 4, the rotational speed is 15000 min ⁻¹ (corresponding to a dmn value of 1275,000) and the outer ring temperature rise value is 25 ° C. The rotation speed was 50 ° C. at 30000 min ⁻¹ .
Therefore, the rolling bearing using the No. 1 ball 3 corresponding to the embodiment of the present invention is under high speed rotation with a dmn value of 1.4 million or more compared to the rolling bearing using No. 2 and 3. It can be seen that the lifetime of the can be sufficiently long.

The relationship between the depth from the surface of the ceramic test piece and the fracture toughness value when the ball mill process is performed on the surface of the ceramic test piece and shot blasted with the method of Patent Document 4 It is a graph to show. It is a fragmentary longitudinal cross-section which shows the structure of the rolling bearing which is 1st Embodiment of this invention. It is a schematic block diagram which shows the rotation test machine which investigates the durability in the state immersed in the corrosive liquid used in 1st Embodiment. It is a fragmentary longitudinal cross-section which shows the structure of the rolling bearing which is 2nd Embodiment of this invention. It is a schematic block diagram which shows the rotation test machine which investigates the seizure resistance in oil air lubrication used in 2nd Embodiment. It is a graph which shows the result of having investigated the change of the outer ring temperature rise value by performing the rotation test by changing rotation speed.

Explanation of symbols

1 Inner ring (second member)
1a Raceway surface 2 Outer ring (first member)
2a raceway surface 3 ball (rolling element)
4 Cage 10 Test Bearing 11 Shaft 11a Shaft Tip 110 Rotating Device 111 Motor 112 Spindle 113 Connection Joint 12 Housing 13 Plate 14 Vibrometer 15 Wire 16 Weight 20 Container 30 Unit 31 Arm 32 Pulley 21 Belt 22 Rotating Shaft 23 Housing 24 Test bearing 25 Support bearing 26 Oil-air introduction channel 26a Oil-air introduction port 27 Thermocouple W Water

Claims (7)

At least a first member and a second member having raceway surfaces arranged opposite to each other, and a plurality of rolling elements arranged so as to be freely rollable between the raceway surfaces of both members, the rolling element rolling A rolling support device in which one of the first member and the second member moves relative to the other, thereby producing a ceramic spherical body used as the rolling element,
By placing a plurality of the same ceramic spherical bodies in the mill pot of the planetary ball mill and operating the planetary ball mill, the spherical body is given a centrifugal force accompanying the revolution generated in the mill pot and a centrifugal force accompanying the rotation. A ceramic ball for a rolling support device , characterized by having a ball mill step of causing the spherical bodies to collide with each other and introducing a residual stress to the surface of the spherical body by colliding the spherical bodies with the inner wall of a mill pot. Production method. 2. The method for producing a ceramic spherical body for a rolling support device according to claim 1, wherein finish polishing is performed after the ball mill process. 3. The method for producing a ceramic spherical body for a rolling support device according to claim 1, wherein at least an inner wall of the mill pot is made of ceramics. The method for producing a ceramic spherical body for a rolling support device according to any one of claims 1 to 3, wherein the inner wall of the mill pot has a Vickers hardness (Hv) of 1000 or more. At least a first member and a second member having raceway surfaces arranged opposite to each other, and a plurality of rolling elements arranged so as to be freely rollable between the raceway surfaces of both members, the rolling element rolling In the rolling support device in which one of the first member and the second member moves relative to the other by
The rolling support device according to claim 2, wherein the rolling element is a ceramic spherical body, obtained by the method according to claim 2, wherein residual stress is uniformly introduced into the surface.   A rolling bearing comprising a silicon nitride spherical body obtained by the method according to claim 2 and having a residual stress uniformly introduced to the surface as a rolling element.   A rolling bearing for an inverter motor of an air conditioner, characterized by having, as a rolling element, a spherical body made of alumina obtained by the method of claim 2 and having a residual stress uniformly introduced on the surface thereof.