JP2003074566A - Rolling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling device having excellent rolling life even under a corrosive environment or an environment required for nonmagnetism. SOLUTION: In a deep groove ball bearing provided with an inner ring 1, an outer ring 2, and a plurality of rolling bodies 3 rotatably disposed between the inner ring 1 and the outer ring 2, the inner and outer rings 1, 2 are constituted of β type or α+βtype titanium alloy of 200 μm or finer in average particle size of β phase crystalline granule and the surface hardness is made to be Hv400 or larger.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing and a linear motion.
The present invention relates to a rolling device such as a guide device, and particularly to a semiconductor manufacturing device,
Like liquid crystal manufacturing equipment, chemical fiber manufacturing equipment, food machinery, etc.
In corrosive environments such as fresh water, salt water, chemicals, corrosive gases, etc.
Equipment used in semiconductor manufacturing equipment, liquid crystal manufacturing equipment
Magnetic field, such as a measuring device using an X-ray or electron beam
In an environment that requires
Rolling device suitably applied to the device used in
You. 2. Description of the Related Art Conventionally, rolling devices such as rolling bearings have been constructed.
The main materials used are mainly high carbon chromium bearing steel and case hardened steel.
Such steel materials were commonly used. In recent years, rolling equipment
The use environment of the equipment is diversified, and water, salt water, acid,
This may be used in corrosive environments such as
When used in an environment where high corrosion resistance is required
Used stainless steel as a material. However, in recent years, the use environment of the rolling device has been increasing.
Has become more severe, and even stainless steel has corrosion resistance
There have been cases where it is not enough. Such a harsh environment
Cold working as a rolling bearing with excellent rolling life even under
Or orbit with titanium alloy reinforced by shot peening
Rolling, consisting of wheels and rolling elements made of ceramic
A bearing is disclosed in JP-A-11-223221.
I have. On the other hand, semiconductor manufacturing equipment, liquid crystal manufacturing equipment, X
Use a magnetic field, such as a measuring device that uses
Measurement accuracy deteriorates due to disturbance of the equipment used and magnetic field
Many devices are being used. This
Rolling devices used in devices such as
Non-magnetic is required so as not to disturb the surrounding magnetic field
So it is composed of non-magnetic stainless steel or beryllium copper
I have. However, an analyzer using an electron beam or the like
Or, in the measuring device, the rolling members constituting the rolling device
Just magnetizing the criminal may cause accuracy failure.
The relative permeability is about 1.04 to 1.002
Conventional non-magnetic stainless steel cannot be used. So, yo
When non-magnetism near perfect is required, the relative permeability
In many cases, beryllium copper of 1.001 or less is used.
No. For example, Japanese Utility Model Laid-Open No. 5-79042 discloses an inner and outer ring.
Is made of beryllium copper and rolling elements are made of ceramic
A disclosed rolling bearing is disclosed. SUMMARY OF THE INVENTION However, titanium
For alloys, cold work or shot piping for strengthening.
And increase the number of these steps
There was a problem that the cost increased. Also,
Strengthen the tongue alloy by cold working or shot peening
Although the rolling life is improved by
Therefore, the effect of improving the rolling life may vary.
Was. On the other hand, for beryllium copper, the constituent elements
Some of the compounds produced from beryllium
Environmental issues are becoming increasingly important
Beryllium copper
There may be restrictions. In the rolling device
Is a high contact pressure between the inner and outer members and the rolling elements.
However, beryllium copper has a hardness of about Hv400.
Therefore, wear tends to occur due to insufficient hardness. for that reason,
Other parts of the machinery where the rolling device is used are worn
Contaminated by powder, shortening the life of the machinery
There was also a problem that there was a risk of spilling. [0008] Accordingly, the present invention provides a conventional inverter as described above.
Solving the problems of power transmission systems, in corrosive environments and non-magnetic
Excellent rolling life even in environments requiring
It is an object of the present invention to provide a rolling device. Means for Solving the Problems [0009] To solve the above problems,
Therefore, the present invention has the following configuration. That is,
The light rolling device includes an inner member, an outer member, and the inner portion.
A plurality of rolling members arranged between the outer member and the outer member.
A rolling element comprising: a rolling element;
And at least one of the outer members is an average of β phase crystal grains.
Β-type or α + β-type titanium alloy with a particle size of 200 μm or less
It is made of gold and its surface hardness is Hv400 or more
It is characterized by. Generally, heat of β-type or α + β-type titanium alloy
The treatment is performed by the following solution treatment and aging treatment.
Is done. Solution treatment is the process of converting the titanium alloy to the α / β transformation point.
Keep at the temperature above or below and cool from that temperature
The metal structure can be transformed into a uniform β-phase structure or α-phase
This is a process for forming a structure in which a small amount of phase remains. In addition, aging treatment
The reason is that the titanium alloy after solution treatment is 350-600 ° C.
By heating to a temperature of about
To finely precipitate the α phase from the β phase to improve the hardness
Processing. Almost the entire metal structure after the solution treatment is the β phase
, Β phase crystal grains are clearly observed. Ma
In addition, the metal structure after aging treatment is due to the precipitation of the α phase.
In some cases, β-phase grains cannot be clearly identified, but metal
Grain boundaries of β phase crystal grains remain in the structure. Note that
In the following description, for convenience of explanation, β after solution treatment
Phase crystal grains are referred to as “β phase crystal grains” and are subject to the aging treatment described above.
Therefore, the β phase crystal grains remaining after the α phase is precipitated
Phase crystals. " However, it is formed during the solution treatment.
The size of the β phase crystal grains changed even after aging treatment
Therefore, the grain size of the β-phase crystal grains and the
You can think of it as one. By the way, rolling of a rolling device such as a rolling bearing is performed.
The service life is determined by the increase in abnormal noise or vibration during use.
Is done. The rolling device that has reached the end of its life
Material or the surface of the rolling element is peeled off by rolling fatigue
Often have. This peeling occurs in the following process.
It is At the point of contact between the inner and outer members and the rolling elements
Produces very high surface pressures. Therefore, for a long time
When rolling devices are used, high surface pressures are repeatedly applied.
Stress in the metal structure due to rolling fatigue
Cracks occur at the concentrated part. Rolling device is used for a longer time
The cracks that have developed will eventually evolve
It is. In the case of a rolling device made of steel material,
Non-metallic inclusions or foreign matter may be trapped
This is the edge of the indentation generated at that time. The rolling members such as the inner member and the outer member are made of titanium.
If it is composed of an alloy, the β phase
While holding at a high temperature such that
Easy to convert. Therefore, even after aging treatment,
The grain boundaries of the old β-phase crystal grains tend to become stress concentrated parts,
It may be the starting point of peeling of the glue fatigue. Therefore,
The light rolling device includes at least one of an inner member and an outer member.
On the other hand, the average grain size of the old β phase crystal grains is 200 μm or less.
It was composed of β type or α + β type titanium alloy. Old β phase crystal grains
Is small, the grain boundary area per unit volume
Increases, and the concentration of stress on the grain boundaries is reduced.
Thus, the rolling life is improved. Stress on grain boundaries
Concentration is reduced and rolling life is further improved.
For this purpose, the average grain size of the old β phase crystal grains is set to 100 μm or less.
It is preferable to improve the life more stably.
In order to make the average grain size of the old β phase crystal grains 50 μm or less,
Is more preferable. The β-phase crystal grains are maintained at a holding temperature during solution treatment.
The higher the degree and the longer the retention time, the larger the tendency
It is in. Therefore, in order to reduce the β phase crystal grains,
The holding temperature during the solidification treatment is higher than the α / β transformation point temperature.
And the difference is preferably 100 ° C. or less.
Smaller β phase crystal grains and stable life improvement
For this purpose, it is more preferable that the temperature difference be 70 ° C. or less.
preferable. For example, in the case of β-type titanium alloy, 800 to 8
50 ° C, 950-1000 for α + β type titanium alloy
° C. In order to make the β phase crystal grains smaller,
During solution heat treatment, the temperature becomes higher than the α / β transformation temperature
Time (the α / β change
Holds at the time and holding temperature after exceeding the station temperature
Time) is preferably 2 hours or less. β phase crystal grains
In order to make the life smaller and stably improve the life,
The time during which the temperature is higher than the α / β transformation point temperature is 1
More preferably, the time is not more than the time. Average grain size of β phase crystal grains and old β phase crystal grains
Shall be obtained by the following methods. Sandals
That is, after solution treatment, after aging treatment, or rolling member of finished product
Is cut and its cross section is polished until a mirror surface is obtained. Soshi
And an etching solution consisting of a mixed aqueous solution of hydrofluoric acid and nitric acid
Metal structure by immersion for a suitable time
Let's take a picture. Using this photograph, JIS H05
The crystal grain size is determined by the quadrature method specified in 01,
This crystal grain size is referred to as the β phase crystal grain of the titanium alloy in the present invention.
Is the average particle size. [0017] JIS H0501 is for copper alloy wrought materials.
It is specified to determine the crystal grain size.
The grain size can be determined in the same way for alloys
You. The quadrature method uses a metallographic photograph, etc.
From the number of grains contained in a circle or rectangle,
It is a method of seeking. Note that the β phase crystal grains should be clearly observed.
Therefore, it is preferable to use the metal structure after solution treatment.
Good. The titanium alloy used for the inner member and the outer member
Gold satisfies the above-mentioned condition of the average grain size of the old β phase crystal grains.
There is no particular limitation if. However, the solution
High hardness due to precipitation hardening by aging treatment and aging treatment
Type (including near β type) or α + β type
Tan alloys are preferred. Specifically, such as AMS4911
Ti-6Al-4V alloy, Ti- such as AMS4972
8Al-1Mo-1V alloy, Ti such as AMS4976
-6Al-2Sn-4Zr-2Mo alloy, AMS49
14 and other Ti-15V-3Cr-3Sn-3Al alloys
Ti-6Al-6V-2Sn system such as gold and AMS4918
Alloy, Ti-5Al-2Sn-2Z such as AMS4995
r-4Cr-4Mo alloy, Ti- such as AMS4981
6Al-2Sn-4Zr-6Mo-based alloy, AMS495
9 and other Ti-13V-11Cr-3Al-based alloys, Stock Association
Ti-15Mo- such as KS15-5-3 of Shakobe Steel Works
5Zr-3Al alloy, Ti-15Mo-5Zr alloy
Gold or Ti-2 such as DAT51 of Daido Steel Co., Ltd.
2V-4Al alloys and the like. An inner member made of a titanium alloy,
Is the surface hardness of the outer member abrasion and load bearing?
By performing a solution treatment and an aging treatment,
v400 or more. Hv less than 400
Then, the condition of the average particle size of the old β phase crystal grain described above is satisfied.
Even if it is, hardness is insufficient and wear resistance and load bearing
It becomes insufficient and the rolling life is shortened. In addition, titanium alloy
Oxidizing the inner and outer members made of gold
Or surface treatment such as providing a lubricating film.
This further improves wear resistance, load resistance, and slidability.
You may let it. The rolling element is made of a steel material or a ceramic.
It can be composed of materials. However, non-magnetic or excellent
For applications requiring high corrosion resistance, use ceramic material.
Is preferred. Specific examples include silicon nitride,
Silicon carbide, aluminum oxide, zirconium oxide
And ceramic materials such as ceramics. Also use electron beam
Where non-magnetic and electrical conductivity are required as in
In this case, it is made of conductive ceramic containing TiN etc.
Use rolling elements that are not
Rolling elements made of non-conductive ceramics, such as CVD
Use TiN coating
Is preferred. The rolling device of the present invention has an inner member and
Using a cage that holds the rolling element between the outer member
Can be. The material of the cage has sufficient heat resistance
Then, there is no particular limitation. For example, Polyamide
, Resin cage made of fluororesin, brass cage, SU
Austenitic stainless steel cage such as S304
Can be exemplified. However, for applications where grease cannot be used
Use a self-lubricating fluororesin cage, etc.
Preferably. Further, the rolling device of the present invention is suitable for its use.
Accordingly, a sealing device such as a seal may be provided. C
Material is limited if it has sufficient heat resistance
Not made, for example, made of rubber such as nitrile rubber
An example is a seal. For applications requiring non-magnetism, S
Austenitic stainless steel seal such as US304
Alternatively, an industrial pure titanium seal is preferable. Furthermore, the rolling device of the present invention has
Grease may be sealed inside. Special grease type
Rolling device used in vacuum, but not limited to
If so, use fluorine grease for vacuum
Is preferred. Next, the preferred use of the rolling device of the present invention will be described.
Will be described. The rolling device according to the present invention has a relative magnetic permeability
Titanium having a high level of non-magnetism of 1.001 or less
Since the inner and outer members are made of alloy, non-magnetic
It can be suitably used for required applications. That is, the rolling device is used in a magnetic field environment.
Magnetic field exerted an attractive force on the rolling device even when used
Operation does not become unstable.
Because the movement does not disturb the surrounding magnetic field, for example,
Semiconductor manufacturing equipment, liquid crystal manufacturing equipment, medical equipment, X-ray or
It is suitable for use in measuring devices using
Can be. Further, in the above-described apparatus, the proximity of
The rolling device operates even when the rolling device is used.
Measurement does not disturb the electron beam, etc.
It can be used favorably without a decrease in the degree.
Wear. Further, the above-mentioned various devices have complicated mechanisms.
Replacement of rolling devices is a big burden.
Although the rolling device according to the present invention is stable,
Because of its long service life, the frequency of replacing rolling devices is reduced.
Can be eliminated. Furthermore, the rolling according to the invention
The equipment is made of titanium alloy, which has excellent corrosion resistance.
Applications where high corrosion resistance is required due to the composition of the material
Can be suitably used. That is, chemicals such as acids and alkalis and corrosive
Rolling device is used in an environment where it comes into contact with gas, etc.
Even so, titanium alloys are very
Hardly corrodes, shortens rolling device life due to corrosion
Hardly ever. So, for example, semiconductor
Cleaning equipment, semiconductor manufacturing equipment, liquid crystal manufacturing equipment, chemical fiber
It can be suitably used in manufacturing equipment, food machinery, etc.
it can. Moreover, the rolling device according to the present invention is stable and has a long service life.
The frequency of replacing rolling devices
can do. The rolling device of the present invention includes a rolling bearing,
Linear guide devices, ball screws, and the like. Also,
In the present invention, the inner member is a rolling device in which a rolling shaft
In the case of the bearing, the inner ring
Guide rail, and in the case of a ball screw, the screw shaft,
Meaning respectively. Further, the outer member of the present invention and
Is the outer ring if the rolling device is a rolling bearing,
In the case of the guide device, the slider and ball screw
In the case, the nut means respectively. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment of a rolling device according to the present invention
The state will be described in detail with reference to the drawings. Figure 1 is a book
A deep groove ball bearing (shaft) which is an embodiment of the rolling device according to the present invention
(Model number: 608). This deep groove ball axis
The bearing is rolled between the inner ring 1, the outer ring 2, and the inner ring 1 and the outer ring 2.
A plurality of ceramic rolling elements 3 movably arranged;
A retainer 4 made of a fluororesin that holds the rolling element 3;
304 seals 5 and 5. Also, the inner ring
Fluorine is in the space surrounded by 1, outer ring 2, and seals 5, 5.
Grease 6 is filled and deep groove ball bearings
Sealed inside. The inner ring 1 and the outer ring 2 are shown in Table 1.
It is composed of such a titanium alloy. That is, α + β type
Ti-6Al-4V, which is a titanium alloy, and β-type titanium alloy
Ti-15Mo-5Zr-3Al and Ti-2 which are gold
2V-4Al is used. [Table 1] The inner ring 1 and the outer ring 2 were made by turning a material.
A solution treatment is applied later, followed by an aging treatment,
It is manufactured by turning and grinding. Solution
The temperature of the chemical treatment is composed of Ti-6Al-4V.
950-1100 ° C, Ti-22V-4Al
700-900 ° C, Ti-15Mo
770 to 95 when composed of -5Zr-3Al
0 ° C, hold at this temperature for 1 hour, then cool with water or gas
Solution treatment by cooling to around room temperature with
Was. In the same type of titanium alloy, the solution
The higher the holding temperature of the treatment, the larger the average grain size of the β phase crystal grains
The average particle size of β phase
Inner ring 1 and outer ring made of titanium alloy having different diameters as shown in Table 1.
2 was produced. The aging treatment is performed at 400 to 650 ° C.
After holding for 8 to 60 hours, perform by cooling the furnace
Was. Cooling by furnace cooling is slow, so
The resulting precipitation structure is further refined, and the hardness is improved. What
The average particle size of β phase crystal grains after solution treatment
It does not change with processing. By performing such processing, the internal
Of the former β phase crystal grains of the titanium alloy forming the outer ring 1 and the outer ring 2
The average particle size is 200 μm or less.
And the surface hardness of the outer race 2 is Hv400 or more.
The rolling element 3 is made of a ceramic material as shown in Table 1.
Has been established. That is, silicon nitride ceramics
Nikkato SUN12), aluminum oxide
Ceramics (SSA99 manufactured by Nikkato Co., Ltd.)
9W), zirconium oxide ceramics
Kato's YTZ) is used. [Rotation test] Next, a deep groove ball shaft as described above
Rotation test for receiving (Examples 1 to 10 and Comparative Examples 1 to 6)
Test results and the results of evaluating the rolling life
I do. The rotation test conditions were as follows: radial load 98N, axial
Al load 10N, rotation speed 500min ^-1 It is. Soshi
And the vibration value rises to twice that immediately after the start of the rotation test (initial value)
The rotation time until the rolling was determined as the rolling life of the ball bearing. What
The rolling life shown in Table 1 and the graph of FIG. 2 described later.
Indicates the case where the rolling life of the bearing of Comparative Example 4 is 1.0.
It is shown as a relative value. Ball axes of Examples 1 to 10 and Comparative Examples 1 to 6
For the bearing, the surface hardness Hv of the inner ring and the outer ring,
The average particle size of the old β-phase crystal grains of the outer ring and the rolling life are displayed.
1 is also shown. The ball bearings of Examples 1 to 10 are
Old β phase formation of titanium alloy constituting (Inner ring 1 and Outer ring 2)
The average grain size of the crystal grains is 200 μm or less. The result
As a result, the grain boundary area per unit volume increases,
Excellent rolling life due to reduced stress concentration at grain boundaries
ing. On the other hand, the ball axes of Comparative Examples 2 and 4 to 6
The average particle size of the old β phase crystal grains exceeded 200 μm
ing. As a result, stress concentration tends to occur at grain boundaries.
Rolling fatigue progresses locally, shortening the service life
I have. In Comparative Examples 1 and 3, the average grain size of the old β phase
Although the diameter is 200 μm or less, the surface hardness is H
v less than 400, poor abrasion resistance and load resistance
ing. As a result, wear and rolling fatigue increase due to the load.
Running, the life was remarkably short. FIG. 2 shows a graph of the results of Table 1.
You. As is clear from this graph, the average of the old β phase crystal grains
When the particle size is 200 μm or less, the rolling life is excellent.
ing. Also, the average grain size of the old β phase crystal grains is 100 μm or less.
If below, the rolling life is better and the old β phase
If the average grain size of the crystal grains is 50 μm or less, rolling
It can be seen that the life is even better. As described above, the ball bearing according to the present embodiment
And the outer ring is made of the above titanium alloy, and its old β
The average grain size of the phase crystal grains is set to 200 μm or less.
Has a surface hardness of Hv400 or more, so the rolling life is
Very good. [Rotation test in a corrosive environment]
For deep groove ball bearings (Examples 11 to 13 and Comparative Examples 7 to 10)
Then, a rotation test was performed in a 5% aqueous sodium chloride solution.
The results of evaluating the rolling life will be described. The materials of the inner ring, outer ring and rolling elements are shown in Table 2.
That's right. Co., Ltd.
Nikkato SUN12 was used. The cage is
Made of fluororesin. [Table 2] The conditions for the rotation test were as follows: a radial load of 49 N;
Axial load 20N, rotation speed 500min ^-1 In
You. The vibration value is 2 immediately after the start of the rotation test (initial value).
The rotation time until the roller bearing doubles is taken as the rolling life of the ball bearing.
Was. In addition, the rolling life of the bearing of Comparative Example 7
And the relative value when the life is 1.0. Implementation
About each ball bearing of Examples 11-13 and Comparative Examples 7-10,
Surface hardness Hv of inner and outer rings and old β phase of inner and outer rings
Table 2 shows the average grain size of the crystal grains and the rolling life.
You. The ball bearings of Examples 11 to 13 are composed of an inner ring and an outer ring.
The wheels are made of titanium alloy with excellent corrosion resistance, and the rolling elements are also resistant
It is composed of ceramic with excellent food properties,
The average grain size of the old β phase crystal grains of the titanium alloy is 200 μm or less
It is below. Therefore, even in a corrosive environment, rolling
The service life is excellent. On the other hand, the ball bearing of Comparative Example 7
SUS44, in which the inner ring, outer ring and rolling elements have poor corrosion resistance
Rolling under corrosive environment because it is composed of 0C
The life was remarkably short. The ball bearing of Comparative Example 8 has an inner ring and an outer ring.
Is made of titanium alloy with excellent corrosion resistance, and the rolling elements are also corrosion resistant
Since it is composed of ceramic with excellent resistance, corrosion
Although the rolling life is not shortened due to the
Since it is less than 400, wear resistance and load resistance are inferior.
I have. As a result, wear and rolling fatigue progress due to the load
And the life was short. Further, the ball bearings of Comparative Examples 9 and 10
The wheel and outer ring are made of titanium alloy with excellent corrosion resistance,
The moving body is also made of ceramic with excellent corrosion resistance.
Therefore, rolling life is not shortened due to corrosion. Only
And the average grain size of the old β phase crystal grains exceeds 200 μm
Therefore, stress concentration tends to occur at the grain boundaries,
Rolling fatigue has progressed and the life has been shortened. [Non-magnetic confirmation test]
8 deep groove ball bearings (Examples 14 to 16 and Comparative Examples 11 and 1)
For 2), conduct a test to confirm whether it has non-magnetism.
The results obtained will be described. Inner ring, outer ring, and rolling elements
Are as shown in Table 3. Silicon nitride ceramic
Use SUN12 manufactured by Nikkato Co., Ltd.
Was. The retainer is made of a fluororesin. [Table 3] Here, the test was performed using the test apparatus shown in FIG.
The method of the nonmagnetic confirmation test will be described. Rotary axis 1
1 is provided with a test bearing 10 and a fixed permanent magnet 1
Rotated between 2,12. And the stellar meter
13, the magnetic flux density is measured, and the rotation of the bearing 10 causes the magnetic flux density to be measured.
It was determined whether the field fluctuated. Magnetic flux due to bearing rotation
Table 3 shows the presence or absence of a change in density. In addition, the inner ring and outer ring
Surface hardness Hv and average grain size of old β phase crystal grains of inner ring and outer ring
Table 3 also shows the diameter. The ball bearings of Embodiments 14 to 16 are composed of an inner ring and an outer ring.
The ring has a high level of non-magnetism with relative permeability of 1.001 or less.
The rolling element also has a relative permeability of 1.0
Ceramics with a high level of non-magnetism of 01 or less
It is configured. Therefore, the magnetic field can be disturbed by rotation.
Suitable for use in environments where non-magnetism is required.
Can be On the other hand, the ball bearing of Comparative Example 11
SUS440C where the wheel, outer ring and rolling elements are ferromagnetic
Due to the configuration, the magnetic field is disturbed by the rotation. Yo
Therefore, it cannot be used in an environment where non-magnetism is required. Ma
In the ball bearing of Comparative Example 12, the inner ring and the outer ring were non-magnetic.
Rolling element is ferromagnetic
SUS440C which is
The magnetic field is disturbed. Therefore, in an environment where non-magnetism is required
Cannot be used. Environment where non-magnetism is required
Below, the rolling element also has a relative magnetic permeability of 1.00 like ceramic.
It is preferable to use a material having 1 or less nonmagnetic properties.
No. This embodiment shows an example of the present invention.
And the present invention is not limited to this embodiment.
There is no. For example, the titanium alloy forming the inner and outer rings
The type depends on the condition of the average particle size of the old β phase
If it satisfies the conditions of
However, the present invention is not limited to this. Also, the type of material constituting the rolling elements and the cage
Are also heat-resistant materials that can withstand the operating temperature of ball bearings.
If there is, it is not limited to the above. example
For example, semiconductor manufacturing equipment and measurement equipment using electron beams
In applications where non-magnetism is required for ball bearings,
It is preferable that the moving body and the cage are made of non-magnetic material.
No. Also, use in corrosive environment such as corrosive gas and chemicals.
When used, the rolling elements and cages should have excellent corrosion resistance.
It is preferred to be composed of a material. Further, in this embodiment, the rolling device
As an example, a deep groove ball bearing has been described.
Say that it is applicable for different types of rolling bearings
Not even. Specifically, angular contact ball bearings, self-aligning
Ball bearings, cylindrical roller bearings, tapered roller bearings, needle roller shafts
Radial rolling bearings such as bearings and spherical roller bearings,
Thrust ball bearings and thrust roller bearings
It is a ball bearing. These can be adapted to operating conditions such as applied load.
The bearing type is selected accordingly. Further, the present invention provides not only a rolling bearing but also
Can be applied to other kinds of various rolling devices
You. For example, a linear motion plan for a ball screw, linear guide device, etc.
The present invention can be suitably applied to an internal device. As described above, the transfer according to the present invention has been described.
The moving device is configured such that at least one of the inner member and the outer member is β
Β-type or α-phase crystal grains having an average grain size of 200 μm or less
+ Β type titanium alloy, and its surface hardness is Hv400
Because of the above, rings that require corrosive environments or non-magnetism
Excellent rolling life even in the subsurface

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial longitudinal sectional view showing a configuration of a deep groove ball bearing which is one embodiment of a rolling device according to the present invention. FIG. 2 is a graph showing a correlation between the average grain size of β phase crystal grains of a titanium alloy and the rolling life of a ball bearing. FIG. 3 is a diagram illustrating a method of a test for confirming non-magnetism of a rolling bearing. [Description of Signs] 1 inner ring 2 outer ring 3 rolling element

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Claims (1)

Claims 1. An inner member, an outer member, and a plurality of rolling elements rotatably disposed between the inner member and the outer member. In a rolling device, at least one of the inner member and the outer member is β
Β-type or α-phase crystal grains having an average grain size of 200 μm or less
+ Β type titanium alloy, and its surface hardness is Hv400
A rolling device characterized by the above.