JP2009103159A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing capable of being used even under an extremely cold environment without degrading lubrication performance. <P>SOLUTION: The rolling bearing 1 includes an inner ring 2; an outer ring 3; and a plurality of rolling bodies 4 rollably arranged between the inner ring 2 and the outer ring 3. A lubricant 6 is filled in a bearing space S1 between the inner ring 2 and the outer ring 3. A temperature-raising device 11 for raising the temperature of the lubricant 6 is provided, For example, the temperature-raising device 11 is made to the one in which a ring-like member 13 for covering an outer side in an axial direction of the bearing space is provided and a heater 12 is mounted to an inner surface in an axial direction of the ring-like member 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing suitable for use in an extremely cold environment such as a railway vehicle bearing or a wind power generator bearing.

The above-mentioned railway vehicle bearings and wind power generator bearings have greatly different environmental conditions depending on regions and seasons. Such a difference in environmental conditions particularly affects the function of the lubricant. Research and development for the purpose of improving the lubrication performance of lubricants for railway vehicle bearings is in progress (for example, Patent Document 1). However, conventional research and development of lubricants is mainly for higher speeds and higher temperatures of bearings, and research on countermeasures for low temperatures is not sufficient. Currently, there are few lubricants that can be used in extremely cold environments of minus 40 ° C. or lower.
Japanese Patent No. 2965794

  When the bearing is used in the extremely cold environment as described above, the lubricant such as grease filled in the bearing is solidified, and the function of the lubricant at the time of starting the operation is greatly deteriorated. Further, the solidified lubricant prevents sliding between the parts of the bearing, and the force for stirring the lubricant becomes enormous, so that the load applied to each part increases. As a result, the cage or the like may be damaged as a worst case. Such a problem occurs both when the lubricant is grease and when it is oil.

  An object of the present invention is to provide a rolling bearing that can be used without deteriorating lubricating performance even in an extremely cold environment.

A rolling bearing according to the present invention includes an inner ring, an outer ring, and a plurality of rolling elements that are arranged to freely roll between the inner ring and the outer ring, and a bearing space between the inner ring and the outer ring is filled with a lubricant. In the rolling bearing, a temperature raising device for raising the temperature of the lubricant is provided.
According to this configuration, even in an extremely cold environment, the temperature of the lubricant can be raised to an appropriate temperature or kept at a constant temperature by the temperature raising device, so that the bearing can always be used with good lubrication performance. .

It is preferable that the temperature raising device is provided with a ring-shaped member that covers an outer side in the axial direction of the bearing space, and a heater is attached to an inner surface in the axial direction of the ring-shaped member. In that case, the ring-shaped component is fixed to the outer ring, for example.
When a ring-shaped member that covers the outer side in the axial direction of the bearing space is provided and a heater is attached to the inner surface in the axial direction of the ring-shaped member, the lubricant filled in the bearing space can be effectively heated by the heater. Further, the ring-shaped member can prevent the heat of the heater from being dissipated outward in the axial direction.

The temperature raising device preferably has temperature detection switching means for detecting a temperature of the bearing space or a space in the temperature raising device between the bearing space and the ring-shaped part and switching the heater on and off according to the detection result. . The thermometry switching means may be a thermostat, or may be one in which a temperature detection unit and a heater on / off switching unit are provided separately.
When the temperature detection switching means is provided, the heater can be switched on and off in accordance with the temperature change of the bearing space or the space inside the temperature raising device, so that the space can always be maintained at an appropriate temperature.

The ring-shaped component preferably has a seal function that shields the bearing space and the space inside the temperature raising device from the outside. In that case, the lubricant may be sealed in the space inside the temperature raising device.
By providing the ring-shaped part with a seal function, it is possible to prevent leakage of the lubricant from the inside of the bearing and entry of foreign matter from the outside into the inside of the bearing. When the lubricant is sealed in the space inside the temperature raising device, a large amount of lubricant can be secured, and the rolling bearing can be used for a long time.

In the case where the ring-shaped part is made of metal and the heater is an electrothermal type, an insulating film may be provided at least at a position where the ring-shaped part contacts the inner ring and the outer ring. Or you may provide the insulating film which interrupts | blocks the electric current from the bearing outer side in the said inner ring | wheel or an outer ring | wheel.
When the ring-shaped part is made of metal and the heater is an electrothermal type, the electricity leaked from the wiring supplying electricity to the heater flows to the inner ring and the outer ring, and the inner ring and the outer ring may cause stray current corrosion. The stray current corrosion can be prevented by providing an insulating film at least at a location where the ring-shaped parts contact the inner ring and the outer ring, or by providing an insulating film that cuts off the current from the outside of the bearing on the inner ring or the outer ring.

  A rolling bearing according to the present invention includes an inner ring, an outer ring, and a plurality of rolling elements that are arranged to freely roll between the inner ring and the outer ring, and a space between the inner ring and the outer ring is filled with a lubricant. Since the temperature raising device for raising the temperature of the lubricant is provided, it can be used without deteriorating the lubricating performance even in an extremely cold environment.

  A first embodiment of the present invention will be described with reference to FIGS. The rolling bearing includes a bearing body 1 and temperature raising devices 11 provided on both sides of the bearing body 1 in the axial direction. The bearing body 1 includes an inner ring 2, an outer ring 3, and a plurality of rolling elements 4 that are arranged between the inner ring 2 and the outer ring 3 so as to be freely rollable. The rolling elements 4 are cylindrical rollers, and each rolling element 4 is held in a plurality of pockets 5 a arranged in the circumferential direction of a ring-shaped cage 5. A pair of flange portions 3a arranged in the axial direction is provided on the inner periphery of the outer ring 3, and the rolling elements 4 are disposed between the pair of flange portions 3a. The bearing space S1 between the inner ring 2 and the outer ring 3 is filled with a lubricant 6.

  The temperature raising device 11 raises the temperature of the lubricant 6 by an electrothermal heater 12 and has a ring-shaped part 13 to which the heater 12 is attached. The ring-shaped part 13 includes a vertical portion 13a perpendicular to the axial direction, an outer cylindrical portion 13b extending inward in the axial direction from the outer peripheral end of the vertical portion 13a, and an inner portion extending inward in the axial direction from the inner peripheral end of the vertical portion 13a. It consists of the peripheral cylinder part 13c. The outer peripheral cylindrical portion 13b extends longer in the axial direction than the inner peripheral cylindrical portion 13c, and the convex portion 14 formed on the outer peripheral side of the distal end of the outer peripheral cylindrical portion 13b is a groove portion 3b formed on the inner peripheral surface of the outer ring 3. The ring-shaped member 13 is fixed to the outer ring 3 by being engaged with the outer ring 3. The ring-shaped part 13 is configured to cover the outer side in the axial direction of the bearing space S1 by adopting the above shape. A space between the ring-shaped part 13 and the bearing space S1 is a space S2 in the temperature raising device.

  The heater 12 is attached to the inner surface in the axial direction of the vertical portion 13 a of the ring-shaped member 13. In accordance with the shape of the vertical portion 13a, the heater 12 has a C shape with a part of the ring interrupted. And the temperature detection switching means for temperature detection and switching is attached to the axial direction inner surface of the ring-shaped member perpendicular | vertical part 13a equivalent to the location where the heater 12 interrupted. In this embodiment, a thermostat 15 is attached as a temperature detection switching means. The thermostat 15 is electrically connected to the heater 12 via a first lead wire 16 and is electrically connected to an external power source (not shown) via a second lead wire 17. It is connected to the. Note that the second lead wire 17 passes through the lead wire hole 18 formed in the ring-shaped member vertical portion 13a and passes from the axially inner side to the outer side of the vertical portion 13a.

  The thermostat 15 detects the temperature of the temperature raising device internal space S2, and when the detected temperature is equal to or lower than a predetermined heat generation start temperature, a current is passed through the heater 12, and the detected temperature is higher than the heat generation start temperature. When the temperature exceeds a predetermined heat generation stop temperature, the current is cut off. That is, the heater 12 generates heat only when the temperature of the temperature raising device inner space S2 is within a certain range. For example, the heat generation start temperature is minus 20 ° C., and the heat generation stop temperature is plus 20 ° C. If the heat generation start temperature is −20 ° C., the temperature can be raised before the lubricant 6 is solidified. Further, if the heat generation stop temperature is set to 20 ° C., it is considered that even at a low temperature, when the bearing starts to rotate, the temperature immediately rises to about room temperature.

The material of the ring-shaped component 13 is, for example, metal. When the ring-shaped part 13 is made of metal, as shown in the partially enlarged view of FIG. 1, an insulating film 19 for preventing stray current corrosion is provided at least on the outer ring 3 where the ring-shaped part 13 contacts. It is good. The insulating coating 19 can be formed by thermal spraying or injection molding of an insulating material such as resin.
In addition, a leakage current may flow into the bearing from the outside of the bearing, and even in this case, electric corrosion may occur. In order to be able to perform this countermeasure simultaneously with the lubrication and solidification countermeasure, an insulating material such as a resin is sprayed on the portion of the inner ring 2 in contact with or close to the shaft side member or the portion of the outer ring 3 in contact with or close to the housing side member. Or by injection molding (not shown).
Further, a method may be used in which the rolling element 4 is made of an insulator such as a ceramic material without applying an insulating coating to the inner ring 2 or the outer ring 3.

This rolling bearing is used as a railway vehicle bearing or a wind power generator bearing. In use, when the temperature of the temperature raising device inner space S <b> 2 becomes equal to or lower than the heat generation start temperature, the lifting / lowering device 11 causes the heater 12 to generate heat by passing a current through the heater 12. Since the heater 12 is provided facing the bearing space S1 filled with the lubricant 6, the lubricant 6 is effectively heated. When the ring-shaped part 13 to which the heater 12 is attached is a metal, the heat of the heater 12 is efficiently transmitted to the bearing body 1 through the ring-shaped part 13. Thereby, when the temperature of the lubricant 6 is raised and the lubricant 6 is solidified, it returns to the fluid, and when it is just before solidification, it is prevented from solidifying. When the temperature of the temperature raising device internal space S2 becomes equal to or higher than the heat generation stop temperature, the current flowing through the heater 12 is cut off and the heat generation of the heater 12 is stopped.
Thus, by switching the heater 12 on and off according to the temperature change in the temperature raising device internal space S2, the temperature of the lubricant 6 can be raised to an appropriate temperature even in an extremely cold environment of minus 40 ° C. or lower, or It can be kept at a constant temperature. For this reason, a bearing can always be used in a state with good lubrication performance.

  3 and 4 show a second embodiment of the present invention. This rolling bearing is different from the first embodiment in the shape of the ring-shaped component 13 of the temperature raising device 11. Unlike the first embodiment, the ring-shaped component 13 of the second embodiment has an inner peripheral cylindrical portion 13c that extends long inward in the axial direction into the bearing space S1, and the tip thereof is close to the outer peripheral surface of the inner ring 2. is doing. Therefore, the bearing space S1 and the temperature raising device internal space S2 are shielded from the outside. That is, the ring-shaped component 13 has a seal function that shields the bearing space S1 and the temperature raising device internal space S2 from the outside. In the second embodiment, the lubricant 6 is also sealed in the temperature raising device inner space S2. When the ring-shaped part 13 is made of metal, as shown in the partially enlarged view of FIG. 3, the ring-shaped part 13 in the inner ring 2 is close to the outer ring 3 in addition to a portion where the ring-shaped part 13 contacts at least. An insulating coating 19 for preventing stray current corrosion is also provided at the location. The other configuration is the same as that of the first embodiment.

  In the rolling bearing according to the second embodiment, the ring-shaped part 13 has a seal function for shielding the bearing space S1 and the temperature raising device inner space S2 from the outside, so that the lubricant 6 leaks from the inside of the bearing. Intrusion of foreign matter from the outside into the bearing can be prevented. Further, since the lubricant 6 is also sealed in the temperature raising device inner space S2, a large amount of the lubricant 6 can be ensured and can be used for a long time.

  Further, in the rolling bearing of the second embodiment, since the bearing space S1 and the temperature raising device inner space S2 are shielded from the outside, oil can also be used as the lubricant 6. Even if the lubricant 6 is oil, it is solidified in an extremely cold environment, so that the application of the present invention is effective.

  In each of the above-described embodiments, the temperature of the heating device internal space S2 is detected by the thermostat 15, but instead of detecting the temperature of the heating device internal space S2, the temperature of the bearing space S1 may be detected. Good. Further, although the thermostat switching means is a thermostat 15, the temperature detection switching means is a temperature detection unit and a heater on / off switching unit separately, and only the temperature detection unit is provided in the temperature raising device 11, and the on / off switching unit is It is good also as a structure provided in the exterior of the temperature apparatus 11. FIG.

  The type of the bearing body 1 in each of the above embodiments is a cylindrical roller bearing, but the present invention can also be applied when the type of the bearing body 1 is a ball bearing or a tapered roller bearing. In addition, the rolling bearings are not limited to railway vehicle bearings and wind power generator bearings, but are used for bearings of any machinery that may be used in cold regions such as generators, general-purpose motors, and automobiles. It is targeted.

It is sectional drawing of the rolling bearing concerning 1st Embodiment of this invention. (A) The front view of the temperature rising apparatus of the rolling bearing, (B) The fracture | rupture side view. It is sectional drawing of the rolling bearing concerning 2nd Embodiment of this invention. (A) The front view of the temperature rising apparatus of the rolling bearing, (B) The fracture | rupture side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Bearing main body 2 ... Inner ring 3 ... Outer ring 4 ... Rolling body 6 ... Lubricant 11 ... Temperature rising device 12 ... Heater 13 ... Ring-shaped component 15 ... Thermostat 19 ... Insulating coating S1 ... Bearing space S2 ... Inside temperature rising device space

Claims (9)

  In a rolling bearing comprising an inner ring, an outer ring, and a plurality of rolling elements arranged to roll between the inner ring and the outer ring, the bearing space between the inner ring and the outer ring is filled with a lubricant. A rolling bearing provided with a temperature raising device for raising the temperature of the agent.   The rolling bearing according to claim 1, wherein the temperature raising device includes a ring-shaped member that covers an outer side in the axial direction of the bearing space, and a heater is attached to an inner surface in the axial direction of the ring-shaped member.   The rolling bearing according to claim 2, wherein the ring-shaped component is fixed to the outer ring.   4. The temperature raising device according to claim 2, wherein the temperature raising device detects a temperature of the bearing space or a space in the temperature raising device between the bearing space and the ring-shaped part, and according to the detection result. A rolling bearing having temperature detection switching means for switching the heater on and off.   5. A rolling bearing according to claim 4, wherein the switching means is a thermostat.   6. The rolling bearing according to claim 2, wherein the ring-shaped component has a seal function that shields the bearing space and the space inside the temperature raising device from the outside.   The rolling bearing according to claim 6, wherein the lubricant is sealed in the space inside the temperature raising device.   The ring-shaped component according to any one of claims 1 to 7, wherein the ring-shaped component is made of metal, and the heater is an electrothermal type, and an insulating coating is provided at a position where the ring-shaped component contacts at least in the inner ring and the outer ring. Rolling bearing provided with   The rolling bearing according to any one of claims 1 to 7, wherein the inner ring or the outer ring is provided with an insulating coating that blocks current from outside the bearing.

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