JP2008025676A - Pre-load measuring method of double-row roller bearing and roller bearing unit of roller-bearing double row - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pre-load measuring method of a double-row roller bearing unit which can measure the pre-load of the double-row roller bearing unit without being subjected to a complicated process and without applying special processing to a bearing by utilizing a thermoelastic effect. <P>SOLUTION: The pre-load measuring method of the double-row roller bearing is characterized by comprising: a first process which elastically deforms a track wheel by relatively operating a pair of the track wheels 6, 10 of the double-row roller bearing which is applied with pre-load; a second process which measures a temperature change appearing on the track wheel which has been elastically deformed by the first process by an infrared-ray stress imaging system composed of a measuring part C and a monitor M; and a third process which converts a pre-load value by collating information on the temperature change of the track wheel obtained by the second process with discrimination information previously recorded with a correlation between the temperature change of the track wheel and the pilot pressure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement in a preload measurement method for a double row rolling bearing. In this specification, the term “wheel” is used to collectively refer to all the wheels of a railway vehicle regardless of the wheels of an automobile.

For example, a double-row ball bearing unit that supports wheels of various vehicles is used in a state in which a preload is applied in order to simultaneously achieve a long life while obtaining high moment rigidity. Such a double-row ball bearing unit is set to a predetermined preload value in advance so that an appropriate preload is obtained when the double row ball bearing unit is incorporated in the axle of the vehicle.
As a double row ball bearing unit, for example, as shown in FIG. 3, a hub 3 having a raceway surface 1 and a flange 2 to which a braking member and a wheel are fixed is provided on the outboard side, and the inboard side of the hub 3 A rotating member (inner ring) 6 as a bearing ring that is fitted to the outer periphery and is constituted by a separate inner ring 5 having a raceway surface 4 adjacent to the raceway surface 1, and a plurality of rows of raceway surfaces 1 of the rotating member 6. , 4 having a plurality of rows of raceway surfaces 7, 8 and a fixed member (outer ring) 10 as a race ring provided with a flange 9 fixed to the vehicle body side, and the raceway surfaces 1, 4 of the rotating member 6 And a plurality of rolling elements 11 incorporated in a double row between the raceway surfaces 7 and 8 of the fixing member 10, and for a wheel bearing assembled in a state in which a predetermined preload is applied in advance. Hub unit bearings are known.

  Normally, the preload of such a hub unit bearing is controlled by the starting torque. In particular, a hub unit bearing for this type of wheel bearing has a built-in seal and a preload within a narrow range. Therefore, the preload guarantee at the starting torque that is affected by the variation of the seal torque is not sufficient.

Therefore, techniques disclosed in Patent Document 1 and Patent Document 2 have been developed as preload management methods that do not depend on the starting torque.
For example, Patent Document 1 discloses a method of managing a preload by temporarily press-fitting an inner ring, measuring a clearance, and re-pressing the inner ring while measuring a displacement.
Patent Document 2 discloses a method of embedding a preload measurement sensor in a double row ball bearing unit.

However, in the method disclosed in Patent Document 1, since the process is complicated, the preload cannot be guaranteed accurately unless a high-rigidity and precise assembly machine is used to accurately measure the displacement.
Further, the method disclosed in Patent Document 2 requires a hole through which a cable for taking out a signal is extracted from the outer ring, so that there is a risk of water entering the bearing from the hole.
Therefore, the inventor of the present application pays attention to a phenomenon in which a temperature change occurs when an object undergoes elastic deformation in an adiabatic manner, that is, a so-called thermoelastic effect, and measures the preload of the double row rolling bearing using the thermoelastic effect. I earnestly researched if I could get it.
Japanese Patent No. 2866282 JP 2005-265175 A

  The present invention has been made in order to solve such a problem, and the object of the present invention is to make use of the thermoelastic effect without taking a complicated process and performing special processing on the bearing. It is an object of the present invention to provide a method for measuring the preload of a double row rolling bearing capable of measuring the preload of the row rolling bearing.

  In order to achieve such an object, a first invention of the present invention is a first invention in which a pair of race rings of a double row rolling bearing to which preload is applied is relatively operated to elastically deform the race rings. The first step, the second step of measuring the temperature change appearing on the raceway elastically deformed in the first step, and the information on the temperature change of the raceway ring obtained in the second step, the temperature change of the raceway and the preload in advance. And a third step of converting the preload value in comparison with the identification information recording the correlation with the preload measurement method for the double row rolling bearing.

  According to a second invention, in the first invention, the pair of track rings are an outer ring as a fixed ring and an inner ring as a rotating ring, and the second step measures a temperature change of the outer diameter surface of the outer ring. This is a preload measurement method for a double row rolling bearing.

  According to a third invention, in the first or second invention, the first step is to rotate the pair of race rings relative to each other so that the rolling elements are loaded by the rolling element load when the rolling elements roll on the raceway surface of the race rings. This is a preload measurement method for a double row rolling bearing characterized by measuring a temperature change due to elastic deformation.

  4th invention is 1st or 2nd invention. WHEREIN: A 1st process vibrates a pair of raceway relatively, and is based on a rolling-element load at the time of a rolling element rolling the raceway surface of a raceway ring. This is a preload measurement method for a double row rolling bearing characterized by measuring a temperature change due to elastic deformation of the raceway.

  A fifth invention is characterized in that, in the second step of any one of the first to fourth inventions, an infrared temperature measuring device for measuring a temperature change state of the race is used as a device for measuring a temperature change. This is a preload measurement method for a double row rolling bearing.

  A sixth invention is a double row rolling bearing characterized in that the preload is measured by the preload measuring method described in the first to fifth aspects and is set to an appropriate preload.

  The seventh invention is a double row rolling bearing characterized in that the double row rolling bearing is a hub unit bearing.

  According to the present invention, it was possible to provide a preload measuring method capable of measuring the preload of a double row rolling bearing using the thermoelastic effect. It is not necessary to perform special processing for measuring the preload. That is, according to the present invention, as described above, preload can be ensured while exhibiting an unprecedented effect, and it is intended to discover other defects, which leads to an improvement in bearing quality.

The present invention measures a preload value of an assembled double row rolling bearing. As one embodiment, for example, the following Example 1 and Example 2 are disclosed, and each example is attached to the accompanying drawings. Will be described with reference to FIG.
In the following embodiments, a hub unit bearing used for supporting an axle of an automobile will be described as an example of a double row rolling bearing to be measured. Note that the configuration of the hub unit bearing is as described in detail in the description of the prior art, and thus detailed description thereof is omitted here.
"Example 1"

  A preload measurement method in this embodiment will be described. The preload measurement method in the present embodiment includes the following first to third steps.

[First step]
In this process, a pair of race rings of the hub unit bearing to which preload is applied, that is, rotating members (inner rings) 6 and fixed members (outer rings) 10 are relatively rotated, so that the rolling elements 11. The fixing member (outer ring) 10 is elastically deformed by the rolling element load when rolling on the raceway surfaces 1, 4, 7, and 8. Arrow R in the figure indicates the direction of rotation.
Since the preload is an internally generated load, the rolling element 11 of the rolling bearing with the preload is loaded with a load. Since the rolling element load by preload is loaded as a pure axial load, all the rolling element loads are the same. Therefore, when the rotating member (inner ring) 6 and the fixed member (outer ring) 10 are relatively rotated, the raceway ring is repeatedly deformed by the passage of the rolling elements 11. In particular, in the case of the hub unit bearing that is the measurement target of this embodiment, the thickness of the fixing member (outer ring) 10 is thin, so this deformation extends to the outer diameter 10a portion. Of course, this deformation differs depending on the rolling element load, that is, the preload.

"Second step"
In this step, the temperature rise distribution appearing on the outer diameter 10a of the fixing member (outer ring) 10 elastically deformed in the first step described above is measured using an infrared temperature measuring device.

  In this embodiment, as an example of an infrared temperature measuring device, for example, as shown in FIG. 1, a measuring unit (infrared heat) installed toward an outer diameter 10a of a fixing member (outer ring) 10 of a hub unit bearing to be measured. An image device (thermo camera) C and a signal of temperature change information (thermal image of temperature rise distribution) measured by the measurement unit C are input, and the information of the temperature change (thermal image of temperature rise distribution) is displayed as an image. An infrared image stress system including a display unit (monitor) M is employed. Such an infrared image stress system is well known and is not particularly limited, and a detailed description of its structure is omitted.

Usually, since the material of the rolling bearing is a steel material having low thermal conductivity, heat generation due to the thermoelastic effect is easily maintained, and it takes a certain amount of time to conduct frictional heat from the raceway surface by rotation.
Therefore, after starting the relative rotation of the rotating member (inner ring) 6 and the fixed member (outer ring) 10, before the frictional heat reaches the outer diameter 10a, the outer diameter 10a after a certain number of rolling elements 11 have passed. The temperature rise distribution is measured with an infrared stress imaging system.

[Third step]
In this step, the temperature change information (thermal image of the temperature increase distribution) of the fixing member (outer ring) 10 obtained in the second step is preliminarily calculated as the temperature increase distribution (thermal image) of the fixing member (outer ring) 10 and the preload. The preload value is converted against the identification information (data) that records the correlation.
Further, identification information (data) in which the correlation between the temperature rise distribution (thermal image) of the fixing member (outer ring) 10 and the preload is recorded in advance in a predetermined area of a computer (not shown) connected to the monitor M, for example. It is displayed on the monitor M when comparing with the temperature change information of the fixing member (outer ring) 10 obtained in the second step. Note that the identification information (data) in which the correlation between the temperature rise distribution (thermal image) of the fixing member (outer ring) 10 and the preload is recorded in advance on a separate paper medium and obtained in the second step. It may be compared with information on temperature change of the member (outer ring) 10.

That is, a thermal image of a temperature rise distribution at the outer diameter 10a of the fixing member (outer ring) 10 when a predetermined hub unit bearing whose preload value is known is rotated at a predetermined time and a predetermined speed, and a fixing member in advance The preload value is converted by comparing the thermal image of the temperature rise distribution of the (outer ring) 10 and the identification information (data) in which the correlation between the preload is recorded.
Since the temperature rise depends on the bearing design, a bearing whose preload value is known in advance is used as a measurement target bearing, and for each bearing design, a thermal image and a preload value of the temperature rise distribution at the outer diameter 10a of the fixed member (outer ring) 10. It is necessary to keep the correlation coefficient (correlation coefficient).

  Therefore, when the preload value of the double row rolling bearing unit measured according to the present invention is not an appropriate preload value predetermined for each bearing type, sufficient preload guarantee can be obtained by reapplying the appropriate preload. Can be achieved.

It is incorporated in the end region F of the rotating member (inner ring) 6 and the fixed member (outer ring) 10 and seals to seal the annular bearing inner space between the rotating member (inner ring) 6 and the fixed member (outer ring) 10. The apparatus includes an inboard side (vehicle body side) sealing device 12 and an outboard side (wheel side) sealing device 13. In this embodiment, the specific configuration is not shown, but the lubricant (for example, grease, oil) sealed in the bearing leaks to the outside of the bearing, or foreign matter (for example, water, dust) A well-known sealing device capable of preventing intrusion or the like, for example, a contact seal or a non-contact seal (including a shield) is appropriately selected within the scope of the present invention. In addition, the design of the presence or absence of a metal core or a seal lip can be changed.
It is also possible to make a part of the cored bar a sliding surface of the seal lip or form a part of the seal.

As an example of this embodiment, the hub unit bearing used for supporting the wheel of an automobile has been described. However, it is merely an example, and other wheels such as a wheel of a railway vehicle may be used. However, it is within the scope of the present invention, and double row rolling bearings are applied within the scope of the present invention.
In this embodiment, the ball bearing is described. However, a roller bearing may be used.

  The apparatus for measuring the temperature change is not limited to the infrared image stress system shown in the present embodiment, and other infrared temperature measurement apparatuses, for example, the amount of infrared energy emitted from the surface of the object are used. It is also possible to adopt a known infrared thermometer that measures the surface temperature of an object in a non-contact manner by converting the temperature.

By measuring the temperature rise distribution around the outer diameter in the present invention, the next outer diameter abnormality can be detected.
In bearings with a cylindrical outer diameter and a constant wall thickness between the raceway surface and the outer diameter, when the roundness of the raceway surface is poor, the portion corresponding to the minor axis of the raceway roundness is the rolling element load. Becomes higher.
Accordingly, the stress appearing at the outer diameter also increases, and the temperature rise distribution around the outer diameter is not constant. Therefore, it is possible to guarantee the roundness by taking the temperature rise distribution around the outer diameter using the infrared image stress system described in the first embodiment.
Even when there is a large material defect in the outer ring, the stress around the outer diameter changes and the temperature rise distribution changes, so that the material defect can be detected.
In addition, as a measuring method of the temperature rise around the outer diameter in this way, the bearing outer diameter may be measured by a plurality of infrared stress imaging systems. Alternatively, measurement may be performed with a single infrared stress image system by rotating the bearing to be measured on a turntable or the like.

In the present embodiment, an example in which the inner ring 6 is a rotating member and the outer ring 10 is a fixing member has been described. However, the inner ring 6 may be a fixing member and the outer ring 10 may be a rotating member. In this case, it is preferable to measure the temperature change of the inner ring which is the fixing member.
"Example 2"

FIG. 2 is a schematic view showing another example of the preload measuring method of the present invention.
This embodiment is different from the first step in Embodiment 1 described above. In this embodiment, the rotating member (inner ring) 6 and the fixed member (outer ring) 10 are relatively vibrated, and the rolling element 11 is fixed to the fixed member ( The first step is to elastically deform the raceway ring by the rolling element load when rolling the raceway surfaces 7 and 8 of the outer ring) 10. In the present embodiment, a predetermined vibration device K is pressed against the fixing member (end surface of the flange 9 of the outer ring 10) for vibration.
Other processes and effects are the same as in the first embodiment. Further, well-known devices can be applied to the vibration device K within the scope of the present invention.

According to the present embodiment, the contact position between the rolling element and the raceway surface changes with the vibration, so that the distribution of the temperature rise also changes due to the preload.
Also in the present embodiment, it is possible to measure the temperature rise distribution around the outer diameter as in the first embodiment. Furthermore, in the case of the present embodiment, it is possible to detect even when there are variations in rolling elements.

  Note that the preload measurement method disclosed in each of the first and second embodiments described above is only one example, and the raceway is elastically operated by relatively operating the raceway as a rotating member and the race as a fixed member. It is only necessary to measure the temperature rise distribution of the deformed and deformed elastic ring, and to measure the preload of the unit from the measured data, and is not limited to the present embodiment. The design can be changed within the scope of the invention.

It is the schematic which shows Example 1 of the preload measuring method of this invention. It is the schematic which shows Example 2 of the preload measuring method of this invention. It is a schematic sectional drawing which shows one Example of a hub unit bearing.

Explanation of symbols

1 raceway surface 3 hub 4 raceway surface 5 separate inner ring 6 rotating member (inner ring)
7, 8 Raceway surface 10 Fixing member (outer ring)
11 Rolling body C Measuring unit (Camera)
M display unit (monitor)

Claims (7)

A first step of elastically deforming the bearing ring by relatively operating the pair of bearing rings of the double row rolling bearing to which the preload is applied;
A second step of measuring temperature changes appearing on the raceway elastically deformed by the first step;
The third step of converting the preload value by comparing the information on the temperature change of the bearing ring obtained in the second step with the identification information in which the correlation between the temperature change of the track ring and the preload is recorded in advance. A preload measuring method for a double row rolling bearing, which is characterized. A pair of race rings are an outer ring as a fixed ring and an inner ring as a rotating ring,
2. The preload measuring method for a double row rolling bearing according to claim 1, wherein the second step measures a temperature change of the outer diameter surface of the outer ring.   The first step is to measure a temperature change due to elastic deformation of the raceway due to a rolling element load when the pair of raceways rotate relative to each other and the rolling element rolls on the raceway surface of the raceway. A preload measurement method for a double row rolling bearing according to 1 or 2.   The first step is characterized in that a pair of race rings are relatively vibrated, and a temperature change due to elastic deformation of the race rings due to a rolling element load when the rolling elements roll on a raceway surface of the race rings is measured. A preload measurement method for a double row rolling bearing according to claim 1 or 2.   5. The double row rolling bearing according to claim 1, wherein, in the second step, an infrared temperature measuring device for measuring a temperature change state of the race is used as a device for measuring the temperature change. Preload measurement method.   6. A double-row rolling bearing, wherein the preload is measured by the preload measuring method according to claim 1 and set to an appropriate preload. The double row rolling bearing according to claim 6, wherein the double row rolling bearing is a hub unit bearing.

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