JPH09257652A - Method for evaluating frictional characteristics of bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively evaluate the frictional characteristics by rotatably supporting the fixed side member and rotary side member of a bearing, provid ing a rotation stopper at the fixed side member rotating the rotary side member, and measuring the urging force operating at the stopper by the rotation. SOLUTION: The fixed and rotary side members 11, 12 of a bearing to be evaluated are rotatably supported together by bearings 21 and 22, 23. An arm 13 is provided on the outer periphery of the member 11, and a stopper 3 is provided therefor. A rotary frictional force (f) is generated on the sliding surface of with the member 12 by the rotation of the member 11. In the case of a thrust baring, the axial load Y is operated, or in the case of radial bearing, a perpendicular load X is operated at the shaft. The urging force operating at the contact position of the arm 13 with the stopper 3 against the force (f) is measured by a load meter. According to this method, the rotary frictional force of the bearing of a rotary driving system of the baring to be evaluated and reduction gear is separated, and only the force (f) of the bearing can be easily grasped, and evaluated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating frictional characteristics of bearings, and more particularly, it is useful for evaluating frictional characteristics of thrust sliding bearings.

[0002]

2. Description of the Related Art When the rotational frictional force of a bearing is large, power loss increases, various obstacles are caused by temperature rise, and shortening of bearing life is unavoidable. Therefore, the rotational friction characteristics of the bearing are indispensable for evaluating the performance of the bearing. Conventionally, when evaluating the rotational friction characteristics of a bearing, the rotating side member of the bearing is fixed in the same manner as when it is used, a strain gauge is attached to the shaft of the rotating side member, and the rotating side member is rotated, and the shaft is rotated. The surface stress is measured and the rotational frictional force is evaluated from the stress.

[0003]

However, in the apparatus for this evaluation, it is necessary to use a speed reducer and another bearing, and to separate the rotational frictional force of these speed reducer and another bearing. In order to measure only the rotational frictional force of the bearing to be evaluated, it is necessary to attach the above-mentioned strain gauge to a limited place, and it is difficult to attach it on the space. It may not be easy to measure only the rotational frictional force of the bearing.

The stress acting on the shaft surface based on the rotational frictional force of the bearing is torsional stress. Therefore, in the case of thrust bearings, it is required to evaluate the rotational friction characteristics by changing the thrust load, and under the action of this thrust load, the axial compressive stress due to the thrust load also acts on the shaft surface. However, since it is necessary to separate the torsional stress and the compressive stress, it is necessary to attach the strain gauges in two different directions, which makes the handling of the strain gauge difficult.

An object of the present invention is to provide a method for easily measuring the frictional force of a bearing by using a load meter and accurately evaluating the frictional characteristic of the bearing from the measured value.

[0006]

According to a method of evaluating frictional characteristics of a bearing according to the present invention, a stationary member and a rotating member of the bearing are rotatably supported, and a stopper is provided for rotation of the stationary member. The rotation side member is rotated, and the pressing force acting on the stopper is measured based on this rotation.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a side explanatory view showing a method for measuring the rotational frictional force of the bearing according to the present invention,
FIG. 1B is an explanatory cross-sectional view of FIG. In FIG. 1A and FIG. 1B, 11
Is a rotary member of the evaluated bearing, 12 is a fixed member, the rotary member 11 is rotatably supported by a bearing 21, and the fixed member 12 is rotatably supported by bearings 22 and 23. . Reference numeral 13 is an arm provided on the outer periphery of the fixed-side member 12, and 3 is a stopper for the arm 12.
Are shown respectively.

In the above, due to the rotation of the rotating member 11, a rotational frictional force f is generated on the slip surface between the rotating member 11 and the fixed member 12. Further, in the case of a thrust bearing, the axial load Y is applied by an appropriate means, and in the case of a radial bearing, a load X in the direction perpendicular to the shaft is applied by an appropriate means. In order to measure the rotational frictional force f generated by the rotation of the rotating side member 11, the rotating side member 11 is rotated to generate the rotational frictional force f, and the arm 13 is resisted against the frictional force f. The pressing force p acting on the contact point e with the stopper-3 is measured with a load meter.

The above-mentioned axial load Y and the load X perpendicular to the axis
On the other hand, since the contact point e is a free fulcrum, the pressing force p at this fulcrum is independent of the loads Y and X. Also,
In the state where the fixed-side member 12 of the evaluated bearing is stationary by the stopper-3, the bearing 2 supporting the fixed-side member 12 is supported.
No frictional force is generated at 2 and 23. Further, even if a rotational frictional force is generated in the bearing 21 that supports the rotation-side member 11, the influence on the rotation speed of the rotation-side member 11 is substantially zero,
Therefore, the rotational frictional force of the bearing 21 does not substantially affect the rotational frictional force f of the evaluated bearing.

Between the pressing force p and the rotational frictional force f,
Assuming that the average distance from the slip surface between the rotating side member 11 and the fixed side member 12 to the shaft center is r, and the distance from the contact point e between the arm 13 and the stopper-3 to the shaft center is R, the rotation mode is Rf = pR is established from the balance of the measurement, and the rotational frictional force f of the evaluated bearing can be easily grasped from the measured pressing force p without receiving disturbances due to the loads Y and X and the rotational friction of another bearing 21. it can.

Conventionally, the fixed side member 12 of the bearing to be evaluated is fixed in the same manner as when the bearing is actually used, the rotary side member 11 is rotated, and a strain gauge is attached to the rotary side member 11. Attached to measure the rotational friction force. However, in order to separate the rotational frictional force of the bearing 21 supporting the rotating side member 11 and measure the rotational frictional force of only the evaluated bearing,
It is necessary to attach a strain gauge to a limited shaft portion between the bearing 21 that supports the rotating-side member 11 and the fixed-side member 12, and this attachment may be difficult due to space. Further, in order to separate the thrust load acting on the shaft and measure only the torsional stress based on the rotational frictional force, it is necessary to attach the strain gauges in two different directions based on the theory of the stress circle of the mole. For example, it is not easy to measure only the rotational friction force f of the evaluated bearing.

Therefore, according to the present invention, the rotational frictional force f of the bearing to be evaluated can be easily grasped without being disturbed by the loads Y, X and the frictional characteristics of the other bearing 21, and the object to be evaluated can be easily evaluated. The friction characteristics of bearings can be accurately evaluated.

[0013]

EXAMPLES The method for evaluating the frictional characteristics of a bearing according to the present invention can be used for evaluation of both thrust bearings and radial bearings.
Further, the present invention can be applied to any type of slide bearing and rolling bearing, but is particularly suitable for evaluation of thrust slide bearings. FIG. 2 is an assembly of a bearing to be evaluated used for evaluating the frictional characteristics of the thrust slide bearing according to the present invention.
Is shown.

In FIG. 2, reference numerals 11, ... Denote rotating members, which are mounted on the shaft 111. 12 are fixed-side members, which are mounted on the inner surface of the casing 14. 14
1, 141 are lubricating oil inlets provided in the casing 14,
Reference numeral 142 is a lubricating oil outlet, and these inlets and outlets are communicated with a slip surface between the rotating side member 11 and the fixed side member 12 via an oil passage in the casing. 15 is a piston housed in the cylinder chamber of the casing rear end 141,
Reference numeral 1 denotes an oil passage for pressurizing the piston. The sliding contact surface between the fixed side member 12 and the rotating side member 11 is pressurized by the pressurization of the piston 15, and the applied pressure is the oil pressure of the oil film on the sliding contact surface. Supported.

FIG. 3A shows a plan view of the evaluation device for the bearing to be evaluated, and FIG. 3B shows a side view thereof. In (a) of FIG. 3 and (b) of FIG. 3, 4
1 is a mount. 42 is a drive motor (inverter control), and 43 is a speed reducer. A is the bearing assembly to be evaluated, the casing is supported by the bearings 23 and 24, the shaft 111 is connected to the output shaft of the reduction gear 43 by the coupler 44, and the shaft portion therebetween is supported by the bearings 21 and 24. Has been done.

Reference numeral 13 is an arm attached to the casing of the bearing assembly A to be evaluated, 30 is a load meter, and the arm 13 is received by the load meter 30. In order to evaluate the frictional characteristics of this evaluated bearing, pressure oil from an external hydraulic source is introduced into the casing from the lubricating oil inlet to form an oil film on the slip surface between the stationary side member and the rotating side member. At the same time, the piston is pressurized, and the applied pressure is supported by the pressure of the oil film, and the rotating side member of the bearing to be evaluated is rotated by the motor under such a state, and the pressing force of the arm based on this rotation. Read with a load cell.

In this case, the pressing force of the piston acts as a thrust load when the bearing to be evaluated is actually used,
The contact surface pressure between the rotating side member and the stationary side member of the bearing is given by the thrust load, and the rotational frictional force under the thrust load can be calculated from the measurement value of the load meter based on the above-mentioned formula. Therefore, the friction characteristics of the thrust slide bearing can be accurately evaluated.

Further, in the above-mentioned embodiment, since the sliding surface of the bearing is smoothed by the rotation at the time of evaluation, it means that the smoothing operation is substantially performed.
00% non-operation is possible. Rotational friction force can be compared by changing the type of lubricating oil. Optimum oil type can be easily selected. Rotational friction force can be compared by changing the surface roughness of the sliding surface. The surface roughness can be easily selected, wear acceleration can be evaluated when the lubricating oil is exhausted, and pressure resistance against thrust load can be easily measured.

[0019]

According to the method for evaluating frictional characteristics of a bearing according to the present invention, the object to be evaluated is separated from the rotational frictional force of another bearing or speed reducer for rotating the rotating side of the bearing to be evaluated. Since only the rotational frictional force of the bearing can be easily grasped and the bearing can be evaluated from this frictional force, a single bearing can be evaluated accurately.

[Brief description of drawings]

1 (a) is an explanatory diagram showing a method for evaluating friction characteristics of a bearing according to the present invention, and FIG. 1 (b) is a cross-sectional view taken along line (b) of FIG. 1 (a).

FIG. 2 is an illustration showing a bearing assembly assembled to evaluate a bearing according to the present invention.

3 (A) is a plan view showing an evaluation device used in the present invention, and FIG. 3 (B) is a side view thereof.

[Explanation of symbols]

 11 Rotating side member 12 Fixed side member 13 Arm 21 Bearing 22 Bearing 23 Bearing 3 Stopper f Rotating frictional force p Pressing force

Claims (1)

[Claims] 1. A stationary side member and a rotating side member of a bearing are rotatably supported, a stopper is provided for rotation of the stationary side member, the rotating side member is rotated, and the stopper is based on this rotation. A method for evaluating the frictional characteristics of a bearing, which comprises measuring an applied pressing force.