JPS6328262B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a bearing life test device, specifically a test device for determining the life of a bearing by applying a radial load or a composite load of a radial load and a thrust load. Regarding.

(Conventional technology and problems) Conventional life testing equipment of this type is representative of the JSPS ball bearing testing equipment developed by the 126th Committee of the Japan Society for the Promotion of Science. Those that require longevity (see page 792 of the Lubrication Handbook (edited by the Japan Lubrication Society, first edition published on April 20, 1970, published by Yokendo Co., Ltd.)), or the Teimken type load test device. ,
Bearings and lubrication handbook (edited by the Bearing and Lubrication Handbook Editorial Committee, published June 30, 1960, published by Nikkan Kogyo Shimbun), page 832 ), or those that apply only a thrust load are known.

Some of the test equipment that now only applies radial loads, such as the Gakushin-type ball bearing test equipment, allows the posture of the outer ring to be adjusted relative to the inner ring of the test bearing, but this is not suitable for thrust loads. cannot be loaded at the same time.

For both types of bearings that carry a combined load of radial load and thrust load, and those that carry only thrust load, two test bearings are installed in one test device, and the outer ring of one bearing is loaded with thrust. A thrust load is transmitted to the inner ring of the other bearing through the inner ring and a rotating shaft (or a member with the same effect, such as a sleeve) that supports the inner ring, by applying a pressing force in the direction of the inner ring and the inner ring. It is not possible to adjust the relative position of the

By the way, the relative position and inclination of the outer ring with respect to the inner ring greatly influences the life of the bearing, and no matter how high the accuracy of the test equipment and the high rigidity of the test equipment, the accuracy of the test bearing and the load applied to it will The true bearing life cannot be determined unless the posture of the inner ring or outer ring is adjusted in response to the relative inclination of the inner and outer rings that occurs.

From this point of view, the applicants of this application have previously applied the radial load, or radial load and thrust load, to the inner ring of the test bearing, as shown in Japanese Patent Application No. 55-35623 (Japanese Unexamined Patent Publication No. 56-13539). We have proposed a life test device that can automatically adjust the outer ring posture under a composite load, and also allows arbitrary adjustment of the outer ring posture manually. This means that in the manual adjustment, the inclination adjustment of the outer ring with respect to the inner ring is
This is carried out using a fixed object such as a pedestal or a fixed stand that is unrelated to the drive shaft of the inner ring, and the outer ring is fixed to the fixed object.

By the way, when the outer ring of the test bearing is fixed to a fixed object unrelated to the drive shaft, when the shaft thermally expands due to heat generated during bearing operation,
Since this adjusting and fixing device prevents the outer ring from moving in the axial direction, an excessive axial load is generated on the test bearing that attempts to move in the axial direction due to the thermal expansion of the shaft.
This not only impairs the stability of the load conditions, which is the lifeblood of a bearing life tester, but also poses a problem in that it may lead to damage such as seizure of the bearing.

The present invention has a function of automatically adjusting the outer ring attitude in each load state of a radial load, a thrust load, or a composite load of a radial load and a thrust load. A test device that allows bearings (including the outer ring) to move in the axial direction due to thermal expansion, etc., and allows bearing life tests to be performed under always stable load conditions, thereby accurately determining the true bearing life. The purpose is to

(Means for Solving the Problems) The present invention has been made in view of such conventional problems, and the bearing life test device of the present invention includes a drive shaft that holds and rotates the inner ring of a test bearing; In a bearing life test device equipped with a bearing box that holds an outer ring, a load frame that supports the bearing box rotatably around a horizontal axis perpendicular to the axis of the drive shaft is provided, and the load frame is driven to the test bearing. The radial load loading mechanism applies a radial load in the vertical axis direction perpendicular to the axis of the shaft, and the thrust load loading mechanism applies a thrust load as a tensile force in the direction of the drive shaft. The thrust load loading mechanism is equipped with a set load holding means that releases the expansion of the drive shaft and prevents a load higher than the set value from being applied to the test bearing, and the thrust load loading mechanism allows the load frame to be thrust loaded. An adjustment frame facing the load frame in the direction of the drive shaft is fixed to connecting rods arranged above and below the load frame to be connected to the mechanism, and a test bearing is placed between the adjustment frame and the load frame. A first inclination adjustment means capable of adjusting the relative inclination of the inner and outer rings around the vertical axis is provided, and brackets facing the load frame in the drive shaft direction are fixedly installed above and below the bearing box, and each bracket and the load are A second inclination adjusting means is provided between the test bearing and the frame, which can adjust the relative inclination of the inner and outer rings of the test bearing around the horizontal axis.

The first inclination adjustment means is constituted by, for example, a pair of adjustment screws that are screwed onto the left and right sides of the adjustment frame and abut against the front surface of the load frame, and the second inclination adjustment means is constituted by, for example, attached to the upper and lower brackets. It consists of a pair of adjustment screws that are screwed together and abut against the front surface of the load frame. In this case, it is preferable that the tips of each of the adjustment screws have a hemispherical surface.

(Function) The force in the tensile direction of the radial load loading mechanism and the thrust load loading mechanism causes the load frame connected to each of the radial and load loading mechanisms to be perpendicular to the axis of the drive shaft that holds the inner ring of the test bearing in rotation. By swinging around a vertical axis and moving the bearing box, which is also supported by the load frame, around a horizontal axis perpendicular to the axis of the drive shaft, the outer ring automatically follows the attitude of the inner ring.

Further, the load frame is swung around the vertical axis by the first inclination adjustment means, and the outer ring is manually adjusted around the vertical axis, while the bearing box is swung around the horizontal axis by the second inclination adjustment means. Then manually adjust the outer ring around the horizontal axis.

Furthermore, the thrust load loading mechanism is equipped with a set load holding means, so that even if the drive shaft expands due to heat generation of the bearing during the test, the axial movement of the test bearing due to this expansion will not change the thrust set load. Permissible.

(Example) FIG. 1 is an explanatory diagram schematically showing the present invention, in which the inner ring of a test bearing 1 is fitted and fixed to the shaft end of a drive shaft 2 driven by an electric motor (not shown), and the outer ring is fixed to the shaft end of a drive shaft 2 driven by an electric motor (not shown). It is mounted and fixedly held in the bearing box 3 via a sleeve 4, shim 4a, etc., as shown in FIG. The bearing box 3 is rotatable around the horizontal axis H on a shaft 6c protruding from the load frame 6 via left and right needle roller bearings 5 located on the horizontal axis H perpendicular to the axis X of the drive shaft 2. Supported by

The load frame 6 has a connecting frame portion 6a extending upward, and is connected to the radial load loading mechanism R via a thrust ball bearing 7 that rotates around a vertical axis V perpendicular to the axis X of the drive shaft 2. It is freely rotatable around the vertical axis V. A shaft 6b located on the vertical axis V is provided projecting above and below the load frame 6, and is connected to the thrust load applying mechanism T via a needle roller bearing 8 and a connecting rod 9. 10 is a bearing device for the drive shaft 2.

FIG. 2 and subsequent figures are diagrams embodying an embodiment of the present invention, in which the same parts as in FIG. 1 are given the same reference numerals.

The radial load loading mechanism R includes a hydraulic cylinder 11 for generating a radial load, and a rod 1 of the cylinder 11.
Upper buffer plate 13 connected to 2, thrust ball bearing 7
The connecting frame portion of the load frame 6 is mounted on the thrust ball bearing 7 via a load converter 16. 6a, a radial load acts on the test bearing 1 as a tensile force upward of the vertical axis V. The thrust ball bearing 7 is for freely rotating the load frame 6 around the vertical axis V, and the thrust ball bearing 7 is for freely rotating the load frame 6 around the vertical axis V.
2 converts the magnitude of the radial load into an electrical output and inputs it to a recorder in a measuring panel (not shown). The recorder records the electrical output and displays it on a digital meter. The radial load can be set to any value within the maximum output range of the hydraulic cylinder 11 by adjusting the pressure of the hydraulic cylinder 11 with a pressure reducing valve (not shown).

The thrust load loading mechanism T includes a load converter 1 attached to a rod 18 of a hydraulic cylinder 17 for thrust load generation.
9 is attached, and the output of the hydraulic cylinder 17 is transmitted via a load converter 19 to a lever 21 pivoted on a fulcrum shaft 20 fixed in the vertical axis direction of the test apparatus.
The lever 21 has its working arm 2 as shown in FIG.
The distal end of 1a is formed into a forked arm and engages with each of the connecting rods 9 disposed above and below the drive shaft 2,
The output direction of the hydraulic cylinder 17 is reversed and transmitted, and a thrust load is applied to the test bearing 1 as a force in a tensile direction along the axis X of the drive shaft 2. The thrust load can be set to any value within the maximum output range of the hydraulic cylinder 17 by adjusting the pressure of the hydraulic cylinder 17 with a pressure reducing valve (not shown). The thrust load thus set is held at its set value by a set load holding means provided in the thrust load applying mechanism T.

Specifically, the set load holding means is a conventionally well-known structure provided in the hydraulic circuit of the hydraulic cylinder 17. That is, in a hydraulic circuit including the hydraulic cylinder 17 and a hydraulic tank (not shown), an oil temperature controller for controlling expansion and contraction of oil due to temperature changes, and a gas-filled constant pressure accumulator are arranged. As a result, when an axial force that exceeds the set value of the thrust load acts on the drive shaft 2, test bearing, etc., the hydraulic cylinder 17
The set load will not change if the rod moves with an axial force that exceeds the set value. The load converter 19 converts the magnitude of the thrust load into an electrical output and inputs it to a recorder in a measurement panel (not shown), and the recorder records the output and displays it on a digital meter.

The radial load loading mechanism R supports the hydraulic cylinder 11 on a frame 22 so as to be movable in the axial direction of the drive shaft 2, and the position of the hydraulic cylinder 11 can be adjusted by a cylinder shift handle 23 mounted on the frame 22. The engaging surface 21b on which the forked portion of the lever 21 of the thrust load loading mechanism T engages with the connecting rod 9 is formed into an arc surface as shown in the figure, so that the thrust load is applied correctly in the direction of the axis X of the drive shaft 2. It is configured to work.

In the above, adjustment of the attitude of the test bearing 1 is an adjustment of the relative inclination of the inner ring and outer ring, and two adjustments are made around the vertical axis V and the horizontal axis H, which are perpendicular to the axis X, with respect to the center of the bearing. determined by

Therefore, in order to adjust the bearing posture around the vertical axis V in response to a radial load, the outer ring is automatically rotated around the vertical axis V following the inner ring under the radial load state using the thrust ball bearing 7 on the load line. Similarly, adjustment around the horizontal axis H is performed by moving the outer ring around the horizontal axis H using a needle roller bearing 5 that supports the bearing box 3 on the load frame 6.
Automatically rotates by following the inner ring.

Adjustment of the load center of the radial load is carried out by moving the radial load loading mechanism R along with the hydraulic cylinder 11 in the axial direction of the drive shaft 2 using the shim 4a or the cylinder shift handle 23, and the load center is adjusted to the point of load application of the test bearing 1. match.

Adjustment of the bearing posture around the vertical axis V in response to a thrust load is performed by the needle roller bearing 8 at the connection between the load frame 6 and the connecting rod 9, which moves the outer ring around the vertical axis V under thrust load. Automatically rotate according to the pattern, and also adjust around the horizontal axis H.
Needle roller bearing 5 that supports the bearing box 3 on the load frame 6
The outer ring is automatically rotated around the horizontal axis H following the inner ring.

The above is a case where the bearing attitude is automatically adjusted under a radial load, a composite load of a radial load and a thrust load, or a thrust load, but the present invention further provides for adjusting the attitude of the outer ring relative to the attitude of the inner ring, that is, the attitude of the outer ring. It is possible to perform a bearing life test by manually adjusting the tilt from zero to any angle range.

That is, at the front end of a connecting rod 9 connected above and below the load frame 6 via needle roller bearings 8, an adjustment frame 24 is provided, which is located in front of the load frame 6 and faces the load frame 6 in the axial direction of the drive shaft 2. A first inclination adjustment means is provided between the adjustment frame 24 and the load frame 6, which can adjust the relative inclination of the inner and outer rings of the test bearing around the vertical axis V. The first inclination adjustment means has adjustment screws 25 screwed onto the left and right sides of the adjustment frame 24, respectively, and the tips of the adjustment screws 25 are brought into contact with the left and right front surfaces of the load frame 6. The tip of the adjusting screw 25 that contacts the load frame 6 is formed into a hemispherical surface to ensure contact with the load frame 6 in any tilted state.

On the other hand, brackets 26 located on the front surface of the load frame 6 and facing the load frame 6 in the axial direction of the drive shaft 2 are fixed above and below the bearing box 3 which is rotatably supported on the load frame 6 around the horizontal axis H. A second inclination adjustment means is provided between the bracket 26 and the load frame 6, which can adjust the relative inclination of the inner and outer rings of the test bearing 1 around the horizontal axis H. The second inclination adjustment means has an adjustment screw 27 screwed into the bracket 26, and its tips are brought into contact with the upper and lower front surfaces of the load frame 6, respectively. The tip of the adjustment screw 27 has a hemispherical surface as described above.

Manual adjustment of the outer ring relative to the inner ring around the vertical axis V is performed by rotating the adjustment screw 25. That is, by loosening one adjustment screw 25 to move its tip away from the front surface of the load frame 6 and tightening the other adjustment screw 25, the relative position of the load frame 6 with respect to the adjustment frame 24 changes around the vertical axis V. . The load frame 6 holds the bearing box 3 rotatably only around the horizontal axis H. Therefore, rotation of the load frame 6 around the vertical axis V similarly rotates the outer ring held in the bearing box 3. to change the inclination with respect to the inner ring.

Manual adjustment of the attitude of the outer ring relative to the inner ring around the horizontal axis H is performed by rotating the adjusting screw 27. That is, loosen one adjustment screw 27 and insert the tip of the adjustment screw 27 into the load frame 6.
When the other adjusting screw 27 is tightened, the tip of the adjusting screw 27 pushes the front surface of the load frame 6, so that the bearing box 3, which is rotatably supported on the load frame 6 around the horizontal axis H, rotates. to change the inclination of the outer ring relative to the inner ring.

After arbitrarily adjusting the inclination of the outer ring around the vertical axis V and the horizontal axis H as described above, adjust the adjustment frame 24 and the load frame 6 using the adjustment screws 25 and 27.
and the relative spacing between the bearing box 3 (bracket 2
6) and the load frame 6, the outer ring can be fixed at an arbitrary inclination.

In other words, it is now possible to manually adjust the relative inclination of the inner and outer rings from zero to any angle range.For example, a bearing life test can be performed with the relative inclination of the inner and outer rings adapted to the usage conditions of the bearing. It becomes possible to do so. Furthermore, when manual tilt adjustment is not required, each adjustment screw 25, 27 may be loosened to separate its tip from the load frame 6.

(Effects of the Invention) As described above, the present invention makes it possible to arbitrarily adjust the relative postures of the inner and outer rings, either automatically or manually, and to achieve the adjustment that best suits the usage conditions of the bearing. It is possible to conduct a lifespan test on the shape.
In addition, since the thrust load loading mechanism is equipped with a set load holding means, the drive shaft may expand due to heat generation of the bearing during the test, causing the test bearing to move in the axial direction. Even if the inclination of the outer ring of the test bearing with respect to the inner ring is regulated by a manual inclination adjustment means, the first
The inclination adjustment means is supported by an adjustment frame fixed to the tip of the connecting rod, so the axial movement force of the test bearing acts on the thrust load loading hydraulic cylinder via the connecting rod, and the cylinder adjusts to the set pressure. In order to release the rod by the above-mentioned moving force, the axial movement of the test bearing is allowed without changing the set load, thereby eliminating the inconvenience of generating an unreasonable axial load. Furthermore, since the second inclination adjustment means is provided between the bearing box on the drive shaft and the load frame, it is not affected by the expansion of the drive shaft.

As described above, this invention prevents the bearing load from changing due to thermal expansion of the drive shaft, etc.
It is possible to stabilize the load conditions and determine accurate bearing life.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram schematically showing this invention;
The figure is a front view of the embodiment, FIG. 3 is a side view showing a part of it in longitudinal section, and FIG. 4 is an enlarged sectional view of section A in FIG. 2.
FIG. 5 is a side view of the main parts, FIG. 6 is a plan view of the thrust load applying mechanism, and FIG. 7 is a rear view of the same. 1... Test bearing, 2... Drive shaft, 3... Bearing box, 5, 8... Needle roller bearing, 7... Thrust ball bearing, 9... Connection rod, 11, 17... Hydraulic cylinder, 16 , 19... Load converter, 24... Adjustment frame, 26... Bracket, 25, 27... Adjustment screw, R... Radial load loading mechanism, T... Thrust load loading mechanism.

Claims (1)

[Scope of Claims] 1. In a bearing life test device equipped with a drive shaft that holds and rotates the inner ring of a test bearing and a bearing box that holds the outer ring, the bearing box is rotated around a horizontal axis perpendicular to the axis of the drive shaft. A radial load loading mechanism applies a radial load to the test bearing in a vertical axis direction perpendicular to the axis of the drive shaft, and a thrust force is applied to the test bearing as a tensile force in the direction of the drive shaft. Each of the thrust load loading mechanisms that apply a load is connected rotatably around a vertical axis perpendicular to the axis of the drive shaft. A set load retaining means for preventing the load from acting is provided, and connecting rods arranged above and below the load frame and pivotally connected to connect the load frame to the thrust load mechanism are opposed to the load frame in the direction of the drive shaft. An adjustment frame is fixedly installed, and a first inclination adjustment means capable of adjusting the relative inclination of the inner and outer rings of the test bearing around the vertical axis is provided between the adjustment frame and the load frame, and a first inclination adjustment means is provided above and below the bearing box. Brackets facing the load frame in the direction of the drive shaft are each fixedly installed, and a second bracket is installed between each bracket and the load frame to adjust the relative inclination of the inner and outer rings of the test bearing around the horizontal axis.
A bearing life test device characterized by being provided with a tilt adjustment means. 2. The bearing life test device according to claim 1, wherein the first inclination adjustment means is constituted by a pair of adjustment screws that are screwed onto the left and right sides of the adjustment frame and abut against the front surface of the load frame. 3. The bearing life test device according to claim 2, wherein the second inclination adjustment means is constituted by a pair of adjustment screws that are screwed into the upper and lower brackets and abut against the front surface of the load frame. 4. The bearing life test device according to claim 2 or 3, wherein the tip of each adjustment screw that comes into contact with the front surface of the load frame is semispherical.