JPS63225137A - Testing apparatus of bearing in vacuum - Google Patents

Abstract

PURPOSE:To make an apparatus small in size and to enable the application of a heavy load on the apparatus, by providing a bellows which applies a load on an outside housing and an inside housing. CONSTITUTION:A construction is so made that a radial load can be applied by a bellows 37 and that the radial load can be varied arbitrarily without changing the structure of the whole of an apparatus. When a load is made to act between an outside housing 35 and an inside housing 36, radial loads being different in directions but equal to each other act on test bearings A, D and B, C. These loads turn to be an inner pressure of a housing element, and therefore only the weight of the housing element and a moment load caused by the bent of a rotating shaft act on the bearings. The rotating shaft 33 is made to rotate in this state and a torque acting on the outside housing 35 is detected by a load cell 40 or the like. Thereby a friction torque of the test bearings A-D can be measured. According to this constitution, a heavy load can be applied in a vacuum, and also a small-sized apparatus can be realized.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) This invention relates to an in-vacuum bearing testing device used to determine the friction torque, etc. of a test bearing in a vacuum environment. .

(Prior Art) Conventionally, devices for testing the friction torque of bearings used in a vacuum environment have only been able to perform tests with low loads.

Figure 4 shows a conventional low-load test device, with a vacuum vessel 10
A rotating shaft 12 is disposed inside the rotating shaft.
Rotational force is transmitted to 2 from the outside via a magnetic seal 11. The rotating shaft 12 is supported by test bearings 13.14. In order to detect the friction torque of the test bearings 13, 14, a torque transducer that detects the load on the rotating shaft 12 outside the magnetic seal 11 is used. The radial load at this time is due to the mass of the rotating shaft 12 itself being the test bearing 13.
It acts as a load of 14. Here, if you want to increase the radial load, in order to increase the mass of the rotating shaft 12 itself, use a metal with high density (mass) as the shaft material, or increase the volume of the rotating shaft 12. There is no other way.

For this reason, there are reports that the test equipment becomes larger. In addition, with this test method, since the friction torque is detected outside the magnetic seal 11,
This includes the load existing on the magnetic seal 110, and there is also the problem that accurate friction torque cannot be measured. In addition, when applying a thrust load to the above test equipment,
A load can be applied by a thrust washer 15 placed in contact with the outer ring of the test bearing 14.

Since the test apparatus described above cannot accurately measure the friction torque of the test bearing due to the mixed load on the magnetic seal 11, an improvement plan as shown in FIG. 5 has been proposed.

That is, a rotor 26 having an integral rotating shaft 22 is provided inside the vacuum container 21, and the rotating shaft 22 is connected to the test bearing 23.2.
4, it is rotatably supported. A stator 27 external to the vacuum vessel 21 acts on the rotor 26 and forms an induction motor. The stator 27 has an air bearing 2
It is floating due to 8. When the rotating shaft 22 is rotated, the friction torque of the test bearings 23 and 24 is transmitted to the stator 27 in a floating state, and the load detection device 29 detects this.

However, with the induction motor type described above, in order to increase the radial load, the mass of the rotating shaft 22 must be increased, as in the device shown in FIG.
The scale of the induction motor must be increased. Therefore, the entire device also becomes larger.

(Problems to be Solved by the Invention) The conventional vacuum load testing device described above has a limit on the load that can be applied to the test bearing, and has no choice but to perform the test with a low load.
Increasing the load requires increasing the size of the device.

Therefore, an object of the present invention is to provide an in-vacuum bearing testing device that is compact and capable of applying a high load.

[Structure of the Invention] (Means for Solving the Problems) This invention provides a vacuum container that creates a vacuum environment, a rotational drive means that transmits rotational force from the outside to a rotational shaft inside the vacuum container, and a passes through two places, and an outer housing is provided with first and second bearings for bearing the rotating shaft in the penetrating portion; an inner housing that penetrates through the passageway and is provided with third and fourth bearings for bearing the rotating shaft in the penetration portion; a bellows that applies a load to the outer housing and the inner housing by supplying fluid pressure through a vibrator;
It also includes a load cell for detecting the moment of the outer housing.

(Function) With the above means, tests can be performed by freely applying various loads to the test bearing using the bellows, and there are no factors other than the test bearing that apply unnecessary loads to the rotating shaft. Highly accurate friction torque measurement is possible.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and 31 is a vacuum container 3.
A fixed support casing 32 is disposed inside the fixed support casing 1, and a rotary shaft 33 is rotatably supported and passes through the inside of the fixed support casing 32. This rotating shaft 33 has a vacuum container 31
A rotational force can be applied from a shaft introduced from the outside through the magnetic seal 34. The rotating shaft 33 is rotatably received by bearings 32a and 32b of the fixed support housing 32.

A double structure of an outer housing 35 and an inner housing 36 is further built inside the fixed support cylinder 32, and the rotating shaft 33 also passes through this double IR housing. . In the penetrating portion of each housing 35, 36, test bearings ASB, C, and D rotatably support the rotating shaft.

Next, a bellows 37 is provided in the space formed by the outer housing 35 and the inner housing 36 so that a radial load can be applied from the outer housing 35 to the inner housing 36. In this case, the load is transmitted between the bellows 37 and the inner housing 36 via the ball 38 to prevent uneven contact.

Furthermore, in order to apply a radial load to the test bearings A-D, hydraulic pressure is applied to the bellows 37, but to supply hydraulic pressure from the atmospheric side, a low-rigidity stainless steel pipe 39, for example, is used to avoid the influence of friction torque measurement. is made smaller.

To measure the friction torque, the rotary shaft 33 is rotated, and the torque applied to the outer housing 35 is measured by the load cell 40. Measurements for the test bearings A to D can be obtained. To measure the temperature characteristics of the lubricating film of a bearing, a location near the outer ring of each test bearing (1
Measurement is carried out by attaching a thermal lightning pair to the housing part (approximately mm).

This invention is constructed as described above, and in principle, as shown in FIG. 2, a radial load can be applied by the bellows 37, and this radial load can be changed arbitrarily without changing the structure of the entire device. be able to. That is, when a load is applied between the inner housing 35 and the outer housing 36, the same radial loads are applied to the test bearings A, D and B, C, although in different directions. Since this load becomes the internal pressure of the housing section, only the weight of the housing section and moment load due to bending of the rotating shaft act on the bearing. In this state, the rotating shaft 33 is rotated, and the outer housing 35
By detecting the torque acting on the bearings using the load cell 40 or the like, it is possible to measure the frictional torque of the test bearings A-D. That is, when the load is small, the moment acting on the outer housing 35 is small, and when the load is large, the moment acting on the outer housing 35 becomes large.

FIG. 3 shows an example of a configuration when the relationship between the oil pressure and the bellows load for the bellows 37 was investigated in a preliminary experiment, and sufficient linearity was obtained in the relationship between the oil pressure and the bellows load. To explain this system, compressed air from an air compression cylinder 41 is sent to a pneumatic cylinder 42, and the pressing force of this cylinder is transmitted to a hydraulic cylinder 43. Then, the hydraulic pressure from the hydraulic cylinder 43 is applied to the bellows 37. 44 is a bellows load 1n1J regular load cell for measuring the load on the bellows 37. According to such a loading method, high pressure can be obtained with a low air pressure that is below the regulations of the High Pressure Gas Control Law.

The above explanation assumes that a radial load is applied, but if wave washers 34a534b are interposed between the test bearings A and B and between C and D as shown in Fig. 2, the load in the thrust direction can be applied. You can also give

Specific numerical values of the above examples are shown for reference. The test bearing was JIS 8001. The pressure of the vacuum container is 10 pa or less, the temperature is room temperature, the rotation speed is 11000 rpm or less, and the load is 2.
00ON or less. Also, the stainless steel vibrator has an outer diameter of 0.
51a+m, but even if a stainless steel tube with an outer diameter of 0.511Im was used, a constant load was reached in about 15 minutes.

The present invention is significant as a testing device for bearings of equipment used in outer space, and can perform tests under high loads. Furthermore, high loads can be easily used to obtain the temperature characteristics of the lubricating film, and its characteristics in vacuum can be clarified.

[Effects of the Invention] As explained above, according to the present invention, a high load can be applied in a vacuum, and the load can be easily changed as desired. It is possible to realize a compact device without having to increase the size of the device to change the load, which is often the case. Further, it is possible to obtain a device that can accurately measure friction torque.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, Fig. 2 is a diagram showing the main parts of the invention, Fig. 3 is an explanatory diagram of the hydraulic pressure supply system for the bellows used in this invention, and Fig. 4 is an explanatory diagram of a conventional vacuum bearing testing device, and FIG. 5 is also an explanatory diagram of a conventional vacuum bearing testing device. 31... Vacuum container, 32... Fixed support housing, 33.
... Rotating shaft, 35... Outer housing, 36... Inner housing, 37... Bellows, 39... Stainless steel pipe, 40... Load cell. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 6

Claims (2)

[Claims] (1) A vacuum container that creates a vacuum environment, a rotational drive means that transmits rotational force from the outside to a rotating shaft inside the vacuum container, and the rotating shaft passes through two places, and the rotating shaft an outer housing provided with first and second bearings for bearing the rotary shaft; an inner housing provided with third and fourth bearings, and an inner housing disposed between the outer housing and the inner housing, and fluid pressure is supplied from the outside via a low-rigidity pipe to the outer housing. An in-vacuum bearing testing device comprising: a bellows for applying a load to the inner housing; and a load cell for detecting the moment of the outer housing while the rotating shaft is rotating. (2) The means for supplying hydraulic pressure to the bellows includes a pneumatic cylinder whose pressure source is pneumatic pressure, and a hydraulic cylinder to which the pressing force of the pneumatic cylinder is applied. The in-vacuum bearing testing device described in Section 1.