CN102175369B - Friction torque testing device for rolling bearing at low temperature - Google Patents

Abstract

The invention relates to a friction torque testing device for rolling bearings at low temperature. It includes a support and a pair of tested rolling bearings of the same type. The pair of tested rolling bearings of the same type are installed at both ends of a shaft and put into a sleeve. On the support, the temperature sensor is drilled into the sleeve near the rolling bearing to measure the temperature change of the bearing; the extension end of the shaft is fixed with two set screws to a balance wheel, and the set screws Both ends are equipped with two balance nuts to fine-tune the eccentricity of the balance wheel. A thin rope goes around the balance wheel and a tray is hung at each end. When the weight is placed in the tray, once the balance wheel rotates, the rolling bearing under test starts. The friction torque can be measured. The invention can effectively control a certain pretightening force to test the performance index of the friction torque of the bearing under different radial loads and different lubricants at low temperature, has simple structure, low manufacturing cost and convenient operation, and can repeatedly test under severe low temperature.

Description

Friction torque test device for rolling bearings at low temperature

technical field

The invention relates to the field of rolling contact bearings, in particular to a friction torque testing device for rolling bearings at low temperature.

Background technique

Rolling bearings are components that support rotating shafts and are widely used in various fields of the machinery industry. Friction torque is a very important performance index of bearings. For some aerospace equipment with large temperature changes, the size and fluctuation of bearing friction torque not only affect the transmission of system energy, but also affect the accuracy of system signal transmission. There are many types of friction torque testers at room temperature, equipped with various control systems, and the structure is relatively complicated. It is expensive to test them under harsh ambient temperature conditions, especially for testing the influence of different lubricants on friction torque at low temperature. A large number of repeated tests, repeated changes in temperature difference will easily reduce the accuracy of the test instrument, or even damage the test instrument. In this regard, a simple device is proposed to realize the harsh low-temperature environment to ensure that the radial load can be changed under the same pre-tightening force for each measurement, and the influence of different lubricants on the performance of the friction torque is analyzed repeatedly.

Contents of the invention

The object of the present invention is to provide a friction torque testing device for rolling bearings at low temperature in view of the defects in the prior art. Realize the starting friction torque performance test of the rolling bearing under the low temperature ambient temperature, in order to achieve the above-mentioned purpose, the design of the present invention is:

Regardless of the support system with zero friction but complex structure such as air bearings, the tested bearing is used to support the rotating shaft and is also the only load. friction torque. Some test systems often require the bearing to have a certain stiffness and a certain preload. Different preloads will cause different friction torque values. Therefore, the same preload must be ensured for each measurement. Because the tested bearing is a rolling bearing, the friction torque is very small, and the friction at other contact points is much smaller than the friction torque of the rolling bearing. The inevitable system error in the measurement can be compensated by the fine-tuning structure, and the measured value is more accurate. The temperature change of the bearing can be accurately measured, but it is necessary to avoid mixing impurities as much as possible.

According to above-mentioned inventive concept, achieve the object of the invention through following technical scheme:

A friction torque test device for rolling bearings at low temperature, including a support and a pair of

No. tested rolling bearing, characterized in that the pair of tested rolling bearings of the same type are installed at both ends of a shaft and put into a sleeve, and the two ends are respectively fixed on the support with the left end cover and the right end cover. On the sleeve, a temperature sensor is drilled in a place close to the rolling bearing to be tested to measure the temperature change of the bearing. The protruding end of the shaft uses two set screws to fix a balance wheel, and the two ends of the set screw are equipped with Use two balance nuts to fine-tune the eccentricity of the balance wheel. A thin rope goes around the balance wheel and a tray is hung at each end. When the weight is placed in the tray, once the balance wheel rotates, the starting friction torque of the rolling bearing to be tested will increase. measurable.

The inner ring of the rolling bearing to be tested is tightly fitted with the shaft, and the outer ring is loosely fitted with the inner ring of the sleeve, which is easy to disassemble without damaging the bearing precision. High requirements, ensure that the two tested rolling bearings are installed on the same straight line.

There is a spring, a spring seat and an inner retaining ring in the left end cover. One end of the spring is in the groove of the inner bottom of the left end cover, and the other end is on the spring seat. There is a gap between the spring and the inner wall of the left end cover. The length of the spring is according to the preset Tightening force setting, one end of the spring seat has a taper, point contact occurs through the guide groove of the inner retaining ring, and the pre-tightening force is evenly applied to the bearing under test at the left end; the end face of the right end cover is finely ground, and is fixed on the right end of the sleeve with screws.

Put the temperature sensor into the hole near the rolling bearing to be tested. The drill hole cannot be connected with the rolling bearing to prevent dust and water vapor from entering the bearing to affect the performance of the bearing lubricant and the friction torque value; the temperature sensor is connected to a digital display to read Take the value.

The trays at both ends can add weights of the same weight to apply radial loads at the same time, and the balance wheel should be as close as possible to the end of the rolling bearing to be tested to reduce the influence of torque as much as possible.

The entire test device is placed in a cold control box. During the cooling and testing process, the cold control box is always open to ensure its cooling requirements, absorb water vapor in the air in time to prevent the bearing from freezing, and will not reach the freezing point of the bearing lubricant. Enter the water vapor impact test.

Compared with the prior art, the present invention has the following significant advantages:

The invention has the advantages of simple structure, low manufacturing cost, simple operation, rapid temperature reduction, and a large number of repeated tests on samples at severe low temperatures.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the sleeve structural representation of band temperature sensor among the present invention;

Fig. 3 is a structural schematic diagram of the combination of the central shaft and the rolling bearing to be tested in the present invention;

Fig. 4 is the structural representation of left end cover spring pretensioning mechanism among the present invention;

Fig. 5 is a structural schematic diagram of adjusting the eccentricity of the balance wheel in the present invention;

Fig. 6 is a structural schematic diagram of the balance wheel in the present invention.

Detailed ways

Preferred embodiments of the present invention are described in detail as follows in conjunction with accompanying drawings:

Embodiment one:

Referring to Fig. 1, the friction torque testing device of the rolling bearing under the low temperature comprises a support (2) and a pair of the same type tested rolling bearings (12), and it is characterized in that the said pair of the same type tested rolling bearings (12) are installed on The two ends of a shaft (10) are put into a sleeve (9), and the two ends are respectively fixed on the support (2) with the left end cover (7) and the right end cover (13). A temperature sensor (3) is drilled in the cylinder (9) close to the tested rolling bearing (12) to measure the temperature change of the bearing, and the protruding end of the shaft (10) is fixed with two set screws (15). Balance wheel (14), the two ends of the set screw (15) are equipped with two balance nuts (16) to fine-tune the eccentricity of the balance wheel (14), a thin rope goes around the balance wheel (14) and the two ends are respectively suspended A tray (17), when the weight (18) is put into the tray (17), once the balance wheel (14) rotates, the starting friction torque of the rolling bearing (12) to be tested can be measured.

Embodiment two:

This embodiment is basically the same as Embodiment 1, and the more specific detailed structure is as follows:

This embodiment is: referring to Fig. 1, the friction torque test device of the rolling bearing under the low temperature, including the cold control box (1) to control the ambient temperature, referring to Fig. 2, the sleeve is drilled to the place close to the bearing, and the temperature sensor PT100 (3) Stick it in the hole, and connect the lead wire to a digital display to display the temperature change. Referring to Fig. 3, a pair of test rolling bearings (12) of the same type are installed on both ends of the shaft (10) with prepared special tooling, the shaft (10) is tightly fitted with the test bearing (12), the shaft shoulder is positioned on the bearing, and the shaft The height of the shoulder is lower than the rib dimension of the inner ring of the bearing.

The above-mentioned device is put into the sleeve (9), and the outer ring of the test bearing (12) is loosely fitted with the inner ring of the sleeve (9), which is convenient for disassembly. The right end cover (13) is fastened with 4 screws (8), and the through hole in the center of the right end cover (13) constitutes a cantilever type radial support to the rotating shaft. See Figure 4, the left end cover (7) has a built-in groove, one end of the spring (6) is in the groove of the left end cover, and the other end is on the spring seat (5). There is a gap between the spring (6) and the inner wall of the left end cover. Tightening force setting, the other end of the spring seat (5) has a taper, point contact occurs through the guide groove of the inner retaining ring (4), and the pre-tightening force is evenly applied to the bearing (12) at the left end to be tested. Tighten the 4 screws (8) on the left end cover to ensure that the pretightening force is constant and evenly applied to the bearing under test.

Above-mentioned device is packed on the support (2), fixes with screw (11). Referring to Fig. 5 and Fig. 6, the balance wheel (14) is placed on the cantilever end of the shaft (10), and the balance wheel (14) is fixed on the shaft (10) by two setscrews (15). The quality tray (17) is suspended at the two ends of the balance wheel (14), respectively equipped with nuts (16) on the set screws (15), and the position of the trimming nuts (16) ensures that the set screws (15) are horizontally balanced. Put the whole device into the ambient temperature cold control box (1), gently put the weight (18) into the tray (17) with tweezers, observe whether the balance wheel (14) rotates, and calculate the gravity of the weight (18) after rotation The product with the radius of the balance wheel (14) is the frictional moment of the two bearings.

Claims (7)

1. the friction torque test device of rolling bearing under the low temperature; Comprise a bearing (2) and the tested rolling bearing of a pair of same model (12); It is characterized in that the tested rolling bearing of said a pair of same model (12) to be installed in the two ends of an axle (10) and put into a sleeve (9); Two ends are used left end cap (7), right end cap (13) to locate respectively and are fixed on the said bearing (2); The locating boring near tested rolling bearing (12) and put into temperature sensor (3) and change of said sleeve (9) to measure this bearing temperature, the external part of said axle (10) is with the fixing balance wheel (14) of two holding screws (15), and this holding screw (15) two ends are equipped with the off-centre that two balance nuts (16) are finely tuned balance wheels (14); Balance wheel (14) walked around by cord and a pallet (17) is respectively hung at two ends; When counterweight (18) is put into this pallet (17), balance wheel (14) is in case rotate, and the starting friction moment of tested rolling bearing (12) just can record.

2. the friction torque test device of rolling bearing under the low temperature as claimed in claim 1; It is characterized in that: said tested rolling bearing (12) inner ring and axle (10) wringing fit; Outer ring and sleeve (9) inner ring loose fit is convenient to dismounting and is not destroyed bearing accuracy, and matching surface requires correct grinding; The right alignment of two mating surfaces of sleeve (9) inner ring and axle (10) requires high, guarantees that two tested rolling bearings (12) are installed on the same straight line.

3. the friction torque test device of rolling bearing under according to claim 1 or claim 2 the low temperature; It is characterized in that: a spring (6), a spring base (5) and an inner shield ring (4) are arranged in the said left end cap (7); In the end groove, an end is on spring base (5), and is gapped between spring (6) and left end cap (7) inwall in left end cap (7) for spring (6) one ends; The length of spring (6) is set according to pretightning force; Spring base (5) one ends have tapering, and the gathering sill origination point contact through inner shield ring (4) evenly is applied to pretightning force on the tested rolling bearing of left end (12); Right end cap (13) end face fine-grinding is screwed at sleeve (9) right-hand member.

4. the friction torque test device of rolling bearing under the low temperature as claimed in claim 1; It is characterized in that: saidly locate boring near tested rolling bearing (12) and put into temperature sensor (3); Boring can not be communicated with tested rolling bearing (12), prevents that as far as possible dust, water vapor from getting into bearing internal influence bearing lubricant performance and moment of friction value; The external digital indicator reading numerical values of temperature sensor (3).

5. the friction torque test device of rolling bearing under the low temperature as claimed in claim 1 is characterized in that: should guarantee that two holding screws (15) are at same horizontal level.

6. the friction torque test device of rolling bearing under the low temperature as claimed in claim 1; It is characterized in that: said two carry a tray (17) can increase the identical weight counterweight simultaneously and apply radial load; Balance wheel (14) is wanted as close as possible tested rolling bearing (12) end, reduces torque influence as far as possible.

7. like claim 1,2,3; The friction torque test device of rolling bearing under 4,5,6 any described low temperature; It is characterized in that: whole testing device is placed in the cold control case (1), and in cooling and test process, cold control case (1) is opened all the time; Guarantee its cooling requirement, in time absorb airborne water vapor and prevent that bearing from freezing, when not reaching the bearing lubricant solidifying point, can not get into water vapor influence test.

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