CN104897401A - Bearing static performance testing apparatus - Google Patents

Abstract

The invention relates to the technical field of bearing testing, in particular to a bearing static performance testing device. The bearing static performance test device includes a base on which a test head assembly and a test loading mechanism are arranged. The test loading mechanism includes an axial force loading mechanism and an overturning force loading mechanism. The overturning force loading mechanism includes a force transmission arm. The input end and the force output end used to transmit the axial force to the tested bearing, the force loading direction of the axial force loading mechanism is always the same as the axial extension direction of the tested bearing. Since the test loading mechanism includes an axial force loading mechanism and an overturning force loading mechanism, and the force loading direction of the axial force loading mechanism is always the same as the axis extension direction of the tested bearing, this loading method is more in line with the actual working conditions of the bearing, thus The bearing static performance test device can accurately simulate the state of the bearing under the overturning force, and improve the accuracy of the results of the bearing static characteristic test.

Description

Bearing static performance test device

technical field

The invention relates to the technical field of bearing testing, in particular to a bearing static performance testing device.

Background technique

With the development of science and technology and the continuous increase of labor costs, the manufacturing industry is developing rapidly towards automation and intelligence. As an important embodiment of advanced manufacturing, robotics and related industries have also developed rapidly. Robot bearings are the key supporting components of industrial robots, which have a very important impact on key indicators such as the robot's smooth operation, repeat positioning accuracy, motion accuracy and work reliability.

In China, due to the late start of robot application engineering, its supporting bearings are generally imported together with the main engine. Industrial robot bearings are a relatively weak link. The existing national standards for bearings cannot meet and guide the design and production of industrial robot bearings, let alone form a systematic robot bearing test technology. Therefore, at present, most of the supporting bearings for domestic industrial robots rely on imports, and the sales in the domestic market account for less than 10% of the total sales. If we can design a test device for robot bearings and find out a set of effective test methods, it will definitely bring strong support to the production and development of robot bearings.

As for the static stiffness test analysis of bearings, previous studies have rarely involved, and even less research has been done on thin-walled bearings for robots. The static parameters of the bearing mainly refer to the static stiffness of the bearing. In essence, the static characteristics of bearings refer to the static contact characteristics of the rolling elements and the contact surfaces of the inner and outer rings of the bearing under load. It is of great value to study the influence of different loading conditions on the static stiffness of thin-walled bearings by using experimental methods.

Regarding the analysis of the static characteristics of bearings, "Nanjing University of Science and Technology" disclosed a test bench for static characteristics of bearings in 2014, wherein the test bench includes a platform and a tested bearing mounting seat arranged on the platform, and the tested bearing is installed The seat is equipped with an axial loading mechanism and a radial loading mechanism. When in use, the axial loading mechanism can be used to apply load to the tested bearing to study the static characteristics of the tested bearing under axial load. Loading is applied to the bearing to study the static characteristics of the tested bearing under radial load. However, bearings, especially thin-walled bearings used in robots, in addition to being subjected to axial loads, in most cases also need to be affected by overturning loads in actual work. test.

Regarding the research on the characteristics of the bearing under the state of overturning moment, the Chinese patent specification with the announcement number CN203869867U and the announcement date of October 8, 2014 discloses a bearing test loading device with overturning moment function. The bearing test loading device is suspended On the output spindle of the drive system, there are test bearings, loading arms, overturning moment loading cylinders and axial loading cylinders; the outer ring of the test bearing is connected to the output main shaft through the test shaft; the inner ring of the test bearing is fixedly connected to the loading arm; One end of the two loading rods set eccentrically with the test bearing is fixedly connected to the loading arm, and the other end is respectively connected to the piston rod of the corresponding overturning moment loading cylinder; the axial loading cylinder is located between the two overturning moment loading cylinders and connected to the loading cylinder. The arm is hinged, and the hinge axis at the hinge position of the axial loading cylinder and the loading arm is perpendicular to the line connecting the two overturning moment loading cylinders. When the overturning moment loading cylinder drives the loading arm to apply overturning moment to the test bearing, the axial loading cylinder Rotate relative to the loading arm at the hinge.

From the above introduction, it can be seen that in the above-mentioned bearing test loading device, the axial force loading cylinder and the loading arm are in a hinged relationship, so when the bearing is subjected to the axial loading moment and overturning moment at the same time, it does not conform to the actual situation. , because during the actual use of the bearing, its axial loading force will not change the angle relative to the bearing due to the existence of the overturning moment. Therefore, the above-mentioned bearing test loading device has the problem of inaccurate test results, and even if it is used in a bearing static test device, accurate test results cannot be obtained.

Contents of the invention

The purpose of the present invention is to provide a bearing static performance test device that can accurately simulate the state of the bearing subjected to overturning force, so as to improve the accuracy of the results of the bearing static characteristic test.

In order to solve the above problems, the bearing static performance test device of the present invention adopts the following technical scheme: the bearing static performance test device includes a base, and the test head assembly and the test loading mechanism for installing the tested bearing are arranged on the base, and the test loading mechanism includes a shaft To the force loading mechanism, the test loading mechanism also includes an overturning force loading mechanism, the overturning force loading mechanism includes a force transmission arm for being eccentrically arranged with the tested bearing, and the force transmission arm has a force input end and is used for The test bearing transmits the force output end of the axial force, and the force loading direction of the axial force loading mechanism is always the same as the axial extension direction of the test bearing.

The force transmission arms are arranged in pairs, and the force transmission arms of each pair are arranged oppositely in the radial direction of the tested bearing.

The force transmission arm is connected with an overturning force loading part through a lever-type force amplification mechanism, and the lever-type force amplification mechanism includes a final lever, and each pair of force transmission arms is connected to the same final lever through an input end, so as to The final lever loading can make the tested bearing bear the overturning force.

The lever type force amplifying mechanism also includes a primary lever, the primary lever is connected to the final lever through a connecting rod, and the overturning force loading part is arranged on the input end of the primary lever.

The overturning force loading part is an overturning force loading weight.

The overturning force loading weight is movably assembled on the primary lever along the length direction of the primary lever.

The axial force loading mechanism includes an axial force loading component supported by the force transmission arm.

The test head assembly includes a mandrel and an outer ring pressing plate for pressing down the outer ring of the bearing. The mandrel has an inner ring installation section for installing the inner ring of the bearing under test. The shaft is matched, and the force output end of the force transmission arm is connected with the outer ring pressure plate or the mandrel.

The end of the inner ring installation section is provided with an inner ring pressure plate for preloading the inner ring of the bearing, and the inner ring pressure plate and the mandrel are guided and positioned through the guide hole and the guide column respectively provided on the two.

The mounting section of the inner ring is provided with a test bearing and a spacer ring for separating the test bearing from the tested bearing.

Because the test loading mechanism of the bearing static performance testing device of the present invention includes an axial force loading mechanism and an overturning force loading mechanism, and the force loading direction of the axial force loading mechanism is always the same as the axial extension direction of the tested bearing, that is, no matter in When the overturning force loading mechanism is working, or when the overturning force loading mechanism is removed, the loading direction of the axial force loading mechanism remains unchanged. This loading method is more in line with the actual working conditions of the bearing, so that the bearing can be accurately simulated The static performance test device of the bearing under the state of overturning force improves the accuracy of the test results of the static characteristic of the bearing.

Description of drawings

Fig. 1 is the structural representation of a kind of embodiment of bearing static performance testing device;

Fig. 2 is a schematic structural view of the test head assembly in Fig. 1;

Fig. 3 is a schematic diagram of the assembly of the overturning force loading part and the primary lever in Fig. 1;

Fig. 4 is a top view of the bearing sleeve;

Fig. 5 is a schematic diagram of the loading force of the test loading mechanism.

Detailed ways

The embodiment of the bearing static performance test device is shown in Figures 1-4, the test device includes a base 11, a test head assembly, a test loading mechanism and a test value acquisition system.

The base 11 is the basis for carrying the entire test device. In this embodiment, the base 11 is a horizontal workbench.

In this embodiment, the test head assembly is arranged on the base 11 through a stepped shaft support seat 12 with a small top and a large bottom. Among them, the support seat 12 and the base 11 are fixed and assembled together by screws. The test head assembly includes a mandrel 13, an outer ring pressure plate 14 and an inner ring pressure plate 15. The mandrel 13 is a stepped shaft, including the upper small diameter section and the lower one. The large-diameter section, wherein the small-diameter section forms an inner ring installation section, and the inner ring installation section is used to install the inner ring of the tested bearing 16 . The mandrel 13 is detachably fixed and assembled on the support base 12 by bolts, and the test head assembly can be replaced as a whole by disassembling the mandrel 13, so as to meet the test of different types of bearings. The inner ring pressure plate 15 is arranged on the upper end of the inner ring installation section, and it is used to provide a preload for the inner ring of the tested bearing 16. Since the tested bearing 16 is a robot thin-walled bearing, its space structure is limited, and the mandrel 13 There is a guide post 17 at the upper end of the inner ring pressure plate 15, and a guide hole corresponding to the guide post 17 is provided. Through the mutual cooperation between the guide post 17 and the guide hole, the tested bearing 16 can be better fixed, and the tested bearing can be solved. 16 Problems that are difficult to locate and make the test device more stable. The lower side of the outer ring pressure plate 14 is fixedly connected with a bearing sleeve 18 and cooperates with the large diameter section of the mandrel 13 through the bearing sleeve 18. The wall of the bearing sleeve 18 is provided with a connecting hole and a measuring hole 19. In this embodiment, The connecting holes are specifically threaded holes. There are six measuring holes 19 distributed around the center line of the bearing sleeve 18. Each measuring hole 19 is a through hole. The axial deformation of the tested bearing 16 can be measured through the measuring holes 19. The axial deformation of the tested bearing 16 can be obtained by measuring the position change of the lower end surface of the bearing sleeve 18 . The inner hole of the bearing sleeve 18 is a stepped hole, thereby forming a step on its inner wall surface that can support the outer ring of the bearing. The disassembly of the step, wherein the petal shape of the step is formed by an arc-shaped through groove 501 opening through the step along the axial direction. In this embodiment, in addition to the aforementioned mandrel 13 , inner ring pressing plate 15 and outer ring pressing plate 14 , the test head assembly also includes an inner gasket 20 , an outer gasket 21 , a spacer ring 22 and a test bearing 23 . The inner gasket 20 is used for padding between the inner ring pressing plate 15 and the inner ring of the tested bearing 16, and the outer gasket 21 is used for padding between the outer ring pressing plate 14 and the outer ring of the tested bearing 16. In this embodiment, There is no integrated gasket directly installed on the inner and outer ring pressure plates, but the inner gasket separated from the inner ring pressure plate and the outer gasket corresponding to the outer ring pressure plate are used. On the one hand, this is to prevent gasket stress Fracture occurs due to concentration, and on the other hand, the load can be evenly applied to the tested bearing 16 to ensure the overall reliability and accuracy of the device. The accompanying test bearing 23 is arranged on the inner ring installation section of the mandrel 13, and the spacer ring 22 is used to be separated between the inner ring of the accompanying test bearing 23 and the inner ring of the tested bearing 16. When in use, the inner ring pressing plate 15 is downward Press the inner gasket 20, and then the inner gasket 20 presses the inner ring of the tested bearing 16, the inner ring of the tested bearing 16 presses the spacer ring 22, the spacer ring 22 presses the inner ring of the accompanying test bearing 23, and finally the accompanying test bearing 23 The inner ring of the inner ring is compressed on the step between the large and small diameter sections of the mandrel 13, thereby preventing the inner ring of the tested bearing 16 from rotating. In addition, the accompanying test bearing 23 can prevent the test head from tipping over. Under the condition of overturning moment, due to the small deformation of the bearing, it is equivalent to that the test bearing and the test bearing have been completely clamped all the time. The accompanying test bearing will offset half of the overturning moment of the test bearing, but will not affect the axial and radial displacement of the test bearing. According to the function of the test companion bearing 23 in the above description, it can be seen that the companion test bearing 23 can actually be omitted, so in other embodiments of the test device, there may be no companion test bearing.

The test loading mechanism includes an axial force loading mechanism and an overturning force loading mechanism.

The overturning force loading mechanism comprises a force transmission arm 24 and an overturning force loading part. In the present embodiment, the force transmission arm 24 has a pair, which is positioned at the radial both sides of the tested bearing 16 when the device is working, and each force transmission arm 24 each includes a force input end and a force output end for transmitting axial force to the tested bearing 16, wherein the force output end of the force transmission arm 24 is fixedly connected with the bearing sleeve 18 by bolts. The overturning force loading component is connected to the force transmission arm 24 through a lever type force amplification mechanism. In this embodiment, the overturning force loading component specifically adopts the overturning force loading weight 25 . The lever-type force amplifying mechanism includes two-stage levers, which are primary lever 26 and final lever 27 respectively. The final lever 27 adopts a split structure, including a force transmission arm connection section 271 and a force access section 272, wherein the force transmission arm The connection section 271 and the force access section 272 are detachably connected. The connection section 271 of the force transmission arm adopts square steel. When pushing the input end of the final lever 27 (the end away from the sliding sleeve), the load will be transmitted to the bearing sleeve 18 through the force transmission arm 24, and then to the outer ring of the tested bearing 16 to form an overturning force load. One end of the primary lever 26 is hinged on the base 11 by a hinge seat 29, and the other end forms a cantilever structure. The input end of the final stage lever 27 is connected together with an end near the hinge seat of the primary lever 26 by a connecting rod 30, wherein The rod 30 includes an upper section 301 and a lower section 302. The upper section 301 and the lower section 302 are connected together by a pin shaft 31, and the upper section and the lower section are connected by a pin shaft, which is somewhat similar to a human joint. Because when the overturning moment is applied to the tested bearing, the device will produce a very slight deflection, and if an integral straight rod is used, it will cause the straight rod to bend. But after adopting the pin-shaft connection structure, the bolts below can be adjusted to keep 301 and 302 in a vertical state. Thereby the smooth transmission of power can be realized. It should be pointed out here that the upper section 301 of the connecting rod 30 is also connected with the final lever 27 through a sliding sleeve, so that the length of the moment arm of the final lever 27 can be adjusted. In order to accurately obtain the final The length of the moment arm of the lever 27 changes, and the position that the final stage lever 27 cooperates with the connecting rod 30 is also provided with a scale sticker 32, and the sliding sleeve on the upper section of the connecting rod 30 is provided with a reading hole 33 for reading the reading of the scale sticker , the lower end of the connecting rod 30 is connected with the primary lever 26 through a bolt structure, which can realize the fine adjustment of the primary lever 26 to keep it horizontal. The overturning force loading part is arranged on the primary lever 26. In this embodiment, the overturning force loading part is arranged on the primary lever 26 through a sliding seat, and the sliding seat includes a sliding block 34 and a limit position on the sliding block 34. The column 35 and the primary lever 26 are provided with a dovetail-type chute corresponding to the slider 34. Through the cooperation of the slider 34 and the chute, the position of the overturning force loading part on the primary lever 26 can be adjusted. Under the situation of the position, the limit post 35 is screwed onto the slide block 34, so that the lower end of the 35 just presses the primary lever 26. Automatically ensure that the position of the limit column and the slider on the primary lever remains unchanged. And then adjust the length of the moment arm of the primary lever 26, in order to read the length of the moment arm of the primary lever 26 at any time, the primary lever is also provided with a scale sticker.

The axial force loading mechanism includes an axial force loading component, which is supported on the force transmission arm 24. In this embodiment, the axial force loading component specifically adopts the axial force loading weight 36, and the force transmission of the final lever A limit rod 37 is arranged on the upper side of the arm connecting section to form an inverted T shape, and the axial force loading weight 36 is set on the limit rod 37 .

The test value acquisition system includes a radial deformation detection sensor and an axial deformation detection sensor, wherein the radial deformation detection sensor is in one-to-one correspondence with the measurement holes on the above-mentioned bearing sleeve to detect the radial deformation of the tested bearing. The axial deformation detection sensor is arranged at the lower end of the bearing sleeve, and is used to obtain the axial deformation of the tested bearing by detecting the position change of the lower end surface of the bearing sleeve.

When using the test device to carry out static performance tests on bearings, first install the tested bearing on the test head assembly, then install the test head assembly as a whole on the support seat, and connect the force transmission arm with the final lever and the bearing sleeve respectively. When it is necessary to study the static characteristics of the bearing under the action of axial torque, the connection section of the force transmission arm of the final lever can be disconnected from the force access section, and only by setting the axial force loading parts, it can be passed through the shaft The deformation detection sensor is used to detect the deformation of the tested bearing under the action of axial torque. During the experiment, the axial force can be adjusted by changing the number of axial force loading weights. When it is necessary to study the static characteristics of the tested bearing under the condition of simultaneously bearing the axial moment and the overturning moment, it is enough to connect the two parts of the final lever. During the test, if the overturning force needs to be adjusted, the The method of reducing the quantity of the overturning force loading weight, adjusting the relative positional relationship between the connecting rod and the final lever, or adjusting the position of the overturning force loading weight on the primary lever, or the above three methods can be used in combination.

Figure 4 shows the schematic diagram of the loading force of the test loading mechanism. In the figure, the weight of the overturning force loading weight is the total weight of the test head assembly, the tested bearing and the test loading mechanism, and the weight of the axial force loading weight is The acting force of the connecting rod on the final lever is the horizontal distance between the connection position of the connecting rod and the primary lever to the hinge position of the primary lever and the hinge seat, and is the distance between the overturning force loading part and the hinge position of the primary lever and hinge seat The horizontal distance is the horizontal distance from the connection position of the connecting rod and the final lever to the axis of the support seat, and is the horizontal distance from the center of mass of the test head assembly, the tested bearing and the test loading mechanism to the axis of the support seat. The overturning moment and axial force loaded on the test bearing can be calculated according to the following calculation formula. The specific test formula is as follows:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; b</span>}}{\mathrm{<span\; class="notranslate">\; a</span>}}\\ {\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; G</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; G</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right.$

Among them, is the total overturning moment acting on the test bearing, and is the total axial force acting on the test bearing.

In other embodiments of the bearing static performance test device, the test loading mechanism can also be connected with the bearing inner ring pressure plate, so as to test the bearing through the inner ring of the tested bearing; the number of force transmission arms can be more than one, and the most It is best to set them in pairs, and each pair of force transmission arms is arranged symmetrically with respect to the center line of the tested bearing in the radial direction of the tested bearing; the axial force loading mechanism and the overturning force loading mechanism can also use cylinders, oil cylinders, wires Lever nut mechanism, etc.

Claims (10)

1. bearing static properties test unit, comprise base, base is provided with the test head group part for installing tested bearing and tests load maintainer, test load maintainer comprises axial force load maintainer, it is characterized in that, described test load maintainer also comprises the power load maintainer that topples, the described power of toppling load maintainer comprises for the power transmission arm with tested bearing eccentric setting, described power transmission arm has power input end and the power output terminal for transmitting axial force to tested bearing, and the power loading direction of described axial force load maintainer is identical with the Axis Extension direction of tested bearing all the time.

2. bearing static properties test unit according to claim 1, is characterized in that, described power transmission arm is arranged in pairs, and the power transmission arm of every a pair is oppositely arranged in the radial direction of tested bearing.

3. bearing static properties test unit according to claim 2, it is characterized in that, described power transmission arm is connected with by lever force amplificatory structure the power loading component that topples, described lever force amplificatory structure comprises final stage lever, the power transmission arm of every a pair is connected to same final stage lever by input end, thus tested bearing can be made to be subject to the power of toppling to final stage lever-loading.

4. bearing static properties test unit according to claim 3, it is characterized in that, described lever force amplificatory structure also comprises primary lever, is connected between primary lever with final stage lever by connecting rod, described in the power loading component that topples be located on the input end of primary lever.

5. bearing static properties test unit according to claim 3, is characterized in that, described in topple power loading component for topple power load counterweight.

6. bearing static properties test unit according to claim 5, is characterized in that, described in power of toppling load counterweight and be movably assemblied on primary lever along the length direction of primary lever.

7. bearing static properties test unit according to claim 1, is characterized in that, axial force load maintainer comprises the axial force loading component supported by described power transmission arm.

8. bearing static properties test unit according to claim 1, it is characterized in that, described test head group part comprises mandrel and the outer ring pressing plate for pressing down bearing outer ring, mandrel has the inner ring construction section for installing tested bearing inner race, described outer ring pressing plate is coordinated with mandrel by tested bearing outside, and the power output terminal of power transmission arm is connected with described outer ring pressing plate or mandrel.

9. bearing static properties test unit according to claim 8, it is characterized in that, the end of described inner ring construction section is provided with the inner ring pressing plate for precompressed bearing inner race, and inner ring pressing plate and mandrel are by being divided into pilot hole on the two and guidepost guide-localization coordinates.

10. bearing static properties test unit according to claim 8, is characterized in that, described inner ring construction section is provided with accompanies examination bearing and accompany examination bearing and the spacer ring of tested bearing for separating.