Device and method for measuring axial load of motor sliding bearing

Abstract

The invention belongs to the technical field of bearing axial load measurement, and particularly relates to a motor sliding bearing axial load measurement device and method, the measurement device comprises a shell, a loading body installed in the shell and a motor driving the loading body to rotate in the shell; the loading body comprises a loading body, a first connecting shaft and a second connecting shaft, the first connecting shaft and the second connecting shaft are located at the two ends of the loading body respectively, the first connecting shaft is sleeved with a sliding bearing, and the second connecting shaft is sleeved with a sliding bearing to be tested; one end, opposite to the sliding bearing to be tested, of the loading body is provided with a contact body, the contact body is in contact with the end face of the sliding bearing to be tested, and the weight of the loading body is applied to the sliding bearing to be tested; one end of the to-be-tested sliding bearing away from the contact body is connected with a pressure sensor. Through the design that the contact body is in contact with the end face of the sliding bearing to be tested, the effect of applying a high load through a small-mass loading body is achieved through the pressure intensity principle.

Description

Technical Field

[0001] The present invention belongs to the technical field of axial load measurement of bearings, and particularly relates to a device and method for measuring the axial load of a sliding bearing of an electric motor. Background Art

[0002] A fuel motor drives the rotation of a pump body (such as an impeller, a rotor, etc.) inside a fuel pump through its rotation, thereby generating a pressure difference to draw fuel out of a fuel tank and transport it to an engine combustion chamber, providing necessary fuel supply for the engine. Fuel motors are divided into built-in fuel motors and external fuel motors according to different structural forms. Built-in fuel motors are usually integrated with a total assembly and installed in a fuel tank. The fuel motor bears large loads and high speeds. In application scenarios with large loads and high speeds, sliding bearings are usually selected. Compared with deep groove ball bearings and cylindrical roller thrust bearings, sliding bearings can bear greater loads. Therefore, it is important to accurately measure the axial load-bearing capacity of sliding bearings. The following problems exist in the devices for measuring axial load capacity in the prior art:

[0003] (1) Most of the devices in the prior art are for measuring the load of rolling bearings, and such devices cannot meet the requirements for measuring the load of sliding bearings.

[0004] (2) In the test method of rolling bearings in the prior art, the motor speed has little influence on the compressive strength of rolling bearings, and the motor speed does not need to be considered during the test process. However, the motor speed has a great influence on the compressive strength of sliding bearings, and it is necessary to consider the influence of the motor speed on the compressive strength of sliding bearings in an oil fluid environment with different viscosities.

[0005] Therefore, there is an urgent need to design a device for measuring the axial load of a sliding bearing of an electric motor to measure the axial load capacity of the sliding bearing. Summary of the Invention

[0006] To solve the problems in the above background art, the present invention provides a device and method for measuring the axial load of a sliding bearing of an electric motor. By setting a contact body on a loading body, the contact area between the loading body and the sliding bearing to be measured is reduced, so as to obtain a larger pressure under the condition of maintaining a smaller pressure.

[0007] The first object of the present invention is to provide a device for measuring the axial load of a sliding bearing of an electric motor, including a housing, a loading body installed in the housing, and a motor for driving the loading body to rotate in the housing;

[0008] The loading body includes a loading main body, a first connecting shaft and a second connecting shaft respectively located at both ends of the loading main body. A sliding bearing is sleeved on the first connecting shaft, and a sliding bearing to be measured is sleeved on the second connecting shaft. The sliding bearing and the sliding bearing to be measured are respectively arranged in the housing through a first end cover and a second end cover; a loading hole axially penetrating the first connecting shaft is formed on the loading body, and the driving shaft of the motor passes through the first end cover and is connected in the loading hole;

[0009] A contact body is arranged at one end of the loading main body opposite to the sliding bearing to be measured. The contact body contacts the end face of the sliding bearing to be measured, and the weight of the loading body is applied to the sliding bearing to be measured; a pressure sensor is connected to the end of the sliding bearing to be measured far from the contact body;

[0010] The housing, the first end cover and the second end cover enclose a cavity, and the cavity is filled with oil. The sliding bearing, the loading body and the sliding bearing to be measured are all immersed in the oil.

[0011] Further, the contact body is an annular protrusion coaxially arranged with the second connecting shaft. The annular protrusion includes a connecting surface connected to the loading main body and a contact surface contacting the sliding bearing to be measured. The radial width of the contact surface is smaller than the radial width of the connecting surface.

[0012] Further, the contact body contacts the outer edge of the end face of the sliding bearing to be measured, and the outer edge line of the contact surface coincides with the outer edge line of the end face of the sliding bearing to be measured.

[0013] Further, the radial width of the contact surface is 1mm - 3mm, and the contact area between the contact body and the sliding bearing to be measured is 10mm 2 -90mm 2 .

[0014] Further, the pressure between the contact body and the sliding bearing to be measured is 1MPa - 20MPa.

[0015] Further, an upward-extending annular cylinder is formed at one end of the housing close to the second end cover. An annular groove is formed between the annular cylinder and the outer wall of the housing. An electromagnetic coil located below the loading main body is installed in the annular groove. There is a gap between the electromagnetic coil and the loading main body. The loading body is an armature made of ferromagnetic material.

[0016] Further, a first permanent magnet is fixed at one end of the loading body opposite to the first end cover. A second permanent magnet corresponding to the first permanent magnet is arranged on the first end cover. The first permanent magnet and the second permanent magnet are arranged with the same poles. An adjusting member acting on the second permanent magnet is arranged on the first end cover. The adjusting member drives the second permanent magnet to move to adjust the distance between the first permanent magnet and the second permanent magnet.

[0017] Further, the adjusting member is an adjusting bolt. A through threaded hole is provided on the first end cover. The adjusting bolt is screwed into the threaded hole and then connected to the second permanent magnet. The rotation of the adjusting bolt drives the second permanent magnet to linearly move axially.

[0018] Further, when the loading body rotates driven by the motor, the load generated after the weight of the loading body is corrected by the buoyancy of the oil is transmitted to the end face of the sliding bearing to be measured through the contact body. The compressive strength of the sliding bearing to be measured is P = (G - F) / S;

[0019] Where: P is the compressive strength borne by the sliding bearing to be measured, G is the weight of the loading body, F is the buoyancy of the loading body in the oil, and S is the contact area between the loading body and the sliding bearing to be measured.

[0020] The second object of the present invention is to provide a method for measuring the axial load bearing capacity of a motor sliding bearing, which is realized based on the motor sliding bearing axial load measuring device of any one of the above. The measuring method includes the following steps:

[0021] S1: Install the sliding bearing to be measured on the second connecting shaft, and fill a certain oil in the shell. Adjust the pressure applied by the loading body to the sliding bearing to be measured. Start the motor to keep it rotating at a certain speed. The motor drives the loading body to rotate. The contact body on the loading body contacts the sliding bearing to be measured, and the pressure applied to the sliding bearing to be measured is fed back through the pressure sensor. After the sliding bearing to be measured operates for a certain time, measure the wear amount of the sliding bearing to be measured. If the wear amount meets the requirements, enter step S2;

[0022] S2: Increase the pressure applied by the loading body to the sliding bearing to be measured, repeat step S1, and continue to measure the wear amount of the sliding bearing to be measured after it operates for a certain time. If the wear amount meets the requirements, continue to repeat step S2; if the wear amount does not meet the requirements, enter step S3;

[0023] S3: Draw the bearing capacity curve of the sliding bearing to be measured in a certain oil and at a certain speed according to steps S1 and S2.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) Through the design concept of the contact body contacting the end face of the sliding bearing to be measured, the present application utilizes the pressure principle to achieve the effect of applying a high load with a small-mass loading body. Compared with the traditional scheme of simply increasing the weight of the loading body, the moment of inertia is significantly reduced, and the safety hazard during high-speed rotation is avoided; moreover, the loading body adopts a symmetrical structure of a double connecting shaft, which is supported by sliding bearings at both ends, forming a more stable rotating loading system, ensuring the uniformity of load transmission and the reliability of test data. At the same time, the cavity is filled with oil, which can accurately simulate the actual working conditions of the sliding bearing, further improving the accuracy of test data.

[0026] (2) The measuring device of the present application does not need to add a rotating shaft. It directly drives the rotating of the loading body by connecting the motor shaft with the loading body, reducing the number of components. And by integrally forming a first connecting shaft and a second connecting shaft on the loading body to realize the rotation of the loading body and the installation of the sliding bearing, a compact structural design is achieved, which is convenient for disassembly, installation and maintenance, and reduces the operation cost of the equipment. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 Side view of the measuring device provided by an embodiment of the present invention;

[0029] Figure 2 For Figure 1 Cross-sectional view A-A in

[0030] Figure 3 For Figure 2 Enlarged view of part B in

[0031] Figure 4 Cross-sectional view of the loading body provided by an embodiment of the present invention;

[0032] Figure 5 For Figure 4 Enlarged view of part C in

[0033] Figure 6 Structural diagram of the sliding bearing to be measured provided by an embodiment of the present invention;

[0034] Figure 7 Cross-sectional view of the measuring device provided by another embodiment of the present invention;

[0035] Figure 8 For Figure 7 Connection structural diagram of the adjusting bolt, the first end cover and the second permanent magnet in

[0036] Wherein: 1 - housing, 11 - annular cylinder, 12 - annular groove, 13 - electromagnetic coil, 2 - loading body, 21 - loading main body, 22 - contact body, 221 - contact surface, 222 - connection surface, 23 - first connecting shaft, 24 - second connecting shaft, 25 - loading hole, 3 - motor, 4 - sliding bearing, 5 - sliding bearing to be measured, 51 - end face, 6 - first end cover, 7 - second end cover, 8 - first permanent magnet, 9 - second permanent magnet, 10 - adjusting bolt. Specific embodiments

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] The following combines the attached Figure 1 to the attached Figure 8 and specific embodiments to elaborate on the present invention in detail.

[0039] Refer to Figures 1 to 8 , the present invention provides a device for measuring the axial load of a motor sliding bearing, including a housing 1, a loading body 2 installed in the housing 1, and a motor 3 for driving the loading body 2 to rotate in the housing 1; the loading body 2 is arranged above the sliding bearing 5 to be measured and contacts the sliding bearing 5 to be measured. The loading body 2 mainly applies a vertical pressure to the sliding bearing 5 to be measured by its own gravity. Therefore, the loading body 2 is usually a solid structure and is made of a material with a relatively large density to achieve the purpose of increasing the weight of the loading body. The measuring device of the present application is mainly applied to the working condition of vertical setting, that is, the loading body 2 is vertically arranged, and the axial (vertical) direction of the loading body 2 is as Figure 2 shown. The sliding bearing 5 to be measured is arranged below the loading body 2 so as to apply the weight of the loading body 2 to the sliding bearing 5 to be measured. It should be noted that in the present application, the volume of the inner cavity formed by the housing 1 is limited, and the volume of the loading body 2 cannot be infinitely large. It is only necessary to ensure that the loading body 2 has a sufficient weight within the limited inner cavity volume as much as possible; in an optional embodiment, the diameter of the loading body 2 is 90 mm, the height is 80 mm, and the weight is 1000 g.

[0040] Refer to Figure 4The loading body 2 of the present application includes a loading body 21 and a first connecting shaft 23 and a second connecting shaft 24 respectively located at both ends of the loading body 21. The first connecting shaft 23 is located at the upper end of the loading body 21, and the second connecting shaft 24 is located at the lower end of the loading body 21. A sliding bearing 4 is mounted on the first connecting shaft 23. The sliding bearing 4 is used to rotate the loading body 2 in the housing. A sliding bearing 5 to be tested is mounted on the second connecting shaft 24. The sliding bearing 5 to be tested assists the rotation of the loading body 2 on the one hand, and is a test bearing on the other hand. The sliding bearing 4 and the sliding bearing 5 to be tested are respectively arranged in the housing 1 through a first end cover 6 and a second end cover 7; usually, the sliding bearing 4 and the sliding bearing 5 to be tested are the same type of bearings and are arranged in pairs at both ends of the loading body 2; in this embodiment, the sliding bearing 4 and the sliding bearing to be tested 5 are both graphite bearings. Graphite bearings are more suitable for installation in an environment with oil, and in an oil medium, the lubricity of graphite bearings will be further enhanced. When the load body 2 rotates in the graphite bearing, an oil film will be formed on the surface of the graphite bearing. When the oil film breaks, the wear of the graphite bearing will be aggravated. Of course, in other embodiments, the sliding bearing 4 and the sliding bearing to be tested 5 can also use other types of bearings, which are not specifically limited in this application. The load body 2 is provided with a loading hole 25 that axially passes through the first connecting shaft 23. The drive shaft of the motor 3 passes through the first end cover 6 and is connected to the loading hole 25, thereby achieving the purpose of driving the load body 2 to rotate by the motor 3. The first end cover 6 and the second end cover 7 in this application are fixed to the housing 1 as a whole by fixing screws. In a preferred embodiment, the load body 2 has a vertically symmetrical structure, and the loading hole 25 axially passes through the load body 2. The loading hole 25 is coaxially arranged with the first connecting shaft 23 and the second connecting shaft 24, so that the load body 2 does not need to distinguish between the upper and lower directions when installing, thereby improving the convenience of installation.

[0041] See Figure 2 and Figure 3, a contact body 22 is provided at one end of the loading body 21 opposite to the sliding bearing 5 to be measured. The contact body 22 contacts the end face 51 of the sliding bearing 5 to be measured, so as to apply the weight of the loading body 2 to the sliding bearing 5 to be measured; a pressure sensor (not shown in the figure) is connected to one end of the sliding bearing 5 to be measured away from the contact body 22. The pressure sensor can be integrated in the second end cover 7. The pressure sensor is used to measure the magnitude of the axial load of the sliding bearing 5 to be measured in real time; in this application, the housing 1, the first end cover 6 and the second end cover 7 enclose a cavity filled with oil. The sliding bearing 4, the loading body 2 and the sliding bearing 5 to be measured are all immersed in the oil to simulate the actual working environment of the sliding bearing. It should be noted that the type of the oil is not limited in this application. Different oils have different viscosities, and the compressive strength of the sliding bearing under different viscosities is also different. Therefore, the axial load bearing capacity of the sliding bearing in the oil environment with different viscosities can be recorded in real time during the measurement. It should be noted that the measuring device of this application is placed in an oil barrel or an oil tank during use. The whole device is immersed in the oil barrel, and the inside of the housing 1 is also filled with the same type of oil. The oil in the housing 1 and the oil in the oil barrel can flow freely, accurately simulating the actual working conditions in the oil environment.

[0042] During the use of the measuring device of this application, the motor 3 drives the loading body 2 to rotate, and the weight of the loading body 2 is loaded onto the end face 51 of the sliding bearing 5 to be measured through the contact body 22, so that a relatively small-weight loading body 2 can apply a relatively large compressive strength to the sliding bearing 5 to be measured. Since the whole device is filled with oil inside, the weight of the loading body 2 minus the buoyancy of the loading body 2 in the oil is the loading force applied to the sliding bearing 5 to be measured. It is worth noting that since the sliding bearing has a strong ability to bear axial loads, if the volume of the loading body 2 is increased to increase the loading force applied to the sliding bearing 5 to be measured, then when the volume of the loading body 2 is very large, its moment of inertia is likely to cause danger during high-speed operation. Therefore, this application breaks through the traditional thinking and creatively designs a contact body on the loading body 21 to achieve the purpose of obtaining a larger pressure by reducing the force-bearing area.

[0043] It is further emphasized that through the design concept of the contact between the contact body 22 and the end face 51 of the sliding bearing 5 to be measured, this application utilizes the pressure principle to achieve the effect of applying a high load with a small-mass loading body 2. Compared with the traditional scheme of simply increasing the weight of the loading body 2, the moment of inertia is significantly reduced, avoiding potential safety hazards during high-speed rotation; and the loading body 2 adopts a symmetric structure with double connecting shafts, cooperating with the sliding bearings at both ends for support, forming a more stable rotational loading system, ensuring the uniformity of load transfer and the reliability of test data. At the same time, the cavity is filled with oil, which can accurately simulate the actual working conditions of the sliding bearing, further improving the accuracy of test data.

[0044] Specifically, refer toFigure 5 The contact body 22 is an annular protrusion coaxially arranged with the second connecting shaft 24. The annular protrusion includes a connecting surface 222 connected to the loading body 21 and a contact surface 221 in contact with the sliding bearing 5 to be measured. The radial width of the contact surface 221 is smaller than the radial width of the connecting surface 222. In other words, the contact body 22 has a structure that is wider at the top and narrower at the bottom, wider at the end close to the loading body 21 and narrower at the end close to the sliding bearing 5 to be measured. This structure can not only ensure a small contact area between the loading body 2 and the sliding bearing 5 to be measured, but also the contact body 22 structure that is wider at the top and narrower at the bottom is not easily damaged or fractured. In this application, by designing the contact body 22 as an annular protrusion structure that is wider at the top and narrower at the bottom, by increasing the bonding area between the connecting surface 222 and the loading body 21, the bending stiffness is significantly improved, avoiding fracture or plastic deformation caused by local stress concentration, and ensuring the reliability of long-term testing. At the same time, by designing the radial width of the contact surface 221 to be smaller than the radial width of the connecting surface 222, the weight of the loading body 2 acts concentratedly on a small annular area of the end face 51 of the sliding bearing 5 to be measured, greatly increasing the local pressure, and enabling the accurate application of a high axial load without increasing the weight of the loading body 2. In this application, the contact body 22 and the second connecting shaft 24 are arranged coaxially, which can ensure that the contact surface 221 and the end face 51 of the sliding bearing 5 to be measured always maintain concentric contact during the high-speed rotation of the loading body 2, eliminating the interference of eccentric load caused by centrifugal force and simulating the axial bearing state of the sliding bearing under real working conditions.

[0045] In a preferred embodiment, the cross-section of the contact body 22 is an isosceles trapezoid structure. The isosceles trapezoid structure enables the pressure to be evenly transmitted along the axis direction of the contact body 22, avoiding the problem of eccentric load caused by an asymmetric structure, effectively reducing the stress distribution fluctuation of the end face 51 of the sliding bearing 5 to be measured, and improving the repeatability and accuracy of the test data. In a more preferred embodiment, there is a smooth transition between the contact surface 221 of the contact body 22 and the side surface of the contact body 22, avoiding the formation of edges that cause unnecessary wear to the oil film and reducing the accuracy of the test.

[0046] In a preferred embodiment, the contact body 22 and the loading body 21 are integrally formed, which can reduce the potential risks of wear or loosening caused by a complex assembly structure.

[0047] In this application, by providing the contact body 22 on the loading body 21, the local pressure can be increased by 500% - 1000% under the same loading weight. At the same time, compared with the contact body 22 structure where the radial widths of the connecting surface 222 and the contact surface 221 are the same, through the design of the contact body with an isosceles trapezoid cross-section in this embodiment, the fracture risk of the contact body 22 can be reduced by more than 80%, improving the service life of the measuring device of this application.

[0048] Specifically, refer to Figure 3, the contact body 22 contacts with the outer edge of the end face of the sliding bearing 5 to be measured, and the outer edge line of the contact surface 221 coincides with the outer edge line of the end face 51 of the sliding bearing 5 to be measured. It should be noted that the greater the distance between the contact body 22 and the rotating shaft of the loading body 2, the greater its linear velocity. The linear velocity is one of the important indicators of the sliding bearing. The reason is: v = w * r, where v is the linear velocity of the motor axis, w is the angular velocity of the motor shaft, and r is the radius. The larger the radius r, the greater the linear velocity v. The oil film formed between the contact body 22 and the sliding bearing 5 to be measured is thinner, the oil film stiffness is small, and it is more prone to wear. After the oil film ruptures, the wear between the contact body 22 and the sliding bearing 5 to be measured will be aggravated. Therefore, the contact body 22 is arranged at a position as far as possible from the rotating shaft of the loading body 2 to test the wear performance at its limit position. It should be noted that in addition to the influence of the linear velocity, the viscosity of the oil also has a great influence on the wear of the sliding bearing 5 to be measured. The higher the viscosity of the oil, the greater the oil film stiffness, the less likely the oil film is to wear, and the smaller the wear of the contact body 22 on the sliding bearing 5 to be measured. During the test process, the influence of both on the wear of the sliding bearing 5 to be measured needs to be considered comprehensively.

[0049] In a preferred embodiment, the radial width of the contact surface 221 is 1 mm - 3 mm, and the contact area between the contact body 22 and the sliding bearing 5 to be measured is 10 mm 2 - 90 mm 2 . The contact surface 221 within the above radial width range and contact area range can greatly increase the local pressure, achieve a higher equivalent load under the same loading weight, and break through the physical limitations of the traditional large-mass loading body 2. Usually, the contact surface 221 with a radial width of 1 mm and a contact area of 10 mm 2 has sufficient structural strength to avoid accelerating the wear of the oil film due to the formation of sharp edges caused by being too narrow. At the same time, an overly narrow contact surface is likely to cause the fracture of the contact body.

[0050] Specifically, the pressure between the contact body 22 and the sliding bearing 5 to be measured is 1 MPa - 20 MPa. The above pressure magnitude can accurately test the load-bearing capacity of most industrial sliding bearings, and the test results have a high degree of accuracy.

[0051] In summary, through the synergistic effect of maximizing the linear velocity and minimizing the contact area, the measuring device of the present application realizes the composite extreme working conditions of high speed and high pressure under a limited loading weight, and accurately tests the axial load-bearing capacity and anti-wear performance of the sliding bearing.

[0052] In some embodiments, refer to Figure 2, on one end of the housing 1 near the second end cap 7, an annular cylinder 11 extending upward is formed. An annular groove 12 is formed between the annular cylinder 11 and the outer wall of the housing 1. An electromagnetic coil 13 located below the loading body 21 is installed in the annular groove 12. The electromagnetic coil 13 is impregnated with insulating paint. The electromagnetic coil 13 is an oil-proof coil, and there is a gap between the electromagnetic coil 13 and the loading body 21. The loading body 2 is an armature made of ferromagnetic material. After the electromagnetic coil 13 is energized, a magnetic field is generated. The loading body 2 serves as the armature of the electromagnetic coil 13, and the magnetic field forms an attractive force on the loading body 2, providing a downward pulling force, forming an adjustable load applied to the bearing, forming a composite loading mode, that is, through the superposition effect of the electromagnetic attraction and the gravity of the loading body 2, a dual loading mechanism is formed in a limited space. And the load is transmitted between the electromagnetic coil 13 and the loading body 2 in a non-contact manner through the magnetic field, eliminating the traditional mechanical connection components, reducing both the friction loss and avoiding the vibration and wear caused by mechanical contact. At the same time, the number of components is reduced, making the measuring device more compact in a limited space.

[0053] In some embodiments, referring to Figure 7 and Figure 8 , a first permanent magnet 8 is fixed to one end of the loading body 2 opposite to the first end cap 6. A second permanent magnet 9 corresponding to the first permanent magnet 8 is arranged on the first end cap 6. The first permanent magnet 8 and the second permanent magnet 9 are arranged with the same poles, so that the first permanent magnet 8 is subjected to a downward repulsive force, and the repulsive force is transmitted to the loading body 2, becoming an axial loading load. Preferably, an adjusting member acting on the second permanent magnet 9 is arranged on the first end cap 6. The adjusting member drives the second permanent magnet 9 to move to adjust the distance between the first permanent magnet 8 and the second permanent magnet 9, so as to achieve the purpose of adjusting the load. Preferably, the adjusting member is an adjusting bolt 10. A threaded hole penetrating through the inside and outside is arranged on the first end cap 6. The adjusting bolt 10 is screwed into the threaded hole and then connected to the second permanent magnet 9. The rotation of the adjusting bolt 10 drives the second permanent magnet 9 to move axially in a straight line. In this embodiment, the load is transmitted between the first permanent magnet 8 and the second permanent magnet 9 in a non-contact manner, eliminating the traditional mechanical connection components, reducing both the friction loss and avoiding the vibration and wear caused by mechanical contact. At the same time, the number of components is reduced, making the measuring device more compact in a limited space.

[0054] Specifically, when the loading body 2 rotates driven by the motor 3, the load generated by the weight of the loading body 2 after being corrected by the buoyancy of the oil fluid is transmitted to the end face 51 of the sliding bearing 5 to be measured through the contact body 22. The compressive strength of the sliding bearing 5 to be measured is P = (G - F) / S;

[0055] Where: P is the compressive strength borne by the sliding bearing 5 to be measured, G is the weight of the loading body 2, F is the buoyancy of the loading body 2 in the oil fluid, and S is the contact area between the loading body 2 and the sliding bearing 5 to be measured.

[0056] The present invention also provides a method for measuring the axial load-bearing capacity of a motor sliding bearing, which is implemented based on the axial load measuring device of the motor sliding bearing according to any one of the above. The measuring method includes the following steps:

[0057] S1: Install the sliding bearing 5 to be measured on the second connecting shaft 24, fill a certain oil in the housing 1, adjust the pressure applied by the loading body 2 to the sliding bearing 5 to be measured, start the motor 3 to make the motor 3 rotate at a certain speed, the motor 3 drives the loading body 2 to rotate, the contact body 22 on the loading body 2 contacts the sliding bearing 5 to be measured, and the pressure applied to the sliding bearing 5 to be measured is fed back through the pressure sensor. After the sliding bearing 5 to be measured operates for a certain period of time, measure the wear amount of the sliding bearing 5 to be measured. If the wear amount meets the requirements, proceed to step S2;

[0058] S2: Increase the pressure applied by the loading body 2 to the sliding bearing 5 to be measured, repeat step S1, and continue to measure the wear amount of the sliding bearing 5 to be measured after it operates for a certain period of time. If the wear amount meets the requirements, continue to repeat step S2; if the wear amount does not meet the requirements, proceed to step S3;

[0059] S3: Draw the bearing capacity curve of the sliding bearing 5 to be measured in a certain oil and at a certain speed according to steps S1 and S2.

[0060] The method of the present application applies all the technical solutions of all embodiments of the above axial load measuring device of the motor sliding bearing. Therefore, it has at least all the beneficial effects brought by the technical solutions of the embodiments of the above axial load measuring device of the motor sliding bearing, which will not be elaborated one by one here.

[0061] The above further describes the present invention with the aid of specific embodiments. However, it should be understood that this specific description should not be construed as a limitation on the essence and scope of the present invention. Various modifications made by those of ordinary skill in the art to the above embodiments after reading this specification all fall within the scope protected by the present invention.

Claims

1. An axial load measuring device for a motor sliding bearing, characterized in that, It includes a housing, a loading body installed inside the housing, and a motor for driving the loading body to rotate inside the housing; The loading body includes a loading main body, a first connecting shaft and a second connecting shaft respectively located at both ends of the loading main body. A sliding bearing is sleeved on the first connecting shaft, and a sliding bearing to be measured is sleeved on the second connecting shaft. The sliding bearing and the sliding bearing to be measured are respectively arranged inside the housing through a first end cover and a second end cover; a loading hole axially penetrating the first connecting shaft is formed on the loading body, and the driving shaft of the motor passes through the first end cover and is connected inside the loading hole; One end of the loading main body opposite to the sliding bearing to be measured is provided with a contact body, and the contact body contacts the end face of the sliding bearing to be measured to apply the weight of the loading body to the sliding bearing to be measured; a pressure sensor is connected to one end of the sliding bearing to be measured away from the contact body; The housing, the first end cover and the second end cover enclose a cavity, and the cavity is filled with oil. The sliding bearing, the loading body and the sliding bearing to be measured are all immersed in the oil.

2. The axial load measuring device for the motor sliding bearing according to claim 1, wherein, The contact body is an annular protrusion coaxially arranged with the second connecting shaft. The annular protrusion includes a connecting surface connected to the loading main body and a contact surface contacting the sliding bearing to be measured. The radial width of the contact surface is smaller than the radial width of the connecting surface.

3. The axial load measuring device for the motor sliding bearing according to claim 2, wherein The contact body contacts the outer edge of the end face of the sliding bearing to be measured, and the outer edge line of the contact surface coincides with the outer edge line of the end face of the sliding bearing to be measured.

4. The axial load measuring device for the motor sliding bearing according to claim 2, wherein, The radial width of the contact surface is 1 mm - 3 mm; the contact area between the contact body and the sliding bearing to be measured is 10 mm 2 - 90 mm 2 .

5. The axial load measuring device for the motor sliding bearing according to claim 4, characterized in that, The pressure between the contact body and the sliding bearing to be measured is 1MPa - 20MPa.

6. The axial load measuring device for the motor sliding bearing according to claim 1, characterized in that An annular cylinder extending upward is formed at one end of the housing close to the second end cover. An annular groove is formed between the annular cylinder and the outer wall of the housing. An electromagnetic coil located below the loading main body is installed in the annular groove. There is a gap between the electromagnetic coil and the loading main body. The loading body is an armature made of ferromagnetic material.

7. The axial load measuring device for the motor sliding bearing according to claim 1, characterized in that, A first permanent magnet is fixed at one end of the loading body opposite to the first end cover. A second permanent magnet corresponding to the first permanent magnet is arranged on the first end cover. The first permanent magnet and the second permanent magnet are arranged with the same poles. An adjusting member acting on the second permanent magnet is arranged on the first end cover. The adjusting member drives the second permanent magnet to move to adjust the distance between the first permanent magnet and the second permanent magnet.

8. The axial load measuring device for the motor sliding bearing according to claim 7, characterized in that, The adjusting member is an adjusting bolt. A threaded hole penetrating inside and outside is formed on the first end cover. The adjusting bolt is screwed into the threaded hole and then connected to the second permanent magnet. The rotation of the adjusting bolt drives the second permanent magnet to move axially in a straight line.

9. The axial load measuring device for the motor sliding bearing according to any one of claims 1-8, characterized in that, When the loading body rotates driven by the motor, the load generated after the weight of the loading body is corrected by the buoyancy of the oil is transmitted to the end face of the sliding bearing to be measured through the contact body. The compressive strength of the sliding bearing to be measured is P = (G - F) / S; Wherein: P is the compressive strength borne by the sliding bearing to be measured, G is the weight of the loading body, F is the buoyancy of the loading body in the oil, and S is the contact area between the loading body and the sliding bearing to be measured.

10. Method for measuring the axial load-bearing capacity of a sliding bearing, implemented based on the axial load measuring device for an electric motor sliding bearing according to any one of claims 1-9, characterized in that, It includes the following steps: S1: Install the sliding bearing to be measured on the second connecting shaft, fill a certain kind of oil in the housing, adjust the pressure applied by the loading body to the sliding bearing to be measured, start the motor to keep it rotating at a certain speed, the motor drives the loading body to rotate, the contact body on the loading body contacts the sliding bearing to be measured, and the pressure applied to the sliding bearing to be measured is fed back through the pressure sensor. After the sliding bearing to be measured operates for a certain period of time, measure the wear amount of the sliding bearing to be measured. If the wear amount meets the requirements, proceed to step S2; S2: Increase the pressure applied by the loading body to the sliding bearing to be measured, repeat step S1, continue to measure the wear amount of the sliding bearing to be measured after it operates for a certain period of time. If the wear amount meets the requirements, continue to repeat step S2; if the wear amount does not meet the requirements, proceed to step S3; S3: Draw the bearing capacity curve of the sliding bearing to be measured in a certain kind of oil and at a certain speed according to steps S1 and S2.

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