Quantitative grease supply device for bearing

Abstract

According to the technical scheme, the quantitative grease supply device is characterized by comprising a proportional valve, the proportional valve is provided with an oil cavity, a quantity limiting valve element is installed in the oil cavity, a long-strip-shaped stepped valve element is fixed to the center of the quantity limiting valve element, the stepped valve element comprises an extending part, and the extending part extends out of the oil cavity in a sliding sealing mode; the diameter of the limiting valve element is larger than that of the stepped valve element. The oil cavity is provided with an inlet / outlet, the inlet / outlet is provided with a control valve, the control valve comprises an oil inlet hole and an oil outlet hole which are controlled by a switch, and the oil inlet hole and the oil outlet hole are communicated with the inlet / outlet; the proportional valve is provided with a limiting column for limiting the extending amount of the extending part through a barrier, and the grease filling amount can be accurately controlled.

Description

Technical Field

[0001] The present invention relates to the field of bearing processing, and more specifically, to a quantitative grease supply device for a bearing. Background Art

[0002] During the processing of the bearing, grease needs to be added to the ball, and then the side of the bearing is sealed with a dust cover or a sealing ring. For smaller precision bearings, the amount of grease added has higher precision requirements. The amount of grease injected into the bearing is within 10mg, and the positive and negative errors cannot be greater than 2mg. It belongs to the grease injection of ultra-micro bearings; the reason for the high grease injection accuracy is that after the bearing is processed, it needs to be inspected to see if it is qualified for assembly. One of the inspection indicators is whether there are missing balls, and the inspection method is to weigh the bearing after counting. If the difference between the weighed number and the counted value is within the error range, it means it is qualified. However, this type of inspection method has extremely high requirements for the amount of grease injected, because the amount of grease injected must be standardized to ensure that the data after the test can be used as inspection data. If the amount of grease injected each time is different, it will affect the final weighing inspection link of the bearing.

[0003] For a ball with a bearing diameter of 1 mm and a material of GCr15, its density is about 7.8 g / cm 3 In this case, the volume of each ball is approximately 0.0005236 cm 3 ; Therefore, the weight of each ball is approximately: 0.0005236cm 3 *7.8g / cm 3 =0.00408408g≈4.08mg;

[0004] Therefore, for bearings with grease injection within 10mg, the weight error of the grease cannot exceed half of the ball weight, and the grease injection error cannot exceed plus or minus 2mg to meet the bearing load inspection and judgment requirements;

[0005] Therefore, a supply device is needed that can accurately control the amount of lubricating grease filled each time. Summary of the invention

[0006] The purpose of the present invention is to provide a grease quantitative supply device for a bearing, which can accurately control the grease filling amount.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions:

[0008] A grease quantitative supply device for a bearing comprises: a quantitative valve, which is provided with an oil chamber, a limiting valve chamber and an air chamber which are connected in sequence, and the oil chamber is used for inputting grease and outputting grease; a valve core assembly, which is provided with a stepped valve core, a limiting valve core and a pneumatic piston which are fixed in sequence, the limiting valve core seal slides in the limiting valve chamber to form a partition seal for the oil chamber and the air chamber, the end faces of the stepped valve core are all fixed on the end faces of the limiting valve core and the two are arranged in parallel, the cross section of the stepped valve core is smaller than the cross section of the limiting valve core, when the stepped valve core slides from the oil chamber into the limiting valve chamber, a quantitative oil injection chamber is formed between the sliding part of the stepped valve core and the limiting valve chamber, and the cross-sectional area range of the quantitative oil injection chamber is 8-10 square millimeters; the quantitative valve has a positioning assembly for adjusting the sliding stop position of both ends of the valve core assembly, the positioning assembly is provided with an adjusting stud for adjusting the spacing between the valve core assemblies, and the pitch of the adjusting stud is ≦1 millimeter.

[0009] Preferably, the positioning assembly includes a piston rod sealingly sliding in the air cavity, and after the pneumatic piston moves to the bottom in the direction of the adjusting stud, the piston rod abuts between the pneumatic piston and the adjusting stud.

[0010] Preferably, the positioning assembly includes an extension portion located on the step valve core, the extension portion extends out of the oil chamber in a sliding sealed manner, the metering valve is provided with a limit column for blocking and limiting the extension amount of the extension portion, a screw sleeve is installed on the outside of the metering valve, the limit column is threadedly connected to the screw sleeve, and the axial direction of the limit column points to the extension portion.

[0011] Preferably, the diameter of the limited valve core is 6 mm, the upper deviation is -0.01 mm, and the lower deviation is -0.03 mm; the diameter of the step valve core is 5 mm, the upper deviation is 0.15 mm, and the lower deviation is 0.1 mm; the material of the valve core assembly is GCr15.

[0012] Preferably, the limiting valve core is provided with a sealing ring.

[0013] Preferably, the cross-sectional areas of the oil cavity and the air cavity are both larger than the cross-sectional area of ​​the limiting valve cavity.

[0014] Preferably, the oil chamber is provided with an inlet and an outlet, and a control valve is installed at the inlet and the outlet. The control valve includes an oil inlet hole and an oil outlet hole controlled by a switch, and both the oil inlet hole and the oil outlet hole are connected to the inlet and the outlet.

[0015] Preferably, the oil inlet hole of the control valve is connected to a grease filling bottle, which is provided with a constant-pressure oil pushing piece, which gives a constant pressure to the grease in the grease filling bottle, and the constant pressure range is 2-4MPa; the grease filling bottle is connected to a grease pump for conveying grease, and a switch valve is provided between the grease filling bottle and the grease pump.

[0016] Preferably, the oil outlet hole is connected to an oil outlet pipe, and the oil outlet pipe is connected to a filter assembly.

[0017] Preferably, an elastic member for reducing the impact force of the protruding part is provided in the screw sleeve, and the end of the protruding part is truncated cone-shaped; a stopper is fixed to the protruding part, and an embedding groove is provided on the end face of the elastic member; when the protruding part extends into the elastic member, the stopper is embedded in the embedding groove to compress the elastic member.

[0018] In summary, the present invention has one of the following beneficial effects:

[0019] (1) The stepped valve core design is used to control the amount of grease injected. The amount of grease injected is controlled to be less than 10 mg when the adjustment stud is rotated one circle, and the error of quantitative grease injection is controlled to be within 2 mg. The stopper limit design of the extension is adopted to prevent the end of the valve core from colliding with the inside of the valve body, so that impurities after the end of the valve core is worn will not enter the grease.

[0020] (2) The combination of the screw sleeve and the limit column has two functions. The rotation of the limit column can facilitate the position adjustment installation so that the collision position of the extension part is accurate. When the extension part increases the wear due to long-term collision, the position of the limit column can be rotated to adjust the position of the extension part so that the extension part can be restored to the accurate position.

[0021] (3) The position adjustment of the piston rod by the stud can realize the adjustment of the amount of grease discharged by the metering valve each time. The amount of grease discharged by the metering valve can be controlled and adjusted. After adjustment, the amount of grease discharged is stable and accurate.

[0022] (4) The high-precision matching of the limited valve core and the limited valve cavity ensures that both have good sealing performance even when the sealing ring is not installed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of a supply device in an embodiment;

[0024] Figure 2 Schematic diagram of the connection relationship between the quantitative valve and the control valve in the embodiment;

[0025] Figure 3 is a cross-sectional view of the quantitative valve when the stepped valve core in the embodiment abuts against the limit post;

[0026] Figure 4 is a cross-sectional view of the quantitative valve when the stepped valve core is separated from the limit post in the embodiment;

[0027] Figure 5 yes Figure 4 Enlarged view of part A in the middle;

[0028] Figure 6 is a longitudinal sectional view of the valve core assembly in the embodiment;

[0029] Figure 7 Schematic diagram of the positions of the oil chamber, the limiting valve chamber and the air chamber in the quantitative valve in the embodiment;

[0030] Figure 8 is a schematic diagram of the structure of the filter assembly in the embodiment;

[0031] Fig. 9 is a partial cross-sectional view of a metering valve with an elastic member installed in an embodiment;

[0032] Fig.10 Schematic diagram of the structure of the elastic member in the embodiment.

[0033] In the figure:

[0034] 1. Dosing valve; 11. Oil chamber; 12. Inlet and outlet; 13. Air chamber; 14. Piston rod; 15. Stud; 16. Limiting valve chamber;

[0035] 20. Pneumatic piston; 21. Limit valve core; 22. Step valve core; 23. Extension part;

[0036] 3. Control valve; 31. Oil inlet hole; 32. Oil outlet hole;

[0037] 41. Limiting column; 42. Screw sleeve;

[0038] 51. Grease filling bottle; 52. Constant pressure oil pusher; 53. Grease pump; 54. Oil outlet pipe; 55. Oil inlet pipe; 56. Original barrel; 57. Switch valve;

[0039] 61. elastic member; 62. stopper; 63. groove;

[0040] 7. Filter assembly; 71. Filter screen;

[0041] 81. Sealing ring. DETAILED DESCRIPTION

[0042] The following is combined with Figure 1-10 The present invention is described in further detail.

[0043] Embodiment 1, a bearing grease quantitative supply device, referring to Figure 1 , including a metering valve 1 and a control valve 3, the control valve 3 is a reversing valve; the control valve 3 inputs grease into the metering valve 1 for grease metering, and the grease after metering is output from the control valve 3 to the oil outlet pipe 54, and an oil outlet filter component 7 is installed at the end of the oil outlet pipe 54.

[0044] The control valve 3 is connected to a grease injection bottle 51 through an oil inlet pipe 55; a constant pressure oil pusher 52 is provided below the grease injection bottle 51, and both are installed on the frame; the grease injection bottle 51 is connected to a grease pump 53 for outputting grease, and the grease pump 53 is connected to a barrel 56 loaded with grease, and the grease pump 53 pumps oil from the barrel 56;

[0045] A pipeline is connected between the inlet of the grease filling bottle 51 and the outlet of the grease pump 53, and a switch valve 57 is installed on the pipeline; the switch valve 57 can be a ball valve or a stop valve; in other embodiments, the switch valve 57 can also be a one-way valve that only flows to the grease filling bottle 51, and the one-way valve can reduce the switching operation process of employees.

[0046] The above is the overall layout of the device, and its working principle is:

[0047] The switch valve 57 is opened, the grease pump 53 fills the grease filling bottle 51 with grease, and then the switch valve 57 is closed; the constant pressure oil pushing member 52 is a constant pressure thrust cylinder, which maintains a constant pressure to push the grease in the grease filling bottle 5, and the pressure is 3MPa; after the grease passes through the metering valve 1, the grease within 10mg is output.

[0048] Since the pressure generated by the oil pump 53 is above 10MPa, it will generate a relatively large pressure on the grease; if the grease pump 53 acts directly on the metering valve 1, the metering valve 1 will be subjected to a continuous large pressure. However, in the actual oil injection process, there will be processes such as bearing detection that cause the oil injection action to pause. During the pause of the bearing transmission, the grease pump 53 provides a continuous injection pressure to the metering valve 1. The sealing performance of the sealing ring of the metering valve 1 will be weakened after long-term use. Under the long-term high pressure during the pause, excess grease will penetrate into the end of the oil outlet pipe 54 along the sealing ring. When the oil injection action is restarted, the first oil injection amount is the sum of the standard oil amount plus the excess grease that seeps out, resulting in the injection of grease exceeding the standard.

[0049] Therefore, in order to overcome the problem of excess grease seepage under high grease pressure, this design uses a combination of a grease filling bottle 51 and a constant pressure oil pushing piece 52 to give a smaller constant pressure thrust to a metering valve 1; the rod of the constant pressure oil pushing piece 52 directly acts on the piston of the grease filling bottle 51, so that the grease filling bottle 51 pushes the grease at a smaller constant pressure. This design uses a constant pressure of 3MPa to push the grease to the metering valve 1 to achieve the purpose of stable oil output.

[0050] Reference Figure 2-Figure 8 Describe below.

[0051] The structures of the quantitative valve 1 and the control valve 3 are described below;

[0052] Reference Figure 7 The metering valve 1 has an oil chamber 11 , a limiting valve chamber 16 and an air chamber 13 connected in sequence. The cross-sectional areas of the oil chamber 11 and the air chamber 13 are both larger than the cross-sectional area of ​​the limiting valve chamber 16 .

[0053] The metering valve 1 includes an oil delivery body and a cylinder, which are fixed with screws, and the oil chamber 11 and the limiting valve chamber 16 are located in the oil delivery body, and the air chamber 13 is located in the cylinder. Therefore, after removing the cylinder, the valve core assembly can be taken out of the oil delivery body and the valve core assembly can be replaced relative to the oil delivery body.

[0054] Reference Figure 2 and Figure 6 A valve core assembly is installed in the quantitative valve 1; the valve core assembly comprises a stepped valve core 22, a limiting valve core 21 and a pneumatic piston 20 which are fixed in sequence.

[0055] Reference Figure 3 and Figure 6 and Figure 7 , the pneumatic piston 20 is sealed and slidable in the air chamber 13, and the cylinder is connected with an air pipe for pushing the pneumatic piston 20 to move back and forth;

[0056] The limiting valve core 21 seals and slides in the limiting valve cavity 16 to form a partition seal for the oil cavity 11 and the air cavity 13;

[0057] The stepped valve core 22 is in the oil chamber 11, and both the stepped valve core 22 and the limited valve core 21 are cylindrical structures, and the cross section of the stepped valve core 22 is smaller than the cross section of the limited valve core 21;

[0058] The axes of the stepped valve core 22 , the limiting valve core 21 and the pneumatic piston 20 are on the same straight line, and one end surface of the stepped valve core 22 is completely fitted and fixed to one end surface of the limiting valve core 21 .

[0059] Obviously, when the pneumatic piston 20 moves back and forth along the axis, the entire valve core assembly moves back and forth synchronously.

[0060] In this solution, the material of the valve core assembly is GCr15.

[0061] The diameter of the limited valve core 21 is 6 mm, the upper deviation is -0.01 mm, and the lower deviation is -0.03 mm;

[0062] The aperture of the limiting valve chamber 16 is 6 mm, the upper deviation is 0.03 mm, and the lower deviation is 0.01 mm;

[0063] The diameter of the stepped valve core 22 is 5 mm, the upper deviation is 0.15 mm, and the lower deviation is 0.1 mm;

[0064] When the stepped valve core 22 slides from the oil chamber 11 into the limited valve chamber 16, a quantitative oil injection chamber 11 is formed between the stepped valve core 22 and the limited valve chamber 16. The cross-sectional area of ​​the quantitative oil injection chamber 11 is (R 2 -r 2 )π=(9-6.25)π=8.63㎜2;

[0065] The quantitative valve 1 has a positioning assembly for adjusting the sliding stop position of both ends of the valve core assembly. The positioning assembly is provided with an adjusting stud 15 for adjusting the spacing of the valve core assembly. The adjusting stud 15 adopts an M8 fine-thread stud 15 with a pitch of 1 mm.

[0066] Adjusting stud 15 rotates one circle to increase the quantitative volume to 8.63mm 3 ;

[0067] The density of grease is 0.93mg / mm 3 ;

[0068] It can be obtained that when the adjusting stud 15 rotates one circle, the amount of grease injected by the quantitative valve 1 is adjusted to 8.02 mg;

[0069] A graduated circle is provided on the outer circle of the adjusting stud 15, and one circle is divided into 8 equal parts, so that one graduated index represents 1 mg, so as to adjust the injection amount of grease within 10 mg. In other embodiments, an adjusting stud 15 with a pitch of 0.5 mm or 0.75 mm may be used.

[0070] The positioning assembly includes a piston rod 14 sealingly sliding in the air cavity 13. After the pneumatic piston 20 moves to the bottom in the direction of the adjusting stud 15, the piston rod 14 abuts between the pneumatic piston 20 and the adjusting stud 15. The adjusting stud 15 is threadedly connected with a nut for locking and positioning.

[0071] The air chamber 13 is provided with a protruding piston rod 14, the cylinder is provided with a guide hole, the piston rod 14 slides through the guide hole, and a sealing ring is provided between the guide hole and the piston rod 14;

[0072] One end of the piston rod 14 points to the pneumatic piston 20 , and the other end of the piston rod 14 points to the adjusting stud 15 ; the distance between the adjusting stud 15 and the piston rod 14 can be adjusted to adjust the pushing stroke of the limiting valve core 21 .

[0073] The positioning assembly includes an extension portion 23 located on the stepped valve core 22, and the extension portion 23 is an extension portion of the stepped valve core 22;

[0074] The protruding portion 23 extends out of the oil chamber 11 in a sliding sealed manner. The metering valve 1 is provided with a limit column 41 for blocking and limiting the extension amount of the protruding portion 23. A screw sleeve 42 is installed outside the metering valve 1. The limit column 41 is threadedly connected to the screw sleeve 42, and the axial direction of the limit column 41 points to the protruding portion 23.

[0075] The rotation of the limit post 41 can adjust the distance between the limit post 41 and the extension part 23; the extension part 23 extends out of the oil chamber 11 in a sliding sealing manner, and the opening of the oil chamber 11 is provided with a sealing assembly composed of a plurality of staggered sealing rings, so the extension part 23 slides in and out of the sealing assembly position without causing leakage.

[0076] The control valve 3 is fixed on the metering valve 1 by screws, and the control valve 3 controls the grease in and out action of the metering valve 1;

[0077] Reference Figure 2-Figure 5 The oil chamber 11 of the quantitative valve 1 is provided with an inlet and outlet 12, and the inlet and outlet 12 is connected to the control valve 3;

[0078] Reference Figure 1 and Figure 8 The control valve 3 includes an oil inlet hole 31 and an oil outlet hole 32 controlled by switches, and both the oil inlet hole 31 and the oil outlet hole 32 are connected to the inlet and outlet 12; the oil inlet hole 31 of the control valve 3 is connected to a grease injection bottle 51 through an oil inlet pipe 55; the oil outlet hole 32 of the control valve 3 is connected to an oil outlet pipe 54, and the outlet of the oil outlet pipe 54 is downward; a filter assembly 7 is installed at the end of the oil outlet pipe 54. A filter net 71 is provided inside the filter assembly 7.

[0079] The control valve 3 is a reversing valve, and its working process is as follows.

[0080] First, the grease is input into the grease filling bottle 51, the oil inlet hole 31 of the control valve 3 is opened, and the oil outlet hole 32 of the control valve 3 is closed. At this time, the grease enters the oil chamber 11 of the metering valve 1;

[0081] Then, the oil inlet 31 of the control valve 3 is closed, the oil outlet 32 ​​of the control valve 3 is opened, and the piston of the metering valve 1 moves, so that the grease in the oil chamber 11 flows from the oil outlet 32 ​​to the oil outlet pipe 54 for discharge, completing the oil filling action.

[0082] Embodiment 2, a bearing grease quantitative supply device, which is different from embodiment 1, referring to Figure 9-10 An elastic member 61 for reducing the impact force of the extension part 23 is provided in the screw sleeve 42, and the end of the extension part 23 is truncated cone-shaped; a stopper 62 is fixed to the extension part 23, and a groove 63 is provided on the end surface of the elastic member 61; when the extension part 23 extends into the elastic member 61, the stopper 62 is embedded in the groove 63 to compress the elastic member 61.

[0083] An elastic member 61 for reducing the impact force of the extension part 23 is provided in the screw sleeve 42. The end of the extension part 23 is truncated cone-shaped. The purpose of the truncated cone-shaped design is to increase the end surface area of ​​the extension part 23 from small to large, so that the extension part 23 can contact and be squeezed with the elastic member 61 first.

[0084] The end surface of the extension portion 23 has the smallest area and will not contact the elastic member 61 . The extension portion 23 will not affect the collision between the extension portion 23 and the limiting column 41 .

[0085] The elastic member 61 is a rubber sleeve, and the end surface of the extension portion 23 penetrates into the rubber sleeve. In other embodiments, the elastic member 61 is a spring, and the end surface of the extension portion 23 penetrates into the spring.

[0086] A stopper 62 is fixed to the extension portion 23 , and an embedding groove 63 is formed on the end surface of the elastic member 61 ; when the extension portion 23 extends into the elastic member 61 , the stopper 62 is embedded in the embedding groove 63 to compress the elastic member 61 .

[0087] The primary purpose of the elastic member 61 is to provide buffering. The supply device needs to refuel once per second, and the step valve core 22 needs to impact more than 86,000 times a day. This high-frequency impact will accelerate the wear of the step valve core 22, shortening the period of quantitative position deviation of the step valve core 22. However, the number of impacts cannot be optimized, but the impact force can be reduced. The design of the elastic member 61 is to convert kinetic energy into elastic potential energy. The step valve core 22 still needs to collide with the limit column 41 to achieve the standard amount of refueling, but due to the reduction in impact force, the wear can be greatly reduced, so that the period of the step valve core 22 being in a cheap position due to wear can be extended.

[0088] The process is that the metering valve 1 is in oil discharge action, the grease injection action, under the push of the cylinder, the extension part 23 and the limit column 41 collide, and the elastic member 61 buffers;

[0089] The metering valve 1 performs a quantitative oil storage action, stores quantitative oil, and exhausts the cylinder. Under the push of the grease pressure, the extension part 23 retreats. At this time, the compressed elastic member 61 assists in pushing the extension part 23 to store quantitative oil. Therefore, the movement of the extension part 23 to the right is achieved by relying on the push of the grease and the elastic force of the elastic member 61.

[0090] Secondly, rotation occurs during the extension and retraction process, which will cause wear of the sealing ring at the piston. The design of the groove 63 and the block 62 in this design reduces the amplitude and situation of the rotation of the stepped valve core 22 during extension and retraction, thereby extending the life of the piston in the metering valve 1. In addition, the advantage of this design is that the rotation is limited to the outside of the valve body, and such a design has the advantages of simple processing and convenient maintenance.

[0091] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A bearing grease quantitative supply device, characterized in that it has: The metering valve (1) is provided with an oil chamber (11), a limiting valve chamber (16) and an air chamber (13) which are connected in sequence, and the oil chamber (11) is used for inputting grease and outputting grease; The valve core assembly comprises a stepped valve core (22), a limiting valve core (21) and a pneumatic piston (20) which are fixed in sequence. The limiting valve core (21) is sealingly slidable in the limiting valve chamber (16) to form a partition seal for the oil chamber (11) and the air chamber (13). The end faces of the stepped valve core (22) are all fixed to the end faces of the limiting valve core (21) and the two are arranged in parallel. The cross section of the stepped valve core (22) is smaller than the cross section of the limiting valve core (21). When the stepped valve core (22) slides from the oil chamber (11) into the limiting valve chamber (16), a quantitative oil injection chamber (11) is formed between the sliding portion of the stepped valve core (22) and the limiting valve chamber (16), and the cross-sectional area of ​​the quantitative oil injection chamber (11) is in the range of 8-10 square millimeters; The quantitative valve (1) has a positioning assembly for adjusting the sliding stop position of the two ends of the valve core assembly. The positioning assembly is provided with an adjusting stud (15) for adjusting the spacing of the valve core assembly. The pitch of the adjusting stud (15) is ≤1 mm.

2. The grease quantitative supply device for a bearing according to claim 1, characterized in that: The positioning assembly includes a piston rod (14) sealingly sliding in the air cavity (13); After the pneumatic piston (20) moves to the bottom in the direction of the adjusting stud (15), the piston rod (14) abuts between the pneumatic piston (20) and the adjusting stud (15).

3. The grease quantitative supply device for a bearing according to claim 2, characterized in that: The positioning assembly comprises a protruding portion (23) located on a stepped valve core (22), the protruding portion (23) protruding out of an oil chamber (11) in a sliding and sealing manner, the metering valve (1) is provided with a limiting column (41) for blocking and limiting the protruding amount of the protruding portion (23), a screw sleeve (42) is installed outside the metering valve (1), the limiting column (41) is threadedly connected to the screw sleeve (42), and the axial direction of the limiting column (41) points to the protruding portion (23).

4. The grease quantitative supply device for a bearing according to claim 1, characterized in that: The diameter of the limiting valve core (21) is 6 mm, the upper deviation is -0.01 mm, and the lower deviation is -0.03 mm; The diameter of the stepped valve core (22) is 5 mm, the upper deviation is 0.15 mm, and the lower deviation is 0.1 mm; The material of the valve core assembly is GCr15.

5. The grease quantitative supply device for a bearing according to claim 1, characterized in that: Its characteristics are: The limiting valve core (21) is provided with a sealing ring (81).

6. The grease quantitative supply device for a bearing according to claim 1, characterized in that: Its characteristics are: The cross-sectional areas of the oil chamber (11) and the air chamber (13) are both larger than the cross-sectional area of ​​the limiting valve chamber (16).

7. The grease quantitative supply device for a bearing according to claim 1, characterized in that: The oil chamber (11) is provided with an inlet and outlet (12), and a control valve (3) is installed at the inlet and outlet (12). The control valve (3) comprises an oil inlet hole (31) and an oil outlet hole (32) controlled by switches, and both the oil inlet hole (31) and the oil outlet hole (32) are connected to the inlet and outlet (12).

8. The grease quantitative supply device for a bearing according to claim 7, characterized in that: The oil inlet hole (31) of the control valve (3) is connected to a grease injection bottle (51), and the grease injection bottle (51) is provided with a constant pressure oil pushing member (52). The constant pressure oil pushing member (52) provides a constant pressure to the grease in the grease injection bottle (51), and the constant pressure range is 2-4 MPa; The grease filling bottle (51) is connected to a grease pump (53) for conveying grease, and a switch valve (57) is provided between the grease filling bottle (51) and the grease pump (53).

9. The grease quantitative supply device for a bearing according to claim 7, characterized in that: The oil outlet hole (32) is connected to an oil outlet pipe (54), and the oil outlet pipe (54) is connected to a filter assembly (7).

10. The grease quantitative supply device for a bearing according to claim 3, characterized in that: An elastic member (61) for reducing the impact force of the extension portion (23) is arranged inside the screw sleeve (42); the end of the extension portion (23) is in a truncated cone shape; A stopper (62) is fixed to the extension portion (23), and an embedding groove (63) is formed on the end surface of the elastic member (61); When the protruding portion (23) extends into the elastic member (61), the stopper (62) is embedded in the embedding groove (63) to compress the elastic member (61).

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