Lubricating unit capable of firstly exhausting air and preventing plunger from returning and sucking back through transition oil cavity

Abstract

The utility model discloses a lubricating unit capable of firstly exhausting air and transitioning an oil cavity to prevent a plunger from returning and sucking back, which belongs to the technical field of lubricating pumps and comprises a pump body and a stepped plunger, the oil cavity is formed in the pump body, and a grease supplementing one-way valve, an exhaust one-way valve and a grease discharge port which are communicated with the oil cavity are arranged on the side wall of the pump body. A communicating opening penetrates through the side wall of the top of the pump body. An oil channel is formed in the stepped plunger, a grease discharging groove communicating with the oil channel penetrates through the side wall of the stepped plunger, and an annular groove is formed in the peripheral side wall of the stepped plunger in the circumferential direction. When the stepped plunger is located at the propelling starting point, the grease discharging groove, the grease discharging opening, the exhaust one-way valve and the grease supplementing one-way valve are sequentially arranged in the propelling direction of the plunger, and the communicating opening communicates with the exhaust one-way valve through the annular groove. In the gradual propelling process of the stepped plunger, the stepped plunger pushes grease in the oil cavity, and part of gas at the top of the oil cavity is pressurized, enters the exhaust one-way valve through the annular groove and is exhausted from the exhaust one-way valve.

Description

Technical Field

[0001] The utility model belongs to the technical field of lubrication pumps, in particular to a lubrication unit which first exhausts air and a transition oil chamber to prevent a plunger from returning and sucking back. Background Art

[0002] In order to improve the service life, efficiency, energy conservation and environmental protection of heavy equipment, all kinds of heavy equipment and vehicles have adopted automatic lubrication systems. The existing automatic lubrication system is mainly composed of an integrated grease supply unit and a distributor. The original intention of the design of this lubrication system is to replenish the grease into the bearing at a fixed time and quantitatively according to the loss of grease in the bearing.

[0003] One of the important defects of the above lubrication system is that the lubrication pump of the integrated grease supply unit is a non-follow-up self-priming neutral-gear squeeze-in plunger pump. Its plunger cannot absorb grease as it moves back during the return stroke after the grease discharge stroke and before it leaves the cylinder body. The continuously expanding volume between the plunger and the cylinder body will inevitably generate negative pressure and then suck back part of the grease that has been discharged into the grease delivery channel, reducing the amount of grease that has been discharged by the plunger during the grease discharge stroke; the sucked back grease also occupies part of the space in the cylinder body, reducing the amount of grease squeezed into the lubrication pump. The sucked back amount is roughly the balance point between the liquid resistance of the sucked back grease flowing through the pipeline and the negative pressure.

[0004] The control mode of the prior art is operating time and interval time control: within the set operating time, the reduction in the amount of grease discharged by the plunger at a single time will inevitably lead to insufficient grease supply in the system during each operating time, resulting in insufficient grease in some bearings, which will cause insufficient lubrication of the bearings and reduce the service life. For the progressive multi-point automatic lubrication system with a wide range of applications, the first round is insufficient grease supply to the rear lubrication points, and the second round is insufficient grease supply to the front lubrication points, and the cycle continues. The second disadvantage of the prior art is that the lubrication system will mix some gas when injecting and sucking grease, and may also suck a small amount of gas during operation. This part of gas will occupy part of the space of the cylinder and grease, resulting in a decrease in the amount of grease pumped out. Utility Model Content

[0005] The utility model aims to provide a lubrication unit which first exhausts air and a transition oil chamber to prevent the plunger from returning and sucking back, so as to solve the problems raised in the prior art.

[0006] Provided is a lubrication unit that first exhausts air and transitions the oil chamber to prevent the plunger from returning and sucking back, comprising:

[0007] A pump body, wherein an oil cavity is formed inside the pump body, a grease replenishing one-way valve, an exhaust one-way valve and a grease discharge port connected to the oil cavity are arranged on the side wall of the pump body, and a communication port is penetrated in the top side wall of the pump body;

[0008] A stepped plunger, the stepped plunger is movably mounted inside the oil chamber so that the oil chamber forms a closed space, an oil passage is formed inside the stepped plunger, a grease discharge groove connected to the oil passage is penetrated through the side wall of the stepped plunger, and an annular groove is opened on the outer side wall of the stepped plunger along the circumferential direction;

[0009] When the stepped plunger is located at the starting point of advancement, the grease discharge groove, grease discharge port, exhaust check valve and grease replenishment check valve are arranged in sequence along the advancement direction of the plunger, and the communication port is connected to the exhaust check valve through the annular groove.

[0010] As a further embodiment of the utility model: when the stepped plunger is pushed forward from the starting point of advancement, the connecting port and the annular groove are disconnected from the connecting state, and the grease discharge groove and the grease discharge port enter the connecting state. This structure realizes the independence of the exhaust mode and the grease discharge mode, and can quickly enter the grease discharge state after leaving the exhaust state, without wasting the stroke of the stepped plunger.

[0011] As a further embodiment of the utility model: the stepped plunger includes a small cylinder and a large cylinder arranged in sequence along the travel direction. When the plunger is pushed from the starting point of advancement, a main oil chamber and a secondary oil chamber are respectively formed between the two ends of the large cylinder and the pump body; the oil channel includes an upper oil channel and a lower oil channel. The upper oil channel connects the main oil chamber with the secondary oil chamber, and the lower oil channel connects the secondary oil chamber with the grease drainage groove.

[0012] When the plunger is pushed forward, the large cylinder pushes the grease in the main oil chamber from the upper oil channel to the auxiliary oil chamber, and the grease in the auxiliary oil chamber then enters the grease discharge groove from the lower oil channel and is discharged from the grease discharge port. When the stepped plunger retreats, due to the negative pressure in the main oil chamber, the grease replenishment check valve replenishes grease into the main oil chamber to balance the negative pressure. At the same time, when the large cylinder retreats and squeezes the grease in the auxiliary oil chamber, part of the grease in the auxiliary oil chamber and the upper oil channel is squeezed back into the main oil chamber under the influence of the negative pressure of the main oil chamber. However, since the upper oil channel, the auxiliary oil chamber and the lower oil channel increase the grease stroke, the grease reflux resistance increases, so the amount of grease in the reflux part is extremely small, thereby eliminating the negative pressure suction effect generated by the grease discharge port when the stepped plunger returns.

[0013] As a further embodiment of the utility model: the grease replenishing one-way valve includes a valve seat, a grease replenishing valve ball, a first spring, a grease replenishing inlet and a grease replenishing outlet. The grease replenishing valve ball is arranged inside the valve seat and is stopped at the grease replenishing inlet by the first spring. The grease replenishing outlet is opened on the side wall of the valve seat. When the stepped plunger moves, the inside of the oil chamber is in a positive pressure state, and the first spring applies a thrust to the grease replenishing valve ball to block the grease replenishing inlet to prevent grease from being discharged from the grease replenishing inlet. When the stepped plunger retreats, the inside of the oil chamber is in a negative pressure state, and the pressure difference at both ends of the grease replenishing valve ball drives the grease replenishing valve ball to overcome the thrust of the first spring and disengage from the grease replenishing inlet, so that grease can enter from the grease replenishing inlet and be discharged from the grease replenishing outlet into the oil chamber, eliminating the negative pressure of the oil chamber.

[0014] As a further embodiment of the utility model: a spring seat is provided at the bottom of the valve seat, and the spring seat is provided with an oil pressure balance port connected to the oil chamber. The spring seat is used to install the first spring. The oil pressure balance port can exchange grease with the oil chamber. When the oil chamber is in a positive pressure state, the grease enters the valve seat from the oil pressure balance port and pushes the grease replenishing valve ball together with the first spring; when the oil chamber is in a negative pressure state, the grease replenishing valve ball overcomes the thrust of the first spring and pushes the grease in the valve seat out of the oil pressure balance port, thereby achieving pressure balance between the valve seat and the oil chamber.

[0015] As a further embodiment of the utility model: the exhaust check valve comprises an exhaust pipe seat, a second spring and an exhaust valve ball, wherein the second spring is clamped between the exhaust pipe seat and the exhaust valve ball. When gas enters the exhaust check valve from the annular groove, the gas pushes the exhaust valve ball to overcome the thrust of the second spring to compress the second spring, and the gas can then enter the exhaust pipe seat and be discharged from the exhaust pipe seat. When the lubrication unit exits the exhaust state, the second spring continues to push the exhaust valve ball to block the port of the annular groove to prevent external gas from entering the annular groove.

[0016] As a further embodiment of the utility model: the grease discharge port is a plurality of output ports through a plurality of small holes at intervals. When the stepped plunger moves, the grease discharge groove gradually communicates with each output port in sequence, and grease is discharged from each output port to supply lubricating oil to different lubrication points.

[0017] As a further embodiment of the utility model: the end of the pump body away from the stepped plunger is threadedly connected with a screw plug. The screw plug can be used to block the pump body, and the screw plug and the pump body can be separated to process the inside of the pump body.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. When the stepped plunger is pushed forward from the starting point, the grease discharge groove and the grease discharge port are not yet in a connected state, and the grease cannot be discharged from the grease discharge port, but at this time the connecting port is connected to the exhaust check valve through the annular groove. During the gradual advancement of the stepped plunger, the stepped plunger pushes the grease in the oil chamber, and the gas pressure at the top of the oil chamber enters from the connecting port, enters the exhaust check valve through the annular groove, and is discharged from the exhaust check valve, realizing the exhaust action before grease discharge.

[0020] 2. As the stepped plunger continues to advance, the annular groove, the connecting port and the exhaust one-way valve gradually lose the connection state. When the exhaust state is about to be lost, the grease discharge groove and the grease discharge port gradually enter the connection state. At this time, as the stepped plunger advances, the grease enters the oil channel of the stepped plunger under the action of internal pressure, and enters the grease discharge port from the grease discharge groove connected to the oil channel, and is finally discharged from the grease discharge port. In this application, the exhaust system and the grease discharge system are integrated with each other, but operate independently of each other, and the switching between the two modes can be achieved only by the movement of the stepped plunger. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0022] Figure 1 The working state of the lubrication unit of the utility model is shown in FIG. Figure 1 ;

[0023] Figure 2 The working state of the lubrication unit of the utility model is shown in FIG. Figure 2 ;

[0024] Figure 3 This is a schematic diagram of the structure of the grease replenishing one-way valve provided by the utility model;

[0025] Figure 4 This is a structural schematic diagram of the exhaust one-way valve provided by the utility model.

[0026] In the figure: 1. pump body; 11. oil chamber; 111. main oil chamber; 112. auxiliary oil chamber; 12. grease replenishing one-way valve; 121. valve seat; 1211. spring seat; 1212. oil pressure balance port; 122. grease replenishing valve ball; 123. first spring; 124. grease replenishing inlet; 125. grease replenishing outlet; 13. exhaust one-way valve; 131. exhaust pipe seat; 132. second spring; 133. exhaust valve ball; 14. grease discharge port; 141. output port; 142. interval; 15. connecting port; 2. stepped plunger; 21. oil channel; 211. upper oil channel; 212. lower oil channel; 22. grease discharge groove; 23. annular groove; 24. small cylinder; 25. large cylinder; 3. screw plug. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0028] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0029] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially the same structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the drawings and the following description are provided to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0030] See also Figure 1-2 As shown, the lubrication unit for first exhausting air and transitioning the oil chamber to prevent the plunger from returning and sucking back in the embodiment of the utility model comprises a pump body 1 and a stepped plunger 2. An oil chamber 11 is formed inside the pump body 1. A grease replenishing one-way valve 12, an exhaust one-way valve 13 and a grease discharge port 14 communicating with the oil chamber 11 are arranged on the side wall of the pump body 1. A connecting port 15 is penetrated in the top side wall of the pump body 1. The stepped plunger 2 is movably mounted in the oil chamber 11 to form a closed space. An oil passage 21 is formed inside the stepped plunger 2. A grease discharge groove 22 communicating with the oil passage 21 is penetrated on the side wall of the stepped plunger 2. An annular groove 23 is opened in the circumferential direction on the outer side wall of the stepped plunger 2. When the stepped plunger 2 is located at the starting point of advancement, the grease discharge groove 22, the grease discharge port 14, the exhaust one-way valve 13 and the grease replenishing one-way valve 12 are arranged in sequence along the advancement direction of the stepped plunger 2, and the connecting port 15 is communicated with the exhaust one-way valve 13 through the annular groove 23.

[0031] The stepped plunger 2 acts as a core body to move forward and backward in the pump body 1. When the stepped plunger 2 moves forward, the volume of the oil chamber 11 at the moving end of the stepped plunger 2 decreases and the internal pressure is increased. When the stepped plunger 2 retreats, the volume of the oil chamber 11 at the moving end of the stepped plunger 2 increases and the internal pressure is reduced. The grease replenishing one-way valve 12 is arranged at the top of the oil chamber 11 at the moving end of the stepped plunger 2 in the pump body 1. When the oil chamber 11 is under negative pressure, the grease replenishing one-way valve 12 can automatically replenish grease to the oil chamber 11. The connecting port 15 is arranged inside the pump body 1 around the grease replenishing one-way valve 12, and is located at the top of the oil chamber 11, so that the gas input into the oil chamber 11 automatically gathers at the top of the oil chamber 11, which facilitates the connecting port 15 to discharge the gas and prevents grease from entering from the connecting port 15.

[0032] When the stepped plunger 2 moves from the starting point of advancement, the connecting port 15 is connected to the exhaust check valve 13 through the annular groove 23, while the grease discharge groove 22 and the grease discharge port 14 are not connected. As the stepped plunger 2 advances, the oil chamber 11 is pressurized and the gas at the top is pressed in from the connecting port 15. The gas flows through the annular groove 23 and enters the exhaust check valve 13 and is discharged from the exhaust check valve 13. After the stepped plunger 2 continues to advance, the annular groove 23 is disconnected from the connecting port 15 and the exhaust check valve 13, and the grease discharge groove 22 and the grease discharge port 14 are connected. After the oil chamber 11 is pressurized, it is no longer exhausted. Instead, as the stepped plunger 2 advances, the grease enters the oil passage 21 and enters the grease discharge port 14 through the grease discharge groove 22, and is output from the grease discharge port 14 to the lubrication point. When the stepped plunger 2 retreats from the end of the stroke, negative pressure is generated in the oil chamber 11, and the grease replenishment check valve 12 automatically replenishes grease into the oil chamber 11 under the action of the pressure difference. When the annular groove 23 passes through the communication port 15 and the exhaust one-way valve 13 again, external air will not enter the oil chamber 11 due to the effect of the one-way valve.

[0033] When the stepped plunger 2 is pushed forward from the starting point of advancement and the connecting port 15 and the annular groove 23 are disconnected from the connecting state, the grease discharge groove 22 and the grease discharge port 14 are connected, so that the exhaust state is quickly switched to the grease discharge state to eliminate the useless advancement stroke of the stepped plunger 2.

[0034] Furthermore, the stepped plunger 2 includes a small cylinder 24 and a large cylinder 25 arranged in sequence along the direction of travel, the outer diameter of the large cylinder 25 is larger than the outer diameter of the small cylinder 24, and the pump body 1, the large cylinder 25 and the small cylinder 24 are fitted to form a stepped structure. When the stepped plunger 2 is pushed from the starting point of the push, an annular secondary oil chamber 112 is formed between the periphery of the small cylinder 24, the end of the large cylinder 25 and the pump body 1, and a main oil chamber 111 is formed between the end of the large cylinder 25 away from the small cylinder 24 and the pump body 1. The main oil chamber 111 is connected to the secondary oil chamber 112 through the upper oil passage 211, and the secondary oil chamber 112 is connected to the grease discharge groove 22 through the lower oil passage 212.

[0035] When the stepped plunger 2 moves forward, the large cylinder 25 squeezes the grease in the main oil chamber 111 and squeezes the grease from the upper oil channel 211 to the auxiliary oil chamber 112. After the grease fills the entire cavity of the auxiliary oil chamber 112, it enters the grease discharge groove 22 through the lower oil channel 212 and is finally discharged from the grease discharge port 14. When the stepped plunger 2 retreats, there is a negative pressure in the main oil chamber 111, so that the grease replenishment check valve 12 replenishes grease to the main oil chamber 111 to balance the negative pressure. At the same time, when the large cylinder 25 retreats and squeezes the grease in the auxiliary oil chamber 112, part of the grease in the auxiliary oil chamber 112 and the upper oil channel 211 is squeezed back into the main oil chamber 111 under the influence of the negative pressure of the main oil chamber 111. However, since the upper oil channel 211, the auxiliary oil chamber 112 and the lower oil channel 212 increase the stroke of the grease, it can be known from the principles of fluid mechanics that increasing the stroke will increase the grease flow loss due to the reflux liquid resistance. Therefore, the amount of grease in the reflux part is extremely small, thereby eliminating the negative pressure suction effect generated by the grease discharge port 14 when the stepped plunger 2 returns.

[0036] See also Figure 1-Figure 3 As shown, the grease replenishing one-way valve 12 includes a valve seat 121, a grease replenishing valve ball 122, a first spring 123, a grease replenishing inlet 124 and a grease replenishing outlet 125. When the stepped plunger 2 moves forward, the large cylinder 25 squeezes the oil chamber 11 so that the pressure of the oil chamber 11 increases in a short time. At this time, the grease replenishing valve ball 122 blocks the grease replenishing inlet 124 under the action of the first spring 123, and the external grease cannot enter the oil chamber 11. When the stepped plunger 2 retreats, a negative pressure state is formed in the oil chamber 11. Under the action of the internal and external pressure difference, the external grease pushes the grease replenishing valve ball 122 so that the grease replenishing valve ball 122 overcomes the thrust of the first spring 123 and moves downward. The grease enters the valve seat 121 through the grease replenishing inlet 124 and is discharged into the oil chamber 11 from the grease replenishing outlet 125 on the side wall of the valve seat 121. This structure uses the pressure change in the oil chamber 11 when the stepped plunger 2 moves forward or retreats to automatically control the replenishment of grease, so that the stepped plunger 2 can replenish grease in time when retreating to eliminate the negative pressure effect of the oil chamber 11 and prevent the grease discharge port 14 from being sucked back due to negative pressure.

[0037] Furthermore, a spring seat 1211 is provided at the bottom of the valve seat 121, and an oil pressure balance port 1212 is provided in the spring seat 1211 and communicated with the oil chamber 11. Grease can enter and exit through the oil pressure balance port 1212, and when the grease replenishing valve ball 122 moves downward, the grease is discharged from the valve seat 121 through the oil pressure balance port 1212; and when the grease replenishing valve ball 122 moves upward, the grease enters the valve seat 121 through the oil pressure balance port 1212, thereby achieving a pressure difference balance between the valve seat 121 and the oil chamber 11, and ensuring that the grease replenishing valve ball 122 can operate normally.

[0038] See also Figure 1 , Figure 2 and Figure 4As shown, the exhaust check valve 13 includes an exhaust pipe seat 131, a second spring 132 and an exhaust valve ball 133, and the second spring 132 is clamped between the exhaust pipe seat 131 and the exhaust valve ball 133. When the gas enters the exhaust check valve 13 from the annular groove 23, the gas pushes the exhaust valve ball 133 to overcome the thrust of the second spring 132 to compress the second spring 132, and the gas can then enter the exhaust pipe seat 131 and be discharged from the exhaust pipe seat 131. When the lubrication unit exits the exhaust state, the second spring 132 continues to push the exhaust valve ball 133 to block the port of the annular groove 23 to prevent external gas from entering the annular groove 23.

[0039] The grease discharge port 14 is divided into a plurality of output ports 141 by the interval 142 of the grease discharge hole. When the plunger moves, the grease discharge groove 22 gradually communicates with each output port 141 in sequence, and grease is discharged from each output port 141 to feed lubricating oil to different lubrication points.

[0040] The end of the pump body 1 away from the stepped plunger 2 is threadedly connected with a plug screw 3, which can be used to seal the pump body 1. The plug screw 3 and the pump body 1 can be separated, so that the inside of the pump body 1 can be cleaned or inspected, or the grease inside the pump body 1 can be discharged by opening the plug screw 3.

[0041] The present application provides a lubrication unit that first exhausts air and a transition oil chamber to prevent the plunger from sucking back during the return stroke, and is composed of a stepped stepped plunger 2 and an upper oil passage 211 and a lower oil passage 212 in the large cylinder 25 of the stepped plunger 2 as the distributor piston of the present lubrication unit; the stepped stepped plunger 2 and a pump body with a stepped oil chamber 11 hole that movably cooperates with it and a plurality of output ports 141 arranged at intervals on the side wall of the pump body 1 constitute the progressive distributor of the present application. The small cylinder 24 is a part of the stepped plunger 2 of the space-occupying lubrication pump of the present lubrication unit, which transmits power and is sealed with the coupling hole of the pump body 1 to form the space-occupying grease supply pump of the present utility model. The present application removes the gas that may be mixed in the oil chamber 11 at the beginning of a running stroke of the stepped plunger 2.

[0042] In the initial state, the main oil chamber 111 between the right end of the large cylinder 25 and the screw plug 3 is filled with grease, and the upper oil passage 211 and the lower oil passage 212 in the large cylinder 25 are also filled with grease. The grease discharge groove 22 on the large cylinder 25 and the grease discharge port 14 on the pump body 1 are separated by a width slightly smaller than the exhaust hole of the exhaust check valve 13. When the power device pushes the stepped plunger 2 to move to the right, it will first squeeze out the gas or grease that may be accumulated in the upper part of the oil chamber 11 with the same volume as the rightward movement of the small cylinder 24 and discharge it from the exhaust check valve 13. After exiting the exhaust mode, as the stepped plunger 2 continues to move, the grease is squeezed into the auxiliary oil chamber 112 at the left end of the large cylinder 25, and the grease of the same volume as the space occupied by the small cylinder 24 is discharged through the grease discharge groove 22 and the output port 141, and the grease is discharged to the first lubrication point on the bearing. As the stepped plunger 2 moves to the right, the grease discharge groove 22 on the stepped plunger 2 gradually completes the grease supply to the output port 141 on the left side of the pump body 1; the stepped plunger 2 continues to move to the right to realize the progressive quantitative grease supply to the second lubrication point. When the stepped plunger 2 ends its right stroke and pulls the stepped plunger 2 to the left, the auxiliary oil chamber 112 between the pump body 1 and the left end of the large cylinder 25 is squeezed, and the grease squeezed in when the stepped plunger 2 moves to the right through the original flow channel to the main oil chamber 111 at the right end of the large cylinder 25. The vacancy equal to the volume of the leftward movement of the small cylinder 24 causes the main oil chamber 111 between the right end of the large cylinder 25 and the screw plug 3 to generate negative pressure. The grease in the grease storage cylinder pushes the grease replenishing valve ball 122 under the action of atmospheric pressure and is sucked into the main oil chamber 111, and is ready for the next grease injection cycle.

[0043] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A lubrication unit that first exhausts the air and transitions the oil chamber to prevent the plunger from returning and sucking back, characterized in that: include: A pump body (1), wherein an oil chamber (11) is formed inside the pump body (1), a grease replenishing one-way valve (12), an exhaust one-way valve (13) and a grease discharge port (14) which are connected to the oil chamber (11) are arranged on the side wall of the pump body (1), and a communication port (15) is penetrated in the top side wall of the pump body (1); A stepped plunger (2), the stepped plunger (2) being movably mounted inside the oil chamber (11) so that the oil chamber (11) forms a closed space, an oil passage (21) is formed inside the stepped plunger (2), a grease discharge groove (22) communicating with the oil passage (21) is penetrated through the side wall of the stepped plunger (2), and an annular groove (23) is formed on the outer side wall of the stepped plunger (2) along the circumferential direction; When the stepped plunger (2) is located at the starting point of advancement, the grease discharge groove (22), the grease discharge port (14), the exhaust check valve (13) and the grease replenishing check valve (12) are arranged in sequence along the advancement direction of the stepped plunger (2), and the communication port (15) is connected to the exhaust check valve (13) through the annular groove (23).

2. A lubrication unit for exhausting air first and transitioning the oil chamber to prevent the plunger from sucking back during return stroke according to claim 1, characterized in that: When the stepped plunger (2) is pushed forward from the starting point of advancement and the communication port (15) and the annular groove (23) are out of communication, the grease discharge groove (22) and the grease discharge port (14) enter into communication.

3. A lubrication unit for exhausting air first and transitioning the oil chamber to prevent the plunger from sucking back during return stroke according to claim 1, characterized in that: The stepped plunger (2) comprises a small cylinder (24) and a large cylinder (25) which are arranged in sequence along the direction of travel. When the stepped plunger (2) is pushed forward from the starting point of pushing forward, a main oil chamber (111) and a secondary oil chamber (112) are respectively formed between the two ends of the large cylinder (25) and the pump body (1). The oil passage (21) comprises an upper oil passage (211) and a lower oil passage (212). The upper oil passage (211) connects the main oil chamber (111) with the secondary oil chamber (112), and the lower oil passage (212) connects the secondary oil chamber (112) with the grease discharge groove (22).

4. A lubrication unit for exhausting air first and transitioning the oil chamber to prevent the plunger from sucking back during return stroke according to claim 1, characterized in that: The grease replenishing one-way valve (12) comprises a valve seat (121), a grease replenishing valve ball (122), a first spring (123), a grease replenishing inlet (124) and a grease replenishing outlet (125); the grease replenishing valve ball (122) is arranged inside the valve seat (121) and is stopped at the grease replenishing inlet (124) by the first spring (123); and the grease replenishing outlet (125) is opened on the side wall of the valve seat (121).

5. A lubrication unit for exhausting air first and preventing the piston from sucking back during return stroke according to claim 4, characterized in that: A spring seat (1211) is provided at the bottom of the valve seat (121), and the spring seat (1211) is provided with an oil pressure balance port (1212) communicating with the oil chamber (11).

6. A lubrication unit for exhausting air first and transitioning the oil chamber to prevent the plunger from sucking back during return stroke according to claim 1, characterized in that: The exhaust check valve (13) comprises an exhaust pipe seat (131), a second spring (132) and an exhaust valve ball (133), wherein the second spring (132) is clamped between the exhaust pipe seat (131) and the exhaust valve ball (133).

7. A lubrication unit for exhausting air first and transitioning the oil chamber to prevent the plunger from sucking back during return stroke according to claim 1, characterized in that: The grease discharge port (14) is formed into a plurality of output ports (141) through a plurality of spaced small holes.

8. A lubrication unit for exhausting air first and transitioning the oil chamber to prevent the plunger from sucking back during return stroke according to claim 1, characterized in that: One end of the pump body (1) away from the stepped plunger (2) is threadedly connected with a screw plug (3).

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