Grease pump and its pump head, plunger assembly

Abstract

The present invention relates to a grease injection pump and its pump head and plunger pair. The plunger pair includes a housing, a grease discharge one-way valve, and a plunger. The housing contains a grease storage chamber and a grease discharge chamber. When the plunger moves toward the direction of compressing the grease discharge chamber, the volume of the grease discharge chamber gradually decreases, grease is discharged from the grease discharge port, the volume of the grease storage chamber gradually increases, and grease enters the grease storage chamber. When the plunger moves toward the direction of compressing the grease storage chamber, the volume of the grease discharge chamber gradually increases, the volume of the grease storage chamber gradually decreases, the grease filling one-way valve opens, grease enters the grease discharge chamber through the grease filling channel, and excess grease in the grease storage chamber is discharged from the grease storage chamber through the overflow structure. The plunger pair changes the plunger from active grease suction to a dual function of active grease suction and external grease pressing, ensuring that the grease storage chamber can be filled with grease during each grease suction process of the plunger under low temperature conditions and viscous grease conditions, thereby solving the technical problem of low oil output efficiency caused by insufficient grease discharge in current lubrication pumps.

Description

Technical Field

[0001] This invention relates to a grease injection pump and its pump head and plunger assembly. Background Technology

[0002] Viscous grease is typically pumped using a plunger-type lubrication pump. The reciprocating motion of the plunger achieves the process of grease suction and discharge. The forward movement of the plunger creates negative pressure in the grease reservoir, drawing grease from the suction port. Then, the plunger moves in the reverse direction, squeezing the grease out of the reservoir. For example, Chinese patent application CN110608165A, published on December 24, 2019, discloses a lubrication pump, specifically a grease injection pump. During operation, the motor rotates, driving an eccentric wheel, which in turn drives the plungers in each plunger assembly. When the plunger moves close to the valve core, it pushes the lubricant between the suction port and the valve core, thus opening the check valve for grease discharge lubrication. When the plunger forces the valve core to move, the check valve closes, and the suction port draws in grease.

[0003] When the ambient temperature of the grease pump is low or the grease itself has a high viscosity, the vacuum generated by the plunger during the pump's operation is insufficient to quickly draw the grease into the reservoir. This results in insufficient grease filling the reservoir, leading to inadequate grease discharge during the plunger's reverse movement. Consequently, the pump's oil output efficiency decreases, failing to meet design requirements. Furthermore, air bubbles are inevitably present in the grease during lubrication pump operation. Some of these bubbles can be very large. When the plunger draws in large bubbles, its reverse discharge action compresses them, resulting in insufficient grease discharge. In extreme cases, if the bubbles are large enough, the plunger will be constantly in a state of both drawing in and compressing air, preventing the grease from being discharged. Summary of the Invention

[0004] The purpose of this invention is to provide a grease pump that solves the technical problem of low oil discharge efficiency or even failure to discharge grease caused by insufficient grease discharge in current grease pumps under conditions such as low temperature, high grease viscosity, and many air bubbles. In addition, the purpose of this invention is to provide a pump head for use with the above-mentioned grease pump. Furthermore, the purpose of this invention is to provide a plunger assembly for use with the above-mentioned grease pump.

[0005] The plunger assembly of the present invention adopts the following technical solution:

[0006] The outer shell contains a fat-draining chamber, and the outer shell is provided with a fat-draining port for communicating with the fat-draining chamber;

[0007] The grease discharge check valve allows the grease in the grease discharge chamber to be discharged in one direction through the grease discharge port;

[0008] The outer shell also contains a fat supply chamber with a diameter larger than that of the fat discharge chamber;

[0009] A plunger, inserted into a housing, has a grease discharge squeezing section, a grease storage squeezing section, and a power connection section. The grease discharge squeezing section is slidably and sealed into the grease discharge chamber to squeeze out the grease in the grease discharge chamber. The grease storage squeezing section is movable and configured in the grease supply chamber. The outer diameter of the grease storage squeezing section is larger than the outer diameter of the grease discharge squeezing section and larger than the outer diameter of the power connection section. The grease storage squeezing section, the power squeezing section, and the grease discharge squeezing section, together with the inner wall of the grease supply chamber, form a grease storage chamber and a breath chamber separated by the grease storage squeezing section. The breath chamber is located between the grease storage chamber and the grease discharge chamber and is used to communicate with the oil tank. The grease storage chamber is used to supply grease to the grease discharge chamber.

[0010] The grease filling channel, located on the plunger or the outer shell, is used to connect the grease storage chamber and the grease discharge chamber. The grease filling channel is equipped with a grease filling check valve to allow the lubricating grease to enter the grease discharge chamber in one direction.

[0011] The grease storage and squeezing section is used to squeeze the grease in the grease storage chamber. The end of the power connection section away from the grease storage and squeezing section extends out of the grease supply chamber to connect with the drive mechanism. The drive mechanism drives the plunger to reciprocate. When the grease discharge and squeezing section squeezes the grease discharge chamber, the direction of the plunger's movement is opposite to the direction of the plunger's movement when the grease storage and squeezing section squeezes the grease storage chamber.

[0012] During the stroke of the plunger, the difference between the maximum and minimum volume of the grease reservoir is greater than the difference between the maximum and minimum volume of the grease discharge chamber. The outer shell or the plunger has an overflow structure for discharging excess grease from the grease reservoir or the grease discharge chamber.

[0013] The outer casing is provided with a grease inlet channel for connecting the grease storage chamber and the oil tank. During the process of the plunger moving towards the compression and discharge chamber, the grease filling check valve is closed. The grease inlet channel is used to connect the grease storage chamber and the oil tank. The grease in the oil tank is introduced into the grease storage chamber, and the discharge check valve opens when it reaches the opening pressure, and the grease in the discharge chamber is squeezed out.

[0014] When the plunger moves toward the compression grease reservoir, the grease discharge check valve closes, and the grease filling check valve opens when it reaches the opening pressure, allowing the grease in the reservoir to enter the grease discharge chamber through the filling channel.

[0015] Beneficial effects: The plunger assembly of this invention has a grease reservoir and a grease discharge chamber. During use, the grease reservoir draws in oil, and as the plunger moves towards the grease reservoir, it squeezes the reservoir, reducing the pressure in the discharge chamber. Grease then enters the discharge chamber through the grease filling check valve. During the plunger's suction and discharge stroke, the volume change of the grease reservoir is greater than that of the discharge chamber, increasing the grease intake in the discharge chamber. By first storing oil in the reservoir, and then using the combined action of the negative pressure in the discharge chamber and the squeezing action of the reservoir compression section to force the grease into the discharge chamber, the grease is discharged under the squeezing action of the discharge compression section. Compared to current plunger assemblies, this invention transforms the plunger's active grease suction into a dual action of active grease suction and external grease injection, improving the grease discharge volume and oil output efficiency under conditions such as low temperature, viscous grease, and high air bubble content.

[0016] The grease inlet channel is further optimized. At least one grease inlet channel is a grease inlet channel located on the wall of the grease reservoir. This grease inlet channel has a one-way grease storage structure. This one-way structure allows grease to enter the grease reservoir in a unidirectional manner when the plunger moves towards the compression and discharge chamber, and closes the grease inlet channel when the plunger moves towards the compression and storage chamber. This one-way grease storage structure ensures that the grease reservoir can draw in grease in a timely manner.

[0017] The grease storage one-way structure can be implemented as follows: the grease storage one-way structure is a one-way valve installed on the outer shell or plunger. The one-way valve has a simple structure and is easy to install.

[0018] The grease storage one-way structure can also adopt the following scheme: the outer shell includes a housing and a cover. The housing has a plunger inlet for inserting a plunger. The cover is located at the plunger inlet and has a cover perforation for the plunger to pass through. There is a cover channel for grease to pass through on the cover or between the cover and the plunger. The grease storage one-way structure is a one-way valve plate located inside the cover. The one-way valve plate has a valve plate perforation for the plunger to pass through. The one-way valve plate can move axially along the plunger, allowing for one-way movement. The valve plate has a sealing position where it seals against the housing cover when the plunger moves towards the grease storage chamber, and a grease inlet position separated from the housing cover when the plunger moves towards the grease discharge chamber. The one-way valve plate has a grease inlet channel, which connects to the housing cover channel when the one-way valve plate is in the grease inlet position, allowing grease to enter the grease storage chamber. When the one-way valve plate is in the sealing position, it is blocked by the housing cover and closed. The valve plate grease inlet channel and the housing cover channel together form the grease inlet channel in the grease storage chamber wall. The one-way valve plate is located at the plunger inlet for easy installation.

[0019] The fit between the one-way valve plate and the plunger is further optimized, with a clearance fit between them. The overflow structure includes the gap between the one-way valve plate and the plunger. The plunger assembly structure is simplified.

[0020] The unidirectional grease storage structure can also adopt the following scheme: The outer shell includes a housing and a cover. The housing has a plunger inlet for inserting the plunger. The cover is located at the plunger inlet and has a cover perforation for the plunger to pass through. A grease inlet channel for the grease storage chamber wall is located on the cover. The unidirectional grease storage structure includes a grease storage one-way valve diaphragm fixed inside the cover to cover the grease inlet channel opening. When the plunger moves towards the compression and discharge chamber, the grease storage one-way valve diaphragm opens the grease inlet channel opening through elastic deformation, allowing grease to enter the grease storage chamber. When the plunger moves towards the compression and grease storage chamber, it covers the grease inlet channel opening, closing the grease inlet channel. The grease storage one-way valve diaphragm cooperates with the cover to allow grease to pass through in one direction, resulting in a simple structure that is easy to install.

[0021] When a one-way valve is used in the grease storage unidirectional structure, the following scheme can be adopted: The grease storage unidirectional structure is an umbrella-shaped one-way valve set on the grease storage extrusion section. The outer edge of the umbrella-shaped one-way valve is in a one-way sealing fit with the outer shell. When the umbrella-shaped one-way valve is open, the annular channel formed between the grease storage extrusion section and the outer shell constitutes the grease inlet channel of the grease storage chamber. The umbrella-shaped one-way valve allows lubricating grease to enter the grease storage chamber unidirectionally from the breather chamber. The umbrella-shaped one-way valve has a large flow area and a fast lubricating grease inlet rate.

[0022] The fit between the grease storage and extrusion section and the inner wall of the grease supply chamber is optimized, and the grease storage and extrusion section and the inner wall of the grease supply chamber are in a sliding sealing fit. The fit structure is simple.

[0023] For the optimization of the overflow structure, the overflow structure includes an overflow gap disposed between the housing and the plunger, the overflow gap being used to connect the grease reservoir to the oil tank. The overflow gap structure is simple and easy to manufacture and install.

[0024] The overflow structure can also be optimized as follows: the overflow structure includes an overflow valve mounted on the housing. The overflow valve has a simple structure and is easy to manufacture and install.

[0025] The installation position of the overflow valve has been further optimized; the overflow valve is located on the wall of the grease discharge chamber or grease storage chamber. The overflow valve is easy to install.

[0026] Another optimized solution for the overflow structure is as follows: the overflow structure includes an overflow channel and an overflow valve installed on the overflow channel. The overflow channel is installed on the power connection section to connect the grease storage chamber and the oil tank.

[0027] Another optimized overflow structure is as follows: the overflow structure includes a damping orifice connecting the grease reservoir and the oil tank, and the damping orifice is located on the plunger or the outer shell. The damping orifice structure is simple and easy to manufacture.

[0028] Further optimization of the grease inlet channel: at least one grease inlet channel is a positioning grease inlet channel located on the wall of the grease supply chamber. This positioning grease inlet channel connects with the grease storage chamber when the plunger moves to the limit position of the compression and discharge chamber. When the plunger moves towards the compression and storage chamber, the positioning grease inlet channel is separated from the storage chamber and closed by the grease storage compression section. This eliminates the need for a unidirectional structure, resulting in a simple structure and good stability.

[0029] Further optimization of the in-place fat inlet channel, wherein the breathing chamber is used to form the in-place fat inlet channel through the breathing channel connected to the oil tank.

[0030] By optimizing the overflow structure, when the plunger moves toward the grease reservoir, the flow resistance of the grease flowing through the overflow structure is greater than the flow resistance flowing through the grease filling channel.

[0031] The technical solution of the pump head of this invention:

[0032] The pump head includes a pump head housing, a plunger assembly disposed within the pump head housing, and a drive mechanism. The plunger assembly includes:

[0033] The outer shell contains a fat-draining chamber, and the outer shell is provided with a fat-draining port for communicating with the fat-draining chamber;

[0034] The grease discharge check valve allows the grease in the grease discharge chamber to be discharged in one direction through the grease discharge port;

[0035] The outer shell also contains a fat supply chamber with a diameter larger than that of the fat discharge chamber;

[0036] A plunger, inserted into a housing, has a grease discharge squeezing section, a grease storage squeezing section, and a power connection section. The grease discharge squeezing section is slidably and sealed into the grease discharge chamber to squeeze out the grease in the grease discharge chamber. The grease storage squeezing section is movable and configured in the grease supply chamber. The outer diameter of the grease storage squeezing section is larger than the outer diameter of the grease discharge squeezing section and larger than the outer diameter of the power connection section. The grease storage squeezing section, the power squeezing section, and the grease discharge squeezing section, together with the inner wall of the grease supply chamber, form a grease storage chamber and a breath chamber separated by the grease storage squeezing section. The breath chamber is located between the grease storage chamber and the grease discharge chamber and is used to communicate with the oil tank. The grease storage chamber is used to supply grease to the grease discharge chamber.

[0037] The grease filling channel, located on the plunger or the outer shell, is used to connect the grease storage chamber and the grease discharge chamber. The grease filling channel is equipped with a grease filling check valve to allow the lubricating grease to enter the grease discharge chamber in one direction.

[0038] The grease storage and squeezing section is used to squeeze the grease in the grease storage chamber. The end of the power connection section away from the grease storage and squeezing section extends out of the grease supply chamber to connect with the drive mechanism. The drive mechanism drives the plunger to reciprocate. When the grease discharge and squeezing section squeezes the grease discharge chamber, the direction of the plunger's movement is opposite to the direction of the plunger's movement when the grease storage and squeezing section squeezes the grease storage chamber.

[0039] During the stroke of the plunger, the difference between the maximum and minimum volume of the grease reservoir is greater than the difference between the maximum and minimum volume of the grease discharge chamber. The outer shell or the plunger has an overflow structure for discharging excess grease from the grease reservoir or the grease discharge chamber.

[0040] The outer casing is provided with a grease inlet channel for connecting the grease storage chamber and the oil tank. During the process of the plunger moving towards the compression and discharge chamber, the grease filling check valve is closed. The grease inlet channel is used to connect the grease storage chamber and the oil tank. The grease in the oil tank is introduced into the grease storage chamber, and the discharge check valve opens when it reaches the opening pressure, and the grease in the discharge chamber is squeezed out.

[0041] When the plunger moves toward the compression grease reservoir, the grease discharge check valve closes, and the grease filling check valve opens when it reaches the opening pressure, allowing the grease in the reservoir to enter the grease discharge chamber through the filling channel.

[0042] Beneficial effects: The plunger assembly of this invention has a grease reservoir and a grease discharge chamber. During use, the grease reservoir draws in oil. When the plunger moves towards the grease reservoir position, it squeezes the grease reservoir, reducing the pressure in the grease discharge chamber and creating a negative pressure. The grease then enters the grease discharge chamber through the grease filling check valve. During the plunger's suction and discharge stroke, the change in volume of the grease reservoir is greater than the change in volume of the grease discharge chamber, increasing the amount of grease entering the grease discharge chamber. By first storing oil in the grease reservoir, and then using the combined action of the negative pressure in the grease discharge chamber and the squeezing action of the grease reservoir compression section to force the grease into the grease discharge chamber, the grease entering the grease discharge chamber is discharged under the squeezing action of the grease discharge compression section. Compared with current plunger assemblies, the plunger assembly of this invention changes the plunger's active grease suction to a dual action of active grease suction and external grease injection, improving the grease discharge volume of the plunger under conditions such as low temperature, viscous grease, and high air bubble content, thus improving oil output efficiency.

[0043] The grease inlet channel is further optimized. At least one grease inlet channel is a grease inlet channel located on the wall of the grease reservoir. This grease inlet channel has a one-way grease storage structure. This one-way structure allows grease to enter the grease reservoir in a unidirectional manner when the plunger moves towards the compression and discharge chamber, and closes the grease inlet channel when the plunger moves towards the compression and storage chamber. This one-way grease storage structure ensures that the grease reservoir can draw in grease in a timely manner.

[0044] The grease storage one-way structure can be implemented as follows: the grease storage one-way structure is a one-way valve installed on the outer shell or plunger. The one-way valve has a simple structure and is easy to install.

[0045] The grease storage one-way structure can also adopt the following scheme: the outer shell includes a housing and a cover. The housing has a plunger inlet for inserting a plunger. The cover is located at the plunger inlet and has a cover perforation for the plunger to pass through. There is a cover channel for grease to pass through on the cover or between the cover and the plunger. The grease storage one-way structure is a one-way valve plate located inside the cover. The one-way valve plate has a valve plate perforation for the plunger to pass through. The one-way valve plate can move axially along the plunger, allowing for one-way movement. The valve plate has a sealing position where it seals against the housing cover when the plunger moves towards the grease storage chamber, and a grease inlet position separated from the housing cover when the plunger moves towards the grease discharge chamber. The one-way valve plate has a grease inlet channel, which connects to the housing cover channel when the one-way valve plate is in the grease inlet position, allowing grease to enter the grease storage chamber. When the one-way valve plate is in the sealing position, it is blocked by the housing cover and closed. The valve plate grease inlet channel and the housing cover channel together form the grease inlet channel in the grease storage chamber wall. The one-way valve plate is located at the plunger inlet for easy installation.

[0046] The fit between the one-way valve plate and the plunger is further optimized, with a clearance fit between them. The overflow structure includes the gap between the one-way valve plate and the plunger. The plunger assembly structure is simplified.

[0047] The unidirectional grease storage structure can also adopt the following scheme: The outer shell includes a housing and a cover. The housing has a plunger inlet for inserting the plunger. The cover is located at the plunger inlet and has a cover perforation for the plunger to pass through. A grease inlet channel for the grease storage chamber wall is located on the cover. The unidirectional grease storage structure includes a grease storage one-way valve diaphragm fixed inside the cover to cover the grease inlet channel opening. When the plunger moves towards the compression and discharge chamber, the grease storage one-way valve diaphragm opens the grease inlet channel opening through elastic deformation, allowing grease to enter the grease storage chamber. When the plunger moves towards the compression and grease storage chamber, it covers the grease inlet channel opening, closing the grease inlet channel. The grease storage one-way valve diaphragm cooperates with the cover to allow grease to pass through in one direction, resulting in a simple structure that is easy to install.

[0048] When a one-way valve is used in the grease storage unidirectional structure, the following scheme can be adopted: The grease storage unidirectional structure is an umbrella-shaped one-way valve set on the grease storage extrusion section. The outer edge of the umbrella-shaped one-way valve is in a one-way sealing fit with the outer shell. When the umbrella-shaped one-way valve is open, the annular channel formed between the grease storage extrusion section and the outer shell constitutes the grease inlet channel of the grease storage chamber. The umbrella-shaped one-way valve allows lubricating grease to enter the grease storage chamber unidirectionally from the breather chamber. The umbrella-shaped one-way valve has a large flow area and a fast lubricating grease inlet rate.

[0049] The fit between the grease storage and extrusion section and the inner wall of the grease supply chamber is optimized, and the grease storage and extrusion section and the inner wall of the grease supply chamber are in a sliding sealing fit. The fit structure is simple.

[0050] For the optimization of the overflow structure, the overflow structure includes an overflow gap disposed between the housing and the plunger, the overflow gap being used to connect the grease reservoir to the oil tank. The overflow gap structure is simple and easy to manufacture and install.

[0051] The overflow structure can also be optimized as follows: the overflow structure includes an overflow valve mounted on the housing. The overflow valve has a simple structure and is easy to manufacture and install.

[0052] The installation position of the overflow valve has been further optimized; the overflow valve is located on the wall of the grease discharge chamber or grease storage chamber. The overflow valve is easy to install.

[0053] Another optimized solution for the overflow structure is as follows: the overflow structure includes an overflow channel and an overflow valve installed on the overflow channel. The overflow channel is installed on the power connection section to connect the grease storage chamber and the oil tank.

[0054] Another optimized overflow structure is as follows: the overflow structure includes a damping orifice connecting the grease reservoir and the oil tank, and the damping orifice is located on the plunger or the outer shell. The damping orifice structure is simple and easy to manufacture.

[0055] Further optimization of the grease inlet channel: at least one grease inlet channel is a positioning grease inlet channel located on the wall of the grease supply chamber. This positioning grease inlet channel connects with the grease storage chamber when the plunger moves to the limit position of the compression and discharge chamber. When the plunger moves towards the compression and storage chamber, the positioning grease inlet channel is separated from the storage chamber and closed by the grease storage compression section. This eliminates the need for a unidirectional structure, resulting in a simple structure and good stability.

[0056] Further optimization of the in-place fat inlet channel, wherein the breathing chamber is used to form the in-place fat inlet channel through the breathing channel connected to the oil tank.

[0057] By optimizing the overflow structure, when the plunger moves toward the grease reservoir, the flow resistance of the grease flowing through the overflow structure is greater than the flow resistance flowing through the grease filling channel.

[0058] The technical solution of the grease pump of this invention:

[0059] The grease pump includes an oil tank and a pump head. The pump head includes a pump head housing, a plunger assembly disposed within the pump head housing, and a drive mechanism. The plunger assembly includes:

[0060] The outer shell contains a fat-draining chamber, and the outer shell is provided with a fat-draining port for communicating with the fat-draining chamber;

[0061] The grease discharge check valve allows the grease in the grease discharge chamber to be discharged in one direction through the grease discharge port;

[0062] The outer shell also contains a fat supply chamber with a diameter larger than that of the fat discharge chamber;

[0063] A plunger, inserted into a housing, has a grease discharge squeezing section, a grease storage squeezing section, and a power connection section. The grease discharge squeezing section is slidably and sealed into the grease discharge chamber to squeeze out the grease in the grease discharge chamber. The grease storage squeezing section is movable and configured in the grease supply chamber. The outer diameter of the grease storage squeezing section is larger than the outer diameter of the grease discharge squeezing section and larger than the outer diameter of the power connection section. The grease storage squeezing section, the power squeezing section, and the grease discharge squeezing section, together with the inner wall of the grease supply chamber, form a grease storage chamber and a breath chamber separated by the grease storage squeezing section. The breath chamber is located between the grease storage chamber and the grease discharge chamber and is used to communicate with the oil tank. The grease storage chamber is used to supply grease to the grease discharge chamber.

[0064] The grease filling channel, located on the plunger or the outer shell, is used to connect the grease storage chamber and the grease discharge chamber. The grease filling channel is equipped with a grease filling check valve to allow the lubricating grease to enter the grease discharge chamber in one direction.

[0065] The grease storage and squeezing section is used to squeeze the grease in the grease storage chamber. The end of the power connection section away from the grease storage and squeezing section extends out of the grease supply chamber to connect with the drive mechanism. The drive mechanism drives the plunger to reciprocate. When the grease discharge and squeezing section squeezes the grease discharge chamber, the direction of the plunger's movement is opposite to the direction of the plunger's movement when the grease storage and squeezing section squeezes the grease storage chamber.

[0066] During the stroke of the plunger, the difference between the maximum and minimum volume of the grease reservoir is greater than the difference between the maximum and minimum volume of the grease discharge chamber. The outer shell or the plunger has an overflow structure for discharging excess grease from the grease reservoir or the grease discharge chamber.

[0067] The outer casing is provided with a grease inlet channel for connecting the grease storage chamber and the oil tank. During the process of the plunger moving towards the compression and discharge chamber, the grease filling check valve is closed. The grease inlet channel is used to connect the grease storage chamber and the oil tank. The grease in the oil tank is introduced into the grease storage chamber, and the discharge check valve opens when it reaches the opening pressure, and the grease in the discharge chamber is squeezed out.

[0068] When the plunger moves toward the compression grease reservoir, the grease discharge check valve closes, and the grease filling check valve opens when it reaches the opening pressure, allowing the grease in the reservoir to enter the grease discharge chamber through the filling channel.

[0069] Beneficial effects: The plunger assembly of this invention has a grease reservoir and a grease discharge chamber. During use, the grease reservoir draws in oil. When the plunger moves towards the grease reservoir position, it squeezes the grease reservoir, reducing the pressure in the grease discharge chamber and creating a negative pressure. The grease then enters the grease discharge chamber through the grease filling check valve. During the plunger's suction and discharge stroke, the change in volume of the grease reservoir is greater than the change in volume of the grease discharge chamber, increasing the amount of grease entering the grease discharge chamber. By first storing oil in the grease reservoir, and then using the combined action of the negative pressure in the grease discharge chamber and the squeezing action of the grease reservoir compression section to force the grease into the grease discharge chamber, the grease entering the grease discharge chamber is discharged under the squeezing action of the grease discharge compression section. Compared with current plunger assemblies, the plunger assembly of this invention changes the plunger's active grease suction to a dual action of active grease suction and external grease injection, improving the grease discharge volume of the plunger under conditions such as low temperature, viscous grease, and high air bubble content, thus improving oil output efficiency.

[0070] The grease inlet channel is further optimized. At least one grease inlet channel is a grease inlet channel located on the wall of the grease reservoir. This grease inlet channel has a one-way grease storage structure. This one-way structure allows grease to enter the grease reservoir in a unidirectional manner when the plunger moves towards the compression and discharge chamber, and closes the grease inlet channel when the plunger moves towards the compression and storage chamber. This one-way grease storage structure ensures that the grease reservoir can draw in grease in a timely manner.

[0071] The grease storage one-way structure can be implemented as follows: the grease storage one-way structure is a one-way valve installed on the outer shell or plunger. The one-way valve has a simple structure and is easy to install.

[0072] The grease storage one-way structure can also adopt the following scheme: the outer shell includes a housing and a cover. The housing has a plunger inlet for inserting a plunger. The cover is located at the plunger inlet and has a cover perforation for the plunger to pass through. There is a cover channel for grease to pass through on the cover or between the cover and the plunger. The grease storage one-way structure is a one-way valve plate located inside the cover. The one-way valve plate has a valve plate perforation for the plunger to pass through. The one-way valve plate can move axially along the plunger, allowing for one-way movement. The valve plate has a sealing position where it seals against the housing cover when the plunger moves towards the grease storage chamber, and a grease inlet position separated from the housing cover when the plunger moves towards the grease discharge chamber. The one-way valve plate has a grease inlet channel, which connects to the housing cover channel when the one-way valve plate is in the grease inlet position, allowing grease to enter the grease storage chamber. When the one-way valve plate is in the sealing position, it is blocked by the housing cover and closed. The valve plate grease inlet channel and the housing cover channel together form the grease inlet channel in the grease storage chamber wall. The one-way valve plate is located at the plunger inlet for easy installation.

[0073] The fit between the one-way valve plate and the plunger is further optimized, with a clearance fit between them. The overflow structure includes the gap between the one-way valve plate and the plunger. The plunger assembly structure is simplified.

[0074] The unidirectional grease storage structure can also adopt the following scheme: The outer shell includes a housing and a cover. The housing has a plunger inlet for inserting the plunger. The cover is located at the plunger inlet and has a cover perforation for the plunger to pass through. A grease inlet channel for the grease storage chamber wall is located on the cover. The unidirectional grease storage structure includes a grease storage one-way valve diaphragm fixed inside the cover to cover the grease inlet channel opening. When the plunger moves towards the compression and discharge chamber, the grease storage one-way valve diaphragm opens the grease inlet channel opening through elastic deformation, allowing grease to enter the grease storage chamber. When the plunger moves towards the compression and grease storage chamber, it covers the grease inlet channel opening, closing the grease inlet channel. The grease storage one-way valve diaphragm cooperates with the cover to allow grease to pass through in one direction, resulting in a simple structure that is easy to install.

[0075] When a one-way valve is used in the grease storage unidirectional structure, the following scheme can be adopted: The grease storage unidirectional structure is an umbrella-shaped one-way valve set on the grease storage extrusion section. The outer edge of the umbrella-shaped one-way valve is in a one-way sealing fit with the outer shell. When the umbrella-shaped one-way valve is open, the annular channel formed between the grease storage extrusion section and the outer shell constitutes the grease inlet channel of the grease storage chamber. The umbrella-shaped one-way valve allows lubricating grease to enter the grease storage chamber unidirectionally from the breather chamber. The umbrella-shaped one-way valve has a large flow area and a fast lubricating grease inlet rate.

[0076] The fit between the grease storage and extrusion section and the inner wall of the grease supply chamber is optimized, and the grease storage and extrusion section and the inner wall of the grease supply chamber are in a sliding sealing fit. The fit structure is simple.

[0077] For the optimization of the overflow structure, the overflow structure includes an overflow gap disposed between the housing and the plunger, the overflow gap being used to connect the grease reservoir to the oil tank. The overflow gap structure is simple and easy to manufacture and install.

[0078] The overflow structure can also be optimized as follows: the overflow structure includes an overflow valve mounted on the housing. The overflow valve has a simple structure and is easy to manufacture and install.

[0079] The installation position of the overflow valve has been further optimized; the overflow valve is located on the wall of the grease discharge chamber or grease storage chamber. The overflow valve is easy to install.

[0080] Another optimized solution for the overflow structure is as follows: the overflow structure includes an overflow channel and an overflow valve installed on the overflow channel. The overflow channel is installed on the power connection section to connect the grease storage chamber and the oil tank.

[0081] Another optimized overflow structure is as follows: the overflow structure includes a damping orifice connecting the grease reservoir and the oil tank, and the damping orifice is located on the plunger or the outer shell. The damping orifice structure is simple and easy to manufacture.

[0082] Further optimization of the grease inlet channel: at least one grease inlet channel is a positioning grease inlet channel located on the wall of the grease supply chamber. This positioning grease inlet channel connects with the grease storage chamber when the plunger moves to the limit position of the compression and discharge chamber. When the plunger moves towards the compression and storage chamber, the positioning grease inlet channel is separated from the storage chamber and closed by the grease storage compression section. This eliminates the need for a unidirectional structure, resulting in a simple structure and good stability.

[0083] Further optimization of the in-place fat inlet channel, wherein the breathing chamber is used to form the in-place fat inlet channel through the breathing channel connected to the oil tank.

[0084] By optimizing the overflow structure, when the plunger moves toward the grease reservoir, the flow resistance of the grease flowing through the overflow structure is greater than the flow resistance flowing through the grease filling channel. Attached Figure Description

[0085] Figure 1 This is a partial structural schematic diagram of a specific embodiment 1 of the grease pump of the present invention;

[0086] Figure 2 This is a schematic diagram of another part of the structure of a specific embodiment 1 of the grease pump of the present invention;

[0087] Figure 3 This is a schematic diagram of the state of the plunger in the plunger pair when the plunger is in the grease discharge position in a specific embodiment 1 of the grease pump of the present invention (the arc arrow in the figure indicates the direction of movement of the eccentric wheel).

[0088] Figure 4This is a schematic diagram of the state of the plunger in the plunger pair moving from the grease discharge position to the grease storage position in a specific embodiment 1 of the grease pump of the present invention (the arc arrow in the figure indicates the direction of movement of the eccentric wheel, and the straight arrow indicates the direction of movement of the plunger).

[0089] Figure 5 This is a schematic diagram of the state of the plunger in the plunger pair when the plunger is in the grease storage position in a specific embodiment 1 of the grease pump of the present invention (the arc arrow in the figure indicates the direction of movement of the eccentric wheel).

[0090] Figure 6 This is a schematic diagram of the state of the plunger in the plunger pair moving from the grease storage position to the grease discharge position in a specific embodiment 1 of the grease pump of the present invention (the arc arrow in the figure indicates the direction of movement of the eccentric wheel, and the straight arrow indicates the direction of movement of the plunger).

[0091] Figure 7 This is a schematic diagram of the connection between the drive mechanism and the plunger in a specific embodiment 1 of the grease pump of the present invention;

[0092] Figure 8 This is a schematic diagram of the plunger assembly in a specific embodiment 2 of the grease pump of the present invention (the arc-shaped arrow in the figure indicates the direction of movement of the eccentric wheel).

[0093] Figure 9 This is a schematic diagram showing the state of the plunger in the plunger assembly when it is in the grease discharge position in a specific embodiment 3 of the grease pump of the present invention;

[0094] Figure 10 This is a schematic diagram of the plunger assembly in a specific embodiment 4 of the grease pump of the present invention;

[0095] Figure 11 This is a schematic diagram of the plunger assembly in a specific embodiment 5 of the grease pump of the present invention (the arc-shaped arrow in the figure indicates the direction of movement of the eccentric wheel).

[0096] Figure 12 This is a schematic diagram of the plunger pair in a specific embodiment 6 of the grease pump of the present invention (the arc-shaped arrow in the figure indicates the direction of movement of the eccentric wheel, and the straight arrow indicates the direction of movement of the plunger).

[0097] Figure 13 This is a structural schematic diagram of another state of the plunger pair in a specific embodiment 6 of the grease pump of the present invention (the arc arrow in the figure indicates the direction of movement of the eccentric wheel, and the straight arrow indicates the direction of movement of the plunger).

[0098] Figure 14 This is a schematic diagram of the plunger pair in a specific embodiment 7 of the grease pump of the present invention (the arc-shaped arrow in the figure indicates the direction of movement of the eccentric wheel, and the straight arrow indicates the direction of movement of the plunger).

[0099] Figure 15This is a structural schematic diagram of another state of the plunger pair in a specific embodiment 7 of the grease pump of the present invention (the arc arrow in the figure indicates the direction of movement of the eccentric wheel, and the straight arrow indicates the direction of movement of the plunger).

[0100] Figure 16 This is a schematic diagram of the shell cover in specific embodiment 7 of the grease pump of the present invention;

[0101] Figure 17 This is a schematic diagram of the plunger assembly in a specific embodiment 8 of the grease pump of the present invention (the arc-shaped arrow in the figure indicates the direction of movement of the eccentric wheel).

[0102] Figures 1 to 16 In the middle section: 1-oil tank; 2-pump head; 3-plunger pair; 31-outer shell; 311-grease reservoir; 312-grease discharge chamber; 313-shell; 314-shell cover; 315-shell cover perforation; 316-grease suction hole; 317-grease discharge port; 318-overflow gap; 319-breathing chamber; 32-grease discharge check valve; 321-valve seat; 322-valve core; 323-spring; 33-plunger; 331-grease discharge compression section; 332-grease reservoir compression section; 333-power connection section; 334-hook; 335-grease filling channel; 34-grease filling check valve; 341-valve ball; 342-spring; 4-drive mechanism; 41-drive shaft; 42-eccentric wheel; 43-ring groove; 6-umbrella-shaped check valve; 7-overflow valve; 3131-valve plate stop surface; 3142 - Housing cover channel; 8 - One-way valve plate; 81 - Valve plate perforation; 82 - Through groove; 10 - One-way valve diaphragm; 3141 - Housing cover oil inlet; 9 - Fixing sleeve; 91 - Annular protrusion;

[0103] Figure 17 In the middle: 33-plunger; 311-grease reservoir; 10-damping orifice. Detailed Implementation

[0104] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0105] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0106] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0107] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0108] Specific embodiment 1 of the grease pump of the present invention:

[0109] like Figure 1 and Figure 2 As shown, the grease pump includes an oil tank 1 and a pump head 2. The pump head 2 includes a pump head housing, a plunger assembly 3, and a drive mechanism 4 for driving the plunger assembly 3. In this embodiment, three plunger assemblies 3 are provided.

[0110] like Figures 3 to 6 As shown, the plunger assembly 3 includes a housing 31 and a grease discharge check valve 32 disposed within the housing 31. The housing 31 contains a grease supply chamber and a grease discharge chamber 312. The housing 31 is provided with a grease discharge port 317 for communicating with the grease discharge chamber 312. The grease discharge check valve 32 is disposed within the housing 31 to allow the grease in the grease discharge chamber 312 to be discharged unidirectionally through the grease discharge port 317.

[0111] The plunger 33 of the plunger assembly 3 is inserted into the housing 31, and the plunger 33 includes a grease discharge squeezing section 331, a power connection section 333, and a grease storage squeezing section 332. The grease discharge squeezing section 331 is slidably sealed with the housing 31. The grease discharge squeezing section 331, the grease discharge one-way valve 32, and the housing 31 form a grease discharge chamber 312. The grease storage squeezing section 332 is located between the grease discharge squeezing section 331 and the power connection section 333. The outer diameter of the grease storage squeezing section 332 is larger than the outer diameter of the grease discharge squeezing section 331 and also larger than the outer diameter of the power connection section 333, dividing the grease supply chamber into a grease storage chamber 311 and a breathing chamber 319. In the axial direction of the plunger, the breathing chamber 319 is located between the grease storage chamber 311 and the grease discharge chamber 312. The breathing chamber 319 and the grease storage chamber 311 are separated by the grease storage squeezing section 332, and the breathing chamber 319 and the grease discharge chamber are separated by the grease discharge squeezing section 331. That is, the plunger and the inner wall of the fat supply chamber form a fat storage chamber and a breathing chamber separated by the fat storage and compression section.

[0112] The outer casing 31 is provided with a liposuction hole 316 for communicating with the fat storage chamber 311, and the breathing chamber 319 communicates with the oil tank through the liposuction hole 316. In this embodiment, the liposuction hole constitutes a fat inlet channel for connecting the fat supply chamber and the oil tank.

[0113] In this embodiment, as Figure 7 As shown, the drive mechanism 4 for the reciprocating motion of the plunger pair 3 includes a drive shaft 41, an eccentric wheel 42 mounted on the drive shaft 41, and an annular groove 43 fixed on the outer circumference of the eccentric wheel 42. The power connection section 333 extends from the grease storage and extrusion section into the grease supply chamber and is equipped with a hook 334 that slides relative to the annular groove 43 within the annular groove 43. This drive mechanism is existing technology and will not be described in detail in this embodiment. In other embodiments, the plunger pair can replace the plunger pair in existing grease pumps, such as a single-plunger pump or a dual-plunger pump.

[0114] like Figure 3 As shown, one end face of the grease-squeezing section 332 faces the grease-discharging chamber 312, and engages with the outer shell 31 when the grease-squeezing section 331 compresses the volume of the grease-discharging chamber 312 to its minimum value. The other end face of the grease-squeezing section 332 faces away from the grease-discharging chamber 312, and engages with the outer shell 31 when the grease-squeezing section 332 compresses the volume of the grease-squeezing chamber 311 to its minimum value. Of course, in other embodiments, the position of the plunger can also be controlled by the formation of the drive mechanism, and the engagement between the end face of the grease-squeezing section and the outer shell is not necessary. Depending on factors such as the volume of the grease-squeezing chamber and the grease-discharging chamber, neither end face of the grease-squeezing section needs to engage with the outer shell.

[0115] The outer casing 31 includes a housing 313 and a cover 314. The housing 313 has a plunger inlet for inserting the plunger 33. The cover 314 is located at the plunger inlet and has a cover through hole 315 for the power connection section 333 of the plunger 33 to pass through. In this embodiment, the power connection section 333 extends out of the housing 313 after passing through the cover 314, and the power connection section 333 is clearance-fitted with the wall of the cover through hole 315. The grease storage chamber 311 is formed by the grease storage and extrusion section 332, the cover 314, the housing 313, and the power connection section. Since the power connection section passes through the grease storage chamber, the grease storage chamber 311 is an annular cavity, and the grease discharge chamber 312 is a cylindrical cavity.

[0116] To address the issue of insufficient grease removal during the grease suction process with plunger assembly 3, this embodiment employs a method where grease is first suctioned from the grease reservoir 311, and then the grease within the reservoir 311 is squeezed into the discharge chamber 312. For example... Figure 1As shown, the plunger 33 is provided with a grease filling channel 335 connecting the grease storage chamber 311 and the grease discharge chamber 312. A grease filling check valve 34 is provided within the grease filling channel 335. When the grease storage compression section 332 compresses the grease storage chamber 311, the grease pressure in the grease storage chamber 311 increases, the grease filling check valve 34 opens, and the grease enters the grease discharge chamber 312 through the grease filling channel 335. After the grease discharge chamber 312 is filled, the grease storage compression section 332 engages with the cover 314 to stop, and the plunger 33 moves in the other direction. The grease discharge compression section 331 compresses the grease discharge chamber 312. At this time, the grease filling check valve 34 closes, the pressure in the grease discharge chamber 312 increases, the grease discharge check valve 32 opens, and the grease is discharged through the grease discharge port 317.

[0117] To ensure sufficient grease is pumped from the grease reservoir 311 to the grease discharge chamber 312, in this embodiment, during the movement of the plunger 33, the difference between the maximum and minimum volume of the grease reservoir 311 is greater than the difference between the maximum and minimum volume of the grease discharge chamber 312, and the rate of change of the volume of the grease reservoir 311 is greater than the rate of change of the volume of the grease discharge chamber 312. In other words, the change in volume of the grease reservoir 311 per unit time is greater than the change in volume of the grease discharge chamber 312 per unit time. In this embodiment, the rate of change is twice that of the grease discharge chamber 311, ensuring that the grease reservoir 311 stores enough grease. In other embodiments, the rates of change can be adjusted according to actual needs, such as 3 times, 1.5 times, or 4 times.

[0118] During its stroke, the plunger 33 has a grease discharge position and a grease storage position, and the plunger 33 reciprocates between the grease discharge position and the grease storage position. When the plunger 33 moves to its limit position towards the grease storage chamber, it is in the grease storage position; when it moves to its limit position towards the grease discharge chamber, it is in the grease discharge position.

[0119] When the plunger 33 is in the grease discharge position, the grease in the grease discharge chamber 312 is squeezed out. The grease discharge chamber 312 has the smallest volume, and the grease storage chamber 311 has the largest volume. The grease suction hole 316 is connected to the grease storage chamber 311, and the grease enters the grease storage chamber 311 to be entered into the grease discharge chamber 312.

[0120] When the plunger 33 is in the grease storage position, the grease storage chamber 311 has the smallest volume and the grease discharge chamber 312 has the largest volume.

[0121] When the plunger 33 moves from the grease storage position to the grease discharge position, that is, moves towards the compression grease discharge chamber, the volume of the grease discharge chamber 312 gradually decreases, the pressure inside the grease discharge chamber 312 increases, the grease discharge check valve 32 opens when it reaches the opening pressure, the grease filling check valve 34 closes, the grease is discharged from the grease discharge port 317, the volume of the grease storage chamber 311 gradually increases, and a negative pressure is formed inside the grease storage chamber 311 until the grease suction port 316 communicates with the grease storage chamber 311, and the grease is sucked into the grease storage chamber 311 through the grease suction port 316.

[0122] When the plunger 33 moves from the grease discharge position to the grease storage position, that is, when it moves towards the compression of the grease storage chamber, the volume of the grease discharge chamber 312 gradually increases, the pressure of the grease discharge chamber 312 decreases, the grease discharge check valve 32 closes, the grease storage compression section 332 compresses the grease storage chamber 311, the grease storage chamber 311 is disconnected from the grease suction hole 316, the pressure of the grease storage chamber 311 increases, and the grease filling check valve 34 opens when it reaches the opening pressure, and the lubricating grease enters the grease discharge chamber 312 through the grease filling channel 335.

[0123] Because the rate of change of volume in the grease reservoir 311 is greater than that in the grease discharge chamber 312, excess grease in the grease reservoir 311 is discharged through an overflow structure to ensure smooth operation. In this embodiment, the overflow structure is a fitting gap between the power connection section 333 and the cover 314, forming an overflow gap 318 for excess grease to overflow from the grease reservoir 311. This gap allows excess grease to overflow, ensuring normal grease storage in the grease discharge chamber 312. When the plunger 33 moves from the grease discharge position to the grease reservoir position, the flow resistance of the grease in the grease reservoir 311 flowing through the overflow structure is greater than the flow resistance flowing through the grease filling channel 335, thus preferentially injecting the grease in the grease reservoir 311 into the grease discharge chamber. The overflow structure should complete the overflow before the grease discharge check valve opens.

[0124] Since the entire plunger assembly 3 is in a grease environment, the overflow gap 318 can also allow a small amount of grease to enter the grease reservoir 311 through the overflow gap 318 when the grease discharge chamber 312 is squeezed and discharged outward.

[0125] In this embodiment, as Figure 3 As shown, the grease filling check valve 34 is located at the end of the grease filling channel 335 near the grease discharge chamber 312. The grease filling check valve 34 includes a valve ball 341 and a spring 342 that applies elastic force to the valve ball 341. The grease discharge check valve 32 includes a valve seat 321 threadedly fixed in the housing 313. A valve core 322 is guided and slidably mounted on the valve seat 321. The valve core 322 includes a valve stem, a sealing gasket fixed on the valve stem, and a pressing block fixed on the valve stem to press the sealing gasket. A spring 323 is also sleeved on the valve stem. The spring 323 presses against the valve seat 321 and the pressing block to apply elastic force to the valve core 322. In other embodiments, the grease discharge check valve can also be a ball valve.

[0126] In this embodiment, the length of the fat storage and squeezing section 332 is relatively small, less than the maximum dimension of the suction port 316 in the axial direction of the plunger 33. This is to prevent the fat storage and squeezing section 332 from blocking the suction port 316. After the fat storage and squeezing section 332 is disconnected from the suction port 316, the breathing chamber 319 communicates with the suction port 316, preventing the formation of a vacuum that could hinder the movement of the plunger 33. In this embodiment, two suction ports 316 are provided, arranged opposite each other to increase the rate of fat intake.

[0127] In this embodiment, when the grease pump is working, the eccentric wheel 42 of the drive mechanism 4 rotates, driving the three plunger pairs 3 to move, such as... Figure 3 The image shows plunger 33 in the grease discharge position. At this time, the suction port 316 is connected to the grease reservoir 311, which is full of grease. The eccentric wheel 42 continues to rotate, pulling plunger 33 outwards from the housing 313. The grease compression section 332 compresses the grease reservoir 311, breaking the connection between the suction port 316 and the grease reservoir 311. The grease in the reservoir 311 is compressed, increasing the pressure. A negative pressure is generated in the discharge chamber 312, closing the discharge check valve 32 and opening the filling check valve 34. The filling channel 335 connects the reservoir 311 and the discharge chamber 312. Under the combined action of the discharge chamber 312 suctioning grease and the reservoir 311 compressing grease, grease enters the discharge chamber 312 through the filling channel 335. Simultaneously, a small amount of excess grease is discharged from the housing 313 through the overflow gap 318. Figure 4 As shown, the eccentric wheel 42 continues to rotate until the grease in the grease reservoir 311 is squeezed out and the grease discharge chamber 312 is filled with grease, as... Figure 5 As shown, at this time, the plunger 33 is in the grease reservoir position, and the grease filling check valve 34 is closed.

[0128] like Figure 6 As shown, the eccentric wheel 42 continues to rotate, and the plunger 33 moves from the grease storage position to the grease discharge position. The pressure in the grease storage chamber 311 decreases, creating a negative pressure. A small amount of grease enters the grease storage chamber 311 through the overflow gap 318. The grease discharge squeezing section 331 squeezes the grease discharge chamber 312, and the grease discharge check valve 32 opens. The grease is discharged through the grease discharge port 317 until the grease in the grease discharge chamber 312 is discharged. The grease storage chamber 311 continues to enlarge, and the grease suction hole 316 connects to the grease storage chamber 311, drawing grease from the oil tank 1 into the grease storage chamber 311. After the grease is discharged from the grease discharge chamber 312, the grease discharge check valve 32 closes, completing one grease storage and discharge cycle. During the rotation of the eccentric wheel 42, the three plunger pairs 3 perform grease discharge operations in sequence.

[0129] When the grease pump of the present invention is working, the grease in the grease reservoir 311 is compressed by the grease compression section 332. If there are air bubbles in the grease reservoir 311, the air bubbles will be fully compressed, greatly reducing the volume occupied by the air bubbles in the grease discharge chamber 312, thus ensuring the grease discharge accuracy of the grease pump. In other embodiments, damping holes can also be added to the wall of the grease reservoir to allow excess grease to be discharged from the damping holes.

[0130] The plunger assembly 3 of the present invention transforms the active grease suction of the plunger 33 into a dual function of active grease suction and external grease injection, ensuring that the grease storage chamber 311 of the plunger 33 can be filled with grease during each grease suction process under conditions of low temperature, viscous grease or grease containing air bubbles, thereby achieving the purpose of precise oil delivery by the grease pump.

[0131] In other embodiments, the rates of change of the fat storage chamber volume and the rate of change of the fat elimination chamber volume can be adjusted according to actual needs. The rate of change of the fat storage chamber volume can be less than or greater than twice the rate of change of the fat elimination chamber volume, but preferably greater than the rate of change of the fat elimination chamber volume. In other embodiments, the rate of change of the fat storage chamber volume does not have to be linear; at a certain moment, the rate of change can be less than the rate of change of the fat elimination chamber volume, but it should satisfy the following: the difference between the maximum and minimum values ​​of the fat storage chamber volume is greater than the difference between the maximum and minimum values ​​of the fat elimination chamber volume. Of course, in other embodiments, the rates of change of both do not have to be constant; for example, the rates of change of both can be equal for a period of time during the movement.

[0132] In a specific embodiment 2 of the grease pump of the present invention, the structure of the grease pump in this embodiment differs from that in specific embodiment 1 above only in that: Figure 8 As shown, in this embodiment, the overflow structure includes an overflow channel 5 and an overflow valve 7 disposed on the overflow channel. The overflow channel 5 is disposed on the power connection section 333 to connect the grease reservoir 311 and the oil tank. Excess grease in the grease reservoir 311 is discharged through the overflow valve 7. The flow resistance of the grease in the grease reservoir flowing through the overflow channel is greater than the flow resistance flowing through the grease filling channel.

[0133] Specific embodiment 3 of the grease pump of the present invention differs from that in specific embodiment 1 only in that: Figure 9 As shown, in this embodiment, an umbrella-shaped one-way valve 6 is provided around the grease storage and compression section 332. The inner ring of the umbrella-shaped one-way valve 6 is fixed to the grease storage and compression section 332, and the outer ring of the umbrella-shaped one-way valve 6 is unidirectionally sliding and sealing with the housing 313. When the plunger 33 moves to the grease discharge position, the large end of the umbrella-shaped one-way valve 6 narrows, allowing grease to enter the grease storage chamber 311 unidirectionally from the breathing chamber. When the plunger 33 moves to the grease storage position, the umbrella-shaped one-way valve 6 is sealed against the inner wall of the grease storage chamber 311, compressing the grease in the grease storage chamber 311 and allowing it to enter the grease discharge chamber 312. The umbrella-shaped one-way valve constitutes a grease storage one-way structure provided on the grease storage and compression section, and the annular channel formed between the grease storage and compression section and the housing constitutes the grease inlet channel of the grease storage chamber 311 wall.

[0134] Specific embodiment 4 of the grease pump of the present invention differs from that in specific embodiment 1 only in that: Figure 10 As shown, if the ambient temperature of the grease pump is too low and the grease viscosity is too high, the excess grease will be discharged from the grease reservoir 311 through the overflow gap alone, resulting in significant resistance and excessive load on the power components of the grease pump. In this embodiment, an overflow valve 7 is provided on the housing cover 314. When the grease discharge resistance is too high, the overflow valve 7 opens, discharging the excess grease into the pump head housing. Figure 10As shown, in this embodiment, the relief valve 7 is a one-way ball valve. In other embodiments, relief can also be achieved solely through the relief valve.

[0135] In a specific embodiment 5 of the grease pump of the present invention, the structure of the grease pump in this embodiment differs from that in specific embodiment 4 above only in that: Figure 11 As shown, in this embodiment, the overflow valve 7 is disposed on the cavity wall of the grease discharge chamber 312. When the plunger 33 moves toward the grease storage chamber, the grease enters the grease discharge chamber 312 through the grease filling check valve 34, and then is discharged through the overflow valve 7. In this embodiment, the overflow valve 7 is used to discharge excess grease from the grease discharge chamber.

[0136] Specific embodiment 6 of the grease pump of the present invention differs from that in specific embodiment 1 only in that: Figure 12 and Figure 13 As shown, there is a cover channel 3142 between the cover 314 and the plunger 33 for grease to pass through. The cover channel 3142 is an annular channel. A one-way valve plate 8 is provided on the inner side of the cover 314. The one-way valve plate 8 has a valve plate through hole 81 for the plunger 33 to pass through. The one-way valve plate 8 can move along the axial direction of the plunger 33. The one-way valve plate 8 has a sealing position that is in contact with the cover 314 when the plunger moves toward the compression grease storage chamber and a grease inlet position that is separated from the cover 314 when the plunger moves toward the compression grease discharge chamber. The housing 313 is provided with a valve plate stop surface 3131 that is in contact with the one-way valve plate 8 and the grease inlet position. When the one-way valve plate 8 is in the sealing position, it is in contact with the cover 314. The one-way valve plate 8 is provided with a grease inlet channel. When the one-way valve plate 8 is in the grease inlet position, the grease inlet channel is connected to the cover channel 3142 to allow lubricating grease to enter the grease reservoir. When the one-way valve plate 8 is in the sealing position, it is blocked by the cover 314 and closed. The grease inlet channel of the valve plate and the cover channel 3142 together form the grease inlet channel of the grease reservoir 311 wall. The one-way valve plate 8 constitutes a one-way grease reservoir structure provided on the wall of the grease reservoir 311.

[0137] In this embodiment, the grease inlet channel of the valve plate is a through groove 82 extending axially along the plunger 33 on the valve plate, and the through groove 82 is located at the edge of the one-way valve plate 8. The outer diameter of the one-way valve plate 8 is larger than the minimum radius of the valve plate stop surface 3131, and the distance from the bottom of the through groove 82 to the axis of the one-way valve plate 8 is smaller than the minimum radius of the valve plate stop surface 3131, so that the through groove 82 is always in communication with the grease storage cavity 311.

[0138] In this embodiment, the one-way valve plate 8 and the plunger 33 are in clearance fit, and the overflow structure includes a gap disposed between the one-way valve plate 8 and the plunger 33. The gap between the one-way valve plate 8 and the plunger 33 is always in communication with the cover channel 3142. In other embodiments, an overflow one-way valve can be provided on the wall of the grease storage chamber.

[0139] When negative pressure is generated in the grease reservoir 311, the sealing fit between the one-way valve plate 8 and the cover 314 is released, allowing grease to enter the grease reservoir 311 from the outside through the cover channel 3142 and then along the valve plate grease inlet channel. Conversely, when positive pressure is generated in the grease reservoir 311, the one-way valve plate 8 and the cover 314 seal, preventing grease from flowing out of the reservoir 311 through the grease inlet channel on the wall. Excess grease can be discharged through the gap between the one-way valve plate 8 and the plunger 33. Because the resistance to grease flowing out through the gap is greater than the flow resistance through the filling channel, a large amount of grease enters the discharge chamber through the filling channel. Before the discharge chamber is completely filled, a small amount of grease is discharged through the overflow structure; after the discharge chamber is full, excess grease is discharged through the overflow structure.

[0140] In other embodiments, through holes may be provided on the one-way valve plate instead of through slots. In other embodiments, a retaining ring may also be provided to stop the one-way valve plate at the grease inlet position.

[0141] Specific embodiment 7 of the grease pump of the present invention differs from that in specific embodiment 5 above only in that: Figures 14 to 16 As shown, in this embodiment, the cover 314 is provided with an oil inlet 3141, and a grease storage check valve diaphragm 10 is provided on the inner orifice of the oil inlet 3141. The cover 314 is provided with a fixing sleeve 9 to fix the grease storage check valve diaphragm 10. The plunger 33 passes through the fixing sleeve 9. The through hole of the cover 314 is a threaded hole. The fixing sleeve 9 is threadedly connected to the through hole of the cover 314. One end of the fixing sleeve 9 that extends into the grease storage cavity 311 is provided with an annular protrusion 91. The grease storage check valve diaphragm 10 is sandwiched between the annular protrusion 91 and the cover 314. The fixing sleeve 9 and the plunger 33 are clearance-fitted, and the overflow structure includes an overflow gap provided between the fixing sleeve 9 and the plunger 33.

[0142] When the pressure inside the grease reservoir 311 decreases, creating a negative pressure, the grease reservoir check valve diaphragm 10 deforms to open the orifice of the cover 314, allowing external grease to enter the grease reservoir 311 through the oil inlet 3141 of the cover. Conversely, when the pressure inside the grease reservoir 311 increases, creating a positive pressure, the grease reservoir check valve diaphragm 10 covers the orifice of the cover 314, closing the oil inlet of the cover 314. In this embodiment, the oil inlet of the cover constitutes a grease inlet channel in the grease reservoir wall, and the orifice of the cover 314 constitutes the grease inlet opening of the grease reservoir wall. The grease reservoir check valve diaphragm deforms to open the grease inlet opening of the grease reservoir wall when the pressure inside the grease reservoir decreases, allowing grease to enter the grease reservoir. The grease reservoir check valve diaphragm constitutes a one-way grease reservoir structure.

[0143] The grease in the grease reservoir 311 can be discharged through the overflow gap 318 between the fixed sleeve and the plunger 33.

[0144] In other embodiments, a one-way valve for lubricating grease to enter the grease reservoir can also be provided on the housing. The valve core of the one-way valve can be a valve ball or a valve plate. In this case, a damping hole can be opened on the valve ball or valve plate. The damping hole forms an overflow structure, and the plunger and the housing slide and seal together.

[0145] Specific embodiment 8 of the grease pump of the present invention differs from that in specific embodiment 2 above only in that: Figure 17 As shown, in this embodiment, a damping orifice 10 is provided on the plunger 33. The damping orifice 10 connects the grease reservoir 311 and the oil tank to discharge excess grease. When the plunger 33 moves toward compressing the grease reservoir 311, the flow resistance of the grease in the grease reservoir 311 flowing through the damping orifice 10 is greater than the flow resistance flowing through the grease filling channel. In other embodiments, the damping orifice can also be provided on the outer casing.

[0146] The specific embodiment of the grease pump of the present invention is 9. The only difference between the structure of the grease pump in this embodiment and that in the specific embodiment 1 above is that the grease filling channel is set on the outer shell.

[0147] In a specific embodiment 10 of the grease pump of the present invention, the structure of the grease pump differs from that in specific embodiment 1 above only in that the plunger also has a guide section passing through the grease discharge chamber, which is an annular cavity. In this case, the outer diameters of the grease discharge extrusion section and the grease storage extrusion section can be equal.

[0148] In the above embodiments, the grease pump is a lubrication pump; in other embodiments, the grease pump may also be an electric grease dispenser.

[0149] A specific embodiment of the pump head of the present invention: The pump head includes a pump head housing, a plunger assembly disposed within the pump head housing, and a drive mechanism. The structure of the plunger assembly is the same as that of the plunger assembly described in the specific embodiment of the grease pump above, and will not be repeated here.

[0150] A specific embodiment of the plunger pair of the present invention: The structure of the plunger pair is the same as that of the plunger pair described in the specific embodiment of the grease pump above, and will not be repeated here.

[0151] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. Plunger assembly, including: The outer shell contains a fat-draining chamber, and the outer shell is provided with a fat-draining port for communicating with the fat-draining chamber; The grease discharge check valve allows the grease in the grease discharge chamber to be discharged in one direction through the grease discharge port; Its features are, The outer shell also contains a fat supply chamber with a diameter larger than that of the fat discharge chamber; A plunger, inserted into a housing, has a grease discharge extrusion section, a grease storage extrusion section, and a power connection section. The grease discharge extrusion section is slidably and sealed into the grease discharge chamber to expel grease from the grease discharge chamber. The grease storage extrusion section is movable and positioned in the grease supply chamber. The outer diameter of the grease storage extrusion section is larger than the outer diameter of the grease discharge extrusion section and larger than the outer diameter of the power connection section. The grease storage extrusion section, the power extrusion section, and the grease discharge extrusion section, together with the inner wall of the grease supply chamber, form a grease storage chamber and a breather chamber separated by the grease storage extrusion section. The breather chamber is located between the grease storage chamber and the grease discharge chamber and is used to communicate with the oil tank. The grease storage chamber is used to supply grease to the grease discharge chamber. The grease filling channel, located on the plunger or the outer shell, is used to connect the grease storage chamber and the grease discharge chamber. The grease filling channel is equipped with a grease filling check valve to allow the lubricating grease to enter the grease discharge chamber in one direction. The grease storage and squeezing section is used to squeeze the grease in the grease storage chamber. The end of the power connection section away from the grease storage and squeezing section extends out of the grease supply chamber to connect with the drive mechanism. The drive mechanism drives the plunger to reciprocate. When the grease discharge and squeezing section squeezes the grease discharge chamber, the direction of the plunger's movement is opposite to the direction of the plunger's movement when the grease storage and squeezing section squeezes the grease storage chamber. During the stroke of the plunger, the difference between the maximum and minimum volume of the grease reservoir is greater than the difference between the maximum and minimum volume of the grease discharge chamber. The outer shell or the plunger has an overflow structure for discharging excess grease from the grease reservoir or the grease discharge chamber. The outer casing is provided with a grease inlet channel for connecting the grease storage chamber and the oil tank. During the process of the plunger moving towards the compression and discharge chamber, the grease filling check valve is closed. The grease inlet channel is used to connect the grease storage chamber and the oil tank. The grease in the oil tank is introduced into the grease storage chamber, and the discharge check valve opens when it reaches the opening pressure, and the grease in the discharge chamber is squeezed out. When the plunger moves toward the compression grease reservoir, the grease discharge check valve closes, and the grease filling check valve opens when it reaches the opening pressure, allowing the grease in the reservoir to enter the grease discharge chamber through the filling channel.

2. The plunger assembly according to claim 1, characterized in that, At least one grease inlet channel is a grease inlet channel provided on the wall of the grease storage chamber. The grease inlet channel is provided with a one-way grease storage structure. When the plunger moves toward the compression and discharge grease chamber, the one-way grease storage structure allows lubricating grease to enter the grease storage chamber in one direction. When the plunger moves toward the compression and grease storage chamber, the grease inlet channel is closed.

3. The plunger assembly according to claim 2, characterized in that, The grease storage one-way structure is a one-way valve installed on the outer shell or plunger.

4. The plunger assembly according to claim 2, characterized in that, The outer casing includes a housing and a cover. The housing has a plunger inlet for inserting a plunger. The cover is located at the plunger inlet and has a cover perforation for the plunger to pass through. There is a cover channel for grease to pass through on the cover or between the cover and the plunger. The grease storage one-way structure is a one-way valve plate located inside the cover. The one-way valve plate has a valve plate perforation for the plunger to pass through. The one-way valve plate can move along the plunger axial direction. The one-way valve plate has a sealing position that is in contact with the cover when the plunger moves toward the compression grease storage chamber, and a grease inlet position that is separated from the cover when the plunger moves toward the compression discharge grease chamber. The one-way valve plate has a valve plate grease inlet channel. When the one-way valve plate is in the grease inlet position, the valve plate grease inlet channel is connected to the cover channel to allow grease to enter the grease storage chamber. When the one-way valve plate is in the sealing position, it is blocked by the cover and closed. The valve plate grease inlet channel and the cover channel together form the grease inlet channel of the grease storage chamber wall.

5. The plunger assembly according to claim 4, characterized in that, The one-way valve plate and the plunger are fitted with a clearance, and the overflow structure includes the clearance between the one-way valve plate and the plunger.

6. The plunger assembly according to claim 2, characterized in that, The outer casing includes a housing and a cover. The housing has a plunger inlet for inserting the plunger, and the cover is located at the plunger inlet. The cover has a cover perforation for the plunger to pass through. A grease inlet channel for the grease storage chamber wall is located on the cover. The grease storage one-way structure includes a grease storage one-way valve diaphragm fixed inside the cover to cover the grease inlet channel opening of the grease storage chamber wall. When the plunger moves toward the compression and discharge chamber, the grease storage one-way valve diaphragm opens the grease inlet channel opening of the grease storage chamber wall through elastic deformation to allow lubricating grease to enter the grease storage chamber. When the plunger moves toward the compression and grease storage chamber, it covers the grease inlet channel opening of the grease storage chamber wall and closes the grease inlet channel.

7. The plunger assembly according to claim 3, characterized in that, The grease storage one-way structure is an umbrella-shaped one-way valve installed on the grease storage extrusion section. The outer edge of the umbrella-shaped one-way valve is in one-way sealing fit with the outer shell. When the umbrella-shaped one-way valve is opened, the annular channel formed between the grease storage extrusion section and the outer shell constitutes the grease inlet channel of the grease storage chamber. The umbrella-shaped one-way valve allows lubricating grease to enter the grease storage chamber one-way from the breathing chamber.

8. The plunger assembly according to any one of claims 1-6, characterized in that, The grease storage and extrusion section is in sliding and sealing fit with the inner wall of the grease supply chamber.

9. The plunger assembly according to any one of claims 1-7, characterized in that, The overflow structure includes an overflow gap disposed between the outer shell and the plunger, the overflow gap being used to connect the grease reservoir to the oil tank.

10. The plunger assembly according to any one of claims 1-7, characterized in that, The overflow structure includes an overflow valve disposed on the housing.

11. The plunger assembly according to claim 10, characterized in that, The overflow valve is installed on the wall of the fat discharge chamber or fat storage chamber.

12. The plunger assembly according to any one of claims 1-7, characterized in that, The overflow structure includes an overflow channel and an overflow valve installed on the overflow channel. The overflow channel is installed on the power connection section to connect the grease reservoir and the oil tank.

13. The plunger assembly according to any one of claims 1-7, characterized in that, The overflow structure includes a damping hole that connects the grease reservoir to the oil tank, and the damping hole is located on the plunger or the outer shell.

14. The plunger assembly according to any one of claims 1-7, characterized in that, At least one grease inlet channel is a positioning grease inlet channel provided on the wall of the grease supply chamber. The positioning grease inlet channel is connected to the grease storage chamber when the plunger moves to the limit position of the compression grease discharge chamber. When the plunger moves in the direction of compressing the grease storage chamber, the positioning grease inlet channel is separated from the grease storage chamber and closed by the grease storage compression section.

15. The plunger assembly according to claim 14, characterized in that, The breathing chamber is used to form the in-place fat inlet channel through a breathing channel that communicates with the fuel tank.

16. The plunger assembly according to any one of claims 1-7, characterized in that, When the plunger moves toward the grease reservoir, the flow resistance of the grease flowing through the overflow structure is greater than the flow resistance flowing through the filling channel.

17. A pump head, comprising a pump head housing, a plunger assembly disposed within the pump head housing, and a drive mechanism, characterized in that, The plunger assembly is the plunger assembly as described in any one of claims 1-16.

18. A grease pump, comprising a tank and a pump head, the pump head comprising a pump head housing, a plunger assembly disposed within the pump head housing, and a drive mechanism, characterized in that, The plunger assembly is the plunger assembly as described in any one of claims 1-16.

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