CN120739689B - Crankshaft pump - Google Patents

Abstract

The utility model relates to a crankshaft pump includes the pump body, bent axle subassembly, a plurality of piston assemblies and business turn over water valve subassembly, has water inlet, delivery port, bent axle chamber, piston chamber, valve pocket in the pump body, and bent axle subassembly is adorned in the bent axle chamber, and piston chamber is located to the piston assembly, and valve pocket intercommunication piston chamber and business turn over water port, business turn over water valve subassembly are in the valve pocket. The piston assembly comprises a piston rod, a sleeve block, a connecting block and a connecting rod, wherein the piston rod is in sealed sliding in a piston cavity, the connecting block is connected with the piston rod and the connecting rod, the connecting rod is connected with the crankshaft assembly, the sleeve block is arranged in the pump body, and the piston rod and the connecting rod are in sealed sliding at two ends in the sleeve block to form a sealed annular gap. The piston rod is provided with a first cooling groove, the connecting rod is provided with a second cooling groove, and a first one-way valve is arranged in the second cooling groove. The pump body is provided with a return channel which is connected with the second cooling groove and the water inlet. When pumping water, the water enters the second cooling groove through the first one-way valve, and returns to the water inlet through the connecting channel, the annular gap, the open groove and the return channel to form circulating cooling, so that heat is taken away, stable operation of the pump is ensured, and the service life is prolonged.

Description

Crankshaft pump

Technical Field

The invention relates to the field of fluid conveying equipment, in particular to a crankshaft pump.

Background

The crankshaft pump is used as common fluid conveying equipment and is widely applied to the fields of industry, agriculture, municipal administration and the like. Crankshaft pumps typically include components such as a crankshaft, connecting rods, pistons, pump bodies, water inlet and outlet check valves, and the like. The crankshaft is used as a key component for power transmission, the piston is driven to reciprocate in the cylinder body through the connecting rod, the pump body provides space for the piston to move and accommodates liquid, the water inlet and outlet one-way valve is used for controlling the flow direction of the liquid, and the liquid is ensured to flow in one direction only, so that the liquid is sucked and discharged.

In the high-speed reciprocating motion of the piston rod, a large amount of heat is generated due to friction, medium impact and the like, the connecting rod bears periodic alternating load and friction force during operation, the material performance is easy to be reduced due to high temperature, if the crankshaft pump works for a long time in a high-temperature state, the working state of the pump is unstable, the fluctuation of parameters such as pressure, flow and the like is large, the output stability cannot be ensured, and the whole service life of the pump is also greatly shortened.

Disclosure of Invention

In order to improve the heat dissipation effect of a crankshaft pump, the application provides the crankshaft pump.

The application provides a crankshaft pump which adopts the following technical scheme:

The crankshaft pump comprises a pump body, a crankshaft assembly, a plurality of piston assemblies and a water inlet and outlet valve assembly, wherein a water inlet, a water outlet, a crankshaft cavity, a plurality of piston cavities and a plurality of valve cavities are arranged in the pump body;

The piston assembly comprises a piston rod, a sleeve block, a connecting block and a connecting rod, wherein the piston rod is arranged in a piston cavity and is in sealing sliding fit with the inner wall of the piston cavity, two ends of the connecting block are respectively arranged on the piston rod and the connecting rod, the other end of the connecting rod is connected with the crankshaft assembly, the sleeve block is arranged in a pump body, the piston rod and the connecting rod are respectively arranged in the sleeve block and are respectively in sealing sliding fit with two ends of the sleeve block, and a sealed annular gap is formed between the sleeve block and the connecting rod and between the sleeve block and the piston rod;

The piston rod is internally provided with a first cooling groove, the connecting rod is internally provided with a second cooling groove, the connecting block is internally provided with a communication groove which is respectively communicated with the first cooling groove and the second cooling groove, the communication groove is internally provided with a first one-way valve which only allows fluid to enter the second cooling groove in a one-way manner, the inner wall of the second cooling groove is provided with a communication channel which is communicated with an annular gap, the sleeve block is penetrated and provided with an opening groove which is communicated with the annular gap, and the pump body is internally provided with a backflow channel which is communicated with the opening groove and the water inlet.

By adopting the technical scheme, the piston rod and the connecting rod can be cooled by utilizing the fluid in the pump body, when the piston rod pumps water, the first one-way valve is closed, when the piston rod pumps water, the water can be pumped out from the water outlet, the first one-way valve can be opened to enter the second cooling tank, then the water in the second cooling tank enters the annular gap through the communicating channel, finally, the water returns to the water inlet through the open channel and the backflow channel, a circulating cooling path is formed, the heat generated by friction and medium impact of the piston rod and the connecting rod is effectively taken away, the material performance of the piston rod and the connecting rod is prevented from being reduced due to high temperature, and therefore long-term stable operation of the crankshaft pump is ensured, and the whole service life of the crankshaft pump is prolonged.

Preferably, a nozzle is installed in the communication groove, and the nozzle is positioned on one side of the first one-way valve facing the second cooling groove.

Through adopting above-mentioned technical scheme, the nozzle can be with getting into the water of second cooling tank and spouting with high-pressure jet form, strengthens contact efficiency and the impact force of water and second cooling tank inner wall, further promotes the radiating effect to the connecting rod, avoids the connecting rod to lead to the material performance to descend because of the high temperature.

Preferably, the nozzle is a hollow cone nozzle.

By adopting the technical scheme, the hollow cone nozzle can enable the cooling fluid to form fan-shaped or cone-shaped diffusion spray, so that the contact area between the cooling fluid and the inner wall of the second cooling tank is greatly enlarged, and compared with a common direct injection nozzle, the connecting rod heating area can be covered more uniformly, and the uniformity and the efficiency of heat dissipation are further optimized.

Preferably, the device further comprises a second one-way valve, a volume changing assembly and an air inlet balance assembly, wherein the second one-way valve is arranged in the connecting channel and only used for enabling water in the second cooling groove to flow to the annular gap, the volume changing assembly comprises a movable piston head which is connected in the second cooling groove in a sliding way, the piston head divides the second cooling groove into a front groove and a rear groove which are not communicated with each other, the nozzle acts in the front groove, and the connecting channel is only communicated with the front groove;

the air inlet balancing component is used for balancing air pressure in the rear groove in the process that the piston head moves towards the front groove side, balancing air pressure in the front groove and the rear groove in the process that the piston head moves towards the rear groove side, and the single water spraying amount of the spray nozzle is smaller than the single volume change amount of the front groove.

By adopting the technical scheme, the second one-way valve can prevent fluid in the check flow channel from flowing backwards to the front groove, ensure the one-way circulation of the cooling loop, and particularly aim at the condition that the water inlet is connected with a high-pressure water source, when the piston rod is in a pumping state, the piston head moves towards one side of the front groove, the first one-way valve is closed at the moment, the piston head presses water in the front groove back to the water inlet together with air under the change of the volume of the front groove, when the piston rod is in a pumping state, the piston head moves towards one side of the rear groove, the first one-way valve is opened at the moment, the second one-way valve is closed, and meanwhile, the front groove is filled with air, so that the circulation is realized.

Preferably, the volume change assembly further comprises a fixing block and a butt joint block, the butt joint block is coaxially fixed on one side surface of the piston head, which faces the rear groove, the fixing block is in an L-shaped structure, an installation groove matched with the fixing block is formed in the pump body, the top end of the fixing block is fixed in the installation groove through a screw, a butt joint ring groove is circumferentially formed in the butt joint block, a sliding groove for sliding the fixing block is formed in the inner wall of one side, which faces the installation groove, of the rear groove, the bottom end of the fixing block penetrates through the sliding groove and then is inserted into the butt joint ring groove, the sliding groove is located on one side, close to the crankshaft assembly, of the annular gap, and the piston head is always located on one side, far away from the crankshaft assembly, of the sliding groove.

Through adopting above-mentioned technical scheme, the fixed block is fixed in the mounting groove of the pump body, and fixed block and butt joint piece fixed connection simultaneously for the piston head remains static with the pump body all the time, and when the bent axle subassembly drove the connecting rod motion, the piston head can take place the mutual slip with the connecting rod, thereby the volume change in control front groove.

Preferably, the air inlet balance assembly comprises a third one-way valve, a mounting hole, a first groove and a second groove, wherein the first groove is formed in the pump body, the first groove is located at one side of the annular gap, which is close to the crankshaft assembly, and is communicated with the sliding groove, the second groove is formed in the outer side wall of the fixed block in a penetrating manner along the length direction of the fixed block, the first groove, the second groove and the sliding groove are mutually communicated, the mounting hole is formed in the connecting rod, two ends of the mounting hole are respectively communicated with the first groove and the front groove, and the third one-way valve is mounted in the mounting hole and used for only allowing external air to enter the front groove.

By adopting the technical scheme, when the piston head moves towards the rear groove, the first one-way valve is opened, water is sprayed out from the spray nozzle, the second one-way valve is closed, meanwhile, external air can enter the front groove through the third one-way valve to balance air pressure, when the piston head moves towards the front groove, the first one-way valve and the third one-way valve are both closed, the second one-way valve is opened, and water and air in the front groove are simultaneously pressed into the annular gap, so that efficient cooling circulation is realized.

Preferably, when the piston rod moves forward to the limit position of the pumping state, and the piston head moves to the abutting block abutting against the end wall of the rear groove, the bottom end of the fixed block is opposite to the abutting ring groove.

By adopting the technical scheme, a reliable position relationship is provided for the butt joint of the fixed block and the butt joint block.

Preferably, a first annular groove is formed in the circumferential outer wall of the sleeve block, and the open groove is communicated with the return channel through the first annular groove.

By adopting the technical scheme, no matter how the sleeve block is installed, the first annular groove can be always kept communicated with the backflow channel, so that the convenience of sleeve block installation is improved.

The technical effects of the invention are mainly as follows:

1. When the piston rod pumps water, the pressure in the piston cavity becomes large, the water can be pumped out from a water outlet, the first one-way valve can be opened to enter the second cooling groove, then the water in the second cooling groove enters an annular gap through a communicating channel, finally, the water returns to a water inlet through an opening groove and a return channel to form a circulating cooling path, heat generated by friction and medium impact of the piston rod and the connecting rod is effectively taken away, and material performance reduction caused by high temperature of the piston rod and the connecting rod is avoided, so that long-term stable operation of the crankshaft pump is ensured, and the whole service life of the crankshaft pump is prolonged;

2. The nozzle can spray water entering the second cooling tank in a high-pressure jet flow mode, so that the contact efficiency and impact force of the water and the inner wall of the second cooling tank are enhanced, the heat dissipation effect on the connecting rod is further improved, and the material performance of the connecting rod is prevented from being reduced due to high temperature;

3. The second one-way valve can prevent the fluid in the non-return flow channel from flowing back to the front groove, so that the one-way circulation of the cooling loop is ensured, and the condition that the water inlet is connected with a high-pressure water source is particularly aimed at; when the piston rod is in a pumping state, the piston head moves towards one side of the front groove, the first one-way valve is closed at the moment, the piston head presses water in the front groove back to the water inlet together with air under the change of the volume of the front groove, and when the piston rod is in a pumping state, the piston head moves towards one side of the rear groove, the first one-way valve is opened at the moment, the second one-way valve is closed, and meanwhile, the front groove is charged with air to realize circulation.

Drawings

Fig. 1 is a schematic overall structure of an embodiment of the present application.

Fig. 2 is a cross-sectional view taken along line A-A of fig. 1.

Fig. 3 is an enlarged view at B in fig. 2.

The reference numerals are 1, a pump body, 11, a water inlet, 12, a water outlet, 13, a crank shaft cavity, 14, a piston cavity, 15, an inlet valve cavity, 16, an outlet valve cavity, 17, a back flow channel, 18, a mounting groove, 2, a crank shaft assembly, 21, a crank shaft, 22, a pump shaft, 3, a piston assembly, 31, a piston rod, 311, a first cooling groove, 32, a connecting block, 321, a communicating groove, 33, a connecting rod, 331, a second cooling groove, 3311, a front groove, 3312, a rear groove, 333, a sliding groove, 34, an annular gap, 35, a communicating channel, 4, a sleeve block, 41, a left block, 42, a right block, 421, a first annular groove, 43, an open groove, 44, a sealing ring, 45, a first sealing ring, 5, a first one-way valve, 6, a water inlet and outlet valve assembly, 61, an inlet one-way valve, 62, an outlet one-way valve, 71, a nozzle, 72, a second one-way valve, 8, a volume change assembly, 81, a piston head, 82, a fixed block, 83, a butt-joint block, 831, an annular groove, 9, a balance assembly, 91, a third one-way valve, 92, a first groove, 93, a first groove.

Detailed Description

The present application will be further described in detail below with reference to fig. 1 to 3, so that the technical solution of the present application is easier to understand and grasp.

The embodiment of the application discloses a crankshaft pump.

Referring to fig. 1-3, a crankshaft pump of the present embodiment includes a pump body 1, a crankshaft assembly 2, a plurality of piston assemblies 3 and a water inlet and outlet valve assembly 6, wherein a water inlet 11, a water outlet 12, a crankshaft cavity 13, a plurality of piston cavities 14 and a plurality of valve cavities are arranged in the pump body 1, the crankshaft assembly 2 is installed in the crankshaft cavity 13, the plurality of piston assemblies 3 are respectively arranged in the plurality of piston cavities 14, the valve cavities are communicated with the piston cavities 14, the water inlet 11 and the water outlet 12, and the water inlet and outlet valve assembly 6 is installed in the valve cavities.

Referring to fig. 1-3, the valve chambers include inlet valve chambers 15 and outlet valve chambers 16, the inlet valve chambers 15 communicate with the piston chamber 14 and the water inlet 11, the outlet valve chambers 16 communicate with the piston chamber 14 and the water outlet 12, the water inlet and outlet valve assembly 6 includes inlet check valves 61 and outlet check valves 62, the inlet check valves 61 are installed in the inlet valve chambers 15, and the outlet check valves 62 are installed in the outlet valve chambers 16.

Referring to fig. 1 to 3, the crankshaft assembly 2 includes a crankshaft 21 and a pump shaft 22, both ends of the crankshaft 21 are supported on an end wall of the crank chamber 13 through bearings, and the crankshaft pump shaft 22 is eccentrically disposed in the middle of the crankshaft 21 and protrudes out of the pump body 1 for connection with a motor.

Referring to fig. 1-3, the piston assembly 3 includes a piston rod 31, a sleeve block 4, a connecting block 32 and a connecting rod 33, the piston rod 31 is disposed in the piston cavity 14 and is in sealing sliding fit with the inner wall of the piston cavity 14, two ends of the connecting block 32 are respectively connected to the piston rod 31 and the connecting rod 33 in a threaded manner, the other end of the connecting rod 33 is connected with the crankshaft assembly 2, the sleeve block 4 is mounted in the pump body 1, the piston rod 31 and the connecting rod 33 are both disposed in the sleeve block 4 and are respectively in sealing sliding fit with two ends of the sleeve block 4, and a sealed annular gap 34 is formed between the sleeve block 4, the connecting rod 33 and the piston rod 31.

Referring to fig. 1-3, a first cooling groove 311 is formed in the piston rod 31, a second cooling groove 331 is formed in the connecting rod 33, a communication groove 321 is formed in the connecting block 32 and is respectively communicated with the first cooling groove 311 and the second cooling groove 331, a first one-way valve 5 which only allows fluid to enter the second cooling groove 331 in one way is installed in the communication groove 321, a communication channel 35 which is communicated with the annular gap 34 is formed in the inner wall of the second cooling groove 331, an opening groove 43 which is communicated with the annular gap 34 is formed in the sleeve block 4 in a penetrating manner, and a backflow channel 17 which is communicated with the opening groove 43 and the water inlet 11 is formed in the pump body 1.

Referring to fig. 1-3, the piston rod 31 and the connecting rod 33 can be cooled by using the fluid in the pump body 1, when the piston rod 31 pumps water, the first one-way valve 5 is closed, when the piston rod 31 pumps water, the first one-way valve 5 can be opened to enter the second cooling groove 331 as well, then the water in the second cooling groove 331 enters the annular gap 34 through the communicating channel 35, finally returns to the water inlet 11 through the open groove 43 and the return channel 17, a circulating cooling path is formed, heat generated by friction and medium impact of the piston rod 31 and the connecting rod 33 is effectively taken away, and material performance reduction caused by high temperature of the piston rod 31 and the connecting rod is avoided, so that long-term stable operation of the crankshaft 21 pump is ensured, and the whole service life of the crankshaft 21 is prolonged.

Referring to fig. 1 to 3, in order to facilitate the installation of the sleeve block 4 and each component, the sleeve block 4 is formed by splicing a split left block 41 and a split right block 42, and the end surfaces of the left block 41 and the right block 42 abut against each other. The left block 41 is in sealing sliding fit with the piston rod 31, a sealing ring 44 is arranged between the left block 41 and the piston rod 31, the right block 42 is in sealing sliding fit with the connecting rod 33, and the sealing ring 44 is arranged between the left block and the connecting rod. The outer walls of the left block 41 and the right block 42 are respectively provided with a sealing ring groove, and a first sealing ring 45 is arranged in each sealing ring groove. Wherein the open slot 43 is open on the right block 42.

Referring to fig. 1-3, the water inlet 11 is located below the water outlet 12, and the return channel 17 is located above the water inlet 11 and below the annular gap 34. The return channel 17 is positioned at one side of the water inlet 11 away from the valve cavity and is obliquely arranged.

Referring to fig. 1 to 3, a nozzle 71 is installed in the communication groove 321, and the nozzle 71 is located at a side of the first check valve 5 facing the second cooling groove 331.

Referring to fig. 1-3, the nozzle 71 can spray the water entering the second cooling tank 331 in a high-pressure jet manner, so as to enhance the contact efficiency and impact force between the water and the inner wall of the second cooling tank 331, further improve the heat dissipation effect on the connecting rod 33, and avoid the material performance degradation of the connecting rod 33 due to high temperature.

Referring to fig. 1-3, the nozzle 71 is a hollow cone nozzle. The hollow cone nozzle can form fan-shaped or cone-shaped diffusion spray on the cooling fluid, greatly expands the contact area between the cooling fluid and the inner wall of the second cooling groove 331, and can cover the heating area of the connecting rod 33 more uniformly than the common direct injection nozzle 71, thereby further optimizing the uniformity and efficiency of heat dissipation.

Referring to fig. 1-3, the air intake balancing assembly 9 further includes a second check valve 72, a volume changing assembly 8, and a second check valve 72 disposed in the communication channel 35 for allowing only water in the second cooling groove 331 to flow to the annular gap 34, the volume changing assembly 8 includes a movable piston head 81, the piston head 81 is slidably connected in the second cooling groove 331, the piston head 81 partitions the second cooling groove 331 into a front groove 3311 and a rear groove 3312 which are not communicated with each other, the nozzle 71 acts in the front groove 3311, and the communication channel 35 is only communicated with the front groove 3311.

Referring to fig. 1 to 3, when the piston rod 31 is in a pumped state, the piston head 81 moves toward the front tank 3311 side, and when the piston rod 31 is in a pumped state, the piston head 81 moves toward the rear tank 3312 side, the intake balancing assembly 9 is used for balancing the air pressure in the rear tank 3312 during the movement of the piston head 81 toward the front tank 3311 side and balancing the air pressure in the front tank 3311 and the rear tank 3312 during the movement of the piston head 81 toward the rear tank 3312 side, and the single water spray amount of the nozzle 71 is smaller than the single volume change amount of the front tank 3311.

Referring to fig. 1-3, the second check valve 72 can prevent the fluid in the backflow channel 17 from flowing backward to the front tank 3311, ensure the unidirectional circulation of the cooling circuit, especially for the condition that the water inlet 11 is connected with a high-pressure water source, the water in the water inlet 11 can fill the annular gap 34 to surround the outside of the connecting rod 33 for cooling, when the piston rod 31 is in a pumping state, the piston head 81 moves towards one side of the front tank 3311, at the moment, the first check valve 5 is closed, under the change of the volume of the front tank 3311, the piston head 81 presses the water in the front tank 3311 back to the water inlet 11 together with air, when the piston rod 31 is in a pumping state, the piston head 81 moves towards one side of the rear tank 3312, at the moment, the first check valve 5 is opened, the second check valve 72 is closed, and at the same time, the front tank 3311 is in air for circulation.

Referring to fig. 1-3, the volume-changing assembly 8 further includes a fixing block 82 and a docking block 83, the docking block 83 is coaxially fixed on a side surface of the piston head 81 facing the rear groove 3312, the fixing block 82 is in an L-shaped arrangement, a mounting groove 18 matching with the fixing block 82 is provided on the pump body 1, the top end of the fixing block 82 is fixed in the mounting groove 18 by a screw, a docking ring groove 831 is circumferentially provided on the docking block 83, a sliding groove 333 for sliding the fixing block 82 is provided on an inner wall of a side of the rear groove 3312 facing the mounting groove 18, the bottom end of the fixing block 82 is inserted into the docking ring groove 831 after passing through the sliding groove 333, the sliding groove 333 is located on a side of the annular gap 34 close to the crankshaft assembly 2, and the piston head 81 is always located on a side of the sliding groove 333 away from the crankshaft assembly 2.

Referring to fig. 1-3, the fixing block 82 is fixed in the mounting groove 18 of the pump body 1, and meanwhile, the fixing block 82 is fixedly connected with the abutting block 83, so that the piston head 81 is kept still with the pump body 1 all the time, and when the crankshaft assembly 2 drives the connecting rod 33 to move, the piston head 81 and the connecting rod 33 can slide mutually, so that the volume change of the front groove 3311 is controlled.

Referring to fig. 1-3, the intake balancing assembly 9 includes a third check valve 91, a mounting hole 92, a first groove 93 and a second groove 94, the first groove 93 is formed in the pump body 1, the first groove 93 is located at one side of the annular gap 34 close to the crankshaft assembly 2, the first groove 93 is communicated with a sliding groove 333, the second groove 94 is formed on the outer side wall of the fixed block 82 in a penetrating manner along the length direction of the fixed block 82, the first groove 93, the second groove 94 and the sliding groove 333 are communicated with each other, the mounting hole 92 is formed in the connecting rod 33, two ends of the mounting hole 92 are respectively communicated with the first groove 93 and the front groove 3311, and the third check valve 91 is mounted in the mounting hole 92 and is used for only allowing external air to enter the front groove 3311.

Referring to fig. 1 to 3, when the piston head 81 moves toward the rear groove 3312, the first check valve 5 is opened, water is sprayed from the spray nozzle 71, the second check valve 72 is closed, and external air can enter the front groove 3311 through the third check valve 91 to balance air pressure, and when the piston head 81 moves toward the front groove 3311, both the first check valve 5 and the third check valve 91 are closed, the second check valve 72 is opened, and water and air in the front groove 3311 are simultaneously pressed into the annular gap 34, thereby realizing efficient circulation of cooling.

Referring to fig. 1-3, when the piston rod 31 is advanced to the extreme position of the pumping state while the piston head 81 is moved to abut against the end wall of the rear tank 3312 by the abutment block 83, the bottom end of the fixing block 82 is faced to the abutment ring groove 831. A reliable positional relationship is provided for the butt joint of the fixing block 82 and the butt joint block 83. In order to further facilitate the connection between the fixing block 82 and the abutting block 83, the end of the abutting ring groove 831 is provided in a flaring shape, so that the fixing block 82 is convenient to insert.

Referring to fig. 1 to 3, a first annular groove 421 is formed in the outer wall of the right block 42 in the circumferential direction, and the open groove 43 communicates with the return channel 17 through the first annular groove 421. Regardless of how the sleeve block 4 is mounted, the first annular groove 421 can be always kept in communication with the return channel 17, and the convenience of mounting the sleeve block 4 is improved.

Of course, the above is only a typical example of the application, and other embodiments of the application are also possible, and all technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of the application claimed.

Claims (6)

1. The crankshaft pump is characterized by comprising a pump body (1), a crankshaft assembly (2), a plurality of piston assemblies (3) and a water inlet and outlet valve assembly (6), wherein a water inlet (11), a water outlet (12), a crankshaft cavity (13), a plurality of piston cavities (14) and a plurality of valve cavities are arranged in the pump body (1), the crankshaft assembly (2) is arranged in the crankshaft cavity (13), the plurality of piston assemblies (3) are respectively arranged in the plurality of piston cavities (14), the valve cavities are communicated with the piston cavities (14), the water inlet (11) and the water outlet (12), and the water inlet and outlet valve assembly (6) is arranged in the valve cavities;

The piston assembly (3) comprises a piston rod (31), a sleeve block (4), a connecting block (32) and a connecting rod (33), wherein the piston rod (31) is arranged in the piston cavity (14) and is in sealing sliding fit with the inner wall of the piston cavity (14), two ends of the connecting block (32) are respectively arranged on the piston rod (31) and the connecting rod (33), the other end of the connecting rod (33) is connected with the crankshaft assembly (2), the sleeve block (4) is arranged in the pump body (1), the piston rod (31) and the connecting rod (33) are respectively arranged in the sleeve block (4) and are respectively in sealing sliding fit with two ends of the sleeve block (4), and a sealed annular gap (34) is formed between the sleeve block (4) and the connecting rod (33) and the piston rod (31);

A first cooling groove (311) is formed in the piston rod (31), a second cooling groove (331) is formed in the connecting rod (33), a communication groove (321) is formed in the connecting block (32) and is respectively communicated with the first cooling groove (311) and the second cooling groove (331), a first one-way valve (5) which only allows fluid to enter the second cooling groove (331) in one way is arranged in the communication groove (321), a communication channel (35) which is communicated with an annular gap (34) is formed in the inner wall of the second cooling groove (331), an opening groove (43) which is communicated with the annular gap (34) is formed in the sleeve block (4) in a penetrating manner, and a backflow channel (17) which is communicated with the opening groove (43) and the water inlet (11) is formed in the pump body (1);

A nozzle (71) is arranged in the communication groove (321), and the nozzle (71) is positioned at one side of the first one-way valve (5) facing the second cooling groove (331);

The device further comprises a second one-way valve (72), a volume change assembly (8) and an air inlet balance assembly (9), wherein the second one-way valve (72) is arranged in the communication channel (35) and only used for enabling water in the second cooling groove (331) to flow to the annular gap (34), the volume change assembly (8) comprises a movable piston head (81), the piston head (81) is slidably connected in the second cooling groove (331), the piston head (81) divides the second cooling groove (331) into a front groove (3311) and a rear groove (3312) which are not communicated with each other, the nozzle (71) acts in the front groove (3311), and the communication channel (35) is only communicated with the front groove (3311);

When the piston rod (31) is in a pumping state, the piston head (81) moves towards the front groove (3311), when the piston rod (31) is in a pumping state, the piston head (81) moves towards the rear groove (3312), the air inlet balancing component (9) is used for balancing air pressure in the rear groove (3312) in the process that the piston head (81) moves towards the front groove (3311), and balancing air pressure in the front groove (3311) and air pressure in the rear groove (3312) in the process that the piston head (81) moves towards the rear groove (3312), and the single water spraying amount of the nozzle (71) is smaller than the single volume change amount of the front groove (3311).

2. A crankshaft pump according to claim 1, wherein the nozzle (71) is a hollow cone nozzle.

3. A crankshaft pump according to claim 1, wherein the volume changing assembly (8) further comprises a fixed block (82) and a butt joint block (83), the butt joint block (83) is coaxially fixed on one side surface of the piston head (81) facing the rear groove (3312), the fixed block (82) is in an L-shaped arrangement, an installation groove (18) matched with the fixed block (82) is formed in the pump body (1), the top end of the fixed block (82) is fixed in the installation groove (18) through a screw, a butt joint ring groove (831) is formed in the butt joint block (83) in the circumferential direction, a sliding groove (333) for the sliding of the fixed block (82) is formed in the inner wall of one side of the rear groove (3312) facing the installation groove (18), the bottom end of the fixed block (82) is inserted into the butt joint ring groove (831) after passing through the sliding groove (333), the sliding groove (333) is located on one side, close to the crankshaft assembly (2), and the piston head (81) is always located on one side, far from the sliding groove (333), of the crankshaft assembly (2).

4. A crankshaft pump according to claim 3, wherein the air intake balance assembly (9) comprises a third one-way valve (91), a mounting hole (92), a first groove (93) and a second groove (94), the first groove (93) is formed in the pump body (1), the first groove (93) is located at one side, close to the crankshaft assembly (2), of the annular gap (34), the first groove (93) is communicated with the sliding groove (333), the second groove (94) is formed in the outer side wall of the fixed block (82) in a penetrating mode along the length direction of the fixed block (82), the first groove (93), the second groove (94) and the sliding groove (333) are communicated with each other, the mounting hole (92) is formed in the connecting rod (33), two ends of the mounting hole (92) are respectively communicated with the first groove (93) and the front groove (3311), and the third one-way valve (91) is mounted in the mounting hole (92) and used for enabling external air to enter the front groove (3311) only.

5. A crankshaft pump according to claim 3, wherein when the piston rod (31) is advanced to the extreme position of the pumping state while the piston head (81) is moved to the abutment block (83) abutting against the end wall of the rear groove (3312), the bottom end of the fixing block (82) is opposite to the abutment ring groove (831).

6. A crank pump according to claim 1, wherein the sleeve block (4) is provided with a first annular groove (421) along the circumferential outer wall, and the open groove (43) is communicated with the return channel (17) through the first annular groove (421).