Cryogenic pump

Abstract

The invention discloses a low-temperature pump, which belongs to the field of low-temperature pumps and mainly comprises a pump body, a cold shield, a cold umbrella, a baffle and a refrigerator, the refrigerator comprises a cylinder, a piston and a lower cover, the cylinder is in sliding fit with the pump body, the cold umbrella is sleeved on the cylinder, and a push plate is arranged at the lower end of the cylinder; the piston is slidably arranged in the cylinder; the lower cover is movably arranged on the lower side of the cylinder; when the lower cover moves to block the lower opening of the air cylinder, the push plate abuts against the lower end of the pump body, and the air cylinder is still. When the lower cover moves away from the lower opening of the cylinder, the push plate can drive the cylinder to reciprocate in the pump body; the lower cover is convenient and fast to disassemble, manpower is not needed, and efficiency is improved; meanwhile, the connecting rod can drive the piston to move in a reciprocating mode, the piston can be poured out in a vibrating mode through cooperation of the connecting rod, the first vibrating rod and the second vibrating rod, time and labor are saved, and the frostbite danger of workers is avoided; and the pump body and the vacuum chamber can be quickly separated, so that the lower cover of the low-temperature pump can be conveniently disassembled.

Description

Technical Field

[0001] The present invention belongs to the technical field of cryogenic pumps, and in particular relates to a cryogenic pump. Background Art

[0002] A cryopump is a vacuum pump that uses a low-temperature surface to condense gas, also known as a condensation pump. Cryopumps can obtain clean vacuum with the highest pumping rate and the lowest ultimate pressure. They are widely used in the research and production of semiconductors and integrated circuits, as well as molecular beam research, vacuum coating equipment, vacuum surface analysis instruments, ion implanters, and space simulation devices. Existing cryopumps are generally provided with a piston structure. Through the reciprocating movement of the piston and the coordination between the inlet valve and the exhaust valve, the gas in the vacuum chamber can be continuously frozen or adsorbed inside the pump to obtain a vacuum. However, due to a series of problems such as wear caused by the reciprocating movement of the piston, the cryopump is prone to a significant decrease in cooling capacity. At this time, the piston needs to be replaced and maintained. Since the cryopump was previously in a working state, the piston temperature is extremely low. In order to avoid frostbite to the staff, the replacement work needs to wait until the piston temperature rises before it can be carried out, which will waste a lot of time. In addition, due to the characteristics of the cryopump structure, when disassembling the piston, it is necessary to first disassemble the cryopump as a whole from the pipeline, and then disassemble the cryopump and remove the piston. This process requires a lot of time and manpower. Summary of the invention

[0003] Technical problem to be solved: A cryogenic pump provided by the present invention can solve the above-mentioned problems.

[0004] Technical solution: In order to achieve the above-mentioned purpose, the present invention adopts the following technical solution, a low-temperature pump, comprising: a pump body, a cold screen, a cold umbrella, a baffle and a refrigerator; the cold screen is arranged in the pump body; the baffle is fixedly connected to the upper opening of the cold screen; the refrigerator described in this embodiment comprises a cylinder, a piston and a lower cover; the cylinder is slidably matched with the pump body, the cold umbrella is fixedly sleeved on the upper end of the cylinder, and the lower end of the cylinder is radially provided with a push plate; the piston is slidably arranged in the cylinder; the lower cover is movably arranged on the lower side of the cylinder; when the lower cover moves to block the lower opening of the cylinder, the push plate abuts against the lower end of the pump body, and the cylinder is stationary; when the lower cover moves away from the lower opening of the cylinder, the cylinder can be driven to reciprocate in the pump body by the push plate.

[0005] As a preferred technical solution of the present invention, the refrigerator also includes a connecting rod, a first vibration rod and a second vibration rod; the connecting rod and the lower cover are slidably connected, the upper end of the connecting rod is provided with a connecting head, and the lower end of the piston is provided with a connecting groove; the first vibration rod and the lower cover are slidably connected; one end of the second vibration rod is hinged to the connecting rod, and the other end is hinged to the first vibration rod; when the lower cover moves to block the lower opening of the cylinder, the connecting head extends into the connecting groove, and the connecting rod can drive the piston to reciprocate; when the lower cover moves away from the lower opening of the cylinder, the connecting head withdraws from the connecting groove, and the first vibration rod can push the push plate to reciprocate.

[0006] As a preferred technical solution of the present invention, the refrigerator also includes a slide, a piston rod, a telescopic spring and a second electric push rod; the upper end of the slide is hinged to the pump body; the piston rod is slidably connected to the slide, and the telescopic end of the piston rod is hinged to the lower cover; the telescopic spring is arranged in the slide to drive the piston rod to move in the direction of extending out of the slide; the mounting end of the second electric push rod is fixedly connected to the pump body, and the telescopic end of the second electric push rod is hinged to the lower cover.

[0007] As a preferred technical solution of the present invention, the refrigerator also includes a swash plate and a motor; the motor and the lower cover are fixedly connected; the swash plate is inclined relative to the axis of the motor output shaft and fixedly connected thereto, an annular groove is provided on the outer circumferential wall of the swash plate, and a ball head is also provided on the connecting rod, and the annular groove and the ball head are slidably connected.

[0008] As a preferred technical solution of the present invention, the refrigerator further comprises a vibration spring; the vibration spring is sleeved on the cylinder to drive the cylinder to move in a direction away from the cold screen.

[0009] As a preferred technical solution of the present invention, the refrigerator also includes a fixing rod and a fixing spring; the fixing rod and the pump body are slidably connected; a fixing groove is provided on the lower cover; the fixing spring is sleeved on the fixing rod to drive the fixing rod to move in a direction extending into the fixing groove.

[0010] As a preferred technical solution of the present invention, the refrigerator also includes an intake valve and an exhaust valve; a room temperature chamber is formed between the lower cover, the piston and the cylinder, a lower cover flow channel is provided in the lower cover, and the lower cover flow channel is connected to the room temperature chamber; the intake valve is fixedly connected to the lower cover, and the intake valve outlet is connected to the lower cover flow channel; the exhaust valve is fixedly connected to the lower cover, and the exhaust valve inlet is connected to the lower cover flow channel.

[0011] As a preferred technical solution of the present invention, the piston includes a large diameter end and a small diameter end, a secondary cold chamber is formed between the upper side of the small diameter end and the cylinder, a secondary heat regenerator and a fourth flow channel are provided in the small diameter end, and the fourth flow channel connects the secondary heat regenerator with the secondary cold chamber; a primary cold chamber is formed between the upper side of the large diameter end, the lower side of the small diameter end and the cylinder, a third flow channel, a second flow channel, a first flow channel and a primary heat regenerator are provided in the large diameter end, and the third flow channel connects the secondary heat regenerator with the primary cold chamber; the second flow channel connects the primary cold chamber with the primary heat regenerator; the first flow channel connects the room temperature chamber with the primary heat regenerator.

[0012] As a preferred technical solution of the present invention, the cryogenic pump also includes a bracket, a first flange, a second flange, and a first electric push rod; the first flange is fixedly connected to the bracket; the second flange is fixedly connected to the pump body, the second flange is rotatably connected to the first flange, and the second flange is provided with a flange groove and a locking groove; the mounting end of the first electric push rod is hinged to the first flange, and a push rod pin is provided on the telescopic end of the first electric push rod, and the push rod pin and the flange groove are slidably connected.

[0013] As a preferred technical solution of the present invention, the cryogenic pump also includes a locking rod and a locking spring; the locking rod is slidably connected to the first flange in a horizontal direction; the locking spring is sleeved on the locking rod to drive the locking rod to move in a direction extending into the locking groove.

[0014] Compared with the prior art, the advantages of the present invention are: 1. By setting a connecting rod, a first vibration rod and a second vibration rod, when the cryogenic pump is working normally, the connecting rod can drive the piston to reciprocate; when the piston needs to be taken out, the push plate is driven to drive the cylinder to vibrate continuously through the cooperation of the connecting rod, the first vibration rod and the second vibration rod, so that the piston in the cylinder can be vibrated out, so that the piston can be taken out without manual dragging, avoiding frostbite of workers, and disassembly does not need to wait for the piston to heat up, saving time and manpower, and reducing the work risks of workers.

[0015] 2. By arranging the piston rod and the second electric push rod to cooperate, the second electric push rod can be controlled to extend to drive the lower cover to exit the cylinder first, and then flip it, so that the disassembly of the lower cover is convenient and quick, without manpower, and the efficiency is improved.

[0016] 3. By arranging the first flange and the second flange at the inlet of the cryopump and controlling the first flange and the second flange to separate, the pump body and the vacuum chamber can be quickly separated, and by rotating the second flange, the bottom of the cryopump can be turned to a horizontal direction, which is convenient for disassembly of the lower cover of the cryopump and can reduce the manpower consumed in the maintenance of the cryopump. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a front view of the present invention; Figure 2 is a cross-sectional view of the present invention; Figure 3 It is a front view of the pump body of the present invention when it is tilted; Figure 4 It is a cross-sectional view of the piston of the present invention during removal; Figure 5 It is a cross-sectional view of the present invention when the lower cover is opened; Figure 6 For the present invention Figure 2 The enlarged image at point I in the middle; Figure 7 For the present invention Figure 4 Enlarged view of II in the middle; Figure 8 For the present invention Figure 5 Enlarged view of point III in the middle; Fig. 9 is a cross-sectional view of the piston of the present invention; Fig.10 It is a three-dimensional view of the connecting rod of the present invention. DETAILED DESCRIPTION

[0018] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0019] See also Figure 1-Figure 10 A cryogenic pump comprises: a pump body 10, a cold shield 11, a cold umbrella 12, a baffle 13 and a refrigerator; the cold shield 11 is arranged in the pump body 10; the baffle 13 is fixedly connected to the upper opening of the cold shield 11; the refrigerator of this embodiment comprises a cylinder 16, a piston 21 and a lower cover 29; the cylinder 16 is slidably matched with the pump body 10, the cold umbrella 12 is fixedly sleeved on the upper end of the cylinder 16, and the lower end of the cylinder 16 is radially provided with a push plate 20; the piston 21 is slidably arranged in the cylinder 16; the lower cover 29 is movably arranged on the lower side of the cylinder 16; when the lower cover 29 moves to block the lower opening of the cylinder 16, the push plate 20 abuts against the lower end of the pump body 10, and the cylinder 16 is stationary; when the lower cover 29 moves away from the lower opening of the cylinder 16, the cylinder 16 can be driven to reciprocate in the pump body 10 through the push plate 20.

[0020] In the present embodiment, when the lower cover 29 moves to block the lower opening of the cylinder 16, the lower cover 29 pushes the push plate 20 to abut against the lower end of the pump body 10, the cylinder 16 is limited and stationary, and the piston 21 can reciprocate to perform refrigeration work; when the lower cover 29 moves away from the lower opening of the cylinder 16, the lower cover 29 is separated from the push plate 20, the limit on the cylinder 16 is released, and the cylinder 16 can be driven to reciprocate in the pump body 10 by the push plate 20, so that the piston 21 can be poured out, and there is no need for workers to drag the piston 21, thereby avoiding frostbite of workers. There is no need to wait for the piston to heat up when disassembling, which saves time and manpower and reduces the work risks of workers.

[0021] See also Figure 2 , Figure 4-Figure 8 , Fig.10 The refrigerator also includes a connecting rod 37, a first vibration rod 41 and a second vibration rod 42; the connecting rod 37 is slidably connected to the lower cover 29, a connecting head 38 is provided at the upper end of the connecting rod 37, and a connecting groove 26 is provided at the lower end of the piston 21; the first vibration rod 41 is slidably connected to the lower cover 29; one end of the second vibration rod 42 is hinged to the connecting rod 37, and the other end is hinged to the first vibration rod 41; when the lower cover 29 moves to block the lower opening of the cylinder 16, the connecting head 38 extends into the connecting groove 26, and the connecting rod 37 can drive the piston 21 to reciprocate; when the lower cover 29 moves away from the lower opening of the cylinder 16, the connecting head 38 withdraws from the connecting groove 26, and the first vibration rod 41 can push the push plate 20 to reciprocate.

[0022] In this embodiment, when the connecting head 38 extends into the connecting groove 26, the connecting rod 37 can drive the piston 21 to move back and forth, thereby controlling the piston 21 to perform refrigeration work; when the connecting head 38 is out of the connecting groove 26, the first vibration rod 41 is driven to move to the vicinity of the push plate 20 through the lower cover 29, and the first vibration rod 41 can be driven to move back and forth through the connecting rod 37. The first vibration rod 41 pushes the push plate 20, and then drives the cylinder 16 to move back and forth to pour out the piston 21.

[0023] See also Figure 1-Figure 8 The refrigerator also includes a slide 34, a piston rod 35, a telescopic spring 36 and a second electric push rod 33; the upper end of the slide 34 is hinged to the pump body 10; the piston rod 35 is slidably connected to the slide 34, and the telescopic end of the piston rod 35 is hinged to the lower cover 29; the telescopic spring 36 is arranged in the slide 34 to drive the piston rod 35 to move in the direction of extending out of the slide 34; the mounting end of the second electric push rod 33 is fixedly connected to the pump body 10, and the telescopic end of the second electric push rod 33 is hinged to the lower cover 29.

[0024] See also Figure 2 , Figure 4-Figure 8The refrigerator also includes a swash plate 43 and a motor 14; the motor 14 is fixedly connected to the lower cover 29; the swash plate 43 is inclined relative to the axis of the output shaft of the motor 14 and is fixedly connected thereto, an annular groove 44 is provided on the outer circumferential wall of the swash plate 43, and a ball head 39 is also provided on the connecting rod 37, and the annular groove 44 and the ball head 39 are slidably connected.

[0025] In this embodiment, the ball head 39, the swash plate 43 and the motor 14 are arranged so that when the swash plate 43 is driven to rotate by the motor 14, the ball head 39 slides in the annular groove 44, driving the connecting rod 37 to move back and forth, thereby realizing the reciprocating movement of the piston 21 and the first vibration rod 41.

[0026] Of course, in other embodiments, an electric push rod may be provided to replace the ball head 39, the swash plate 43 and the motor 14. For example, the electric push rod may be fixedly connected to the connecting rod 37, and the connecting rod 37 may be driven to move back and forth by controlling the electric push rod to continuously extend and retract.

[0027] See also Figure 2 , Figure 4 , Figure 5 The refrigerator further includes a vibration spring 15 ; the vibration spring 15 is sleeved on the cylinder 16 to drive the cylinder 16 to move in a direction away from the cold screen 11 .

[0028] In this embodiment, by setting the slide cylinder 34, the piston rod 35, the telescopic spring 36 and the second electric push rod 33, when it is necessary to open the lower cover 29, the second electric push rod 33 is controlled to extend, driving the lower cover 29 to move with it. Due to the action of the telescopic spring 36, the piston rod 35 extends out of the slide cylinder 34, and at the same time, due to the action of the vibration spring 15, the cylinder 16 is pushed to slide with it, so that the bottom of the cylinder 16 and the bottom of the pump body 10 are separated; when the piston rod 35 extends out of the slide cylinder 34 to the longest, the second electric push rod 33 pushes the lower cover 29 to just exit the cylinder 16, and then the second electric push rod 33 is controlled to continue to extend. Since the slide cylinder 34 and the pump body 10 are rotatably connected, the lower cover 29 is driven to flip through the pull of the piston rod 35, so that the connector 38 exits the connecting groove 26; when the second electric push rod 33 is fully extended, it drives the lower cover 29 to flip away from the cylinder 16, and makes the first vibration rod 41 come near the push plate 20, at this time, the lower opening of the cylinder 16 is fully opened; when it is necessary to open the lower cover When the cylinder 16 is blocked, the second electric push rod 33 is controlled to retract. Due to the action of the telescopic spring 36, the piston rod 35 cannot retract into the slide cylinder 34, so that the second electric push rod 33 first drives the lower cover 29 to rotate. When the lower cover 29 rotates to face the cylinder 16, the lower cover 29 and the lower end side of the piston rod 35 fit together. At this time, the slide cylinder 34 and the pump body 10 fit together, so that the lower cover 29 cannot continue to rotate. Since there is an arc chamfered structure in the connecting groove 26 and it is set downward at this time, When the connecting head 38 rotates with the lower cover 29, it can smoothly enter the connecting groove 26, and then control the second electric push rod 33 to continue to shrink, and then drive the piston rod 35 through the lower cover 29 to overcome the contraction of the telescopic spring 36, so that the lower cover 29 enters the cylinder 16 and pushes the cylinder 16 to overcome the movement of the vibration spring 15. When the cylinder 16 and the lower end of the pump body 10 are in contact, the lower cover 29 is blocked, so that the opening and blocking of the lower cover 29 does not require manual disassembly, which is convenient and fast, saving manpower.

[0029] See also Figure 2 , Figure 4-Figure 8 The refrigerator further comprises a fixing rod 45 and a fixing spring 46; the fixing rod 45 is slidably connected to the pump body 10; a fixing groove 31 is provided on the lower cover 29; the fixing spring 46 is sleeved on the fixing rod 45 to drive the fixing rod 45 to move in a direction extending into the fixing groove 31.

[0030] See also Figure 2 , Figure 4-Figure 8 The refrigerator also includes an intake valve 32 and an exhaust valve 40; a room temperature chamber 19 is formed between the lower cover 29, the piston 21 and the cylinder 16, a lower cover flow channel 30 is provided in the lower cover 29, and the lower cover flow channel 30 is connected to the room temperature chamber 19; the intake valve 32 is fixedly connected to the lower cover 29, and the air outlet of the intake valve 32 is connected to the lower cover flow channel 30; the exhaust valve 40 is fixedly connected to the lower cover 29, and the air inlet of the exhaust valve 40 is connected to the lower cover flow channel 30.

[0031] See also Figure 2 , Figure 4 , Figure 5 , Fig. 9 The piston 21 includes a large diameter end and a small diameter end. A secondary cold chamber 17 is formed between the upper side of the small diameter end and the cylinder 16. A secondary heat regenerator 27 and a fourth flow channel 25 are provided in the small diameter end. The fourth flow channel 25 connects the secondary heat regenerator 27 with the secondary cold chamber 17. A primary cold chamber 18 is formed between the upper side of the large diameter end, the lower side of the small diameter end and the cylinder 16. A third flow channel 24, a second flow channel 23, a first flow channel 22 and a primary heat regenerator 28 are provided in the large diameter end. The third flow channel 24 connects the secondary heat regenerator 27 with the primary cold chamber 18. The second flow channel 23 connects the primary cold chamber 18 with the primary heat regenerator 28. The first flow channel 22 connects the room temperature chamber 19 with the primary heat regenerator 28.

[0032] See also Figure 1-Figure 5 The cryogenic pump also includes a bracket 1, a first flange 2, a second flange 3, and a first electric push rod 8; the first flange 2 is fixedly connected to the bracket 1; the second flange 3 is fixedly connected to the pump body 10, the second flange 3 is rotatably connected to the first flange 2, and a flange groove 4 and a locking groove 5 are provided on the second flange 3; the mounting end of the first electric push rod 8 is hinged to the first flange 2, and a push rod pin 9 is provided on the telescopic end of the first electric push rod 8, and the push rod pin 9 and the flange groove 4 are slidably connected.

[0033] See also Figure 2 The cryogenic pump further comprises a locking rod 6 and a locking spring 7; the locking rod 6 is slidably connected to the first flange 2 in a horizontal direction; the locking spring 7 is sleeved on the locking rod 6 to drive the locking rod 6 to move in a direction extending into the locking groove 5.

[0034] The working principle of this cryogenic pump is as follows: like Figure 2The internal structure of the present invention is as follows. When the present invention is used normally, the first flange 2 is connected to the vacuum chamber, the motor 14 is started to drive the swash plate 43 to rotate, and the ball head 39 and the annular groove 44 are slidably connected, and the connecting rod 37 is driven to reciprocate through the continuous rotation of the swash plate 43. Since the connecting head 38 is in the connecting groove 26 at this time, the piston 21 can be driven to reciprocate in the cylinder 16; when the connecting rod 37 drives the piston 21 to the top of the cylinder 16, the intake valve 32 is controlled to open, the exhaust valve 40 is closed, and the piston 21 moves downward from the top, through the external The compressor acts to introduce high-pressure helium into the inlet valve 32, and the high-pressure helium enters the room temperature chamber 19 through the lower cover flow channel 30, and enters the primary regenerator 28 through the first flow channel 22. The high-pressure helium is cooled by the primary regenerator 28, and then the high-pressure helium passing through the primary regenerator 28 enters the primary cold chamber 18 through the second flow channel 23, and then enters the secondary regenerator 27 through the third flow channel 24. The temperature of the high-pressure helium is further reduced by the action of the secondary regenerator 27, and the high-pressure helium passing through the secondary regenerator 27 enters the secondary cold chamber 17 through the fourth flow channel 25, so that the primary cold chamber 18 The second and second cold chambers 17 are in a high pressure state; when the connecting rod 37 drives the piston 21 to the bottom, the inlet valve 32 is controlled to be closed, the exhaust valve 40 is opened, and the piston 21 moves upward from the bottom. At this time, the second and first cold chambers 17 and 18 are connected to the compressor inlet, so that the helium therein is rapidly decompressed and expanded, so that the temperature of the helium is rapidly reduced, and the movement of the piston 21 pushes the helium in the second and first cold chambers 17 and 18 out. When the helium passes through the second and first regenerators 27 and 28, the second and first regenerators 27 and 28 can be cooled to make their temperature The temperature is reduced, and helium enters the compressor through the exhaust valve 40 to form a cycle. Through the continuous reciprocating movement of the piston 21 and the continuous cooperation of the intake valve 32 and the exhaust valve 40, the temperature in the primary cold chamber 18 and the secondary cold chamber 17 can be gradually reduced, thereby cooling the cold umbrella 12, and continuous refrigeration can be achieved. When the air in the vacuum chamber passes through the first flange 2, the second flange 3, and the baffle 13 and enters the cold shield 11, due to the low temperature in the cold shield 11, the air and water vapor will condense on the cold umbrella 12, and then the air and water vapor will be removed from the vacuum chamber, thereby achieving a high vacuum in the vacuum chamber.

[0035] When the present invention is working, if it is found that the refrigeration efficiency is significantly reduced or the cooling capacity is significantly reduced, the piston 21 needs to be replaced. First, the motor 14 is controlled to stop working, and the connecting rod 37 is controlled to stop at the lowest position. Then, the locking spring 7 is overcome to pull the locking rod 6 to make it withdraw from the locking groove 5. Then, the first electric push rod 8 is controlled to retract. Since the first flange 2 and the second flange 3 are rotatably connected, the push rod pin 9 is slidably connected in the flange groove 4, and then the second flange 3 is driven to rotate through the first electric push rod 8, thereby driving the pump body 10 to follow the flip. When the pump body 10 rotates to the inclined position (such as Figure 3 As shown), the fixing spring 46 is overcome to pull the fixing rod 45 to make it withdraw from the fixing groove 31, and then the second electric push rod 33 is controlled to extend, driving the lower cover 29 to follow the movement. Due to the action of the telescopic spring 36, the piston rod 35 extends out of the slide cylinder 34. At the same time, due to the action of the vibration spring 15, the cylinder 16 is pushed to follow the sliding, so that the bottom of the cylinder 16 and the bottom of the pump body 10 are separated; when the piston rod 35 extends out of the slide cylinder 34 to the longest, the second electric push rod 33 pushes the lower cover 29 to just withdraw from the cylinder 16 (as shown in FIG. Figure 7 As shown), the second electric push rod 33 is controlled to continue to extend. Since the slide cylinder 34 and the pump body 10 are rotatably connected, the piston rod 35 pulls the lower cover 29 to flip, so that the connector 38 exits the connecting groove 26; when the second electric push rod 33 is fully extended, the lower cover 29 is driven to flip away from the cylinder 16, and the first vibration rod 41 comes near the push plate 20 (as shown). Figure 8As shown), at this time, the lower opening of the cylinder 16 is fully opened, and then the control motor 14 continues to rotate, thereby driving the connecting rod 37 to move back and forth. Since one end of the second vibration rod 42 is hinged to the connecting rod 37 and the other end is hinged to the first vibration rod 41, the first vibration rod 41 and the lower cover 29 are slidably connected, thereby driving the first vibration rod 41 to move back and forth, so that the first vibration rod 41 continuously pushes the push plate 20. At the same time, under the action of the vibration spring 15, the cylinder 16 continuously reciprocates in a small amplitude along the axial direction, thereby generating vibration, which can be The internal piston 21 is shaken off, and the worker can use the collection container to recover the piston 21 to avoid the risk of frostbite; when the removal is completed, the first electric push rod 8 is controlled to continue to retract, driving the pump body 10 to continue to flip to a horizontal position, and then the new piston 21 is pushed into the cylinder 16 to a proper position, and the connecting groove 26 is kept facing downward, and then the second electric push rod 33 is controlled to retract. Due to the action of the telescopic spring 36, the piston rod 35 cannot retract into the slide cylinder 34, so that the second electric push rod 33 first drives the lower cover 29 to rotate, and then the lower cover 29 is turned back. When the lower cover 29 is turned to face the cylinder 16, the lower cover 29 and the lower end side of the piston rod 35 are in contact with each other. At this time, the slide cylinder 34 and the pump body 10 are in contact with each other, so that the lower cover 29 cannot continue to rotate. Since there is an arc chamfered structure in the connecting groove 26 and it is set downward at this time, the connecting head 38 can smoothly enter the connecting groove 26 when following the rotation of the lower cover 29, and then the second electric push rod 33 is controlled to continue to contract, and then the piston rod 35 is driven by the lower cover 29 to overcome the contraction of the telescopic spring 36, so that the lower cover 29 enters the cylinder 16 and pushes the cylinder 16 to overcome the vibration spring. The spring 15 moves, and when the cylinder 16 and the lower end of the pump body 10 are fitted together, the fixing groove 31 and the fixing rod 45 are aligned. Under the action of the fixing spring 46, the fixing rod 45 enters the fixing groove 31 to lock the lower cover 29, the cylinder 16 and the pump body 10. Then the first electric push rod 8 is controlled to extend, driving the second flange 3 to reverse and reset, so that the first flange 2 and the second flange 3 are re-fitted, and the locking rod 6 and the locking groove 5 are aligned. Under the action of the locking spring 7, the locking rod 6 is pushed into the locking groove 5 to lock the first flange 2 and the second flange 3 to complete the maintenance work.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cryogenic pump, comprising: A pump body (10), a cold screen (11), a cold umbrella (12), a baffle (13) and a refrigerator; the cold screen (11) is arranged in the pump body (10); the baffle (13) is fixedly connected to the upper opening of the cold screen (11); the refrigerator comprises a cylinder (16), a piston (21) and a lower cover (29); the cylinder (16) and the pump body (10) are slidably matched, the cold umbrella (12) is fixedly sleeved on the upper end of the cylinder (16), and the lower end of the cylinder (16) is radially provided with a push plate (20); the piston (21) is slidably arranged in the cylinder (16); the lower cover (29) is movably arranged on the lower side of the cylinder (16); When the lower cover (29) moves to block the lower opening of the cylinder (16), the push plate (20) abuts against the lower end of the pump body (10), and the cylinder (16) remains stationary; When the lower cover (29) moves away from the lower opening of the cylinder (16), the cylinder (16) can be driven to move back and forth in the pump body (10) through the push plate (20).

2. A cryopump according to claim 1, characterized in that: The refrigerator further comprises a connecting rod (37), a first vibration rod (41) and a second vibration rod (42); The connecting rod (37) and the lower cover (29) are slidably connected, a connecting head (38) is provided at the upper end of the connecting rod (37), and a connecting groove (26) is provided at the lower end of the piston (21); The first vibration rod (41) and the lower cover (29) are slidably connected; One end of the second vibration rod (42) is hinged to the connecting rod (37), and the other end is hinged to the first vibration rod (41); When the lower cover (29) moves to block the lower opening of the cylinder (16), the connecting head (38) extends into the connecting groove (26), and the connecting rod (37) can drive the piston (21) to move back and forth; When the lower cover (29) moves away from the lower opening of the cylinder (16), the connecting head (38) exits the connecting groove (26), and the first vibration rod (41) can push the push plate (20) to move back and forth.

3. A cryopump according to claim 1, characterized in that: The refrigerator further comprises a slide cylinder (34), a piston rod (35), a telescopic spring (36) and a second electric push rod (33); The upper end of the slide cylinder (34) is hinged to the pump body (10); The piston rod (35) and the slide cylinder (34) are slidably connected, and the telescopic end of the piston rod (35) and the lower cover (29) are hinged; The telescopic spring (36) is arranged in the slide cylinder (34) and is used to drive the piston rod (35) to move in a direction extending out of the slide cylinder (34); The mounting end of the second electric push rod (33) is fixedly connected to the pump body (10), and the telescopic end of the second electric push rod (33) is hinged to the lower cover (29).

4. A cryopump according to claim 2, characterized in that: The refrigerator further comprises a swash plate (43) and a motor (14); The motor (14) and the lower cover (29) are fixedly connected; The swash plate (43) is arranged to be inclined relative to the axis of the output shaft of the motor (14) and is fixedly connected thereto; an annular groove (44) is provided on the outer circumferential wall of the swash plate (43); a ball head (39) is also provided on the connecting rod (37); the annular groove (44) and the ball head (39) are slidably connected.

5. A cryopump according to claim 1, characterized in that: The refrigerator further comprises a vibration spring (15); The vibration spring (15) is sleeved on the cylinder (16) to drive the cylinder (16) to move in a direction away from the cold screen (11).

6. A cryopump according to claim 1, characterized in that: The refrigerator further comprises a fixing rod (45) and a fixing spring (46); The fixing rod (45) and the pump body (10) are slidably connected; The lower cover (29) is provided with a fixing groove (31); The fixing spring (46) is sleeved on the fixing rod (45) to drive the fixing rod (45) to move in a direction extending into the fixing groove (31).

7. A cryopump according to claim 1, characterized in that: The refrigerator further comprises an air inlet valve (32) and an air outlet valve (40); A room temperature chamber (19) is formed between the lower cover (29), the piston (21) and the cylinder (16); a lower cover flow channel (30) is provided in the lower cover (29); the lower cover flow channel (30) is in communication with the room temperature chamber (19); The air inlet valve (32) is fixedly connected to the lower cover (29), and the air outlet of the air inlet valve (32) is in communication with the lower cover flow channel (30); The exhaust valve (40) is fixedly connected to the lower cover (29), and an air inlet of the exhaust valve (40) is in communication with the lower cover flow channel (30).

8. A cryopump according to claim 7, characterized in that: The piston (21) comprises a large diameter end and a small diameter end, a secondary cold chamber (17) is formed between the upper side of the small diameter end and the cylinder (16), a secondary heat regenerator (27) and a fourth flow channel (25) are provided in the small diameter end, and the fourth flow channel (25) connects the secondary heat regenerator (27) and the secondary cold chamber (17); a primary cold chamber (18) is formed between the upper side of the large diameter end, the lower side of the small diameter end and the cylinder (16), a third flow channel (24), a second flow channel (23), a first flow channel (22) and a primary heat regenerator (28) are provided in the large diameter end, and the third flow channel (24) connects the secondary heat regenerator (27) and the primary cold chamber (18); the second flow channel (23) connects the primary cold chamber (18) and the primary heat regenerator (28); and the first flow channel (22) connects the room temperature chamber (19) and the primary heat regenerator (28).

9. The cryopump according to claim 1, characterized in that: The cryogenic pump further comprises a bracket (1), a first flange (2), a second flange (3), and a first electric push rod (8); The first flange (2) and the bracket (1) are fixedly connected; The second flange (3) is fixedly connected to the pump body (10), the second flange (3) is rotatably connected to the first flange (2), and the second flange (3) is provided with a flange groove (4) and a locking groove (5); The mounting end of the first electric push rod (8) is hinged to the first flange (2), and a push rod pin (9) is provided on the telescopic end of the first electric push rod (8), and the push rod pin (9) is slidably connected to the flange groove (4).

10. A cryopump according to claim 9, characterized in that: The cryogenic pump further comprises a locking rod (6) and a locking spring (7); The locking rod (6) is slidably connected to the first flange (2) in a horizontal direction; The locking spring (7) is sleeved on the locking rod (6) to drive the locking rod (6) to move in a direction extending into the locking groove (5).

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