Process for cooling shaft by using liquid nitrogen and then assembling shaft

Abstract

The invention discloses a process for cooling and reassembling a shaft by using liquid nitrogen, a rotating assembly is arranged on the inner side of a cryogenic box body, a driving motor for driving the rotating assembly to rotate is arranged at the bottom of the cryogenic box body, the rotating assembly comprises a cooling rotating seat for rotating and supporting, and further comprises a stand column mounted at the top of the cooling rotating seat; a chuck fixing seat is installed at the top of the stand column, and the shaft rod clamping disc is arranged on the outer side of the chuck fixing seat; when the device in the process is used for cooling and assembling, an assembly used for rotating is arranged in the device, a part shaft can be directly placed on the rotating assembly during machining and rotates slowly at a constant speed, and compared with the mode that the part shaft is directly placed in equipment for cooling, the structure can ensure that the part shaft is cooled more uniformly, and the machining efficiency is improved. And the performance change of the part during machining is avoided, and meanwhile, the practicability and functionality of the device are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid nitrogen assembly technology, and in particular relates to a technology for assembling a shaft after cooling it with liquid nitrogen. Background Art

[0002] The liquid nitrogen assembly process is an advanced technology that uses the ultra-low temperature characteristics of liquid nitrogen to realize parts assembly. The assembly of the motor rotor core and shaft is an important link in the motor manufacturing process. The assembly quality directly affects the performance and life of the motor. Liquid nitrogen cooling is usually used for assembly in this equipment. The liquid nitrogen assembly process has the advantages of simple operation, safety, reliability, economy and efficiency. It is widely used in machinery manufacturing, automobile maintenance, new energy and other fields.

[0003] Patent application No. 201610338797.5 discloses a liquid nitrogen cooling device and method for a roll forging die of an automobile front axle. The application adopts an infrared thermometer to accurately measure the temperature of the roll forging die, and adopts a position sensor to accurately determine the position of the roll forging die. The control center accurately controls the opening and opening degree of the automatic control valve according to the above information, so that the liquid nitrogen injector sprays nitrogen to cool the roll forging die. The whole device has a simple structure and is easy to install. It can quickly and accurately cool the roll forging die, thereby improving the quality of the automobile front axle and improving production efficiency. In combination with the above application and in connection with the existing assembly process, in the process of using liquid nitrogen to cool the shaft, the shaft is usually placed directly in a deep cooling device. During the cooling process after placement, the shaft surface is easily cooled unevenly, which affects the cooling effect of the shaft and may also cause damage to the shaft surface, thereby affecting the practicality of the existing assembly process and affecting the cooling effect of the process. For this reason, we propose a process of cooling the shaft with liquid nitrogen and then assembling it. Summary of the invention

[0004] The object of the present invention is to provide a process for cooling a shaft by liquid nitrogen and then assembling the shaft, so as to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a process for cooling a shaft by liquid nitrogen and then assembling the shaft, specifically comprising the following steps; S1. Clean and dry the parts to be assembled, remove impurities on the surface, and check the reference dimensions of the parts; S2, connecting the liquid nitrogen supply device to the cryogenic box, and filling the liquid nitrogen into the cryogenic box; S3, open the deep cold cover, and then put the parts to be assembled into the deep cold cover for freezing treatment. When placing, place the part shaft in the shaft mounting hole opened on the shaft clamping plate, and the bottom of the shaft is supported by the shaft tray. Then drive the motor to drive the cooling turntable to rotate, and the surface of the part shaft is evenly cooled by rotation. The temperature is detected synchronously during the freezing process to ensure that the parts reach the preset freezing temperature; S4. After the parts are frozen to the required temperature, they are quickly taken out and assembled. During assembly, assembly tools such as presses and hammers are used to press or knock the parts into place.

[0006] Preferably, a rotating assembly is provided on the inner side of the cryogenic box, and a driving motor for driving the rotating assembly to rotate is provided on the bottom of the cryogenic box. The rotating assembly includes a cooling turntable for rotation support, a column installed on the top of the cooling turntable, and a shaft clamping plate for placing the workpiece.

[0007] Preferably, a chuck fixing seat is installed on the top of the column, a shaft rod clamping disk is arranged on the outer side of the chuck fixing seat, and a corresponding shaft rod mounting hole is opened on the surface of the shaft rod clamping disk.

[0008] Preferably, a shaft rod tray is provided at the bottom of the column, and an arc groove is provided on the shaft rod tray corresponding to the shaft rod mounting hole.

[0009] Preferably, a lifting limit groove is opened on the inner side of the column, a lifting threaded rod is installed in the lifting limit groove, and a lifting rotary rod is arranged at one end of the lifting threaded rod located at the top of the column.

[0010] Preferably, a lifting connecting rod is arranged on the inner side of the chuck fixing seat, and an integrated lifting nut sleeve is arranged on the lifting connecting rod.

[0011] Preferably, the lifting threaded rod is installed in the lifting nut sleeve through a thread, and the lifting nut sleeve and the lifting connecting rod are driven by the lifting threaded rod to limit the lifting and lowering in the lifting limit groove, and the shaft rod clamping disk is synchronously lifted and lowered.

[0012] Preferably, a clamping disc is installed on the inner side of the shaft mounting hole, and a clamping screw is provided at one end of the clamping disc. The clamping screw is threadedly screwed through the edge of the shaft mounting disc, and the clamping disc is adjusted and moved in the shaft mounting hole through the clamping screw.

[0013] Preferably, sliding limit grooves are symmetrically provided at both ends of the inner side of the shaft mounting hole, and sliding limit blocks are provided at both ends of the clamping disk. When the clamping disk moves, the sliding limit grooves and the sliding limit blocks are used for sliding limit, and the clamping disk is an arc-shaped structure.

[0014] Preferably, a cryogenic cover plate is installed on the top of the cryogenic box, a box lock is installed between the cryogenic box and the front surface of the cryogenic cover plate, an electric control box is also installed on one side of the top of the cryogenic box, an operation panel is provided on the front surface of the electric control box, and a circulating fan is also installed on one side of the interior of the cryogenic box.

[0015] Compared with the prior art, the present invention has the following beneficial effects: When the device in the process is used for cooling assembly, a rotating component is arranged inside the device, and the shaft of the part during processing can be directly placed on the rotating component and rotated slowly and uniformly. Compared with directly placing the part inside the equipment for cooling, this structure can ensure that the shaft of the part is cooled more evenly, avoid the performance change of the part during processing, and improve the practicality and functionality of the device; The structure is also arranged to be adjustable in a lifting manner. When the part shaft is placed in the device for cooling, it can be adaptively adjusted according to the height of the part shaft. When the lengths of the part shaft are different, it can be placed more stably, thereby increasing the application range of the device, better cooling processing use, and further improving the practicality of the device. At the same time, when the device is used for processing, a clamping structure is also provided in the shaft mounting hole on the shaft clamping plate. When the part shaft is placed in the shaft mounting hole for processing and cooling, if the diameters of the part shaft are different, in order to ensure the stability of the part shaft during processing and avoid shaking and bumping of the part shaft during rotation, the clamping structure is set up to play a clamping and fixing role, thereby better placing part shafts of different diameters for processing and use, thereby better improving the practicability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a schematic diagram of the internal structure of the cryogenic box of the present invention; Figure 3 It is a schematic diagram of the installation structure of the column and the shaft rod clamping plate of the present invention; Figure 4 It is a schematic diagram of the longitudinal section structure of the column of the present invention; Figure 5 It is a schematic diagram of the cross-sectional structure of the shaft rod clamping disk of the present invention; In the figure: 100, cryogenic box; 101, cryogenic cover; 102, box lock; 103, electric control box; 104, operation panel; 105, circulation fan; 200, column; 201, chuck fixing seat; 202, shaft clamping plate; 203, shaft mounting hole; 204, shaft tray; 205, drive motor; 206, cooling swivel; 300, lifting rotary rod; 301, lifting limit groove; 302, lifting threaded rod; 303, lifting nut sleeve; 304, lifting connecting rod; 400, clamping clamping plate; 401, clamping screw; 402, sliding limit groove; 403, sliding limit block. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1 See also Figure 1 and Figure 2 The present invention provides a technical solution: a process for assembling a shaft after cooling it with liquid nitrogen. The operation steps of the process are as follows: cleaning and drying the parts to be assembled to ensure that there is no impurities such as oil, moisture, etc. on the surface thereof, and checking the reference size of the parts; connecting the liquid nitrogen supply device to the cryogenic box 100, and filling the cryogenic box 100 with liquid nitrogen, opening the cryogenic cover plate 101, and then placing the parts to be assembled into the cryogenic cover plate 101 for freezing treatment; when placing the parts, the shaft of the parts is placed in the shaft mounting hole 203 opened on the shaft clamping plate 202, and the bottom of the shaft is supported by the shaft tray 204, and then the driving motor 205 drives the cooling swivel 206 to rotate, and the surface of the shaft of the parts is evenly cooled by the rotation; the temperature is synchronously detected during the freezing process to ensure that the parts reach the preset freezing temperature; after the parts are frozen to the required temperature, they are quickly taken out and assembled; during assembly, assembly tools such as a press and a hammer method are used to press or knock the parts into place; after the assembly is completed, the assembly quality is inspected. Check whether the fit of parts, assembly accuracy, etc. meet the requirements. If adjustment is necessary, fine-tune it while ensuring safety until the ideal assembly effect is achieved.

[0019] Embodiment 2 See also Figure 1 , Figure 2 and Figure 3The present invention provides a technical solution: a process of cooling the shaft by liquid nitrogen before assembling. The assembly of the motor rotor core and the shaft requires strict control of key factors such as matching accuracy, assembly sequence, assembly pressure, and assembly temperature, so as to ensure that the performance and life of the motor meet the requirements. A rotating assembly is arranged on the inner side of a cryogenic box 100. A driving motor 205 for driving the rotating assembly to rotate is arranged at the bottom of the cryogenic box 100. The rotating assembly includes a cooling swivel seat 206 for rotation support, a column 200 installed on the top of the cooling swivel seat 206, and a shaft clamping plate 202 for placing a workpiece. A cryogenic cover plate 101 is installed on the top of the cryogenic box 100. The front surfaces of the cryogenic box 100 and the cryogenic cover plate 101 are A box lock 102 is installed in between, an electric control box 103 is also installed on the top side of the cryogenic box 100, an operation panel 104 is provided on the front surface of the electric control box 103, and a circulating fan 105 is also installed on the inner side of the cryogenic box 100. When the process in the application is used to assemble and process the shaft and the motor rotor core, the cryogenic box 100 is connected to the liquid nitrogen storage device, and the liquid nitrogen is sent into the cryogenic box 100. When the liquid nitrogen enters the approved amount, the cryogenic cover 101 is opened through the box lock 102, and the shaft to be frozen is placed in the cryogenic box 100 for cooling. After placement, the cryogenic cover 101 is closed and sealed and locked by the box lock 102. After freezing for a predetermined time, the shaft is taken out for quick assembly.

[0020] Specifically, a chuck fixing seat 201 is installed on the top of the column 200, and the chuck fixing seat 201 is sleeved on the column 200, and an integrated shaft rod clamping plate 202 is arranged on the outer side of the chuck fixing seat 201, and a through shaft rod mounting hole 203 is opened on the surface of the shaft rod clamping plate 202. At the same time, a shaft rod tray 204 is arranged at the bottom of the column 200, and an arc groove is opened on the shaft rod tray 204 corresponding to the shaft rod mounting hole 203. When the part shaft is placed, the stability of the placement can be better guaranteed. When the shaft is placed in the deep cold box 100 for freezing, the shaft is placed vertically on the shaft rod clamping plate 202. The bottom of the shaft is then in contact with the shaft tray 204. After the shaft is placed, the driving motor 205 at the bottom of the deep cold box 100 works to drive the cooling turntable 206 to rotate. When the cooling turntable 206 rotates, it drives the column 200 to rotate, and synchronously drives the shaft tray 204 and the shaft clamping plate 202 to rotate slowly. The shaft placed and installed on the shaft clamping plate 202 can be evenly cooled during the rotation process, ensuring that the shaft is evenly cooled, thereby better ensuring the cooling effect and avoiding damage to the shaft during the cooling process, thereby improving the practicability of the device during use.

[0021] Embodiment 3 See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The present invention provides a technical solution: a process of cooling the shaft by liquid nitrogen and then assembling it, a lifting limit groove 301 is opened on the inner side of the column 200, a lifting threaded rod 302 that can be rotatably adjusted is installed in the lifting limit groove 301, one end of the lifting threaded rod 302 is located at the top of the column 200 and a lifting rotary rod 300 is arranged, a lifting connecting rod 304 is arranged on the inner side of the chuck fixing seat 201, and an integrated lifting nut sleeve 303 is arranged on the lifting connecting rod 304, and the lifting is adjusted by the structure of the nut and the thread sleeve, and the structure is simple and the operation is convenient.

[0022] Specifically, the lifting threaded rod 302 is installed in the lifting nut sleeve 303 through a thread, and the lifting nut sleeve 303 and the lifting connecting rod 304 are driven by the lifting threaded rod 302 to limit the lifting and lowering in the lifting limit groove 301. At the same time, the shaft rod clamping plate 202 is synchronously lifted and lowered. Before the shaft is placed and installed, it can also be adjusted according to the length of the shaft to better adapt to the cooling of shafts of different lengths. When adjusting, the lifting rotary rod 300 on the top of the column 200 is rotated, and the lifting rotary rod 300 drives the lifting limit groove 301 in the column 200. The lifting threaded rod 302 inside rotates, and when the lifting threaded rod 302 rotates, the lifting nut sleeve 303 is driven to rise and fall through the thread, and the lifting nut sleeve 303 is connected to the chuck fixing seat 201 through the lifting connecting rod 304. When the lifting nut sleeve 303 is lifted, the chuck fixing seat 201 and the shaft rod clamping plate 202 are driven to rise and fall synchronously, thereby adjusting the distance between the shaft rod clamping plate 202 and the shaft rod tray 204, so that shafts of different lengths can be placed in the device for cooling processing, thereby better improving the practicability and functionality of the device.

[0023] Embodiment 4 See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5The present invention provides a technical solution: a process of cooling the shaft by liquid nitrogen and then assembling it, a clamping disc 400 is installed on the inner side of the shaft mounting hole 203, and the clamping disc 400 is an arc-shaped structure, and a clamping screw 401 is arranged at one end of the clamping disc 400, and the clamping screw 401 is screwed through the edge of the shaft clamping disc 202 by threading, and the clamping disc 400 is adjusted and moved in the shaft mounting hole 203 by the clamping screw 401, when the shaft is installed and placed in the shaft mounting hole 203 for cooling processing, in order to prevent bearings of different diameters from shaking unsteadily during rotation, or bumping and causing When the shaft is put in, the clamping screw 401 installed at the edge of the shaft clamping disk 202 can be rotated, and the clamping screw 401 rotates to push the clamping clamping disk 400 to move in the shaft mounting hole 203, and the shaft is clamped and fixed by the clamping clamping disk 400, and when the clamping clamping disk 400 moves, it is limited by the sliding limit groove 402 and the sliding limit block 403, thereby ensuring the stability of the clamping clamping disk 400 when moving. After the shaft is clamped by the clamping clamping disk 400, it can be better rotated and cooled, and at the same time, the bearing is prevented from bumping and shaking, which further improves the practicability and functionality of the device.

[0024] Specifically, sliding limit grooves 402 are symmetrically provided at both ends of the inner side of the shaft mounting hole 203, and sliding limit blocks 403 are provided at both ends of the clamping disk 400. When the clamping disk 400 moves, the sliding limit grooves 402 and the sliding limit blocks 403 are used for sliding limit, thereby limiting the movement of the clamping disk 400 and improving the stability during clamping.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for assembling a shaft after cooling it with liquid nitrogen, characterized in that: Specifically include the following steps: S1. Clean and dry the parts to be assembled, remove impurities on the surface, and check the reference dimensions of the parts; S2, connecting the liquid nitrogen supply device to the cryogenic box (100), and filling the cryogenic box (100) with liquid nitrogen; S3, opening the cryogenic cover plate (101), and then placing the parts to be assembled into the cryogenic cover plate (101) for freezing treatment. When placing the parts, the shaft of the parts is placed in the shaft mounting hole (203) opened on the shaft clamping plate (202), and the bottom of the shaft is supported by the shaft tray (204). Then, the motor (205) drives the cooling swivel (206) to rotate, and the surface of the shaft of the parts is evenly cooled by the rotation. The temperature is simultaneously detected during the freezing process to ensure that the parts reach the preset freezing temperature; S4. After the parts are frozen to the required temperature, they are quickly taken out and assembled. During assembly, assembly tools such as presses and hammers are used to press or knock the parts into place.

2. The process of cooling the shaft with liquid nitrogen and then assembling it according to claim 1, characterized in that: A rotating assembly is disposed inside the cryogenic box (100), and a driving motor (205) for driving the rotating assembly to rotate is disposed at the bottom of the cryogenic box (100). The rotating assembly includes a cooling swivel seat (206) for rotation support, a column (200) mounted on the top of the cooling swivel seat (206), and a shaft clamping plate (202) for placing a workpiece.

3. The process of assembling the shaft after cooling it with liquid nitrogen according to claim 2, characterized in that: A chuck fixing seat (201) is installed on the top of the column (200), a shaft rod clamping plate (202) is arranged on the outside of the chuck fixing seat (201), and a corresponding shaft rod mounting hole (203) is opened on the surface of the shaft rod clamping plate (202).

4. The process of assembling the shaft after cooling it with liquid nitrogen according to claim 3, characterized in that: A shaft tray (204) is provided at the bottom of the column (200), and an arc-shaped groove is provided on the shaft tray (204) corresponding to the shaft mounting hole (203).

5. The process of assembling the shaft after cooling it with liquid nitrogen according to claim 3, characterized in that: A lifting limit groove (301) is provided on the inner side of the column (200), a lifting threaded rod (302) is installed in the lifting limit groove (301), and a lifting rotary rod (300) is provided at one end of the lifting threaded rod (302) located at the top of the column (200).

6. The process of assembling the shaft after cooling it with liquid nitrogen according to claim 5, characterized in that: A lifting connecting rod (304) is arranged on the inner side of the chuck fixing seat (201), and an integrated lifting nut sleeve (303) is arranged on the lifting connecting rod (304).

7. The process of assembling the shaft after cooling it with liquid nitrogen according to claim 6, characterized in that: The lifting threaded rod (302) is installed in the lifting nut sleeve (303) through a threaded penetration, and the lifting nut sleeve (303) and the lifting connecting rod (304) are driven to lift and lower in the lifting limit groove (301) through the lifting threaded rod (302), and the shaft rod clamping plate (202) is lifted and lowered synchronously.

8. The process of assembling the shaft after cooling it with liquid nitrogen according to claim 3, characterized in that: A clamping disc (400) is installed on the inner side of the shaft mounting hole (203), and a clamping screw (401) is provided at one end of the clamping disc (400). The clamping screw (401) is screwed through the edge of the shaft mounting disc (202) through a thread, and the clamping disc (400) is adjusted and moved in the shaft mounting hole (203) through the clamping screw (401).

9. The process of assembling the shaft after cooling it with liquid nitrogen according to claim 8, characterized in that: Sliding limit grooves (402) are symmetrically provided at both ends of the inner side of the shaft rod mounting hole (203), and sliding limit blocks (403) are provided at both ends of the clamping plate (400). When the clamping plate (400) moves, the sliding limit grooves (402) and the sliding limit blocks (403) are used for sliding limit. Meanwhile, the clamping plate (400) is an arc-shaped structure.

10. The process of assembling a shaft after cooling it with liquid nitrogen according to claim 2, characterized in that: A cryogenic cover plate (101) is installed on the top of the cryogenic box (100), a box lock (102) is installed between the front surface of the cryogenic box (100) and the cryogenic cover plate (101), an electric control box (103) is also installed on one side of the top of the cryogenic box (100), an operation panel (104) is provided on the front surface of the electric control box (103), and a circulating fan (105) is also installed on one side of the interior of the cryogenic box (100).

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