Assembly method of motor for low-temperature equipment

Abstract

The invention relates to an assembling method of a motor for low-temperature equipment, and the assembling method comprises the steps: S1, cutting felt, embedding the felt into a fixing groove of a fixing ring to form a lubricating assembly, immersing the lubricating assembly into lubricating grease until the lubricating assembly is completely infiltrated, fishing out the lubricating assembly, and draining floating grease on the surface of the lubricating assembly. S2, the lubricating assembly obtained in the step S1 is embedded into a mounting cavity of the lubricating base; s3, the supporting bearing and the check ring assembly are installed on the installation shell, and the rotating shaft penetrates through the check ring assembly and then is connected with the supporting bearing in an assembled mode; and then the stator mechanism is installed on the installation shell, and the wiring process is completed. S4, a lubricating base is fixed to the mounting shell; s5, a dustproof assembly is installed at the cover shell and placed on press-fitting equipment, and the installation shell obtained in the S3 is installed on the press-fitting equipment and arranged opposite to the cover shell; the cover shell and the mounting shell are in press-fitting and close-fitting connection through press-fitting equipment, so that one end of the rotating shaft penetrates through the dustproof assembly and extends out of the cover shell; and S6, an end cover is pressed to seal the other end of the mounting shell. And the assembling steps are matched, so that the assembling precision is improved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a method for assembling a motor for cryogenic equipment. Background Technology

[0002] Motors used in cryogenic equipment such as cryogenic refrigeration equipment and cryogenic experimental devices need to operate stably for extended periods. This places stringent requirements on the motor's assembly precision, lubrication reliability, sealing performance, and structural stability. The cryogenic environments are typically below 0°C, and in some cases, below -40°C. Cryogenic equipment includes fan units, which are driven by motors to circulate gas within the equipment's internal space. Due to the limited installation space in cryogenic equipment, the axial installation dimensions of the motor must be small to avoid the fan unit occupying excessive wall space and affecting insulation performance. For example, the publication document CN212162977U provides a stator-enclosed brushless DC motor. The motor includes a housing containing a stator and circuit board, with a rotor housed within the stator. A front cover is located on one side of the housing, and a rear cover is located on the other side. Both the front and rear covers are sealed to the housing. The rotor's two ends are mounted in the front and rear covers respectively via bearings.

[0003] However, with bearings at both the front and rear ends of the motor, it is difficult to effectively reduce the axial installation dimensions. This results in significant misalignment between the rotor mechanism and the bearings, exacerbating vibration during operation and affecting the motor's lifespan. Furthermore, in low-temperature environments where external grease replenishment is not possible for extended periods, the motor needs to maintain stable performance. The bearings require grease lubrication to ensure smooth rotation. However, existing lubrication components are insufficiently wetted, and grease fluidity decreases at low temperatures, easily leading to bearing lubrication failure, causing motor jamming or wear. This necessitates the technical challenge of periodically replenishing grease, and therefore requires improvement. Summary of the Invention

[0004] To overcome the problems existing in related technologies, embodiments of the present invention provide an assembly method for a motor used in cryogenic equipment, which solves the technical problems of large axial installation dimensions and low grease storage in the motor.

[0005] According to a first aspect of the present invention, a method for assembling a motor for cryogenic equipment is provided. The motor includes a housing, a rotor mechanism, a stator mechanism, and a support bearing. The housing includes a mounting shell, a cover, and a lubrication seat. The assembly method includes the following steps: S1, after cutting the oil felt, embed it into the fixing groove of the fixing ring to form a lubrication assembly, so that the oil felt is flush with or slightly exceeds the opening of the fixing groove; the bottom of the fixing groove is provided with a plurality of lubrication holes arranged at intervals; immerse the lubrication assembly in lubricating grease until it is completely wetted, and then take it out and drain the surface grease. S2, embed the lubrication component obtained in step S1 into the mounting cavity of the lubrication seat, so that a grease storage space is formed between the fixing ring and the bottom of the mounting cavity, and fill the grease storage space with grease; S3, install the support bearing and retaining ring assembly to the mounting housing respectively, and connect the rotor shaft of the rotor mechanism through the retaining ring assembly to the support bearing, so that a grease-separating space is formed between the end face of the retaining ring assembly and the support bearing; then install the stator mechanism to the mounting housing and complete the wiring process; S4, fix the lubrication seat to the mounting shell, with the oil felt facing the support bearing and maintaining a preset lubrication gap; S5, install the dustproof component on the cover and place it on the press-fitting equipment, install the mounting shell obtained in S3 onto the press-fitting equipment and set it opposite to the cover; press the cover and mounting shell tightly connected by the press-fitting equipment, so that one end of the rotating shaft passes through the dustproof component and extends out of the cover; S6, press the end cap to seal the other end of the mounting housing.

[0006] In one embodiment, the pressing and tight fitting connection of the cover and the mounting shell using a press-fitting device includes: A preset pressing area is defined on the outer peripheral wall of the mounting housing; The pressing area is cleaned with a cleaning agent and then dried after cleaning. A lubricant of a predetermined thickness is applied to the surface of the pressing area; Control the pressing equipment to descend and press the cover to the preset pressing area of ​​the mounting shell.

[0007] In one embodiment, the control of the pressing device to descend and press-fit the cover to the preset pressing area of ​​the mounting shell includes: The cover is placed into the positioning base of the tooling and fixed by the positioning pin. Then the mounting shell is placed into the tooling and positioned by the guide sleeve. Control the pressing speed of the pressing equipment to 5 mm / s ~ 10 mm / s and apply pressure; Real-time monitoring of the pressure curve of the press-fitting equipment; After the pressing equipment reaches the designated position, maintain pressure for 5 to 10 seconds to ensure a tight fit between the cover and the mounting shell.

[0008] In one embodiment, the real-time monitoring of the pressure curve of the press-fitting equipment includes: Pressure parameters are collected by sensors installed on the pressure head; The displacement parameters of the indenter are collected by a displacement sensor; Compare the built-in standard pressure-displacement curves based on the pressure and displacement parameters; If the pressure and displacement parameters are within the deviation range, continue the pressing process; If the pressure parameters and / or displacement parameters exceed the deviation range, the pressing process should be stopped.

[0009] In one embodiment, the mounting housing forms a sealing protrusion at the edge of the press-fit area, and the height of the sealing protrusion is 3mm-5mm; The pressing connection of the cover to the preset pressing area of ​​the mounting shell includes: heating the end of the cover to 120-150°C using induction heating, holding it at that temperature for 2-3 minutes, and then pressing the cover into the pressing area until the end of the cover gradually unfolds and fits along the sealing protrusion.

[0010] In one embodiment, immersing the lubrication assembly in grease until it is completely wetted includes: Place multiple lubrication components into the grease in the immersion tank; Send the immersion chamber into the negative pressure equipment, control the immersion chamber to be in a negative pressure environment, the immersion environment temperature is 0℃-5℃, and let it stand for 10 min-20 min under these conditions. The negative pressure device is slowly restored to standard atmospheric pressure, and then the lubrication components are removed from the immersion tank.

[0011] In one embodiment, the rotating shaft is provided with an annular oil return groove and at least one branch oil passage, the branch oil passage being connected to the annular oil return groove; the annular oil return groove is located within the grease-separating space formed in step S3, and the oil outlet of the branch oil passage extends to the end of the rotating shaft; before assembling the rotor mechanism, grease is first applied to the inner walls of the annular oil return groove and the branch oil passage.

[0012] In one embodiment, the support bearing is an oil-impregnated bearing.

[0013] In one embodiment, the dustproof component includes a fixing member and a silicone sealing ring installed on the fixing member. The inner ring of the silicone sealing ring is provided with an annular lip, and the annular lip is interference-fitted with the rotating shaft. When installing the dustproof component, first apply a ring of sealant to the mounting groove of the cover, then embed the dustproof component into the mounting groove and press it firmly. After standing and curing for 5-8 minutes, press the cover and mounting shell together.

[0014] In one embodiment, at least three positioning bosses are uniformly protruding along the circumferential direction on the outer peripheral wall of the stator mechanism, and the inner wall of the mounting shell is provided with matching positioning grooves corresponding to the positioning bosses. When assembling the stator mechanism, align the positioning boss of the stator mechanism with the positioning groove of the mounting housing and insert it so that the positioning boss and the positioning groove are interference fit.

[0015] The technical solutions provided by the embodiments of the present invention can include the following beneficial effects: the lubrication assembly is fully impregnated with grease to increase the grease storage capacity and stabilize the lubrication area, thereby extending the lubrication time. A grease reservoir space is also provided between the lubrication assembly and the mounting cavity, which can further increase the grease storage capacity. The retaining ring assembly confines the grease to both sides of the supporting bearing, thereby reducing the risk of grease entering the rotor mechanism's active area and reducing the risk of grease leakage. The various assembly steps are well-coordinated, improving assembly accuracy. The press-fitting of the cover and mounting shell improves the tightness of the connection and reduces the outer peripheral wall size, eliminating the need for fastener locking connections. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] Figure 1 This is a flowchart illustrating a method for assembling an electric motor according to one embodiment.

[0018] Figure 2 This is a cross-sectional structural schematic diagram of an electric motor according to one embodiment.

[0019] Figure 3 This is a schematic diagram of the exploded structure of an electric motor according to one embodiment.

[0020] Figure 4 This is a physical diagram of a motor according to one embodiment.

[0021] In the figure, the stator mechanism is 10; the rotor mechanism is 20; the rotating shaft is 21; the annular oil return groove is 211; the branch oil passage is 212; the housing is 30; the mounting shell is 31; the bearing hole is 311; the retaining ring hole is 312; the press-fit area is 313; the sealing protrusion is 314; the cover is 32; the lubrication seat is 33; the mounting cavity is 331; the end cover is 34; the support bearing is 40; the lubrication assembly is 50; the oil felt is 51; the fixing ring is 52; the lubrication hole is 521; the fixing groove is 522; the retaining ring assembly is 60; the rigid support part is 61; the elastic part is 62; the dustproof assembly is 70; the fastener is 71; the silicone sealing ring is 72; and the sealing ring is 80. Detailed Implementation

[0022] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images, and should not be construed as limiting the invention. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art.

[0023] like Figures 1 to 4As shown, the present invention provides a method for assembling a motor for cryogenic equipment. The motor includes a housing 30, a rotor mechanism 20, a stator mechanism 10, and a support bearing 40. The housing 30 includes a mounting shell 31, a cover 32, and a lubrication seat 33. Preferably, the mounting shell 31 is formed by casting, die casting, or machining. Preferably, the lubrication seat 33 is a rigid seat structure that can be used in combination with the mounting shell 31.

[0024] The assembly method of the motor includes the following steps: S1, the roofing felt 51 is cut and embedded into the fixing groove 522 of the fixing ring 52 to form a lubrication assembly 50, so that the roofing felt 51 is flush with or slightly exceeds the opening of the fixing groove 522; the bottom of the fixing groove 522 has multiple spaced lubrication holes 521. The lubrication assembly 50 is immersed in grease until fully saturated, and then drained of excess grease. In this step, the roofing felt 51 is cut into a shape that fits the fixing groove 522 of the fixing ring 52 and embedded into the fixing groove 522, ensuring that the roofing felt 51 is flush with the opening of the fixing groove 522. The fixing ring 52 has a disc-shaped structure, and the outer peripheral wall of the fixing ring 52 is adapted to the inner wall structure of the mounting cavity 331. The fixing groove 522 has a recessed groove structure, optionally a circular groove, a rectangular groove, or a groove structure with positioning protrusions inside. The fixing groove 522 can accommodate and limit the roofing felt 51.

[0025] Optionally, the bottom of the fixing groove 522 may have four, six, eight, twelve, or twenty evenly spaced lubrication holes 521; or, the bottom of the fixing groove 522 may have a sieve structure with spaced holes. The lubrication holes 521 can connect the space outside the bottom of the fixing groove 522 with the oil felt 51 inside the fixing groove 522, allowing grease to enter the fixing groove 522. In particular, when the motor is in use, if the height of the space at the bottom of the fixing groove 522 is greater than the opening height of the fixing groove 522, the oil felt 51 can maintain contact with the external grease.

[0026] To improve the wetting effect of grease in the lubrication assembly 50, a negative pressure low-temperature synergistic wetting process is adopted. The lubrication assembly 50 is wetted with grease under negative pressure to increase the grease content and expel gas. The wetting process of the lubrication assembly 50 includes the following steps: S11, multiple lubrication components 50 are placed into the grease in the immersion tank; the multiple lubrication components 50 are evenly arranged in the grease in the immersion tank to ensure that each lubrication component 50 is completely submerged and does not contact each other, so as to avoid insufficient local immersion due to the stacking of lubrication components 50.

[0027] S12, place the impregnation chamber into the negative pressure equipment, control the impregnation chamber to be in a negative pressure environment, and maintain the impregnation environment temperature at 0℃-5℃, allowing it to stand for 10-20 minutes under these conditions. Smoothly place the impregnation chamber into the sealed cavity of the negative pressure equipment, close the sealing door, and ensure the sealing of the negative pressure equipment cavity is reliable. The sealing door ensures the airtightness of the negative pressure equipment, preventing negative pressure leakage from affecting the impregnation effect and ensuring the stable implementation of the negative pressure low-temperature synergistic impregnation process.

[0028] The immersion environment temperature is within the low-temperature range of 0℃-5℃. Compared to immersion at room temperature, this low-temperature environment prevents the grease from softening and leaking due to excessive heat, ensuring that the grease adheres stably to the interior of the component after immersion. The immersion environment temperature is higher than the dropping point temperature of the grease, ensuring that the grease still possesses sufficient penetrating fluidity to achieve deep wetting of the micropores inside the lubrication component 50. Preferably, the negative pressure equipment monitors the ambient temperature inside the immersion chamber in real time using a temperature sensor to stabilize the ambient temperature within the 0℃-5℃ range.

[0029] Under the aforementioned negative pressure and low temperature environment, the immersion time of the lubrication component 50 is controlled to be 10 min - 20 min. Through the continuous negative pressure, the grease gradually penetrates into each micropore structure of the lubrication component 50, thereby achieving a full-area immersion effect of the lubrication component 50.

[0030] S13, the negative pressure device is slowly restored to standard atmospheric pressure, and then the lubrication component 50 is removed from the immersion chamber. After the lubrication component 50 is immersed, the negative pressure device is slowly restored to standard atmospheric pressure. The pressure restoration rate inside the negative pressure device is controlled between 0.01MPa / s and 0.03MPa / s to effectively avoid the instantaneous impact force caused by sudden pressure changes from damaging the grease adsorption structure already formed inside the lubrication component 50, and to prevent the grease from precipitating out of the micropores due to sudden pressure changes, thus ensuring the stability of the immersion effect. After the lubrication component 50 is slowly removed from the immersion chamber, the surface grease of the lubrication component 50 is drained using a cleaning tool. At this time, the micropores inside the lubrication component 50 are completely filled with grease, providing stable conditions for the continuous lubrication of the motor in low-temperature environments. Preferably, the negative pressure device monitors the pressure inside the immersion chamber in real time through a pressure sensor to accurately control the negative pressure establishment and restoration rate.

[0031] S2, the lubrication component 50 obtained in step S1 is embedded into the mounting cavity 331 of the lubrication seat 33, forming a grease reservoir between the fixing ring 52 and the bottom of the mounting cavity 331, and grease is filled into the grease reservoir. The mounting cavity 331 has a stepped cavity structure, wherein the lubrication component 50 is installed in the mounting cavity 331 and abuts against the stepped surface of the mounting cavity 331. A closed grease reservoir is formed between the lubrication component 50 and the bottom of the mounting cavity 331, and the grease reservoir contacts the oil felt 51 through the lubrication hole 521, allowing for secondary replenishment of the oil felt 51 with grease. Preferably, a 3mm-5mm thick oil reservoir is formed between the fixing ring 52 and the bottom of the mounting cavity 331, and low-temperature stable grease is filled into the oil reservoir.

[0032] S3. Install the support bearing 40 and the retaining ring assembly 60 onto the mounting housing 31 respectively. Pass the rotor shaft 21 of the rotor mechanism 20 through the retaining ring assembly 60 and assemble it with the support bearing 40, so that a grease-separating space is formed between the end faces of the retaining ring assembly 60 and the support bearing 40. Then install the stator mechanism 10 onto the mounting housing 31 and complete the wiring process.

[0033] The support bearing 40 is installed into the bearing hole 311 on the bottom wall of the mounting housing 31, and the retaining ring assembly 60 is installed into the retaining ring hole 312. The bearing hole 311 and the retaining ring hole 312 are coaxial and have a stepped structure. The outer wall of the support bearing 40 is tightly fitted to the bearing hole 311. The retaining ring assembly 60 is installed into the mounting housing 31, and the rotating shaft 21 of the rotor mechanism 20 is passed through the retaining ring assembly 60 and assembled with the support bearing 40, so that a grease-separated space is formed between the end face of the retaining ring assembly 60 and the support bearing 40.

[0034] The retaining ring assembly 60 includes a rigid support portion 61 and a centrally located elastic portion 62. The elastic portion 62 is elastically connected to the rotating shaft 21 via at least two sealing lips to form a multi-seal structure, which prevents grease from entering the rotating area of ​​the rotor mechanism 20. The rigid support portion 61 is connected to the mounting housing 31 by a tight fit, fastener locking, or plug-in tight fit.

[0035] The retaining ring assembly 60 is installed on the mounting housing 31, and then the rotor shaft 21 of the rotor mechanism 20 is inserted into the support bearing 40 after passing through the elastic hole formed by the elastic part 62. Optionally, a grease-isolating space with a thickness of 2mm-5mm is formed between the end face of the retaining ring assembly 60 and the support bearing 40 to block the grease and prevent the grease from affecting the stability of motor operation.

[0036] The stator mechanism 10 is installed on the mounting housing 31, and the wiring process is completed. Optionally, multiple positioning bosses are evenly protruding along the circumferential direction on the outer peripheral wall of the stator mechanism 10, and the inner wall of the mounting housing 31 has matching positioning grooves corresponding to the positioning bosses. The positioning bosses of the stator mechanism 10 are aligned with the positioning grooves of the mounting housing 31 and inserted, and the positioning bosses and positioning grooves are press-fitted together. Preferably, an elastic buffer pad made of low-temperature resistant rubber is pasted on the bottom surface of the positioning groove to improve the shock absorption effect and assembly convenience.

[0037] The wiring process between the stator mechanism 10 and the external circuitry is completed, and insulation testing is performed. The interference fit between the positioning boss and the positioning groove of the stator mechanism 10, as well as the setting of the low-temperature resistant elastic buffer pad, ensures the coaxiality of the stator assembly and absorbs operational vibrations, thereby improving the overall structural stability.

[0038] S4, fix the lubrication seat 33 to the mounting housing 31, with the oil felt 51 facing the support bearing 40 and maintaining a preset lubrication gap. After the lubrication seat 33 is installed in place, there is a lubrication gap between the oil felt 51 and the support bearing 40, which can maintain the flexible rotation of the support bearing 40 and the reliability of lubrication. For example, the lubrication gap can be set to 0.1mm-0.5mm. Specifically, the lubrication gap can be preset to 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm. The support bearing 40 is an oil-impregnated bearing, which can improve the rotational smoothness of the shaft 21.

[0039] Preferably, a sealing ring 80 is provided at the crimping part of the lubrication seat 33 and the mounting shell 31. The sealing ring 80 surrounds the lubrication gap to form an annular elastic seal and prevent leakage at the joint.

[0040] S5, install the dustproof component 70 on the cover 32 and place it on the press-fitting equipment, and install the mounting shell 31 obtained in S3 onto the press-fitting equipment and set it opposite to the cover 32. Press the cover 32 and the mounting shell 31 together with the press-fitting equipment to make one end of the rotating shaft 21 pass through the dustproof component 70 and extend out of the cover 32.

[0041] The dustproof component 70 includes a fastener 71 and a silicone sealing ring 72 installed on the fastener 71. A ring of low-temperature sealant is applied inside the mounting groove of the cover 32. The dustproof component 70 is embedded into the mounting groove and compacted with a pressure block. It is left to cure for 5-8 minutes to fix the dustproof component 70 and the cover 32.

[0042] The mounting housing 31 is snapped onto the opening of the cover 32 for press-fitting preparation, with one end of the rotating shaft 21 extending out of the cover 32 along the dustproof assembly 70. A preset press-fitting area 313 is defined on the outer peripheral wall of the mounting housing 31, extending from the opening of the mounting housing 31 along the axial direction of the motor. For example, the preset press-fitting area 313 is defined as a region extending downward from the opening of the mounting housing 31 with a width of 20mm.

[0043] The cover 32 is placed into the positioning base of the tooling and fixed by the positioning pin. Then, the mounting shell 31 is placed into the tooling and positioned by the guide sleeve. The pressing equipment is controlled to descend at a preset pressing speed, and pressing pressure is applied to the cover 32 through the mounting shell 31. When the pressing equipment is in the correct position, the cover 32 and the mounting shell 31 are pressed tightly connected. At this time, one end of the rotating shaft 21 passes through the dustproof component 70 and extends out of the cover 32. The annular lip of the silicone sealing ring 72 is elastically sealed with the rotating shaft 21.

[0044] To improve the tightness of the connection between the mounting shell 31 and the cover 32 at the pressing part and the smoothness of the pressing, anhydrous ethanol cleaning agent is used to clean the pressing area 313. After natural drying, a lubricant with a thickness of 0.1 mm is applied to the surface of the pressing area 313 to improve the smoothness of the pressing.

[0045] S6, press the end cap 34 to seal the other end of the mounting housing 31. The end cap 34 is a thin-walled housing structure. After the lubrication seat 33 is installed to the bottom of the mounting housing 31, the end cap 34 closes the opening of the mounting housing 31 and covers the lubrication seat 33 accordingly. The end cap 34 and the mounting housing 31 are press-fitted together to improve the tightness and sealing of the fit.

[0046] The pressing equipment is controlled to descend and press-fit the cover 32 to the preset pressing area 313 of the mounting shell 31. This pressing process includes the following steps: S51, place the cover 32 into the positioning base of the tooling and fix it by the positioning pin, then install the shell 31 into the tooling and position it by the guide sleeve. S52, control the pressing speed of the pressing equipment to be between 5 mm / s and 10 mm / s, and apply pressure; S53 monitors the pressure curve of the pressing equipment in real time. A high-precision pressure sensor installed on the press head collects pressing pressure parameters in real time, and a laser displacement sensor collects the displacement parameters of the press head, enabling the control system of the pressing equipment to obtain accurate monitoring data in real time. The control system fits the collected pressure and displacement parameter data to form a real-time curve and compares the real-time curve with a built-in standard pressure-displacement curve. The standard curve is pre-generated based on the assembly parameters of different motor specifications, and the allowable deviation range between the real-time curve and the standard curve is set to ±5%. When the pressure and displacement parameters are within the deviation range, the pressing equipment continues pressing; when the pressure and / or displacement parameters exceed the deviation range, the pressing equipment stops pressing.

[0047] The control system fits the collected pressure and displacement parameters into a real-time curve. This process involves pressure sensors synchronously acquiring pressure and displacement parameters for their corresponding pressure heads. The raw data is transmitted to the data processing module via a high-speed data transmission line. The data processing module filters the raw data to remove abnormal noise caused by environmental vibrations, electromagnetic interference, and other factors. For example, a Kalman filter algorithm is used with a filter coefficient set to 0.05. Subsequently, the processed pressure and displacement data are correlated and matched according to the time series to generate a real-time curve, which is then displayed in real-time on the monitoring terminal as a dynamic curve.

[0048] S54, after the pressing equipment reaches the designated pressing position, pressure is maintained for 5 to 10 seconds to ensure a tight fit between the cover 32 and the mounting shell 31. The downward displacement of the pressing head is monitored by a displacement sensor. When the displacement reaches a preset threshold, the pressing position is determined to be in place. The pressure-holding procedure is then initiated, with the holding time controlled between 5 and 10 seconds. During the pressure-holding process, the pressing pressure is kept stable to ensure full contact between the mating surfaces of the cover 32 and the mounting shell 31, using the pressing pressure to shape the mating surfaces. After the pressure-holding is completed, the pressing equipment is slowly moved upwards to reset, avoiding the tensile force generated during reset that could damage the tight fit between the cover 32 and the mounting shell 31. The cover 32 and the mounting shell 31 maintain a tight and reliable fit even in low-temperature environments.

[0049] Furthermore, the mounting shell 31 forms a sealing protrusion 314 at the edge of the pressing area 313. The sealing protrusion 314 can be a stepped structure or a partially protruding structure. The sealing protrusion 314 gradually bends from the top towards the opening side of the mounting shell 31 to form a conical surface or a curved surface. The sealing protrusion 314 defines the edge of the pressing area 313 and flattens the end face of the cover 32, facilitating the positioning of the pressing area 313 and the pressing fit of the cover 32.

[0050] To further improve the smoothness of the press-fitting of the cover 32 and the firmness of the press-fitting parts, the cover 32 is press-fitted by heating. Optionally, the end of the cover 32 is heated to 130℃~155℃ by induction heating and held at that temperature for 1 min to 2.5 min.

[0051] In one specific embodiment, the cover 32 is placed into the positioning base of the tooling and fixed by the positioning pin. Then, the mounting shell 31 is placed into the tooling and positioned by the guide sleeve. The pressing equipment is controlled to descend at a pressing speed of 8 mm / s, applying a pressure of 15 kN to the cover 32. At the same time, the pressure parameters are collected by the pressure sensor installed on the pressing head, and the displacement parameters of the pressing head are collected by the displacement sensor. The pressure parameters and displacement parameters are compared with the built-in standard pressure-displacement curve, where the deviation range is set to ±5%. When the pressing equipment reaches the pressing position, the end of the cover 32 gradually unfolds along the pressing area 313 and fits against the sealing protrusion 314. The pressure is held for 8 seconds to complete the press-fit connection between the cover 32 and the mounting shell 31.

[0052] The pressing process of mounting shell 31 and cover 32 adopts positioning tooling limit, precise speed control and real-time monitoring of pressure curve. Combined with the sealing protrusion 314 structure and induction heating assembly process, the fitting accuracy of the two is greatly improved. Even after the material shrinks in low temperature environment, it can still maintain a tight fit and avoid loosening.

[0053] like Figure 2 and Figure 3 As shown, in one embodiment, the rotating shaft 21 is provided with an annular oil return groove 211 and at least one branch oil passage 212, which is connected to the annular oil return groove 211. The annular oil return groove 211 is located within the grease-separating space formed in step S3, and the oil outlet of the branch oil passage 212 extends to the end of the rotating shaft 21. The rotating shaft 21 is integrated with the annular oil return groove 211 and at least one branch oil passage 212, forming an integrated lubrication circulation structure in which the annular oil return groove 211 collects oil and the branch oil passage 212 returns it. The oil inlet end of the branch oil passage 212 is deeply connected to the annular oil return groove 211, and the oil outlet of the branch oil passage 212 extends to the end of the rotating shaft 21, realizing efficient recovery and directional guidance of grease.

[0054] The annular oil return groove 211 is an annular recess located on the outer peripheral wall of the rotating shaft 21, within the grease-separating space area formed in step S3. During the operation of the support bearing 40, the overflowing grease quickly collects in the annular oil return groove 211 under the combined action of centrifugal force and gravity, preventing grease buildup in the grease-separating space from causing sealing blockage or lubrication failure. Simultaneously, the grease-separating space provides a stable oil collection environment for the annular oil return groove 211.

[0055] The branch oil passage 212 adopts an inclined guide hole structure. The oil inlet of the branch oil passage 212 is located at the lowest point of the annular oil return groove 211, and the oil outlet of the branch oil passage 212 extends to the non-fitting area at the end of the rotating shaft 21. The branch oil passage 212 utilizes the inclined angle to form a natural oil return gradient. Combined with the centrifugal force when the rotating shaft 21 is rotating, the grease collected in the annular oil return groove 211 can be quickly returned to the oil felt 51 area at the end of the rotating shaft 21, realizing the recycling of grease.

[0056] The oil circuit structure is integrally machined with the rotating shaft 21, eliminating the need for additional piping assembly. This simplifies the assembly process, avoids sealing issues caused by pipe connections, and enhances the structural strength of the rotating shaft 21. It also adapts to changes in material mechanical properties under low-temperature conditions and prevents stress concentration in the rotating shaft 21 due to additional openings.

[0057] Before assembling the rotor mechanism 20, a layer of grease is evenly applied to the inner wall of the annular oil return groove 211 and the branch oil passage 212 to form an initial lubrication film, which further reduces the frictional resistance during low-temperature start-up.

[0058] It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed in this invention.

Claims

1. A method for assembling a motor for cryogenic equipment, the motor comprising a housing, a rotor mechanism, a stator mechanism, and a support bearing, characterized in that, The shell comprises an installation shell, a cover shell and a lubricating seat, and the assembly method comprises the following steps: S1, cut the oil felt and embed it into the fixing groove of the fixing ring to form a lubricating assembly, so that the oil felt is flush with or slightly exceeds the opening of the fixing groove; a plurality of lubricating holes are arranged at the bottom of the fixing groove; immerse the lubricating assembly in lubricating grease until it is completely soaked, and then drain the surface grease after taking it out; S2, embed the lubricating assembly obtained in step S1 into the installation cavity of the lubricating seat to form a grease storage space between the fixing ring and the bottom of the installation cavity, and fill the grease storage space with lubricating grease; S3, install the support bearing and the retainer assembly to the installation shell respectively, pass the rotating shaft of the rotor mechanism through the retainer assembly, and then assemble and connect the rotating shaft with the support bearing, so as to form a grease separation space between the retainer assembly and the end face of the support bearing; then install the stator mechanism on the installation shell, and complete the wiring process; S4, fix the lubricating seat to the installation shell, and keep the oil felt facing the support bearing and maintaining a predetermined lubrication gap; S5, install a dustproof assembly at the cover shell and place it on a press fitting device, install the installation shell obtained in S3 on the press fitting device and arrange it opposite to the cover shell; press fit the cover shell and the installation shell through the press fitting device, so that one end of the rotating shaft passes through the dustproof assembly and extends out of the cover shell; S6, press and close the other end of the installation shell with an end cover.

2. The method of assembly of claim 1, wherein, The press fitting of the cover shell and the installation shell through the press fitting device comprises: determining a predetermined press fitting area on the outer peripheral wall of the installation shell; cleaning the press fitting area with a cleaning agent, and drying after cleaning; coating a predetermined thickness of lubricant on the surface of the press fitting area; controlling the press fitting device to move downward and press fit the cover shell and the predetermined press fitting area of the installation shell.

3. The method of assembly of claim 2, wherein, The control of the press fitting device to move downward and press fit the cover shell and the predetermined press fitting area of the installation shell comprises: put the cover shell into the positioning base of the tool and fix it by positioning pins, then put the installation shell into the tool and position it by the guide sleeve; control the press fitting speed of the press fitting device to be 5 mm / s ~ 10 mm / s, and apply pressure; real-time monitoring of the pressure curve of the press fitting device; when the press fitting device is in place, keep the pressure for 5 s ~ 10 s, so that the cover shell and the installation shell are tightly fitted.

4. The method of assembly of claim 3, wherein, The real-time monitoring of the pressure curve of the press fitting device comprises: collecting pressure parameters through the sensor installed on the press head; collecting displacement parameters of the press head through the displacement sensor; comparing the pressure parameters and the displacement parameters with the built-in standard pressure displacement curve; if the pressure parameters and the displacement parameters are within the deviation range, continue to press fit; if the pressure parameters and / or displacement parameters exceed the deviation range, stop press fitting.

5. The method of assembly of claim 2, wherein, The installation shell forms a sealing protrusion at the edge of the press fitting area, and the height of the sealing protrusion is 3mm-5mm; The press fitting of the cover shell and the predetermined press fitting area of the installation shell comprises: heating the end of the cover shell to 120-150℃ by induction heating, keeping warm for 2-3min, then press the cover shell into the press fitting area until the end of the cover shell gradually unfolds along the sealing protrusion and fits.

6. The method of assembly of claim 1, wherein, The step of immersing the lubricating assembly into the grease to complete wetting comprises: putting a plurality of lubricating assemblies into the grease in the wetting box; sending the wetting box into a negative pressure device, controlling the wetting box to be in a negative pressure environment, controlling the temperature of the wetting environment to be 0-5℃, and standing for 10-20 minutes under this condition; controlling the negative pressure device to slowly recover to standard atmospheric pressure, and then taking out the lubricating assembly from the wetting box.

7. The method of assembly of claim 1, wherein, The rotating shaft is provided with an annular oil return groove and at least one branch oil path, the branch oil path is communicated with the annular oil return groove, the annular oil return groove is located in the grease separation space formed in step S3, the oil outlet of the branch oil path extends to the end of the rotating shaft, and the annular oil return groove and the branch oil path are coated with grease before assembling the rotor mechanism.

8. The method of assembly of claim 1, wherein, The supporting bearing is an oil-containing bearing.

9. The method of assembly of claim 1, wherein, The dustproof assembly comprises a fixing member and a silica gel sealing ring mounted on the fixing member, an inner ring of the silica gel sealing ring is provided with an annular lip, the annular lip is in interference fit with the rotating shaft, a circle of sealing glue is coated in the mounting groove of the cover shell when the dustproof assembly is mounted, the dustproof assembly is embedded in the mounting groove and compacted, and the cover shell and the mounting shell are pressed and assembled after standing for 5-8 minutes for solidification.

10. The method of assembly of claim 1, wherein, The outer peripheral wall of the stator mechanism is uniformly provided with at least three positioning bosses in the circumferential direction, and the inner wall of the mounting shell is provided with adapted positioning grooves corresponding to the positioning bosses. When the stator mechanism is assembled, the positioning bosses of the stator mechanism are aligned with the positioning grooves of the mounting shell and embedded, so that the positioning bosses and the positioning grooves are in interference fit.

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