Oil sealing structure for sealing motor shaft

Abstract

The oil sealing structure comprises the motor shaft, a motor shell and a bearing, the motor shaft is rotationally connected with the motor shell, the bearing is arranged on the outer side of the motor shaft in a sleeving mode, the motor shell is provided with an end cover used for supporting the bearing, the oil sealing structure further comprises an inner cover, and the end cover is provided with a mounting hole. The bearing is located in the mounting hole and attached to the inner wall of the mounting hole, the bearing is provided with a storage cavity used for containing lubricating grease, the inner cover is located in the motor shell, the end cover is provided with a positioning pin used for positioning the inner cover, the inner cover is fixedly provided with a positioning ring, the positioning ring extends into the mounting hole and attached to the inner wall of the mounting hole, and a labyrinth oil seal is arranged between the inner cover and the bearing. The inner cover is provided with an installation groove used for containing the labyrinth oil seal, the labyrinth oil seal is arranged on the outer side of the motor shaft in a sleeving mode and abuts against the bearing, the side, away from the motor shaft, of the labyrinth oil seal is provided with a first oil cavity communicated with the oil storage cavity, the side, away from the bearing, of the labyrinth oil seal is fixedly provided with a plurality of protruding rings, and the inner cover is provided with grooves corresponding to the protruding rings. And a labyrinth oil way is formed by a gap between the convex ring and the groove. The oil sealing structure has the effect that the space occupied by the oil sealing structure is reduced while the oil sealing requirement is met.

Description

Technical Field

[0001] The invention relates to the field of motor structures, and in particular to an oil sealing structure used for sealing a motor shaft. Background Art

[0002] The motor mainly consists of two parts: the stator and the rotor. The rotor is the power output component of the motor, which is used to output torque to the outside world. Since the rotor needs to rotate at high speed when the motor is working, in order to reduce the wear of the rotor during the rotation process, a bearing is usually set at the connection between the rotor and the motor housing. In order to further reduce the friction of the bearing during operation, grease is poured into the bearing, and an oil seal structure is installed at the end of the bearing to prevent grease leakage.

[0003] The common oil seal structure is mainly realized by an annular oil sealing baffle ring. For related technology, please refer to the Chinese patent with announcement number CN118728858A, which discloses a motor bearing sealing structure, in which a first seal and a second seal are arranged between the outer small cover and the motor shaft, and a third seal is arranged between the inner small cover and the motor shaft; the outer small cover is provided with oil injection and drain holes connected to the oil chamber of the outer small cover; the first seal, the second seal and the third seal have the same structure, and all include a metal support frame, the support frame is wrapped with high temperature resistant and wear-resistant rubber, the cross-section of the support frame is a semi-closed rectangle, and an annular metal spring is arranged in the rectangle; a shaft shoulder is arranged on the motor shaft, and the shaft shoulder is axially abutted against the seal.

[0004] With respect to the above-mentioned related technologies, in order to install the first oil seal, the second oil seal and the third oil seal, the end cover and the inner small cover of the bearing need to open an annular chamber adapted to the oil seal to install the first, second and third oil seals. Therefore, the mating surface between the end cover and the inner small cover and the rotor is required to have a larger thickness. However, for compact motors, the overall design space is limited. When the thickness of the end cover and the inner small cover is thicker, it will occupy the design space of other structures, increasing the design difficulty. Summary of the invention

[0005] In order to reduce the space occupied by the oil sealing structure while meeting the oil sealing requirements, the present application provides an oil sealing structure for use in motor shaft sealing.

[0006] The present application provides an oil sealing structure for use in motor shaft sealing, which adopts the following technical solution: An oil sealing structure for use in sealing a motor shaft comprises a motor shaft, a motor housing and a bearing, wherein the motor shaft is located inside the motor housing and is rotatably connected to the motor housing, the bearing sleeve is arranged outside the motor shaft, the motor housing is provided with an end cover for supporting the bearing, and further comprises an inner cover, the end cover is provided with a mounting hole, the bearing is located in the mounting hole and is fitted with the inner wall of the mounting hole, the inner cover is located in the motor housing and is fitted with the end cover, the gap between the bearing and the inner cover constitutes a storage cavity for placing grease, the end cover is provided with a positioning pin for positioning the inner cover, a positioning ring is fixedly arranged on a side of the inner cover close to the bearing, and the positioning ring is away from the inner cover One end of the cover extends into the mounting hole and fits against the inner wall of the mounting hole. A labyrinth oil seal is arranged between the inner cover and the bearing. The labyrinth oil seal is located on the side of the positioning ring close to the motor shaft. The inner cover is provided with a mounting groove for placing the labyrinth oil seal. The labyrinth oil seal sleeve is arranged on the outside of the motor shaft, and the side of the labyrinth oil seal facing away from the inner cover abuts against the bearing. A first oil chamber connected to the oil storage chamber is arranged on the side of the labyrinth oil seal facing away from the motor shaft. A plurality of convex rings are fixed on the side of the labyrinth oil seal facing away from the bearing. The inner cover is provided with grooves corresponding to the convex rings one by one. The gap between the convex ring and the groove constitutes a labyrinth oil path connected to the first oil chamber.

[0007] By adopting the above technical solution, the motor housing supports the motor shaft and fixes the end cover. The end cover supports the motor shaft through the bearing, and the bearing is conducive to reducing the friction between the motor shaft and the end cover. The end cover fixes the inner cover through the positioning pin, and the outer circle of the positioning ring cooperates with the mounting hole, thereby increasing the contact area at the connection between the end cover and the inner cover to improve the sealing between the inner cover and the end cover. The inner cover accommodates the labyrinth oil seal through the mounting groove, and the convex ring cooperates with the groove to form a curved labyrinth oil circuit. The labyrinth oil seal connects the labyrinth oil circuit with the oil storage chamber through the first oil chamber. When the grease in the oil storage chamber has a tendency to leak, the labyrinth oil circuit is conducive to extending the oil leakage path of the grease, and the resistance to the outflow of the grease is increased by the self-tension of the grease, thereby improving the effect of preventing the outflow of the grease. At the same time, there is no need to design the oil tank and oil seal separately, which is conducive to reducing the design space and meeting the design and processing requirements of compact motors.

[0008] Optionally, the inner cover is fixedly connected with a plurality of abutment blocks, which are all located in the mounting groove and arranged circumferentially along the mounting groove, and one end of all the abutment blocks close to the bearing abuts against the convex ring.

[0009] By adopting the above technical solution, the inner cover pushes the labyrinth oil seal to fit the bearing through the abutment ring block, thereby improving the sealing between the labyrinth oil seal and the bearing and reducing the probability of grease leakage from the connection between the labyrinth oil seal and the bearing.

[0010] Optionally, the abutment block is a hemispherical block, which protrudes toward the bearing, and the convex ring is provided with an arc groove corresponding to the hemispherical block, and the end of the hemispherical block facing away from the inner cover is located in the arc groove and fits against the inner wall of the arc groove.

[0011] By adopting the above technical solution, the hemispherical block is helpful to reduce the contact area between the inner cover and the labyrinth oil seal. At the same time, the arc groove is used to store a small amount of grease, thereby reducing the friction between the hemispherical block and the labyrinth oil seal when the labyrinth oil seal rotates with the bearing.

[0012] Optionally, a second oil chamber connected to the first oil chamber is provided on one side of the positioning ring close to the motor shaft axis, the second oil chamber is arranged along the circumference of the positioning ring, and the second oil chamber is located on the side of the oil storage chamber away from the motor shaft.

[0013] By adopting the above technical solution, when the motor shaft is placed horizontally, the grease slowly flows downward under the action of gravity, and the grease is temporarily stored in the second oil chamber, further reducing the probability of grease leakage from the maze oil circuit.

[0014] Optionally, the inner cover is provided with an oil filling hole connected to the second oil chamber, and the inner cover is provided with a threaded hole adapted to the positioning pin, one end of the positioning pin passes through the inner cover and is threadedly matched with the threaded hole, and the end of the oil filling hole away from the second oil chamber is threadedly connected to the threaded hole.

[0015] By adopting the above technical solution, in the initial state, one end of the positioning pin is located in the threaded hole and is threadedly matched with the threaded hole, and the positioning pin blocks the oil filling hole. The positioning pin is removed so that the oil filling hole connects the oil storage cavity with the outside, thereby facilitating the replenishment of grease or the inspection of the grease quality.

[0016] Optionally, the inner cover is provided with an exhaust hole, and the exhaust hole is connected to an end of the labyrinth oil circuit away from the first oil chamber, and the exhaust hole is filled with expansion fibers.

[0017] By adopting the above technical solution, a large amount of heat generated when the motor shaft rotates will cause the grease in the oil storage chamber to expand due to the heat. At this time, the air in the labyrinth oil circuit is discharged through the exhaust hole, thereby reducing the probability of grease leaking from between the bearing and the end cover or between the inner cover and the end cover under the action of pressure. Furthermore, when the grease enters the exhaust hole along the labyrinth oil circuit, the expansion fiber expands after contacting the grease, thereby sealing the exhaust hole, which is beneficial to reduce the probability of grease leaking from the exhaust hole.

[0018] Optionally, the labyrinth oil seal is provided with an expansion chamber connected to the first oil chamber, a heat shrink ring is provided in the expansion chamber, the heat shrink ring is made of heat shrinkable material, the heat shrink ring bends in a direction close to the bearing under normal conditions, and shrinks in a direction away from the bearing when at working temperature, the labyrinth oil seal is also provided with an air guide hole connected to the expansion chamber, the air guide hole is located on the side of the heat shrink ring away from the bearing, and the end of the air guide hole away from the expansion chamber is connected to the labyrinth oil circuit.

[0019] By adopting the above technical solution, in the initial state, the heat shrink ring is in a fixed state. At this time, the labyrinth oil seal limits the heat shrink ring through the expansion cavity. When the motor shaft is working and generates a large amount of heat, the grease in the oil storage cavity expands due to the heat and has a tendency to flow to the labyrinth oil circuit. At this time, the heat shrink ring is recovered in the direction away from the bearing under the action of heat, thereby expanding the space between the heat shrink ring and the bearing. During the deformation of the heat shrink ring, the gas in the receiving groove is discharged through the air guide hole, thereby providing space for the deformation of the heat shrink ring. After the heat lock ring is deformed, the expanded grease enters the expansion groove, thereby reducing the probability of the grease entering the labyrinth oil circuit after expansion.

[0020] Optionally, an outer cover is provided on the side of the bearing facing away from the inner cover, the outer cover is located in the mounting hole and fits with the inner wall of the mounting hole, the outer cover is provided with fixing bolts, the fixing bolts pass through the outer cover and are threadedly connected to the end cover, and a sealing ring is fixed on the side of the outer cover close to the bearing, and the sealing ring fits with the bearing.

[0021] By adopting the above technical solution, the end cover is fixed to the outer cover by fixing bolts, and the outer cover is sealed on the side of the bearing away from the inner cover by a sealing ring, thereby reducing the probability of grease leakage from the end of the bearing away from the inner cover and improving the sealing effect of the grease.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: 1. The motor housing supports the motor shaft and fixes the end cover. The end cover supports the motor shaft through bearings, which help reduce the friction between the motor shaft and the end cover. The end cover fixes the inner cover through positioning pins, and the outer circle of the positioning ring cooperates with the mounting hole, thereby increasing the contact area at the connection between the end cover and the inner cover to improve the sealing between the inner cover and the end cover. The inner cover accommodates the labyrinth oil seal through the mounting groove, and the convex ring cooperates with the groove to form a curved labyrinth oil circuit. The labyrinth oil seal connects the labyrinth oil circuit with the oil storage chamber through the first oil chamber. When the grease in the oil storage chamber has a tendency to leak, the labyrinth oil circuit helps to extend the oil seepage path of the grease, and increases the resistance to grease outflow through the grease's own tension, thereby improving the effect of preventing grease outflow. At the same time, there is no need to design the oil tank and oil seal separately, which helps to reduce the design space and meet the design and processing requirements of compact motors; 2. When the motor shaft rotates, a large amount of heat is generated, which causes the grease in the oil storage chamber to expand due to heat. At this time, the air in the labyrinth oil circuit is discharged through the exhaust hole, thereby reducing the probability of grease leaking from between the bearing and the end cover or between the inner cover and the end cover under the action of pressure. Furthermore, when the grease enters the exhaust hole along the labyrinth oil circuit, the expansion fiber expands after contacting with the grease, thereby blocking the exhaust hole, which is beneficial to reduce the probability of grease leaking from the exhaust hole; 3. In the initial state, the heat shrink ring is in a fixed state. At this time, the labyrinth oil seal limits the heat shrink ring through the expansion chamber. When the motor shaft is working and generates a lot of heat, the grease in the oil storage chamber expands due to the heat and has a tendency to flow to the labyrinth oil circuit. At this time, the heat shrink ring is recovered in the direction away from the bearing under the action of heat, thereby expanding the space between the heat shrink ring and the bearing. During the deformation of the heat shrink ring, the gas in the receiving groove is discharged through the air guide hole, thereby providing space for the deformation of the heat shrink ring. After the heat lock ring is deformed, the expanded grease enters the expansion groove, reducing the probability of the grease entering the labyrinth oil circuit after expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The utility model is a schematic diagram of the overall structure of an oil sealing structure used for sealing a motor shaft.

[0024] Figure 2 Schematic diagram of the structure of the labyrinth oil seal in Example 1.

[0025] Figure 3 It is a schematic diagram of the position of the oil filling hole in Example 2.

[0026] Figure 4 It is a schematic diagram of the exhaust hole position in Example 3.

[0027] Figure 5 It is a schematic diagram of the heat shrink ring installation structure in Example 4.

[0028] Explanation of the accompanying drawings: 1. Motor shaft; 2. Motor housing; 21. End cover; 211. Mounting hole; 212. Locating pin; 22. Fixing bolt; 3. Bearing; 4. Inner cover; 41. Locating ring; 411. Second oil chamber; 42. Mounting groove; 43. Groove; 44. Abutment block; 45. Threaded hole; 451. Oil filling hole; 46. Exhaust hole; 461. Expansion fiber; 5. Labyrinth oil seal; 51. First oil chamber; 52. Convex ring; 521. Arc groove; 53. Expansion chamber; 54. Heat shrink ring; 55. Air guide hole; 6. Outer cover; 61. Sealing ring. DETAILED DESCRIPTION

[0029] The present application is further described in detail below in conjunction with all the accompanying drawings.

[0030] The embodiment of the present application discloses an oil sealing structure for use in sealing a motor shaft.

[0031] Embodiment 1: Reference Figure 1 and Figure 2An oil sealing structure for sealing a motor shaft comprises a motor shaft 1, a motor housing 2 and a bearing 3. The motor housing 2 is hollow, the motor shaft 1 is located inside the motor housing 2, and one end of the motor shaft 1 passes through the motor housing 2 and extends outside the motor housing 2. The bearing 3 is sleeved on the outside of the motor shaft 1 and fits with the motor shaft 1. The motor shaft 1 is provided with a shoulder for mounting the bearing 3.

[0032] An end cover 21 is provided between the motor housing 2 and the bearing 3. The end cover 21 is provided with a mounting hole 211 for placing the bearing 3. The bearing 3 includes an inner ring, an outer ring and a plurality of balls. The inner ring is sleeved on the outside of the motor shaft 1 and fits the motor shaft 1. The outer ring is located outside the inner ring and is coaxial with the inner ring. A plurality of balls are evenly arranged between the inner ring and the outer ring. The inner ring is rollingly connected to the outer ring through rollers. The plurality of balls cooperate to support the inner ring and the outer ring to rotate relative to each other.

[0033] The bearing 3 is located in the mounting hole 211 and the outer ring is fitted with the inner wall of the mounting hole 211. The motor housing 2 positions the bearing 3 through the end cover 21, so that the end cover 21 supports the rotation of the motor shaft 1 through the bearing 3. An inner cover 4 is provided in the motor housing 2, and the inner cover 4 is fitted with the end cover 21. The end cover 21 is provided with a plurality of positioning pins 212 along the circumferential direction. The end of the positioning pin 212 along the length direction is fixed with a threaded column. The inner cover 4 is provided with a threaded hole 45 corresponding to the threaded column. The threaded column passes through the end cover 21 and is threadedly matched with the corresponding threaded hole 45. The end cover 21 is matched with the positioning pin 212, so that the inner cover 4 is fitted with the end cover 21.

[0034] An oil storage chamber is provided on the side of the bearing 3 close to the inner cover 4, and the oil storage chamber is located between the inner ring and the outer ring. When the bearing 3 is installed, grease is placed in the oil storage chamber to reduce the friction between the inner ring, the outer ring and the ball. A positioning ring 41 is fixed on the side of the inner cover 4 close to the end cover 21. The positioning ring 41 is located in the mounting hole 211, and the side of the positioning ring 41 away from the motor shaft 1 is in contact with the inner wall of the mounting hole 211. The positioning ring 41 is conducive to increasing the contact area between the inner cover 4 and the end cover 21, so as to reduce the probability of grease leakage from between the inner cover 4 and the end cover 21.

[0035] An outer cover 6 is provided on the side of the bearing 3 facing away from the inner cover 4. The outer cover 6 is located in the mounting hole 211 and fits the inner wall of the mounting hole 211. The outer cover 6 is provided with a plurality of fixing bolts 22. The plurality of fixing bolts 22 are arranged along the circumference of the end cover 21, and all the fixing bolts 22 pass through the outer cover 6 and are threadedly connected to the end cover 21. The end cover 21 positions the outer cover 6 through the fixing bolts 22. A sealing ring 61 is fixed on the side of the outer cover 6 close to the bearing 3. The sealing ring 61 contacts both the inner ring and the outer ring, thereby reducing the probability of the grease in the oil storage cavity passing through and leaking between the inner ring and the outer ring.

[0036] The inner cover 4 is provided with a mounting groove 42 on one side close to the bearing 3. The mounting groove 42 is arranged along the circumference of the motor shaft 1. A labyrinth oil seal 5 is arranged in the mounting groove 42. The labyrinth oil seal 5 is annular and sleeved on the outer side of the motor shaft 1. The labyrinth oil seal 5 is provided with a plurality of convex rings 52 on one side close to the inner cover 4. The plurality of convex rings 52 are coaxially arranged. The inner cover 4 is provided with a groove 43 adapted to the convex ring 52. The convex ring 52 is located in the corresponding groove 43 and does not contact the inner wall of the groove 43.

[0037] A plurality of abutment blocks are fixedly arranged on one side of the inner cover 4 close to the bearing 3. The abutment blocks are hemispherical blocks, which protrude toward the direction close to the bearing 3 and contact the convex ring 52. The inner cover 4 pushes the oil seal ring toward the bearing 3 through the hemispherical blocks, so that the inner cover 4 fits the inner ring of the bearing 3, thereby reducing the probability of grease leakage from the connection between the labyrinth oil seal 5 and the inner ring. The convex ring 52 is provided with an arc groove 521 adapted to the hemispherical blocks, and all the hemispherical blocks are located in the arc groove 521 and fit the inner wall of the arc groove 521.

[0038] The arc groove 521 is arranged along the circumference of the labyrinth oil seal 5. When the motor shaft 1 rotates, the inner ring of the bearing 3 is driven to rotate. When the labyrinth oil seal 5 contacts the inner ring, the inner ring drives the labyrinth oil seal 5 to rotate through friction. During the rotation of the labyrinth oil seal 5, the grease is driven to rotate to apply centrifugal force to the grease, thereby reducing the probability of grease leakage from the inner cover 4 and the motor shaft 1. In this process, the labyrinth oil seal 5 temporarily stores a small amount of grease through the arc groove 521 to reduce the friction between the hemispherical block and the labyrinth oil seal 5.

[0039] A first oil chamber 51 is provided on the side of the labyrinth oil seal 5 close to the bearing 3. The first oil chamber 51 is connected to the oil storage chamber, and the gap between the convex ring 52 and the groove 43 constitutes a labyrinth oil circuit. When the motor shaft 1 is working, it drives the bearing 3 to generate a large amount of heat. When the grease in the oil storage chamber expands due to heat, it enters the first oil chamber 51 and spreads along the labyrinth oil circuit. The labyrinth oil circuit is conducive to extending the oil seepage path of the grease, and when the grease flows along the labyrinth oil circuit, the resistance to the flow of the grease is increased by the tension of the grease itself, further reducing the probability of grease leakage from the inner cover 4 and the motor shaft 1. No oil seal ring and corresponding oil groove structure are required, which is conducive to saving design space and meeting the design and processing requirements of compact motors.

[0040] A second oil chamber 411 is formed in the circumferential direction on one side of the positioning ring 41 close to the axis of the motor shaft 1, and the second oil chamber 411 is located on the side of the labyrinth oil path away from the first oil chamber 51. When the motor shaft 1 is arranged horizontally, the liquid grease in the oil storage chamber flows into the second oil chamber 411 under the action of gravity, and the inner cover 4 temporarily stores the grease through the second oil chamber 411, thereby reducing the probability of the grease flowing into the labyrinth oil path due to gravity and leaking along the labyrinth oil path.

[0041] The implementation principle of Example 1 is as follows: by setting a labyrinth oil seal 5, the convex ring 52 and the groove 43 cooperate to form a labyrinth oil circuit. The labyrinth oil circuit is used to extend the length of the oil seepage path of the grease. At the same time, when the grease flows along the labyrinth oil circuit, the grease is affected by its own tension, thereby increasing the resistance encountered by the grease when flowing. While reducing the probability of grease leakage, there is no need to set an oil seal and an oil seal mounting structure, which is conducive to saving design space.

[0042] Example 2 Reference Figure 3 The difference between this embodiment and embodiment 1 is that the structure of the inner cover 4 is different. The inner cover 4 is provided with an oil filling hole 451. One end of the oil filling hole 451 is connected to the second oil chamber 411, and the other end is connected to the threaded hole 45. It should be noted that for a horizontally operating motor, the oil filling hole 451 of the inner cover 4 is located at the upper end of the inner cover 4. When the positioning pin 212 is located in the threaded hole 45 and is threadedly engaged with the threaded hole 45, the oil filling hole 451 is blocked. When it is necessary to add grease to the oil storage chamber, or to check the quality of the grease in the oil storage chamber, the positioning pin 212 at the upper end of the inner cover 4 is removed. At this time, the oil storage chamber is connected to the outside through the oil filling hole 451.

[0043] Example 3 Reference Figure 4 The difference between this embodiment and embodiment 1 is that the structure of the inner cover 4 is different. In this embodiment, the inner cover 4 is provided with an exhaust hole 46, which is located on the side of the inner cover 4 close to the motor shaft 1, and one end of the exhaust hole 46 is connected to the labyrinth oil path, and the other end is located on the end face of the inner cover 4 away from the bearing 3. When the grease in the oil storage cavity expands due to heat and flows along the labyrinth oil path, the gas in the labyrinth oil path is discharged through the exhaust hole 46, thereby reducing the probability of grease leaking from the gap between the inner cover and the end cover 21, or between the end cover 21 and the bearing 3 due to excessive pressure in the labyrinth oil path.

[0044] The exhaust hole 46 is filled with expansion fibers 461, and the expansion fibers 461 can be oil-absorbing cotton, high oil-absorbing expansion resin or cellulose-based aerogel, etc., which are prior arts and will not be described in detail here. In the initial state, the expansion fibers 461 are in a dry state, so that it is convenient to discharge the gas in the labyrinth oil circuit through the exhaust hole 46. When the grease enters the exhaust hole 46 along the labyrinth oil circuit, it contacts the expansion fibers 461. At this time, the expansion fibers 461 absorb the grease and gradually expand, thereby sealing the exhaust hole 46, which is beneficial to reduce the probability of grease leakage from the exhaust hole 46. When the grease cools and shrinks, the expansion fibers 461 separate from the grease. When the motor shaft 1 is working normally and the grease is not in contact with the expansion fibers 461, the grease absorbed by the expansion fibers 461 evaporates under the action of the heat generated by the motor shaft 1, thereby facilitating the recovery of the expansion fibers 461.

[0045] Example 4 Reference Figure 5 The difference between this embodiment and the first embodiment is that the structure of the labyrinth oil seal 5 is different. In this embodiment, the labyrinth oil seal 5 is provided with an expansion chamber 53 communicating with the first oil chamber 51. A heat shrink ring 54 is provided in the expansion chamber 53. The heat shrink ring 54 is fixedly connected to the inner wall of the expansion chamber 53. The heat shrink ring 54 is made of a heat shrinkable material, such as polyethylene, and its shrinking temperature is adapted to the temperature generated when the motor shaft 1 is working. At room temperature, the heat shrink ring 54 protrudes toward the direction close to the bearing 3, and at this time, the heat shrink ring 54 blocks the grease from entering the expansion chamber 53.

[0046] The labyrinth oil seal 5 is provided with an air guide hole 55 connected with the expansion chamber 53. The air guide hole 55 is located on the side of the heat shrink ring 54 away from the bearing 3, and the end of the air guide hole 55 away from the expansion chamber 53 is connected with the labyrinth oil path. When the heat generated by the motor shaft 1 during operation causes the grease to expand, the heat shrink ring 54 gradually shrinks in the direction away from the bearing 3 under the action of the heat. During the shrinking process of the heat shrink ring 54, the gas in the expansion chamber 53 is discharged from the air guide hole 55, so that the grease enters the accommodating chamber, and then the expanded grease enters the accommodating chamber. The grease is temporarily stored in the accommodating chamber, thereby reducing the probability of the grease leaking along the labyrinth oil path after expansion.

[0047] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An oil sealing structure for use in sealing a motor shaft, comprising a motor shaft (1), a motor housing (2) and a bearing (3), wherein the motor shaft (1) is located inside the motor housing (2) and is rotatably connected to the motor housing (2), the bearing (3) is sleeved on the outside of the motor shaft (1), and the motor housing (2) is provided with an end cover (21) for supporting the bearing (3), characterized in that: The motor (21) further comprises an inner cover (4), an end cover (21) having a mounting hole (211), a bearing (3) being located in the mounting hole (211) and being in contact with the inner wall of the mounting hole (211), an inner cover (4) being located in the motor housing (2) and being in contact with the end cover (21), a gap between the bearing (3) and the inner cover (4) constituting a storage cavity for storing grease, a positioning pin (212) being provided on the end cover (21) for positioning the inner cover (4), a positioning ring (41) being fixedly provided on a side of the inner cover (4) close to the bearing (3), an end of the positioning ring (41) facing away from the inner cover (4) extending into the mounting hole (211) and being in contact with the inner wall of the mounting hole (211), and a labyrinth oil seal (5) being provided between the inner cover (4) and the bearing (3). ), the labyrinth oil seal (5) is located on a side of the positioning ring (41) close to the motor shaft (1), the inner cover (4) is provided with a mounting groove (42) for placing the labyrinth oil seal (5), the labyrinth oil seal (5) is sleeved on the outside of the motor shaft (1), and the side of the labyrinth oil seal (5) away from the inner cover (4) is in contact with the bearing (3), the side of the labyrinth oil seal (5) away from the motor shaft (1) is provided with a first oil chamber (51) connected to the oil storage chamber, the side of the labyrinth oil seal (5) away from the bearing (3) is fixed with a plurality of convex rings (52), the inner cover (4) is provided with grooves (43) corresponding to the convex rings (52), and the gap between the convex rings (52) and the grooves (43) constitutes a labyrinth oil path connected to the first oil chamber (51).

2. The oil sealing structure for motor shaft sealing according to claim 1, characterized in that: The inner cover (4) is fixedly connected with a plurality of abutment blocks (44), which are all located in the mounting groove (42) and are arranged circumferentially along the mounting groove (42), and the ends of all the abutment blocks (44) close to the bearing (3) are in abutment with the convex ring (52).

3. The oil sealing structure for motor shaft sealing according to claim 2, characterized in that: The abutment block (44) is a hemispherical block that protrudes in a direction close to the bearing (3). The convex ring (52) is provided with an arc-shaped groove (521) corresponding to the hemispherical block. The end of the hemispherical block that is away from the inner cover (4) is located in the arc-shaped groove (521) and fits against the inner wall of the arc-shaped groove (521).

4. The oil sealing structure for motor shaft sealing according to claim 1, characterized in that: A second oil chamber (411) communicating with the first oil chamber (51) is provided on one side of the positioning ring (41) close to the axis of the motor shaft (1); the second oil chamber (411) is arranged along the circumference of the positioning ring (41), and the second oil chamber (411) is located on a side of the oil storage chamber that is away from the motor shaft (1).

5. The oil sealing structure for motor shaft sealing according to claim 4, characterized in that: The inner cover (4) is provided with an oil filling hole (451) connected to the second oil chamber (411), and the inner cover (4) is provided with a threaded hole (45) adapted to the positioning pin (212). One end of the positioning pin (212) passes through the inner cover (4) and is threadedly matched with the threaded hole (45), and one end of the oil filling hole (451) away from the second oil chamber (411) is threadedly connected to the threaded hole (45).

6. The oil sealing structure for motor shaft sealing according to claim 1, characterized in that: The inner cover (4) is provided with an exhaust hole (46), and the exhaust hole (46) is connected to an end of the labyrinth oil path away from the first oil chamber (51), and the exhaust hole (46) is filled with expansion fibers (461).

7. The oil sealing structure for motor shaft sealing according to claim 1, characterized in that: The labyrinth oil seal (5) is provided with an expansion chamber (53) connected to the first oil chamber (51), a heat shrink ring (54) is provided in the expansion chamber (53), the heat shrink ring (54) is made of a heat shrinkable material, the heat shrink ring (54) bends in a direction close to the bearing (3) under normal conditions, and shrinks in a direction away from the bearing (3) when at working temperature, the labyrinth oil seal (5) is also provided with an air guide hole (55) connected to the expansion chamber (53), the air guide hole (55) is located on a side of the heat shrink ring (54) away from the bearing (3), and an end of the air guide hole (55) away from the expansion chamber (53) is connected to the labyrinth oil circuit.

8. The oil sealing structure for motor shaft sealing according to claim 1, characterized in that: An outer cover (6) is provided on the side of the bearing (3) facing away from the inner cover (4); the outer cover (6) is located in the mounting hole (211) and is in close contact with the inner wall of the mounting hole (211); the outer cover (6) is provided with a fixing bolt (22); the fixing bolt (22) passes through the outer cover (6) and is threadedly connected to the end cover (21); a sealing ring (61) is fixedly provided on the side of the outer cover (6) close to the bearing (3); the sealing ring (61) is in close contact with the bearing (3).

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