A reducer sealing structure

Abstract

The application discloses a sealing structure of a speed reducer and belongs to the technical field of speed reducers. The sealing structure comprises an oil return mechanism installed in an oil return hole, a sealing ring arranged between the oil return hole and the oil return mechanism, and a rotary shaft transmission connection of the oil return mechanism, wherein an input gear is installed on the rotary shaft, the input gear is connected with an input end of a gearbox, the gearbox is installed on a speed reducer box body, an output end is transmission connected with the oil return mechanism, and the oil return amount of the oil return mechanism is matched with the rotary shaft rotating speed. The oil return mechanism is additionally arranged at the position of the traditional oil return hole, and the oil return mechanism is transmission connected with the rotary shaft through a gear train, so that the oil return is matched with the rotary shaft rotating speed, namely, the rotary shaft rotating speed is improved, the centrifugal force of the centrifugal ball in the oil return mechanism changes the amplitude of the inner diameter of the contraction ring, thereby the oil return amount of the oil return ring is increased, the oil return of the oil return mechanism is matched with the oil inlet of the circular gap, the oil pressure peak value in the oil cavity is reduced, and the sealing problem of the speed reducer at the position is solved.

Description

Technical Field

[0001] This invention belongs to the field of speed reducer technology, and in particular to a speed reducer sealing structure. Background Technology

[0002] A speed reducer is a modern mechanical device that matches the speed and transmits torque between a prime mover and a driven machine or actuator. Oil leakage is one of the most common and difficult-to-avoid failures in speed reducers. In terms of sealing design to prevent lubricating oil leakage from mating surfaces and to prevent foreign objects from entering the speed reducer, there are generally two types: static sealing and dynamic sealing.

[0003] Currently, after the reducer's rotating shaft passes through the housing, a circumferential gap is created between them. Lubricating oil inside the housing leaks out through this gap. To solve the sealing problem in this gap, an oil seal is installed between the rotating shaft and the housing. The oil seal blocks the leaking lubricating oil into the oil cavity formed by the housing, rotating shaft, and oil seal. To prevent the lubricating oil in the oil cavity from accumulating and putting a burden on the oil seal, a return oil hole is provided on the housing to allow the lubricating oil in the oil cavity to flow back to the housing. However, the size of the return oil hole is designed based on the return oil volume, while the amount of lubricating oil leaking from the circumferential gap is a variable directly related to the rotating shaft speed. This means that the size of the return oil hole can only be selected from the middle value of the leakage volume. In this design, the size of the return oil hole cannot match the rotating shaft speed, resulting in an imbalance between oil leakage and return between the oil cavity and the housing. This causes the amount of lubricating oil in the oil cavity to fluctuate, leading to continuous changes in the lubrication pressure on the oil seal and accelerating the entry of external dust into the oil cavity. The risk of blockage of the return oil hole is high, which is detrimental to the reducer's sealing.

[0004] In addition, there are many types and structures of seals for speed reducers. Unless a serious leak is detected in time, most of the time the abnormality of the speed reducer seal is judged by monitoring the oil level of the lubricating oil. At present, the diagnosis of oil leakage in speed reducers relies mainly on the maintenance experience of workers. The inspection cycle of the oil leakage location is uncertain, which has a great impact on production and is not conducive to the maintenance of speed reducers. Summary of the Invention

[0005] Purpose of the invention: To provide a sealing structure for a speed reducer to solve the above-mentioned problems existing in the prior art.

[0006] Technical solution: A speed reducer sealing structure includes a speed reducer housing, a rotary shaft mounted on the speed reducer housing, an oil seal fitted on the rotary shaft, an oil chamber formed between the rotary shaft, the oil seal, and the speed reducer housing, an oil return hole communicating with the interior of the speed reducer housing in the oil chamber, an oil return mechanism installed in the oil return hole, a sealing ring between the oil return hole and the oil return mechanism, the oil return mechanism being drivenly connected to the rotary shaft, an input gear mounted on the rotary shaft, the input gear being connected to the input end of a gearbox, the gearbox being mounted on the speed reducer housing, and its output end being drivenly connected to the oil return mechanism, the oil return volume of the oil return mechanism being matched with the rotational speed of the rotary shaft.

[0007] Furthermore, the oil return mechanism includes an oil return ring, a sleeve, a transmission gear, and a bearing. An oil return ring is installed inside one end of the sleeve, and the inner diameter of the oil return ring matches the rotational speed of the rotating shaft. The moving ring of the bearing is interference-fitted onto the outside of the other end of the sleeve, and the fixed ring of the bearing is overfitted into the oil return hole. A transmission gear is fixedly installed in the middle of the sleeve, and the transmission gear is connected to the output end of the gearbox.

[0008] Furthermore, the return oil ring includes a shrink ring body, a traction rope, traction ribs, and a centrifugal ball. The shrink ring body is fitted with several traction ribs, which are evenly distributed in a circular shape. A traction rope is connected to each traction rib, and the end of the traction rope extends out of the shrink ring body and is connected to a centrifugal ball. A cable-spinning groove is provided on the sleeve, through which the traction rope passes. The centrifugal ball controls the inner diameter of the shrink ring body through centrifugal force.

[0009] Furthermore, the traction ribs are arc-shaped metal sheets, and the bending direction of several of the traction ribs is towards the outer edge of the contraction ring.

[0010] Furthermore, the outer wall of the shrink ring is attached to the sleeve with sealant. The shrink ring is made of flexible rubber, and the outer thickness of the shrink ring is greater than the inner thickness. The inner diameter of the shrink ring is related to the oil return volume.

[0011] Furthermore, the traction rope is a flexible steel wire rope.

[0012] Beneficial effects: This invention adds an oil return mechanism to the traditional oil return hole position and connects the oil return mechanism to the rotary shaft through a gear train, realizing the coordination between the oil return and the rotary shaft speed. That is, as the rotary shaft speed increases, the centrifugal force of the centrifugal ball in the oil return mechanism changes the inner diameter of the contraction ring by a large margin, thereby increasing the oil return volume of the oil return ring. This achieves the coordination between the oil return of the oil return mechanism and the oil inlet of the circumferential gap. Compared with the traditional oil return hole, the peak oil pressure in the oil chamber is greatly reduced, thereby alleviating the sealing problem of the reducer at this location. Attached Figure Description

[0013] Figure 1 This is a partial schematic diagram of the oil return mechanism installed on the reducer in this invention.

[0014] Figure 2 This is a schematic diagram of the oil return mechanism in this invention.

[0015] Figure 3 In this invention Figure 2 Exploded view.

[0016] Figure 4 This is a schematic diagram of the oil return ring in this invention.

[0017] Figure 5 This is a front cross-sectional view of the oil return ring in this invention.

[0018] Figure 6 This is a side sectional view of the oil return ring in this invention.

[0019] Figure 7 This is a schematic diagram of the integrated structure of the traction rib in this invention.

[0020] The attached diagram is labeled as follows: 1. Oil return ring; 11. Shrink ring body; 12. Traction rope; 13. Traction rib; 14. Centrifugal ball; 15. Integrated traction rib; 2. Sleeve; 21. Spinning groove; 3. Transmission gear; 4. Bearing; 41. Moving ring; 42. Fixed ring; 5. Gearbox housing; 51. Oil return hole; 6. Rotary shaft; 61. Gearbox; 62. Input gear; 7. Oil seal; 8. Oil chamber; 9. Oil return mechanism. Detailed Implementation

[0021] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0022] like Figure 1 As shown, a speed reducer sealing structure includes a speed reducer housing 5, a rotary shaft 6 mounted on the speed reducer housing 5, an oil seal 7 fitted on the rotary shaft 6, an oil chamber 8 formed between the rotary shaft 6, the oil seal 7 and the speed reducer housing 5, an oil return hole 51 communicating with the interior of the speed reducer housing 5 on the oil chamber 8, an oil return mechanism 9 installed in the oil return hole 51, a sealing ring between the oil return hole 51 and the oil return mechanism 9, the oil return mechanism 9 being drivenly connected to the rotary shaft 6, an input gear 62 mounted on the rotary shaft 6, the input gear 62 being connected to the input end of a gearbox 61, the gearbox 61 being mounted on the speed reducer housing 5 and its output end being drivenly connected to the oil return mechanism 9, the oil return amount of the oil return mechanism 9 being matched with the rotational speed of the rotary shaft 6.

[0023] As the rotational speed of the rotary shaft 6 increases, the fluidity of the lubricating oil in the gap between the rotary shaft 6 and the reducer housing 5 increases, and the speed at which lubricating oil penetrates into the oil chamber 8 accelerates. The oil return mechanism 9 is connected to the rotary shaft 6 via the gearbox 61, so that the operation of the oil return mechanism 9 is linked to the rotational speed of the rotary shaft 6. This allows the oil return volume of the oil return mechanism 9 to match the rotational speed of the rotary shaft 6, achieving matching of oil inlet (lubricating oil penetrates into the oil chamber 8 from the gap between the rotary shaft 6 and the reducer housing 5) and oil return (lubricating oil flows back from the oil return mechanism 9 to the inside of the reducer housing 5). Compared with the traditional oil return hole 51, the peak oil pressure in the oil chamber 8 is reduced, alleviating the sealing problems caused by changes in the rotational speed of the rotary shaft 6 (high oil pressure increases the working burden of the oil seal 7, and may even exceed the working limit of the oil seal 7, resulting in lubricating oil leakage; low oil pressure will accelerate the entry of air into the oil chamber 8, and the dust in the air will form sludge with the lubricating oil, which will lead to oil return blockage, thereby causing high oil pressure and lubricating oil leakage).

[0024] like Figures 1-3 As shown, the oil return mechanism 9 includes an oil return ring 1, a sleeve 2, a transmission gear 3, and a bearing 4. The oil return ring 1 is installed inside one end of the sleeve 2, and the inner diameter of the oil return ring 1 matches the rotational speed of the rotating shaft 6. The moving ring 41 of the bearing 4 is interference-fitted to the outside of the other end of the sleeve 2, and the fixed ring 42 of the bearing 4 is overfitted into the oil return hole 51. The transmission gear 3 is fixedly installed in the middle of the sleeve 2, and the transmission gear 3 is connected to the output end of the gearbox 61.

[0025] The components of the oil return mechanism 9 are closely assembled. The sleeve 2 and the transmission gear 3 can be welded or keyed together. In addition, the fixed ring 42 of the bearing 4 is over-assembled in the oil return hole 51, which makes the mechanism structurally strong. In terms of production, it does not overlap with other components of the gearbox, which is convenient for mass production. The oil return mechanism 9 is over-assembled in the oil return hole 51 through the fixed ring 42 of the bearing 4 for easier assembly and easier disassembly and maintenance in the later stage.

[0026] like Figures 4-6 As shown, the return oil ring 1 includes a contraction ring body 11, a traction rope 12, traction ribs 13, and a centrifugal ball 14. Several traction ribs 13 are embedded inside the contraction ring body 11. The traction ribs 13 are evenly distributed in a circular shape. The traction rope 12 is connected to the traction ribs 13. The end of the traction rope 12 extends to the outside of the contraction ring body 11 and is connected to the centrifugal ball 14. A wire-spinning groove 21 is opened on the sleeve 2. The traction rope 12 passes through the wire-spinning groove 21. The centrifugal ball 14 controls the inner diameter of the contraction ring body 11 by centrifugal force.

[0027] As a key component of the oil return mechanism 9 that controls the amount of oil return, the return ring 1 rotates. The centrifugal ball 14, as a counterweight structure, transmits centrifugal force to the traction rib 13 through the traction rope 12 under centrifugal action. The deformation of the traction rib 13 causes the shrinking ring 11 to undergo a large deformation. The deformation of the shrinking ring 11 is an amplified deformation of the inner hole. The deformation of the shrinking ring 11 increases the cross-sectional area of ​​the lubricating oil return, thereby realizing the change of the amount of oil return under the rotating environment. With the transmission action of the transmission gear 3, the gearbox 61 and the input gear 62, the return ring 1 can adjust the amount of oil return according to the rotation speed of the rotating shaft 6.

[0028] like Figure 5 and Figure 7 As shown, the traction rib 13 is an arc-shaped metal sheet, and the bending direction of several traction ribs 13 is towards the outer edge of the contraction ring 11. The traction rib 13 can be designed as multiple discontinuous, dispersed structures, or as a continuous, integral structure (such as...). Figure 7 The integrated traction rib 15 shown can evenly distribute the centrifugal force transmitted from the traction rope 12 onto the shrink ring 11, and the bending direction of the traction rib 13 can significantly change the inner diameter of the shrink ring 11, so that the shrink ring 11 can deform rapidly.

[0029] like Figure 2 and Figure 6 As shown, the outer wall of the shrink ring 11 is adhered to the sleeve 2 with sealant. The shrink ring 11 is made of flexible rubber, and the outer thickness of the shrink ring 11 is greater than the inner thickness. The inner diameter of the shrink ring 11 is related to the oil return volume. The flexible material of the shrink ring 11 allows it to be used for a long time under lubricating oil while meeting deformation requirements. The structure of the shrink ring 11, which is thinner inside and thicker outside, not only ensures structural stability after deformation but also guides the oil return, preventing the accumulation of wear debris or sludge, and plays an important role in preventing clogging.

[0030] like Figures 5-6 As shown, the traction rope 12 is a flexible steel wire rope. The traction rope 12 is made of flexible steel wire rope in order to connect and support the centrifugal ball 14 and prevent the centrifugal ball 14 from colliding with other components and causing abnormal noise during operation.

[0031] In use, the rotary shaft 6 rotates, and the input gear 62 mounted on the rotary shaft 6 rotates accordingly. The input gear 62 inputs power from the rotary shaft 6 to the gearbox 61. The output end of the gearbox 61 drives the transmission gear 3 in the oil return mechanism 9, causing the oil return mechanism 9 to rotate within the oil return hole 51. The rotation of the oil return mechanism 9 causes the centrifugal ball 14 to tighten the traction rope 12. Under centrifugal force, the centrifugal force of the centrifugal ball 14 is transmitted to the traction rib 13 through the traction rope 12. If the rotary shaft 6 is large, the centrifugal force is large, and the traction rib can be adjusted accordingly. The structure 13 enlarges the inner hole of the shrink ring 11, meaning the deformation of the shrink ring 11 is related to the rotary shaft 6. The deformation of the shrink ring 11 increases the area of ​​the oil return cross section, thereby increasing the oil return volume. This increases the amount of lubricating oil that permeates into the oil chamber 8 from the gap between the rotary shaft 6 and the reducer housing 5, as well as the amount of lubricating oil flowing out from the oil return mechanism 9, when the rotary shaft 6 operates at high speed. This dynamic balance design, which changes continuously with the rotation of the rotary shaft 6, can effectively reduce the peak oil pressure in the oil chamber 8 and alleviate the sealing problem of the reducer in this structure.

[0032] The deformation characteristics of the shrink ring and the centrifugal force generated by the centrifugal ball 14 need to be matched according to the working mode of the reducer in order to make the optimal sealing design.

[0033] The preferred embodiments of the invention have been described in detail above with reference to the accompanying drawings. However, the invention is not limited to the specific details of the above embodiments. Within the scope of the inventive concept, various equivalent transformations can be made to the technical solutions of the invention, and all such equivalent transformations fall within the protection scope of the invention.

Claims

1. A speed reducer sealing structure, comprising a speed reducer housing (5), a rotary shaft (6) mounted on the speed reducer housing (5), an oil seal (7) fitted on the rotary shaft (6), an oil cavity (8) formed between the rotary shaft (6), the oil seal (7) and the speed reducer housing (5), and an oil return hole (51) communicating with the interior of the speed reducer housing (5) is provided on the oil cavity (8), characterized in that, An oil return mechanism (9) is installed inside the oil return hole (51). A sealing ring is provided between the oil return hole (51) and the oil return mechanism (9). The oil return mechanism (9) is connected to the rotary shaft (6) in a transmission. An input gear (62) is installed on the rotary shaft (6). The input gear (62) is connected to the input end of the gearbox (61). The gearbox (61) is installed on the reducer housing (5), and its output end is connected to the oil return mechanism (9) in a transmission. The oil return amount of the oil return mechanism (9) is matched with the rotation speed of the rotary shaft (6). The oil return mechanism (9) includes an oil return ring (1), a sleeve (2), a transmission gear (3), and a bearing (4). The oil return ring (1) is installed inside one end of the sleeve (2). The inner diameter of the oil return ring (1) matches the rotation speed of the rotating shaft (6). The moving ring (41) of the bearing (4) is interference-fitted to the outside of the other end of the sleeve (2). The fixed ring (42) of the bearing (4) is overfitted into the oil return hole (51). The transmission gear (3) is fixedly installed in the middle of the sleeve (2). The transmission gear (3) is connected to the output end of the gearbox (61). The return oil ring (1) includes a shrink ring body (11), a traction rope (12), traction ribs (13) and a centrifugal ball (14). The shrink ring body (11) is fitted with a number of traction ribs (13), which are evenly distributed in a circle. The traction ribs (13) are connected to the traction ropes (12), and the ends of the traction ropes (12) extend to the outside of the shrink ring body (11) and are connected to the centrifugal ball (14). The sleeve (2) is provided with a wire-spinning groove (21), and the traction ropes (12) pass through the wire-spinning groove (21). The centrifugal ball (14) controls the inner diameter of the shrink ring body (11) by centrifugal force.

2. The speed reducer sealing structure according to claim 1, characterized in that, The traction rib (13) is an arc-shaped metal sheet, and the bending direction of several of the traction ribs (13) is toward the outer edge of the contraction ring (11).

3. The speed reducer sealing structure according to claim 1, characterized in that, The outer wall of the shrink ring (11) is attached to the sleeve (2) with sealant. The shrink ring (11) is made of flexible rubber. The outer thickness of the shrink ring (11) is greater than the inner thickness. The inner diameter of the shrink ring (11) is related to the oil return volume.

4. The speed reducer sealing structure according to claim 1, characterized in that, The traction rope (12) is a flexible steel wire rope.

Images