Respirator and transmission shaft containing the respirator

Abstract

The present invention relates to the field of mechanical transmission shafts, and in particular to a respirator and a transmission shaft including the respirator. The respirator comprises a respirator housing, a filter element cover and a filter element. An outer ring groove is arranged on the outer wall of the respirator housing, and a plurality of air vents are arranged in the outer ring groove. The filter element cover is used to seal the filter element inside the respirator housing or on a spline shaft of a transmission shaft. The transmission shaft is mounted with the respirator, and the respirator housing is fixedly mounted on the inner wall of the spline sleeve, one end of the spline shaft is movably connected in the spline sleeve, and one end of the spline shaft outside the spline sleeve is connected with a universal joint, and a sealing sleeve is connected between the universal joint and the spline sleeve. The respirator can effectively avoid the imbalance of pressure inside and outside the transmission shaft sealing sleeve caused by the change of the internal sealing volume when the spline is extended and retracted, so that the transmission shaft has a breathing function, balances the pressure inside and outside the sealing sleeve, and avoids the damage caused by the increase of the internal pressure of the sealing sleeve.

Description

Technical Field

[0001] The present invention relates to the field of mechanical transmission shafts, and in particular to a respirator and a transmission shaft comprising the respirator. Background Art

[0002] In the prior art, in order to adapt to the position change between the input end and the output end of the transmission shaft, a sliding spline pair is usually set on the transmission shaft in order to adapt to the change in the position between the input end and the output end of the transmission shaft. The relative sliding between the spline shaft and the spline sleeve is used to adapt to the change in the length of the transmission shaft during the transmission process. Since the transmission shaft is in a high-speed rotation state during operation, there are high requirements for the dynamic balance performance of the transmission shaft. The matching accuracy of the spline shaft and the spline sleeve has a great influence on this performance index. When the matching clearance between the spline shaft and the spline sleeve is too large due to processing errors or wear during use, it often leads to an increase in the misalignment between the spline shaft and the spline sleeve, thereby deteriorating the dynamic balance performance of the transmission shaft during high-speed rotation, generating vibration, noise, heat and other undesirable phenomena, and then causing the failure of the transmission shaft. In order to extend the service life of the spline pair and improve the dynamic balance performance of the transmission shaft, the current method is not only to further improve the processing accuracy of the spline, but also to increase the spline matching accuracy and reduce the wear of the spline by coating nylon on the spline surface, thereby better improving and maintaining the dynamic balance performance of the transmission shaft, preventing the movement of the transmission shaft, and reducing the noise of the transmission shaft. However, the above methods increase the difficulty of processing the transmission shaft, make the manufacturing process complicated, and increase the cost significantly.

[0003] The lubrication and maintenance of the unequal-speed transmission shaft in the prior art are not convenient enough, and there is an opportunity for improvement. Chinese patent technologies CN201710956327.X, CN201721322884.8, and CN202021793026.3 provide a sealing sleeve to improve the convenience of lubrication and maintenance, thereby eliminating daily lubrication. However, when the spline is extended or retracted, the change in the volume of the sealing space causes an imbalance in the pressure inside and outside the sealing sleeve, which causes certain damage to the sealing sleeve and affects product quality, and urgently needs to be improved. Summary of the invention

[0004] The main purpose of the present invention is to provide a respirator and a transmission shaft including the respirator, so as to solve the problem in the prior art that when the spline is extended and retracted, the change in the volume of the sealing space causes pressure imbalance inside and outside the sealing sleeve, which causes certain damage to the sealing sleeve and affects product quality.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A respirator is installed inside a transmission shaft, comprising a respirator housing, a filter element cover and a filter element. An outer ring groove is provided on the outer wall of the respirator housing, a plurality of air holes are provided in the outer ring groove, and the filter element cover is used to seal the filter element in a filter element cavity 11 or on the spline shaft of the transmission shaft.

[0007] Furthermore, one end of the respirator housing is closed, and a filter element cover is detachably installed on the other end. The filter element is sealed inside the respirator housing through the filter element cover. A filter element cavity is formed between the filter element, the respirator housing and the filter element cover. The air vent connects the outer ring groove and the filter element cavity. An internal breathing hole is also provided on the end face of the filter element cover.

[0008] Furthermore, the filter element cover and the respirator housing are connected by threads.

[0009] Furthermore, both ends of the respirator housing are open, and the filter element is encapsulated in the spline shaft of the transmission shaft through a filter element cover. The filter element cover is a retaining ring, and an inner breathing hole is opened along the diameter direction of the spline shaft.

[0010] Furthermore, the filter element is a closed airbag, the mouth of which is fixed on the inner breathing hole of the filter element cover 6, and the active inner cavity is connected to the inner cavity of the airbag through the inner breathing hole, and the volume change of the airbag is adjusted to adapt to the change of the volume of the active inner cavity of the transmission shaft. When the volume of the active inner cavity decreases due to the expansion and contraction of the spline shaft, the excess air in the active inner cavity will be squeezed into the airbag through the inner breathing hole, and the volume of the airbag will increase to temporarily accommodate the excess air, preventing the pressure of the active inner cavity from increasing and damaging the transmission shaft sealing sleeve; on the contrary, when the volume of the active inner cavity increases due to the expansion and contraction of the spline shaft, the air in the airbag will be replenished into the active inner cavity through the inner breathing hole in time, and the volume of the increased part of the active inner cavity will be filled in time, preventing the active inner cavity from having excessive negative pressure and affecting the normal expansion and contraction of the sealing sleeve. While adjusting the volume change of the active inner cavity, the airbag can completely cut off the connection between the active inner cavity and the external air, prevent the loss of lubricating oil in the active inner cavity, and help maintain the performance of the lubricating oil.

[0011] A transmission shaft is provided with the above-mentioned respirator, the respirator shell is fixedly installed on the inner wall of the spline sleeve, one end of the spline shaft is movably connected in the spline sleeve, the end of the spline shaft outside the spline sleeve is connected with a universal joint, a sealing sleeve is connected between the universal joint and the spline sleeve, and the sealing sleeve is corrugated.

[0012] Furthermore, an active inner cavity is formed between the spline shaft of the transmission shaft, the spline sleeve, the respirator housing and the sealing sleeve.

[0013] Furthermore, the spline shaft is provided with a vent hole, which penetrates the spline shaft along the central axis direction and is connected to the active inner cavity; the spline sleeve is provided with an external breathing hole, which is connected to the outer ring groove. When the airbag of the respirator expands with the expansion and contraction of the spline shaft, the air in the filter element cavity 11 is displaced and can be discharged to the outside of the transmission shaft through the vent hole and the external breathing hole; conversely, when the volume of the airbag is reduced, the external air can be replenished into the filter element cavity 11 through the external breathing hole and the vent hole.

[0014] Furthermore, at least one supporting ring groove is coaxially arranged in the inner cavity of the spline sleeve, and the supporting ring is placed in the supporting ring groove. The outer surface of the supporting ring is coaxially matched with the spline sleeve, and the inner surface of the supporting ring is coaxially matched with the spline shaft. The supporting ring forms a positioning and guiding support for the spline shaft matched with the spline sleeve, thereby ensuring the coaxial matching of the spline shaft in the spline sleeve and maintaining coaxial axial sliding between the two.

[0015] Furthermore, the support ring is an open support belt structure made of composite material.

[0016] Furthermore, the number of the supporting rings is two, and two supporting ring grooves are correspondingly arranged at a certain distance in the inner cavity of the spline sleeve, and the supporting rings are correspondingly placed in the supporting ring grooves.

[0017] The present invention has the following beneficial effects:

[0018] (1) The breather can effectively avoid the imbalance of pressure inside and outside the transmission shaft sealing sleeve caused by the change of the volume of the active inner cavity when the spline shaft and the spline sleeve slide relative to each other, so that the transmission shaft has a breathing function, balances the pressure inside and outside the sealing sleeve, and avoids the damage caused by the change of the pressure difference between the inside and outside of the sealing sleeve;

[0019] (2) By arranging a sealing sleeve and a breather on the transmission shaft, the problem of inconvenient maintenance of the unequal speed transmission shaft in the prior art is solved. By arranging the sealing sleeve, a sufficient amount of butter can be injected at one time, eliminating the trouble of frequent buttering in daily life;

[0020] (3) A support ring is provided on the spline sleeve, and the outer surface of the support ring is coaxially matched with the spline sleeve, and the inner surface of the support ring is coaxially matched with the spline shaft, forming a positioning and guiding effect on the spline shaft, ensuring the coaxial matching of the spline shaft in the spline sleeve and maintaining the coaxial axial sliding between the two, thereby ensuring the matching quality of the spline, improving the dynamic balance performance of the transmission shaft, effectively improving the working conditions of the spline, and extending the service life of the spline. At the same time, the structure is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is one of the structural schematic diagrams of the present invention;

[0022] Figure 2 This is the second structural schematic diagram of the present invention;

[0023] Figure 3 This is the third structural schematic diagram of the present invention;

[0024] Figure 4 This is the fourth structural schematic diagram of the present invention; wherein, the above-mentioned figure includes the following figure marks: 1, universal joint; 2, sealing sleeve; 3, spline shaft; 4, supporting ring; 5, spline sleeve; 6, filter element cover; 7, respirator shell; 8, external breathing hole; 9, external ring groove; 10, air vent; 11, filter element cavity; 12, filter element; 13, internal breathing hole; 14, ventilation hole; 15, movable inner cavity. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] Example 1

[0027] like Figure 1 As shown, a respirator is installed inside the transmission shaft, the respirator includes a respirator housing 7, a filter element cover 6 and a filter element 12, one end of the respirator housing is closed, and the other end is detachably mounted with a filter element cover through a thread, the filter element is sealed inside the respirator housing through the filter element cover, a filter element cavity 11 is formed between the filter element, the respirator housing and the filter element cover, an inner breathing hole 13 is also provided on the end surface of the filter element cover, an outer ring groove 9 is provided on the respirator housing, and the outer ring groove and the filter element cavity are connected through a plurality of air holes 10 provided in the outer ring groove.

[0028] A transmission shaft with the above-mentioned respirator, the respirator shell is fixedly installed on the inner wall of the spline sleeve, one end of the spline shaft 3 is movably connected in the spline sleeve, the end of the spline shaft outside the spline sleeve is connected to a universal joint 1, a sealing sleeve 2 is connected between the universal joint and the spline sleeve, the sealing sleeve is corrugated and has a certain axial elasticity, an active inner cavity 15 is formed between the sealing sleeve of the transmission shaft, the spline shaft, the spline sleeve 5 and the respirator shell, and an inner breathing hole 13 is also provided on the end surface of the filter element cover to communicate with the active inner cavity 15 of the transmission shaft.

[0029] The spline shaft is provided with a vent hole 14, which penetrates the spline shaft along the central axis direction; the spline sleeve is provided with an outer breathing hole 8, which is communicated with the outer ring groove.

[0030] The respirator shell is fixed in the inner cavity of the spline sleeve of the transmission shaft, and its outer ring groove is connected with the outer breathing hole correspondingly arranged on the spline sleeve; the external air can enter the outer ring groove through the outer breathing hole of the spline sleeve, and then enter the filter element cavity through the air vent in the outer ring groove, and further pass through the filter element in the filter element cavity to be filtered into clean air, and then enter the active inner cavity through the inner breathing hole, and further enter the transmission shaft sealing sleeve through the air vent, so as to realize the breathing connection of the air inside and outside the transmission shaft sealing chamber, so as to adapt to the change in the volume of the transmission shaft sealing chamber caused by the expansion and contraction of the spline shaft in the spline sleeve during the operation of the transmission shaft, maintain the balance of the pressure inside and outside the sealing sleeve, and protect the sealing sleeve.

[0031] Example 2

[0032] like Figure 2 As shown, the difference between this embodiment and embodiment 1 is that both ends of the respirator shell are open, the filter element is encapsulated in the spline shaft of the transmission shaft through the filter element cover, the filter element cover is a retaining ring, and an inner breathing hole is opened on the spline shaft along the diameter direction of the spline shaft. The inner breathing hole connects the filter element cavity and the active inner cavity, and the universal joint is a cross-axis universal joint. External air can enter the outer ring groove through the outer breathing hole of the spline sleeve, and then enter the filter element cavity through the air vent in the outer ring groove, and further pass through the filter element in the filter element cavity to filter into clean air, and then enter the sealing sleeve from the air vent. At the same time, the gas also enters the active inner cavity from the inner breathing hole to balance the air pressure of the active inner cavity and the outside.

[0033] Example 3

[0034] like Figure 1 , Figure 2 As shown, the difference between this embodiment and embodiment 1 and embodiment 2 is that at least one supporting ring groove 4 is coaxially arranged in the inner cavity of the spline sleeve, and the supporting ring is placed in the supporting ring groove. The outer surface of the supporting ring is coaxially matched with the spline sleeve, and the inner surface of the supporting ring is coaxially matched with the spline shaft. The supporting ring forms a positioning and guiding support for the spline shaft matched with the spline sleeve, thereby ensuring the correct fit of the spline shaft in the spline sleeve and maintaining the coaxial axial sliding between the two. The support ring can ensure the coaxiality of the spline shaft and the spline sleeve, avoiding the vibration and noise of the transmission shaft during high-speed rotation caused by poor coaxiality between the two, and improving the dynamic balance performance of the transmission shaft; in addition, the support ring also assumes the centering function of the spline, eliminating the problem of decreased dynamic balance performance of the transmission shaft caused by decreased spline centering ability due to spline wear during use, and increasing the service life of the spline; the positioning and guiding effect of the support ring on the spline shaft can be beneficial to the matching and axial sliding of the spline, improve the meshing transmission conditions of the spline, reduce the resistance during axial sliding, and make the axial expansion and contraction of the spline shaft in the spline sleeve smoother.

[0035] The support ring can refer to the support ring structure used in the piston rod guide sleeve of the oil cylinder industry. The support ring is an open support belt made of composite materials, such as Figure 4 shown.

[0036] Example 4

[0037] The difference between this embodiment and embodiment 3 is that there are two supporting rings, and two supporting ring grooves are arranged at a certain distance in the inner cavity of the spline sleeve. The supporting rings are placed in the supporting ring grooves accordingly. The structure of the supporting ring can adopt various forms, and can adopt the open composite material supporting belt form commonly used in the cylinder guide sleeve of the hydraulic industry, or a split bearing structure, or an ordinary sliding bearing, a sleeve, etc., which can be flexibly changed according to the needs of the structural setting.

[0038] Example 5

[0039] like Figure 3 As shown, a respirator, the filter element of the respirator is a closed airbag, the mouth of the airbag is fixed on the inner breathing hole, the active inner cavity is connected with the inner cavity of the airbag through the inner breathing hole, and the volume change of the airbag is adjusted to adapt to the change of the volume of the active inner cavity of the transmission shaft. When the volume of the active inner cavity of the transmission shaft decreases due to the expansion and contraction of the spline shaft, the excess air in the active inner cavity will be squeezed into the airbag through the inner breathing hole, and the volume of the airbag will increase to temporarily accommodate the excess air, preventing the pressure of the active inner cavity of the transmission shaft from increasing and damaging the transmission shaft sealing sleeve; on the contrary, when the volume of the active inner cavity increases due to the expansion and contraction of the spline shaft, the active inner cavity generates negative pressure, and the air in the airbag is sucked into the active inner cavity through the inner breathing hole to timely fill the volume of the increased part of the active inner cavity, preventing the excessive negative pressure in the active cavity from affecting the normal expansion and contraction of the sealing sleeve. While adjusting the volume change of the active inner cavity, the airbag can completely cut off the connection between the active inner cavity and the external air, prevent the loss of lubricating oil in the active inner cavity, and help maintain the performance of the lubricating oil.

[0040] A transmission shaft is provided with the above-mentioned respirator. When the airbag of the respirator expands with the expansion and contraction of the spline shaft, the air in the filter element cavity 11 is expelled and can be discharged to the outside of the transmission shaft through the air vent and the external air vent; conversely, when the volume of the airbag is reduced, the external air can be replenished into the filter element cavity 11 through the external air vent and the air vent.

[0041] In the description of the present invention, it should be noted that the terms "front end", "rear end", "left and right", "up", "down", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0042] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Obviously, various changes can be made according to actual needs, such as: changes in the structure and quantity of the support rings, changes in the support position and setting method, changes in the external structure of the respirator and the air flow path, changes in the filter element structure, etc. Any technician familiar with the field, within the technical scope disclosed by the present invention, shall make equivalent replacements or changes according to the embodiments of the present invention and its inventive concept, which shall be covered within the protection scope of the present invention.

Claims

1. A transmission shaft, characterized in that: A respirator is installed inside, the respirator comprising a respirator housing (7), a filter element cover (6) and a filter element (12); an outer ring groove (9) is provided on the outer wall of the respirator housing (7); a plurality of air holes (10) are provided in the outer ring groove (9); the filter element cover (6) is used to seal the filter element (12) inside the filter element cavity (11) or on the spline shaft (3) of the transmission shaft; One end of the respirator housing (7) is closed, and a filter element cover (6) is detachably mounted on the other end. The filter element (12) is sealed inside the respirator housing (7) through the filter element cover (6). A filter element cavity (11) is formed between the filter element (12), the respirator housing (7) and the filter element cover (6). The air vent (10) connects the outer ring groove (9) and the filter element cavity (11). An inner breathing hole (13) is also arranged on the end surface of the filter element cover (6). The filter element cover (6) and the respirator housing (7) are connected by threads. Alternatively, the respirator housing (7) is open at both ends, and the filter element (12) is encapsulated in the spline shaft (3) of the transmission shaft through the filter element cover (6). The filter element cover (6) is a retaining ring and has an inner breathing hole (13) along the diameter direction of the spline shaft (3). The respirator housing (7) is fixedly mounted on the inner wall of the spline sleeve (5) of the transmission shaft, one end of the spline shaft (3) is movably connected in the spline sleeve (5), the end of the spline shaft (3) outside the spline sleeve (5) is connected to a universal joint (1), a sealing sleeve (2) is connected between the universal joint (1) and the spline sleeve (5), and the sealing sleeve (2) is corrugated; The spline shaft (3) is provided with a vent hole (14), which penetrates the spline shaft (3) along the central axis direction; the spline sleeve (5) is provided with an outer breathing hole (8), which is communicated with the outer ring groove (9).

2. The transmission shaft according to claim 1, characterized in that: At least one supporting ring groove is coaxially arranged in the inner cavity of the spline sleeve (5), and the supporting ring (4) is placed in the supporting ring groove. The outer surface of the supporting ring (4) is coaxially matched with the spline sleeve (5), and the inner surface of the supporting ring (4) is coaxially matched with the spline shaft (3), so as to form a positioning and guiding support for the spline shaft (3) matched with the spline sleeve (5), ensure that the spline shaft (3) is coaxially matched in the spline sleeve (5), and can maintain the coaxial axial sliding between the two.

3. The transmission shaft according to claim 2, characterized in that: There are two supporting rings (4), and two supporting ring grooves are arranged at a certain distance in the inner cavity of the spline sleeve (5), and the supporting rings (4) are placed in the supporting ring grooves accordingly.

4. The transmission shaft according to claim 3, characterized in that: The supporting ring is an open-type supporting belt structure made of composite materials.

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