Low-pressure-resistant dynamic sealing structure of planetary reducer

Abstract

A low-pressure-resistant dynamic sealing structure of a planetary reducer comprises a shell of the planetary reducer and a supporting shaft which extends into the shell and is assembled between the shell and an input shaft of the planetary reducer, and the shell and the supporting shaft are coaxially supported through a bearing, and the low-pressure-resistant dynamic sealing structure of the planetary reducer is characterized in that the supporting shaft and the shell are sealed through a framework oil seal; a ventilation channel communicated with an inner cavity of the planetary reducer is formed in the supporting shaft, a one-way ventilation valve is assembled on an outer port of the ventilation channel, the ventilation channel is sealed through the one-way ventilation valve, and the one-way ventilation valve is opened to be communicated with the outside along with pushing of gas in the ventilation channel. Low-pressure-resistant dynamic sealing is formed at the input end of the speed reducer, the sealing reliability and the service life of the framework oil seal are guaranteed, forming and machining of the shell and the supporting shaft are simpler, the assembling cost is lower, oil bubbles are reduced, the ventilation efficiency is improved, and the ventilation effect is improved.

Description

Technical Field

[0001] The utility model relates to a low-pressure dynamic sealing structure for a planetary reducer, and belongs to the technical field of planetary reducer assembly. Background Art

[0002] The reducer installed on the crawler chassis of the host or the upper part of the automobile chassis is generally a horizontal high-speed planetary reducer. The amount of oil in the assembly occupies at least 1 / 3 of the internal cavity and no more than 1 / 2. Considering the use environment of the engineering machinery reducer, such as Figure 1 As shown, a pressure-resistant floating oil seal is preferred for dynamic sealing between the planetary reducer's input housing and the support shaft, and no air vents are designed into the reducer. The floating oil seal consists of two wear-resistant steel rings in contact side by side, and O-rings clamped onto each wear-resistant steel ring. The seal is achieved by the contact surface of the two wear-resistant steel rings and the O-rings clamping the wear-resistant steel rings. When the reducer is in continuous operation, its internal temperature rises, causing the internal air pressure to increase. Pressure resistance can only be achieved by the oil seal itself and the sealing contact surface. Using a floating oil seal for dynamic sealing also has the following problems:

[0003] 1. The processing size of the parts for assembling floating oil seals is relatively complex, the processing is difficult, and the assembly cost is high.

[0004] 2. The oil and gas mixture generated during the operation of the reducer is prone to form oil bubbles, resulting in low ventilation efficiency and making it difficult to accommodate the oil splashed during the operation of the reducer. The oil impacts the floating oil seal and causes oil leakage. Utility Model Content

[0005] The low-pressure dynamic sealing structure of the planetary reducer provided by the utility model forms a low-pressure dynamic seal for the input end of the reducer, reduces the pressure of the skeleton oil seal when the planetary reducer is running, ensures the sealing reliability and service life of the skeleton oil seal, simplifies the molding and processing of the housing and the support shaft, and reduces the assembly cost. The opening of the air duct increases the gas and oil holding space inside the reducer, can effectively hold the oil and gas mixture generated when the reducer is running, reduces the formation of oil bubbles, improves the ventilation efficiency, and improves the ventilation effect. The one-way ventilation valve can effectively prevent external impurities and water vapor from entering the interior of the reducer.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] The low-pressure dynamic sealing structure of a planetary reducer includes a housing of the planetary reducer, a support shaft extending into the housing and assembled between the housing and the input shaft of the planetary reducer, and the housing and the support shaft are coaxially supported by bearings. It is characterized in that: the support shaft and the housing are sealed by a skeleton oil seal, an air duct connected to the inner cavity of the planetary reducer is opened on the support shaft, and a one-way air valve is assembled on the outer port of the air duct. The one-way air valve seals the air duct and opens to communicate with the outside as the gas in the air duct pushes.

[0008] Preferably, the outer end of the support shaft is integrally formed with a radially arranged mounting column, and the air duct consists of an axial air duct opened axially on the support shaft and a radial exhaust duct connected to the axial air duct and passing through the mounting column. The inner diameter of the axial air duct is larger than the inner diameter of the radial exhaust duct, and the one-way air valve is assembled on the mounting column to seal the radial exhaust duct.

[0009] Preferably, the one-way vent valve includes a valve sleeve threadedly inserted into the mounting column, a spring arranged in the valve sleeve and compressed by the valve sleeve, a sealing steel ball compressed by the spring against the inner wall of the valve sleeve to seal the valve sleeve, and a breathable cover covering the valve sleeve and forming a breathable gap between the valve sleeve and the valve sleeve, and the sealing steel ball moves upward as pushed by the gas in the ventilation duct to open the valve sleeve.

[0010] Preferably, the inner wall of the valve sleeve is composed of a lower section with an inner diameter smaller than the diameter of the sealing steel ball, an upper section located above the lower section and with an inner diameter larger than the diameter of the sealing steel ball, and an arc-shaped inner wall that transitions between the upper section and the lower section and cooperates with the sealing steel ball. The spring pushes the sealing steel ball against the arc-shaped inner wall to seal the air duct.

[0011] Preferably, the top surface of the valve sleeve has a flange that is folded downward by 90 degrees, the flange is pressed on the spring, and the air permeable cover is riveted and fixed to the top of the valve sleeve.

[0012] Preferably, the valve sleeve has an annular positioning surface that abuts against the end face of the mounting post, an annular groove is provided on the annular positioning surface, a sealing ring is assembled in the annular groove, and the sealing ring is pressed against the end face of the mounting post.

[0013] The beneficial effects of the utility model are:

[0014] The utility model discloses a low-pressure dynamic sealing structure for a planetary reducer, wherein a skeleton oil seal is used to seal between the support shaft and the housing, an air duct is provided on the support shaft, and is connected to the inner cavity of the reducer, and a one-way air valve is installed on the outer port of the air duct, and the one-way air valve is in a normally closed state to seal the air duct. When the air pressure in the reducer increases, the one-way air valve is pushed open to form a connection between the air duct and the outside, thereby releasing the internal pressure of the reducer and reducing the pressure on the skeleton oil seal. When the air pressure in the reducer decreases, the one-way air valve returns to a normally closed state to seal the air duct. , avoid oil leakage, form a low-pressure resistant dynamic seal on the input end of the reducer, reduce the pressure of the skeleton oil seal when the planetary reducer is running, ensure the sealing reliability and service life of the skeleton oil seal, and make the molding and processing of the housing and support shaft simpler, and the assembly cost is lower. The opening of the air duct increases the gas and oil holding space inside the reducer, and can effectively accommodate the oil and gas mixture generated when the reducer is running, reduce the formation of oil bubbles, improve the ventilation efficiency, and improve the ventilation effect. The one-way breather valve can effectively prevent external impurities and water vapor from entering the reducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of a floating oil seal installed between the support shaft and the housing of a planetary reducer in the prior art.

[0016] Figure 2 It is a schematic diagram of the low-pressure dynamic sealing structure of the planetary reducer in a specific implementation manner.

[0017] Figure 3 It is a half-section schematic diagram of a one-way vent valve.

[0018] Figure 4 Schematic diagram of the valve sleeve. DETAILED DESCRIPTION

[0019] The following combination Figures 2-4 The embodiments of the present utility model are described in detail.

[0020] The low-pressure dynamic sealing structure of the planetary reducer includes a planetary reducer housing 1, a support shaft 2 extending into the housing 1 and assembled between the housing 1 and the input shaft of the planetary reducer, and the housing 1 and the support shaft 2 are coaxially supported by bearings. It is characterized in that: the support shaft 2 and the housing 1 are sealed by a skeleton oil seal 3, and an air duct 4 connected to the inner cavity of the planetary reducer is opened on the support shaft 2, and a one-way air valve 5 is installed on the outer port of the air duct 4. The one-way air valve 5 seals the air duct 4 and opens to communicate with the outside as the gas in the air duct 4 pushes.

[0021] The low-pressure dynamic sealing structure of the planetary reducer described above is sealed with a skeleton oil seal 3 between the support shaft 2 and the housing 1, and an air duct 4 is opened on the support shaft 2 to communicate with the inner cavity of the reducer. A one-way air valve 5 is installed on the outer port of the air duct 4. The one-way air valve 5 is in a normally closed state to seal the air duct 4. When the air pressure in the reducer increases and the one-way air valve 5 is pushed open, the air duct 4 is connected to the outside, the internal pressure of the reducer is released, and the pressure on the skeleton oil seal 6 is reduced. When the air pressure in the reducer decreases, the one-way air valve 5 returns to the normally closed state, forming a ventilation The sealing of the air duct 4 avoids oil leakage, forms a low-pressure-resistant dynamic seal on the input end of the reducer, reduces the pressure of the skeleton oil seal 3 when the planetary reducer is running, ensures the sealing reliability and service life of the skeleton oil seal 3, and makes the molding and processing of the housing and support shaft simpler, and the assembly cost is lower. The opening of the air duct 4 increases the gas and oil holding space inside the reducer, and can effectively accommodate the oil and gas mixture generated when the reducer is running, reduce the formation of oil bubbles, improve the ventilation efficiency, and improve the ventilation effect. The one-way breather valve can effectively prevent external impurities and water vapor from entering the reducer.

[0022] The outer end of the support shaft 2 is integrally formed with a radially arranged mounting post 21. The air passage 4 is composed of an axial air passage 41 axially opened on the support shaft 2 and a radial exhaust passage 42 connected to the axial air passage 41 and passing through the mounting post 21. The inner diameter of the axial air passage 41 is larger than the inner diameter of the radial exhaust passage 42. The one-way air valve 5 is assembled on the mounting post 21 to seal the radial exhaust passage 42. The mounting post 21 is set at the outer end of the support shaft 2, and the air passage 4 is formed by punching holes outward from the outer end of the support shaft 2. The processing and molding are simple. The axial air passage 41 is opened on the support shaft 2, and its larger diameter can effectively accommodate the oil and gas mixture generated when the reducer is running, reducing the shape of oil bubbles. The inner diameter of the radial exhaust passage 42 is smaller, which is convenient for forming an increased air pressure to push open the one-way air valve 5.

[0023] The one-way vent valve 5 includes a valve sleeve 6 threadedly inserted into the mounting post 21, a spring 7 disposed within the valve sleeve 6 and compressed by the valve sleeve 6, a sealing steel ball 8 pressed against the inner wall of the valve sleeve 6 by the spring 7 to seal the valve sleeve 7, and a vent cap 9 covering the valve sleeve 6 and forming a breathable gap between the valve sleeve 6 and the valve sleeve 6. The sealing steel ball 8 moves upward in response to the push of gas in the airway 4, opening the valve sleeve 6. The spring 7 presses the sealing steel ball 8 against the inner wall of the valve sleeve 6, sealing the valve sleeve 6. When the air pressure in the airway 4 is less than the pressure of the spring 7, the sealing steel ball 8 is compressed by the spring 7, and the one-way vent valve 5 is normally closed. When the air pressure in the airway is greater than the pressure of the spring 4, the sealing steel ball 8 is pushed upward, opening the valve sleeve 6 to the outside and releasing the internal pressure of the reducer. The one-way vent valve 5 is an upward, one-way structure that effectively prevents the ingress of water vapor and prevents water vapor impurities from entering the reducer through the airway 4.

[0024] The inner wall of the valve sleeve 6 comprises a lower section 61 with an inner diameter smaller than that of the sealing ball 8, an upper section 62 located above the lower section 61 and with an inner diameter larger than that of the sealing ball 8, and an arcuate inner wall 63 that transitions between the upper and lower sections 62 and cooperates with the sealing ball 8. A spring 7 pushes the sealing ball 8 against the arcuate inner wall 63, sealing the air passage 4. The inner diameter of the upper section 62 is larger than that of the sealing ball 8. When the sealing ball 8 moves upward, it opens the valve sleeve 6, allowing internal gas to be discharged through the valve sleeve 6, thereby releasing pressure within the reducer.

[0025] The top surface of the valve sleeve 6 has a flange 64 that is folded downward 90 degrees. The flange 64 presses on the spring 7. The breathable cover 9 is riveted to the top of the valve sleeve 6. The breathable cover 9 is fixed to the top of the valve sleeve 6, forming a breathable gap between the cover and the valve sleeve 6 for ventilation. The flange 64 is used to compress the spring 7. The assembly and installation of the one-way vent valve 5 are convenient and simple.

[0026] The valve sleeve 6 has an annular positioning surface 65 that abuts against the end face of the mounting post 21. An annular groove is formed on the annular positioning surface 65. A sealing ring 66 is mounted in the annular groove and pressed against the end face of the mounting post 21. The sealing ring 66 seals the valve sleeve 6 and the mounting post 21 to prevent oil leakage between the valve sleeve 6 and the mounting post 21.

[0027] The above is a complete description of the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the embodiments described are only part of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

Claims

1. A low-pressure dynamic sealing structure for a planetary reducer, comprising a planetary reducer housing, a support shaft extending into the housing and assembled between the housing and the input shaft of the planetary reducer, wherein the housing and the support shaft are coaxially supported by bearings, and characterized by: The support shaft and the shell are sealed by a skeleton oil seal, an air duct connected to the inner cavity of the planetary reducer is opened on the support shaft, and a one-way air valve is installed on the outer port of the air duct. The one-way air valve seals the air duct and opens to communicate with the outside as the gas in the air duct pushes.

2. The low-pressure dynamic sealing structure of a planetary reducer according to claim 1, characterized in that: The outer end of the support shaft is integrally formed with a mounting column arranged radially. The air duct consists of an axial air duct opened axially on the support shaft and a radial exhaust duct connected to the axial air duct and passing through the mounting column. The inner diameter of the axial air duct is larger than the inner diameter of the radial exhaust duct. The one-way air valve is assembled on the mounting column to seal the radial exhaust duct.

3. The low-pressure dynamic sealing structure of a planetary reducer according to claim 2, characterized in that: The one-way vent valve includes a valve sleeve that is threaded and extends into the mounting column, a spring arranged in the valve sleeve and compressed by the valve sleeve, a sealing steel ball that is pressed against the inner wall of the valve sleeve by the spring to seal the valve sleeve, and a breathable cover that covers the valve sleeve and forms a breathable gap with the valve sleeve. The sealing steel ball moves upward to open the valve sleeve as it is pushed by the gas in the ventilation duct.

4. The low-pressure dynamic sealing structure of a planetary reducer according to claim 3, characterized in that: The inner wall of the valve sleeve is composed of a lower section with an inner diameter smaller than the diameter of the sealing steel ball, an upper section located above the lower section and with an inner diameter larger than the diameter of the sealing steel ball, and an arc-shaped inner wall that transitions between the upper and lower sections and cooperates with the sealing steel ball. The spring pushes the sealing steel ball against the arc-shaped inner wall to seal the air duct.

5. The low-pressure dynamic sealing structure of a planetary reducer according to claim 4, characterized in that: The top surface of the valve sleeve is provided with a flange folded downward by 90 degrees, the flange is pressed on the spring, and the air-permeable cover is fixed to the top of the valve sleeve by riveting.

6. The low-pressure dynamic sealing structure of a planetary reducer according to claim 3, characterized in that: The valve sleeve is provided with an annular positioning surface which abuts against the end surface of the installation column. An annular groove is provided on the annular positioning surface. A sealing ring is installed in the annular groove and is pressed tightly against the end surface of the installation column.

Images