A gearbox breather cap connection device

Abstract

The application discloses a gearbox air-permeable cap connecting device, which comprises a connecting pipe, the upper end of the connecting pipe is used for connecting the air-permeable cap, the lower end of the connecting pipe is used for connecting the gearbox, a gas blocking plug is matched and installed in the connecting pipe, the gas blocking plug is in a cylindrical shape, the outer wall of the lower part of the gas blocking plug is communicated with the inner wall of the connecting pipe and is provided with a plurality of annular pressure relief grooves which are distributed along the axial direction of the gas blocking plug, the outer wall of the upper part of the gas blocking plug forms a sealing part which is tightly matched with the inner wall of the connecting pipe, a communication hole is formed in the gas blocking plug, one end of the communication hole is connected with the communication gap between the sealing part and the pressure relief groove, and the other end of the communication hole is distributed through the upper end surface of the gas blocking plug. The application can realize normal ventilation function and greatly reduce oil and gas overflow.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gearbox, in particular to a kind of gearbox breather cap connecting device. BACKGROUND

[0002] The gearbox currently produced is generally provided with breather cap, makes the air pressure balance inside and outside gearbox by breather cap, avoids oil leakage at oil seal etc.But the breather cap currently used in long time use process, oil gas is often due to gearbox internal pressure too big and runs out through breather cap, meets cold cooling, and forms oil stain after depositing solidification and mixing with dust etc around breather cap, it affects environment, even causes security risk.

[0003] To solve the above problems, gearbox factory producers generally increase the length of connecting pipe between breather cap and gearbox to increase the travel of oil gas flow, thereby increasing air resistance and reducing oil gas overflow.But thereby cause the height of breather cap to increase, increase the overall height of gearbox, affect the installation space layout of scene, for example Figure 5 The high breather cap in the square frame greatly increases the overall height of gearbox. SUMMARY

[0004] The present application aims to provide a kind of gearbox breather cap connecting device, which realizes normal ventilation function and can greatly reduce oil gas overflow.

[0005] In order to solve the above technical problems, the specific scheme adopted by the present application is: a kind of gearbox breather cap connecting device, including connecting pipe, the upper end of connecting pipe is used to connect breather cap, the lower end is used to connect gearbox, the air resistance plug is installed in connecting pipe, the air resistance plug is cylindrical, the outer wall of the lower part of the air resistance plug is communicated with the inner wall of the connecting pipe and is provided with a plurality of annular pressure relief grooves distributed along the axial direction of the air resistance plug, the outer wall of the upper part of the air resistance plug forms a sealing part in close cooperation with the inner wall of the connecting pipe, a communication hole is provided in the air resistance plug, one end of the communication hole is connected with the communication gap between the sealing part and the pressure relief groove, and the other end penetrates the upper end face of the air resistance plug.

[0006] Preferably, the communication hole includes a plurality of radial segments distributed along different radial directions of the air resistance plug and an axial segment connected with the inner ends of all radial segments.

[0007] Preferably, the lower end of the connecting pipe is provided with an external thread connected to the gearbox, and the upper end is provided with an internal thread connected to the breather cap.

[0008] Preferably, a retaining ring is arranged in the connecting pipe above the air resistance plug, and a spring is connected between the retaining ring and the air resistance plug, and the spring pushes out part of the pressure relief grooves outside the connecting pipe in the natural elongation state.

[0009] Preferably, the retaining ring is screwed on the internal thread provided in the connecting pipe.

[0010] Preferably, the sealing part of the gas blocking plug is in sliding fit with the inner wall of the connecting pipe, a protruding positioning ring is arranged at the upper end face of the gas blocking plug, and a positioning step for bearing the positioning ring is arranged on the inner wall of the connecting pipe; the communication hole is distributed in the height direction of the gas blocking plug and forms an oil collecting bend at the position of the turning point near the lower end of the gas blocking plug, the bottom of the oil collecting bend is funnel-shaped, a conical plug is fixedly arranged at the lower end of the connecting pipe and extends into the oil collecting bend, an oil leakage gap is formed between the outer periphery of the conical plug and the bottom of the oil collecting bend when the positioning ring falls on the positioning step, and the outer periphery of the conical plug is attached to the bottom of the oil collecting bend and the oil leakage gap is closed after the gas blocking plug is lifted up by the high-pressure oil gas in the transmission.

[0011] Preferably, a tray for supporting the conical plug is arranged at the lower end of the connecting pipe, and a plurality of connecting rods are arranged on the outer periphery of the tray and are fixed to the lower end of the connecting pipe.

[0012] Preferably, the communication hole includes at least two segments in communication with the oil collecting bend, and the two segments are respectively in the shape of a bend.

[0013] Preferably, the cross-sectional shape of the pressure relief groove is rectangular.

[0014] The vent cap connecting device of the present application is composed of a connecting pipe and a gas blocking plug. There is a communication gap between the connecting pipe and the gas blocking plug, allowing oil gas to pass through, and a plurality of rectangular annular pressure relief groove teeth are arranged on the outer circle of the gas blocking plug to greatly increase the outflow resistance of oil gas. After passing through the communication gap between the two and the layer-by-layer pressure relief grooves, the outflow pressure of oil gas has been greatly reduced, and finally the pressure-reduced oil gas enters the vent cap for condensation through the gas blocking plug, thereby avoiding or reducing the occurrence of the case that oil gas is condensed outside the vent cap after being sprayed out of the vent cap. Further, on the basis of achieving the effect of avoiding or reducing oil gas outflow, the height of the vent cap connecting pipe can be reduced through the present application, further reducing the size requirement of the installation space of the transmission case; reducing or even avoiding the generation of oil stains around the vent cap of the transmission case, which is conducive to safety production and environmental protection, and saves the material of the connecting pipe. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 FIG. 1 is a sectional view of the structure of the present application, embodiment 1;

[0016] Figure 2 FIG. 2 is a sectional view of the structure of the present application, embodiment 2;

[0017] Figure 3 FIG. 3 is a sectional view of the structure of the present application, embodiment 3;

[0018] Figure 4 FIG. 4 is a schematic view of the state of the gas blocking plug in FIG. 1 after being lifted up by high-pressure oil gas; Figure 3

[0019] Figure 5 ​This is a schematic diagram of a long connecting pipe installed between the transmission and the vent cap in the prior art to prevent high-pressure oil and gas from being ejected externally;

[0020] The markings in the diagram are: 1. Internal thread, 2. Sealing part, 3. Connecting pipe, 4. Air choke, 5. External thread, 6. Pressure relief groove, 7. Connecting gap, 8. Connecting hole, 801. Radial section, 802. Axial section, 9. Nut, 10. Retaining ring, 11. Spring, 12. Oil leakage gap, 13. Conical plug, 14. Tray, 15. Oil collection bend, 16. Connecting rod, 17. Positioning step, 18. Positioning ring. Detailed Implementation

[0021] The technical solution of the present invention will be described below through three embodiments:

[0022] Example 1

[0023] like Figure 1 As shown, the main structure of a gearbox vent cap connecting device in this embodiment is a connecting pipe 3 and an air-blocking plug 4 disposed in the connecting pipe 3.

[0024] The upper end of the connecting pipe 3 is provided with an internal thread 1 and is connected to the vent cap through the internal thread 1. The lower end of the connecting pipe 3 is provided with an external thread 5 and is connected to the top of the gearbox housing through the external thread 5. The connecting pipe 3 connects the gearbox housing and the vent cap to maintain the pressure inside the gearbox housing and the external environment in balance.

[0025] The vent plug 4 is cylindrical and its function is to reduce the pressure of oil and gas venting from the gearbox, preventing high-pressure oil and gas from directly spraying out of the vent cap and causing condensation in the environment, which could lead to pollution and safety hazards. The outer diameter of the lower part of the vent plug 4 is smaller than the inner diameter of the corresponding connecting pipe 3, thus forming a communication gap 7 between the lower outer wall of the vent plug 4 and the inner wall of the corresponding connecting pipe 3. The lower part of the communication gap 7 is open and directly exposed to the inner cavity of the gearbox housing, allowing high-pressure oil and gas in the gearbox housing to enter. The outer diameter of the top part of the vent plug 4 corresponds to the inner diameter of the corresponding connecting pipe 3, forming a sealing part 2. The sealing part 2 prevents high-pressure oil and gas in the gearbox housing from being directly discharged to the vent cap through the top of the communication gap 7. To allow the oil and gas entering the communication gap 7 to be discharged and achieve pressure balance, a communication hole 8 is provided inside the vent plug 4 for the oil and gas entering the communication gap 7 to be discharged. In this embodiment, the connecting hole 8 is composed of multiple radial segments 801 located below the sealing part 2 and an axial segment 802 concentrically opened on the top of the air-blocking plug 4. The outer ends of all radial segments 801 penetrate the periphery of the air-blocking plug 4 and are evenly spaced. The inner ends of all radial segments 801 are connected to the lower end of the axial segment 802. The upper end of the axial segment 802 penetrates the upper end face of the air-blocking plug 4, so that oil and gas are discharged from the air-blocking plug 4 and enter the vent cap.

[0026] The lower part of the vent plug 4 is provided with pressure relief grooves 6 distributed circumferentially along the circumference of the vent plug 4. The pressure relief grooves 6 are rectangular toothed grooves, multiple in number, and evenly spaced along the circumference of the vent plug 4. In this embodiment, during implementation, the high-pressure oil and gas generated inside the gearbox passes through the connecting gap 7 between the connecting pipe 3 and the vent plug 4, and through the layers of pressure relief grooves 6, significantly reducing the oil and gas overflow pressure. The depressurized oil and gas enters the vent plug 4 through the radial section 801, then converges in the axial section 802 and is discharged to the vent cap for condensation, thereby reducing or preventing oil and gas from spraying out.

[0027] Example 2

[0028] like Figure 2 As shown, the main structure of this embodiment is the same as that of embodiment 1. The difference is that in this embodiment, a retaining ring 10 is provided at the upper part of the connecting pipe 3, and a spring 11 is connected between the retaining ring 10 and the upper end face of the air-blocking plug 4. The surface of the sealing part 2 is smooth so that it can slide flexibly with the inner wall of the connecting pipe 3, so that the spring 11 pushes the lower part of the air-blocking plug 4 out of the connecting pipe 3 in the natural extension state, and exposes part of the pressure relief groove 6 to the outside of the connecting pipe 3.

[0029] In this embodiment, during implementation, the air-blocking plug 4, under the action of the retaining ring 10 and the spring 11, is initially positioned as follows: Figure 2 At the indicated position, the number of pressure relief grooves 6 participating in pressure relief is relatively small. When the transmission starts running, oil and gas pressure is generated, and the oil and gas are depressurized by passing through the flow gap and layers of pressure relief grooves 6. As the transmission continues to run, the temperature rises, and the oil and gas overflow pressure increases. At this time, the oil and gas act on the lower end of the vent plug 4, pushing the vent plug 4 to overcome the thrust of the spring 11 and the vent plug 4's own weight and move upward, so that more pressure relief grooves 6 participate in the work, thereby further reducing the oil and gas overflow pressure. This embodiment can automatically adjust and adapt according to the pressure state in the transmission. That is, when the pressure in the transmission is high, more pressure relief grooves 6 participate in pressure relief to avoid high-pressure oil and gas spraying out; while when the pressure in the transmission is low, fewer pressure relief grooves 6 are used for residual pressure relief to avoid excessive pressure relief grooves 6 participating in pressure relief, which would reduce the pressure of the oil and gas entering the vent cap to an unnecessarily low pressure state, and at the same time, prevent the pressure inside the transmission from being released in time, leading to oil seal leakage.

[0030] Furthermore, in this embodiment, the retaining ring 10 is fitted onto the internal thread 1, and a nut 9 is provided on the top of the retaining ring 10. The height of the retaining ring 10 can be adjusted by turning the nut 9, so that this embodiment can be applied to gearbox-vent cap connections of different models or operating conditions, and the aforementioned technical effect of automatically adjusting and adapting according to the pressure state in the gearbox can be achieved by adjusting the height of the retaining ring 10.

[0031] Example 3

[0032] As Figure 3 shown, the structure of the present embodiment is similar to that of Embodiment 1, except that the communication holes 8 in the present embodiment are distributed in a folded-back manner along the height direction of the gas blocking plug 4 and form an oil collecting bend 15 at the position of the folded-back point near the lower end of the gas blocking plug 4, and the shapes of the two end communication holes 8 located on both sides of the oil collecting bend 15 are both folded. The communication holes 8 formed in this shape can make full use of the internal space of the gas blocking plug 4 without increasing the height of the gas blocking plug 4 and the whole, and prolong the travel of the oil and gas through the gas blocking plug 4, so as to, on the one hand, further reduce the flow rate or pressure of the oil and gas during the flow through the communication holes 8 by impacting the sawtooth in the communication holes 8, and reduce the probability of the oil and gas being sprayed out of the vent cap; on the other hand, the longer travel in the gas blocking plug 4 is conducive to the oil and gas being re-condensed into liquid during the discharge from the gas blocking plug 4, which can further reduce the oil and gas being sprayed out of the vent cap, and also reduce the daily maintenance burden of the vent cap due to the reduced amount of oil and gas from the gas blocking plug 4 to the vent cap.

[0033] In addition, the bottom of the oil collecting bend 15 in the present embodiment is funnel-shaped with a taper, and is provided with a taper plug 13 matched therewith, the lower end of the taper plug 13 is fixed on a tray 14 after being extended out of the gas blocking plug 4, and the tray 14 is fixed to the lower end of the connecting pipe 3 through a plurality of connecting rods 16, so as to control the opening and closing of the oil collecting bend 15 through the position change of the gas blocking plug 4 caused by different states of the gearbox. Specifically:

[0034] The sealing part 2 of the gas blocking plug 4 is in sliding fit with the inner wall of the connecting pipe 3, and a protruding positioning ring 18 is arranged at the upper end surface of the gas blocking plug 4, and a positioning step 17 is arranged on the inner wall of the connecting pipe 3. The positioning ring 18 and the positioning step 17 are matched, and in the initial state, the gas blocking plug 4 has a downward sliding tendency due to gravity, and the positioning ring 18 is overlapped on the positioning step 17 to avoid continuous downward sliding, i.e. to reach the initial state as Figure 3 shown. At this time, an oil leakage gap 12 is generated between the taper surface of the taper plug 13 and the bottom of the oil collecting bend 15, and the lubricating oil condensed and falling in the oil collecting bend 15 can flow back into the gearbox through the oil leakage gap 12 for reuse. During the continuous operation of the gearbox, the taper plug 13 is pushed to slide upward due to the continuous increase of pressure, and the taper surface of the taper plug 13 tightly contacts with the bottom of the oil collecting bend 15 to achieve a sealing effect, as Figure 4 shown. At this time, the oil and gas are forced to pass through the communication holes 8 for further pressure reduction and condensation. After the gearbox is stopped, the condensed liquid lubricating oil flows back again through the oil leakage gap 12 due to the decrease of the temperature and pressure in the gearbox, so that the gas blocking plug 4 falls to the state as Figure 3 shown under the action of its own gravity, thereby making the condensed liquid lubricating oil flow back again.

Claims

1. A gearbox vent cap connecting device, comprising a connecting pipe (3), the upper end of the connecting pipe (3) being used to connect to the vent cap, and the lower end being used to connect to the gearbox, characterized in that: A vent plug (4) is installed in the connecting pipe (3). The vent plug (4) is cylindrical. The outer wall of the lower part of the vent plug (4) has a communication gap (7) with the inner wall of the connecting pipe (3) and multiple annular pressure relief grooves (6) are provided along the axial direction of the vent plug (4). The outer wall of the upper part of the vent plug (4) forms a sealing part (2) that is in tight fit with the inner wall of the connecting pipe (3). A connecting hole (8) is provided in the vent plug (4). One end of the connecting hole (8) is connected to the communication gap (7) between the sealing part (2) and the pressure relief groove (6), and the other end is distributed through the upper end face of the vent plug (4). The lower end of the connecting pipe (3) is provided with an external thread (5) connected to the transmission, and the upper end is provided with an internal thread (1) connected to the vent cap. A retaining ring (10) is provided in the connecting pipe (3) above the air choke (4). A spring (11) is connected between the retaining ring (10) and the air choke (4). When the spring (11) is in its natural extended state, it pushes part of the pressure relief groove (6) out of the connecting pipe (3). When the pressure in the gearbox is high, more pressure relief grooves (6) can participate in pressure relief, and when the pressure in the gearbox is low, fewer pressure relief grooves (6) can remain in pressure relief. The sealing part (2) of the air choke (4) slides with the inner wall of the connecting pipe (3). A protruding positioning ring (18) is provided on the upper end face of the air choke (4). A positioning step (17) for supporting the positioning ring (18) is provided on the inner wall of the connecting pipe (3). The connecting hole (8) is distributed in a folding direction along the height of the air choke (4) and forms an oil collection bend (15) near the folding point of the lower end of the air choke (4). The bottom of the oil collection bend (15) is funnel-shaped. A conical plug (13) is fixedly provided at the lower end of the connecting pipe (3) and extends into the oil collection bend (15). When the positioning ring (18) falls on the positioning step (17), an oil leakage gap (12) is formed between the outer periphery of the conical plug (13) and the bottom of the oil collection bend (15). After the air choke (4) is pushed upward by the high pressure oil and gas in the transmission, the outer periphery of the conical plug (13) and the bottom of the oil collection bend (15) are attached and the oil leakage gap (12) is sealed.

2. The gearbox vent cap connecting device as described in claim 1, characterized in that: The connecting hole (8) includes multiple radial segments (801) distributed along different radial directions of the air choke (4) and an axial segment (802) connected to the inner end of all radial segments (801).

3. The gearbox vent cap connecting device as described in claim 1, characterized in that: The retaining ring (10) is screwed onto the internal thread (1) opened in the connecting pipe (3).

4. The gearbox vent cap connecting device as described in claim 1, characterized in that: The lower end of the connecting tube (3) is provided with a tray (14) for supporting the conical plug (13), and the outer periphery of the tray (14) is provided with multiple connecting rods (16) fixed to the lower end of the connecting tube (3).

5. The gearbox vent cap connecting device as described in claim 1, characterized in that: The connecting hole (8) includes at least two segments that communicate with the oil collection bend (15), and the two segments are bent.

6. The gearbox vent cap connecting device as described in any one of claims 1-5, characterized in that: The cross-sectional shape of the pressure relief groove (6) is rectangular.

Images