Ventilation lubricating structure of gearbox and vehicle power system

Abstract

The utility model provides a ventilation lubrication structure of a gearbox and a vehicle power system. The ventilation lubricating structure can comprise a shell (100) of the gearbox and an output bearing (800) supported on the shell, the shell is provided with a ventilation connector, a ventilation hole is formed in the ventilation connector, an oil discharge hole (160) is further formed in the shell, and the ventilation hole is communicated to an inner cavity of the shell only through the oil discharge hole (160); a vent plug (200) attached to the vent joint; and an oil cover (300), the oil cover is in interference fit with the housing, an oil collecting cavity (130) is arranged between the oil cover and the housing, a bearing lubrication hole (170) is also formed in the housing, and the bearing lubrication hole extends from the oil collecting cavity to the vicinity of the output bearing (800) and is used for guiding oil in the oil collecting cavity to the output bearing so as to lubricate the output bearing. And the oil collecting cavity is not communicated with the vent hole (110) and the oil discharge hole (160).

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to electric axles that can be used in pure electric vehicles and hybrid vehicles. Background Technology

[0002] Gearboxes are widely used in pure electric and hybrid vehicles. They are connected to the vehicle's power source to change the torque from that source. Typically, a gearbox includes a housing and a gear transmission mechanism housed within it, which performs the torque-changing function. The gearbox housing also stores a fluid (e.g., oil) for lubricating the gear transmission mechanism. During gearbox operation, the fluid's temperature rises, causing some of it to vaporize. This can lead to excessive pressure within the gearbox housing. Therefore, the gearbox also incorporates a valve assembly mounted on the housing to balance the pressure inside and outside the gearbox. The valve assembly allows gas to escape from the gearbox to balance the pressure and prevents fluid loss by preventing fluid leakage.

[0003] Existing valve assemblies are prone to clogging. Utility Model Content

[0004] The purpose of this application is to provide a venting and lubrication structure for a gearbox in which the vent plug (or valve assembly) is less prone to clogging.

[0005] Embodiments of this application provide a ventilation and lubrication structure for a gearbox, comprising:

[0006] The gearbox housing and the output bearing supported on the housing are provided with a vent connector, a vent hole is formed in the vent connector, and an oil drain hole is also formed in the housing. The vent hole is connected to the inner cavity of the housing only through the oil drain hole.

[0007] A vent plug, installed on the vent connector, is used to balance the air pressure inside and outside the gearbox; and

[0008] An oil cap is interference-fitted to the housing. An oil collection chamber is provided between the oil cap and the housing. A bearing lubrication hole is also formed in the housing, extending from the oil collection chamber to the vicinity of the output bearing, for guiding the oil in the oil collection chamber to the output bearing to lubricate the output bearing.

[0009] The oil collection chamber is not connected to either the vent or the drain hole.

[0010] In at least one embodiment, the vent is located above the drain hole, the diameter of the drain hole is larger than the diameter of the vent, and the drain hole and the vent are connected at an angle relative to each other.

[0011] In at least one embodiment, the vent extends vertically at one axial end of the housing, and the oil drain hole is located closer to the inside of the gearbox than the vent.

[0012] In at least one embodiment, the oil cap includes:

[0013] The inner wall is flat, and the inner wall is a trapezoid with an arc-shaped bottom edge. The width of the inner wall gradually decreases from its top edge to its bottom edge.

[0014] Sidewalls located on both sides of the inner wall in the width direction, the sidewalls extending from the inner wall axially outwards from the housing; and

[0015] A bottom wall extends axially outward from the bottom edge of the inner wall toward the outer side of the housing, and the bottom wall is connected to the side wall.

[0016] In at least one embodiment, the oil cap has a mirror-symmetric structure, and the angle between the sidewall and the symmetry plane of the oil cap is 30 to 45 degrees.

[0017] In at least one embodiment, the oil cap is a steel oil cap, and the maximum width of the oil cap is 3 to 6 times the maximum height.

[0018] In at least one embodiment, the ventilated lubrication structure further includes a gear support bearing and an oil retainer ring.

[0019] The oil baffle ring is clamped and fixed between the housing and the outer ring of the gear support bearing to prevent the oil lubricating the gear support bearing from entering the oil drain hole.

[0020] In at least one embodiment, the oil baffle ring includes an outer ring portion, an inner ring portion, and a connecting portion. The connecting portion extends axially and circumferentially along the housing. The outer ring portion extends radially outward from the axially inner end of the connecting portion. The outer ring portion is clamped and fixed between the housing and the outer ring of the gear support bearing. The inner ring portion extends radially inward from the axially outer end of the connecting portion. The extension line of the central axis of the oil drain hole passes through the inner ring portion.

[0021] In at least one embodiment, the oil baffle ring is a steel oil baffle ring.

[0022] The output bearing is a bearing that supports the output shaft in the gearbox. The outer diameter of the gear support bearing is larger than the outer diameter of the output bearing, and the gear support bearing is located on the axial inner side of the housing than the output bearing.

[0023] Embodiments of this application also provide a vehicle powertrain system including a ventilated lubrication structure for a gearbox according to this application.

[0024] The vent plug of the above-mentioned ventilation and lubrication structure is not prone to clogging. Attached Figure Description

[0025] Figures 1A to 1D This illustrates a ventilation and lubrication structure for a gearbox that the inventors are aware of.

[0026] Figure 2 This is a partial perspective view of a gearbox according to one embodiment of the present application.

[0027] Figure 3A It shows Figure 2 A partial cross-sectional view of the ventilation and lubrication structure of the gearbox.

[0028] Figure 3B It shows Figure 2 An axial view of the ventilation and lubrication structure of the gearbox, where the oil cap is not shown.

[0029] Figure 3C It shows Figure 2 An axial view of the ventilation and lubrication structure of the gearbox, showing the oil cap.

[0030] Figure 3D It shows Figure 2 A partial cross-sectional view of the ventilation and lubrication structure of the gearbox.

[0031] Figure 4A and Figure 4B They are shown respectively Figure 2 Axial view and perspective view of the oil cap of the ventilation and lubrication structure of the gearbox.

[0032] Figure 5A and Figure 5B They are shown respectively Figure 2 A perspective view and an axial sectional view of the oil baffle ring of the ventilation and lubrication structure of the gearbox. Detailed Implementation

[0033] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaustively describe all possible methods of this application, nor to limit the scope of this application.

[0034] Figures 1A to 1D This illustrates a ventilation and lubrication structure for a gearbox that the inventors are aware of.

[0035] The venting and lubrication structure is disposed in the housing 1 of the gearbox. This structure includes a vent plug 2, which allows gaseous oil to pass through but prevents liquid oil from passing through. For example, the vent plug 2 may include a fiber filter element and a filter membrane. The housing 1 may include a vent connector with a vent hole 10 formed therein, to which the vent plug 2 can be installed. The venting and lubrication structure also includes an oil cap 3, which is connected to the housing 1 by two screws 4.

[0036] The housing 1 and the oil cap 3 define a vent chamber 5, which is connected to a vent hole 10. The oil cap 3 prevents large amounts of liquid oil from entering the vent chamber 5. However, there is a gap between the oil cap 3 and the housing 1. Liquid oil agitated by gears or other structures in the gearbox may enter the vent chamber 5 through this gap. A drain hole 6 is located at the bottom of the vent chamber 5. When liquid oil enters the vent chamber 5, the drain hole 6 can drain the liquid oil.

[0037] The housing 1 is also provided with a bearing lubrication hole 7. The oil collected by the oil cap 3 can be discharged to the bearing 8 and the seal 9 through the bearing lubrication hole 7 to lubricate the bearing 8 and the seal 9.

[0038] With the development of high-speed electric drive systems (electric shafts), more and more electric drive systems have increased their maximum speed and are applied to more complex working conditions. During testing, the inventors discovered that under certain working conditions, such as when the motor speed and torque of the electric drive system are high and the tilt is large, the vent plug 2 may malfunction. However, this malfunction did not occur in lubrication simulations. The inventors found that liquid oil containing air bubbles rises to the vent plug 2, flows to the vent hole 10, and under the gas expansion caused by heat that cannot be considered in lubrication simulations, the oil rises to the vent hole 10 and blocks the vent plug 2.

[0039] Lubrication simulations also show that at large gearbox tilt angles (corresponding to situations such as a vehicle driving on an inclined road or turning), liquid oil may leak from the gap between the oil cap 3 and the housing 1, and less oil may enter the bearing lubrication hole 7. Therefore, the bearing 8 and seal 9 will not receive adequate lubrication, thus shortening their service life. Under normal operating conditions, oil should not enter the vent hole 10, but under certain operating conditions there is a risk of oil entering the vent hole 10. In this case, the vent plug 2 will lose its function of balancing the internal pressure of the gearbox with the external atmospheric pressure.

[0040] It should be understood that, although the above explanation Figures 1A to 1D The illustrated venting and lubrication structure of the gearbox has some drawbacks, but it still has certain advantages compared to some existing technologies. Figures 1A to 1D The above description still constitutes part of the disclosure or implementation of this application.

[0041] The following innovative solution is proposed in consideration of the above circumstances.

[0042] In the following description, axial, radial, and circumferential refer to the axial, radial, and circumferential directions of the gearbox housing 100, respectively. Axial inner side refers to the side relatively close to the axial midpoint of the gearbox housing 100 along axial direction A; axial outer side refers to the side relatively far from the axial midpoint of the gearbox housing 100 along axial direction A. Radial inner side refers to the side relatively close to the central axis of the housing (output shaft) along radial direction R; radial outer side refers to the side relatively far from the central axis of the housing (output shaft) along radial direction R.

[0043] See Figures 2 to 5B One embodiment of this application provides a venting and lubrication structure for a gearbox (hereinafter, sometimes simply referred to as "venting and lubrication structure").

[0044] The venting and lubrication structure may include a gearbox housing 100 and an output bearing 800 supported on the housing 100. The housing 100 is provided with a vent connector, within which a vent hole 110 is formed. The housing 100 also has an oil drain hole 160, which connects the vent hole 110 to the inner cavity of the housing 100. The vent hole 110 is connected to the inner cavity of the housing 100 only via the oil drain hole 160. Here, the inner cavity of the housing 100 may be the inner cavity of the housing 100 that houses the gear transmission mechanism.

[0045] The ventilation and lubrication structure may also include a vent plug 200, which is installed on the ventilation connector to balance the air pressure inside and outside the gearbox.

[0046] The ventilation and lubrication structure may also include an oil cap 300, which can be interference-fitted to the housing 100. An oil collection chamber 130 is provided between the oil cap 300 and the housing 100. A bearing lubrication hole 170 is also formed in the housing 100. The bearing lubrication hole 170 extends from the oil collection chamber 130 to the vicinity of the output bearing 800, and is used to guide the oil in the oil collection chamber 130 to the output bearing 800 to lubricate the output bearing 800.

[0047] Here, the oil collection chamber 130 is not connected to the vent hole 110 or the oil drain hole 160. This disconnection means that oil in the oil collection chamber 130 will not flow into the vent hole 110 or the oil drain hole 160 without passing through the inner cavity of the housing 100. Similarly, oil (if any) in the vent hole 110 or the oil drain hole 160 will not flow into the oil collection chamber 130 without passing through the inner cavity of the housing 100. Of course, oil in the inner cavity of the housing 100 will continuously enter the oil collection chamber 130 to lubricate the output bearing 800. Gaseous oil in the inner cavity of the housing 100 will also enter the oil drain hole 160 and the vent hole 110.

[0048] In the above embodiment, the oil collection chamber 130 is not connected to the vent hole 110 and the oil drain hole 160. In this way, the oil in the oil collection chamber 130 will not enter the oil drain hole 160 and the vent hole 110, thereby preventing the vent plug 200 from being blocked.

[0049] The ventilation and lubrication structure in the embodiments of this application is eliminated. Figures 1A to 1D The vent chamber 5 is shown. The oil drain hole 160 and the vent hole 110 in the housing 100 are directly connected. In other words, the vent hole 110 is connected to the inner cavity of the housing 100 only through the oil drain hole 160. In this way, liquid oil in the inner cavity of the housing 100 is not easy to enter the vent hole 110, which can prevent the vent plug 200 from being blocked.

[0050] The oil cap 300 is interference-fitted to the housing 100 to eliminate the gap between the oil cap 300 and the housing 100, so that the oil in the oil collection chamber 130 is not easy to flow out through the gap. Thus, the oil in the oil collection chamber 130 can flow to the output bearing 800 through the bearing lubrication hole 170, thereby fully lubricating the output bearing 800.

[0051] and Figures 1A to 1D Compared to the structure shown, the two screws 4 are eliminated, reducing the number of parts. The design of the oil cap 300 is simpler and less expensive.

[0052] It is understandable that the oil collection chamber 130 can be used to collect the liquid oil agitated by the gears and other components in the gearbox.

[0053] Here, the vent 110 is located above the oil drain hole 160. Both the oil drain hole 160 and the vent 110 can be round holes. The diameter of the oil drain hole 160 can be larger than the diameter of the vent 110, and the oil drain hole 160 and the vent 110 are connected at an angle relative to each other.

[0054] The vent 110 is located above the oil drain hole 160, preventing liquid oil in the inner cavity of the housing 100 from easily entering the vent 110. The diameter of the oil drain hole 160 is larger than that of the vent 110, allowing liquid oil formed by the condensation of gaseous oil in the oil drain hole 160 to easily return to the inner cavity of the housing 100 through the oil drain hole 160. The oil drain hole 160 and the vent 110 are connected at an angle relative to each other, further preventing liquid oil in the inner cavity of the housing 100 from easily entering the vent 110 and facilitating the machining of both the oil drain hole 160 and the vent 110.

[0055] Here, the vent 110 can extend vertically at one axial end of the housing 100, and the oil drain hole 160 is located inside the gearbox than the vent 110. Here, the structure of the axial end of the gearbox housing 100 can be fully utilized, and the oil drain hole 160 and the vent 110 can be easily constructed.

[0056] See Figure 4BIn one example, the oil cap 300 may include: an inner wall 310; side walls 320 and 330 located on both sides of the inner wall 310 in the width direction; and a bottom wall 340.

[0057] The inner wall 310 can be flat or trapezoidal with an arc-shaped bottom edge, and the width of the inner wall 310 can gradually decrease from its top edge to its bottom edge. The side walls 320 and 330 can extend from the inner wall 310 to the axially outer side (e.g., one axial side) of the housing 100.

[0058] The bottom wall 340 can extend from the bottom edge of the inner wall 310 to the axially outer side (e.g., one axial side) of the housing 100, and the bottom wall 340 is connected to the side walls 320, 330.

[0059] Here, the oil cap 300 can be a one-piece molded structure.

[0060] The generally trapezoidal structure of the oil cap 300 facilitates adaptation to the structure of the housing 100 located on the upper side of the output shaft of the gearbox. The side walls 320, 330 and bottom wall 340 of the oil cap 300, which are bent relative to the inner wall 310, facilitate interference fit with the peripheral wall of the cavity of the housing 100, facilitate the elimination of gaps, and facilitate the formation of the oil collection cavity 130 together with the housing 100.

[0061] See Figure 3C and Figure 4A The oil cap 300 can be a mirror-symmetric structure (left-right symmetric structure), and the included angle α between the side walls 320, 330 and the symmetry plane X of the oil cap 300 can be 30 degrees to 45 degrees. This ensures a large upper opening for the oil collection chamber 130, and also allows for proper lubrication when the gearbox or vehicle power system with this venting and lubrication structure is tilted (e.g., ...). Figure 3C (The heights of the left and right sides are different) to ensure the oil collection capacity of the oil collection chamber 130.

[0062] Here, the oil cap 300 can be a steel oil cap. The maximum width of the oil cap 300 ( Figure 4A The width in the left and right directions can be the maximum height. Figure 4A The height in the vertical direction is 3 to 6 times that of the height in the middle.

[0063] The oil cap 300 is made of steel, which facilitates an interference fit with the housing 100, which is usually made of steel. The two have the same coefficient of thermal expansion, which can prevent the oil cap 300 from falling off. The width of the oil cap 300 is greater than its height, so the opening can be larger within the same volume, which has a strong oil receiving capacity and facilitates the lubrication of the output bearing 800.

[0064] The oil cap 300 can be made by stamping a metal sheet, and the thickness of the sheet forming the oil cap 300 can be 1 to 2 mm.

[0065] See Figure 3DThe oil cap 300 can be designed such that when the vehicle tilts (here, it can mean that the left and right heights are inconsistent) or turns, the top of the oil cap 300 is still higher than the bearing lubrication hole 170. Therefore, the oil collected in the oil collection chamber 130 will not spill out and will lubricate the output bearing 800 through the bearing lubrication hole 170.

[0066] Here, an output seal 900 can be provided on the axial outer side of the output bearing 800, and oil from the bearing lubrication hole 170 can lubricate both the output bearing 800 and the output seal 900. The output seal 900 can be used to seal the gap between the output shaft and the housing.

[0067] See Figure 3A , Figure 5A , Figure 5B The ventilation and lubrication structure here may also include a gear support bearing 700 and an oil retainer ring 400. The oil retainer ring 400 is clamped and fixed between the housing 100 and the outer ring of the gear support bearing 700 to prevent oil, especially oil that lubricates the gear support bearing 700, from entering the oil drain hole 160.

[0068] The oil baffle ring 400 is an optional component that prevents oil from entering the drain hole 160.

[0069] The oil baffle ring 400 may include an outer ring portion 410, an inner ring portion 420, and a connecting portion 430, the connecting portion 430 extending axially A and circumferentially C along the housing 100. The outer ring portion 410 extends radially outward from the axially inner end of the connecting portion 430, and is clamped and fixed between the housing 100 and the outer ring of the gear support bearing 700. The inner ring portion 420 extends radially inward from the axially outer end of the connecting portion 430. The extension of the central axis of the oil drain hole 160 passes through the inner ring portion 420.

[0070] See Figure 3A The aforementioned structure and installation method of the oil retainer ring 400 can prevent oil, especially oil lubricating the gear support bearing 700, from being thrown up by the rotating body (shown as a ball) of the gear support bearing 700, from entering the oil drain hole 160. It can be understood that the oil retainer ring 400 can also prevent at least a portion of the oil thrown up by other gears from entering the oil drain hole 160.

[0071] The oil baffle ring 400 has a stepped structure, and the diameter of the connecting part 430 can be slightly smaller than the inner diameter of the corresponding housing position to avoid interference with the housing 100.

[0072] Here, gear support bearing 700 refers to a bearing that directly or indirectly supports the gears of the gear transmission mechanism in the gearbox. As an example, gear support bearing 700 can support the planet carrier in a planetary set.

[0073] Here, the oil retainer ring 400 can be a steel oil retainer ring. This facilitates compatibility with the thermal expansion coefficients of the housing 100 and the gear support bearing 700, and makes it easy to achieve stable installation of the oil retainer ring.

[0074] The output bearing 800 can be a bearing that supports the output shaft in the gearbox at the axial end of the housing 100. The outer diameter of the gear support bearing 700 can be larger than the outer diameter of the output bearing 800. The gear support bearing 700 can be located axially inside the housing 100 than the output bearing 800. The oil drain hole 160 can be located axially outside the housing 100 than the gear support bearing 700.

[0075] Here, the oil retainer ring 400 can be formed by stamping a metal sheet, and the thickness of the sheet forming the oil retainer ring 400 can be 1 to 2 mm. The outer diameter of the outer ring portion 410 can be the same as the outer diameter of the outer ring of the gear support bearing 700.

[0076] Comparison Figures 1A to 1D The structure shown in this application, the ventilation and lubrication structure of the embodiment, can be easily obtained from existing housings. It retains most of the original structural features, requiring only minor modifications to the housing, resulting in minimal changes and ease of implementation. Eliminating the complex (existing) oil cap and two screws on the housing reduces the number of parts and lowers costs.

[0077] The ventilation and lubrication structure of the embodiments of this application can improve the performance of the gearbox and the vehicle on which the gearbox is installed, making it suitable for more complex working conditions, and without damaging the vent plug.

[0078] Embodiments of this application also provide a vehicle powertrain system including a ventilated lubrication structure for a gearbox according to this application.

[0079] It is understood that the vehicle powertrain can be, for example, an electric drive system (electric shaft) for a pure electric vehicle or a hybrid vehicle. The vehicle powertrain may include a gearbox and a motor. The gearbox may include a gear transmission mechanism, for example, a planetary gear set. The motor and gear transmission mechanism may be located in two chambers of the same housing or in two separate housings.

[0080] This application also provides a gearbox including the above-described gearbox with a ventilation and lubrication structure, and a vehicle including the gearbox or the above-described vehicle power system.

[0081] It should be understood that at least some aspects or features of the above-described implementation methods, embodiments, or examples can be appropriately combined.

[0082] It is understood that, in this application, when the number of parts or components is not specifically limited, the number can be one or more, where multiple refers to two or more. For cases where the number of parts or components shown in the drawings and / or described in the specification is, for example, two, three, four, etc., this specific number is generally exemplary and not restrictive, and can be understood as multiple, i.e., two or more; however, this does not mean that this application excludes the case of one.

[0083] It should be understood that the above-described embodiments, examples, or examples are merely exemplary and are not intended to limit this application. Those skilled in the art can make various modifications and changes to the above-described embodiments, examples, or examples under the teachings of this application without departing from the scope of this application.

Claims

1. A ventilation and lubrication structure for a gearbox, characterized in that, include: The gearbox housing and the output bearing supported on the housing are provided with a vent connector, a vent hole is formed in the vent connector, and an oil drain hole is also formed in the housing. The vent hole is connected to the inner cavity of the housing only through the oil drain hole. A vent plug, which is installed on the vent connector, is used to balance the air pressure inside and outside the gearbox; as well as An oil cap is interference-fitted to the housing. An oil collection chamber is provided between the oil cap and the housing. A bearing lubrication hole is also formed in the housing, extending from the oil collection chamber to the vicinity of the output bearing, for guiding the oil in the oil collection chamber to the output bearing to lubricate the output bearing. The oil collection chamber is not connected to either the vent or the drain hole.

2. The ventilation and lubrication structure of the gearbox according to claim 1, characterized in that, The vent is located above the drain hole, the diameter of the drain hole is larger than the diameter of the vent, and the drain hole and the vent are connected at an angle relative to each other.

3. The ventilation and lubrication structure of the gearbox according to claim 2, characterized in that, The vent extends vertically at one axial end of the housing, and the oil drain hole is located on the inner side of the gearbox than the vent.

4. The ventilation and lubrication structure of the gearbox according to claim 1, characterized in that, The oil cap includes: The inner wall is flat, and the inner wall is a trapezoid with an arc-shaped bottom edge. The width of the inner wall gradually decreases from its top edge to its bottom edge. Sidewalls located on both sides of the inner wall in the width direction, the sidewalls extending from the inner wall axially outwards from the housing; and A bottom wall extends axially outward from the bottom edge of the inner wall toward the outer side of the housing, and the bottom wall is connected to the side wall.

5. The ventilation and lubrication structure of the gearbox according to claim 4, characterized in that, The oil cap has a mirror-symmetric structure, and the angle between the sidewall and the symmetry plane of the oil cap is 30 to 45 degrees.

6. The ventilation and lubrication structure of the gearbox according to claim 1, characterized in that, The oil cap is a steel oil cap, and the maximum width of the oil cap is 3 to 6 times the maximum height.

7. The ventilation and lubrication structure of the gearbox according to claim 1, characterized in that, It also includes gear support bearings and oil retainer rings. The oil baffle ring is clamped and fixed between the housing and the outer ring of the gear support bearing to prevent the oil lubricating the gear support bearing from entering the oil drain hole.

8. The ventilation and lubrication structure of the gearbox according to claim 7, characterized in that, The oil baffle ring includes an outer ring portion, an inner ring portion, and a connecting portion. The connecting portion extends along the axial and circumferential directions of the housing. The outer ring portion extends radially outward from the axial inner end of the connecting portion. The outer ring portion is clamped and fixed between the housing and the outer ring of the gear support bearing. The inner ring portion extends radially inward from the axial outer end of the connecting portion. The extension line of the central axis of the oil drain hole passes through the inner ring portion.

9. The ventilated and lubricated structure of the gearbox according to claim 7, characterized in that, The oil baffle ring is a steel oil baffle ring. The output bearing is a bearing that supports the output shaft in the gearbox. The outer diameter of the gear support bearing is larger than the outer diameter of the output bearing, and the gear support bearing is located on the axial inner side of the housing than the output bearing.

10. A vehicle powertrain system, characterized in that, The gearbox includes the ventilation and lubrication structure according to any one of claims 1 to 9.

Images