Shell of reduction gearbox and bridge system
By adopting a variable cross-section structure in the oil return window design of the gearbox, the compatibility problem between small and large flow rates is solved, achieving a balance between lubrication and heat dissipation at different vehicle speeds, and improving the overall efficiency and lubrication effect of the gearbox.
Patent Information
- Application Number
- CN202520501910.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-03-21
AI Technical Summary
The existing gearbox oil return window design is difficult to simultaneously accommodate both low and high flow conditions, resulting in large oil churning losses and poor lubrication at low speeds, while the oil level is insufficient at high speeds, affecting heat dissipation and lubrication efficiency.
The variable cross-section oil return window design, with an opening structure whose width gradually increases in the vertical direction, is designed in the form of T-shape, trapezoid, semi-circle or multi-hole shape, to ensure low-flow lubrication at low speed and high-flow cooling at high speed, thus balancing heat dissipation and lubrication efficiency.
It achieves a balance between oil return speed and lubrication effect at different vehicle speeds, improves the overall efficiency and lubrication effect of the gearbox, and has a simple structure and low cost.
Smart Images
Figure CN223825568U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of oil return technology for gearboxes in electric vehicle axle systems, and particularly to the gearbox housing and the axle system. Background Technology
[0002] An oil-cooled electric bridge system comprises a motor system, a gearbox system, a controller system, and oil-cooling accessories, which typically include a filter, oil pump, and heat exchanger. This system cools the motor and cools and lubricates the gearbox. The typical oil path is: oil pan – filter – oil pump – heat exchanger – stator cooling / rotor cooling / gearbox cooling and lubrication – oil pan; this is the internal circulation system within the electric bridge system.
[0003] For the oil return process of "gearbox cooling and lubrication - oil pan", the gearbox oil returns to the oil pan through the return window. The height of the return window depends on the required oil level, and the width depends on the required return speed. In actual design, the size of the return window is defined based on the oil level and return speed, and then verified through lubrication simulation and lubrication testing.
[0004] In an electric axle system, the gearbox oil cools and lubricates the gear set, involving a balance between heat dissipation, lubrication, and efficiency. Generally, efficiency is maximized while ensuring adequate heat dissipation and lubrication; therefore, the oil pump's output is controlled at different vehicle speeds. At low vehicle speeds, the gear meshing generates less heat, so the oil pump delivers a small flow of oil for gear lubrication. At high vehicle speeds, the gear meshing generates more heat, so the oil pump delivers a large flow of oil for both cooling and lubrication.
[0005] like Figure 1 As shown, the inventor understands that the oil return window 500 has a single cross-section and is located on the housing 510. It is difficult to simultaneously accommodate both low-flow and high-flow oil return states in terms of height and width. If the height and width of the oil return window 500 are defined according to the low-flow state, then in the high-flow state, the oil level in the gearbox is relatively high, resulting in more oil churning in the gear set, leading to greater churning losses and reduced efficiency. If the height and width of the oil return window 500 are defined according to the high-flow state, then in the low-flow state, the oil level in the gearbox is relatively low, the gear set cannot churn the oil, and the lubrication effect is poor. Utility Model Content
[0006] To address or mitigate at least one of the problems mentioned in the background art, this application provides a gearbox housing and an electric bridge system.
[0007] The housing of the reduction gearbox provided by the embodiments of the present application comprises a variable cross-section oil return window formed as an opening communicating the inside and outside of the housing, the width of at least a partial area of the variable cross-section oil return window gradually increases from low to high in the vertical direction, or
[0008] The width of the variable cross-section oil return window in the first height area is constant, the width of the variable cross-section oil return window in the second height area is constant, the width of the variable cross-section oil return window in the second height area is greater than that in the first height area, and the second height area is higher than the first height area.
[0009] In at least one embodiment, the variable cross-section oil return window comprises a first window portion and a second window portion, the second window portion is located above the first window portion, and the first window portion and the second window portion are connected to form one opening or not connected to form two openings.
[0010] In at least one embodiment, the first window portion and the second window portion are both formed in a rectangular shape, and the width of the first window portion is smaller than that of the second window portion, so that the variable cross-section oil return window is formed in a T shape.
[0011] In at least one embodiment, the first window portion is formed in a trapezoidal shape with the width of the top being greater than that of the bottom, the second window portion is formed in a rectangular shape, and the width of the second window portion is equal to that of the top of the first window portion.
[0012] In at least one embodiment, the first window portion is formed in a semicircular or arc shape, the second window portion is formed in a rectangular shape, and the width of the second window portion is equal to that of the top of the first window portion.
[0013] In at least one embodiment, the variable cross-section oil return window is formed in a trapezoidal shape with the width of the top being greater than that of the bottom, or
[0014] The variable cross-section oil return window is formed in a semicircular or arc shape.
[0015] In at least one embodiment, the variable cross-section oil return window is located at the bottom of the side wall of the housing, and the variable cross-section oil return window communicates the inside of the reduction gearbox and the oil storage space of the oil pan.
[0016] In at least one embodiment, a variable cross-section oil return window communicating the inside and outside of the housing is arranged on the housing, the variable cross-section oil return window comprises a first window portion and a second window portion, in the vertical direction, the second window portion is located above the first window portion,
[0017] The first window portion includes a first hole, and the second window portion includes a second hole. The sum of the cross-sectional areas of the second holes in the second window portion is greater than the sum of the cross-sectional areas of the first holes in the first window portion, or
[0018] The first window portion includes multiple layers of first holes arranged in an array, from low to high, the sum of the cross-sectional areas of the first holes in each layer is equal or increasing. The second window portion includes multiple layers of second holes arranged in an array, from low to high, the sum of the cross-sectional areas of the second holes in each layer is equal or increasing. The sum of the cross-sectional areas of the first holes in the highest layer of the first window portion is less than the sum of the cross-sectional areas of the second holes in the lowest layer of the second window portion.
[0019] The bridge system provided in this application includes the housing of the gearbox as described above.
[0020] In at least one embodiment, the bridge system includes a motor and a gearbox mounted in parallel, and the variable cross-section oil return window is located at the bottom of the partition wall between the motor cavity and the gearbox cavity in the bridge system.
[0021] The cross-sectional opening size of the variable cross-section return oil window provided in this application varies with height. For example, when the oil pump outputs a small flow rate of oil, the oil returns to the oil pan only through the first window. The opening (e.g., width) of the first window is small, thus reducing the return oil speed and ensuring that the oil level in the gearbox is at a certain height, which is beneficial for churning and lubrication. When the oil pump outputs a large flow rate of oil, the oil level in the gearbox exceeds the first window and can then return to the oil pan through the larger opening of the second window, thereby increasing the return oil speed, reducing churning losses in the gearbox, and improving efficiency. Attached Figure Description
[0022] Figure 1 A schematic diagram of a return oil window known to the inventor is shown.
[0023] Figure 2 An isometric view of a gearbox in an electric bridge system according to an embodiment of this application is shown.
[0024] Figure 3 An axonometric view of a housing in an electric bridge system according to a first embodiment of this application is shown, showing the side of the housing facing the interior space of the gearbox, in which a variable cross-section oil return window is provided.
[0025] Figure 4 It shows Figure 3 A second-view axonometric view of the housing, showing the side of the housing away from the internal space of the gearbox, with a variable cross-section oil return window in the housing.
[0026] Figure 5A structure diagram of the variable cross-section oil return window in the housing is shown. Figure 3 A structure diagram of the variable cross-section oil return window in the housing is shown.
[0027] Figure 6 A first perspective view of the housing in the electric bridge system according to the second embodiment of the present application is shown, which shows the side of the housing facing the inside space of the reduction gearbox, and the housing has the variable cross-section oil return window therein.
[0028] Figure 7 A second perspective view of the housing in the electric bridge system is shown, which shows the side of the housing facing away from the inside space of the reduction gearbox, and the housing has the variable cross-section oil return window therein. Figure 6 A second perspective view of the housing in the electric bridge system is shown, which shows the side of the housing facing away from the inside space of the reduction gearbox, and the housing has the variable cross-section oil return window therein.
[0029] Figure 8 A structure diagram of the variable cross-section oil return window in the housing is shown. Figure 6 A structure diagram of the variable cross-section oil return window in the housing is shown.
[0030] Figure 9 A structure diagram of the variable cross-section oil return window according to the third embodiment of the present application is shown.
[0031] Figure 10 A structure diagram of the variable cross-section oil return window according to the fourth embodiment of the present application is shown.
[0032] Figure 11 A structure diagram of the variable cross-section oil return window according to the fifth embodiment of the present application is shown.
[0033] Figure 12 A structure diagram of the variable cross-section oil return window according to the sixth embodiment of the present application is shown.
[0034] Explanation of Reference Signs
[0035] 100 variable cross-section oil return window
[0036] 110 first window portion
[0037] 111 first hole
[0038] 120 second window portion
[0039] 121 second hole
[0040] 200 housing
[0041] 300 electric machine
[0042] 400 reduction gearbox
[0043] 500 oil return window
[0044] 510 housing DETAILED DESCRIPTION
[0045] Exemplary embodiments of the present application are described herein with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the application, are given by way of illustration only, since various changes and modifications within the scope of the application will become apparent to those skilled in the art from this detailed description.
[0046] The embodiments of the present application provide a housing of a reduction gearbox and a bridge system.
[0047] Referring to Figure 2 , Figure 3 The housing of the reduction gearbox can include a variable cross-section oil return window 100 which can be formed as an opening to communicate the inside and outside of the housing 200. For example, the oil in the reduction gearbox 400 can be configured to return to an oil pan (not shown in the figure) through the variable cross-section oil return window 100.
[0048] Further, in the vertical direction (or height direction), from low to high, the width of at least a partial area of the variable cross-section oil return window 100 gradually increases (as shown in Figures 8 to 11 Alternatively, the width of the variable cross-section oil return window 100 is constant in the first height area, constant in the second height area, and the variable cross-section oil return window 100 in the second height area has a width greater than that of the variable cross-section oil return window 100 in the first height area (as shown in Figure 5 The second height area is higher than the first height area.
[0049] The variable cross-section oil return window 100 can include a first window portion 110 and a second window portion 120, the second window portion 120 being located above the first window portion 110. The first window portion 110 and the second window portion 120 can be connected to form one opening (see the embodiments below), or not connected to form two openings (not shown in the figure).
[0050] The variable cross-section oil return window 100 provided by the present application has a cross-sectional opening size (width) that changes with height and at least two states. When the vehicle is running at low speed, the gear in the reduction gearbox 400 generates low heat, and the oil pump outputs a small amount of oil (e.g., lubricating oil, same below). The oil returns to the oil pan only through the first window portion 110, and the first window portion 110 has a small opening, so as to reduce the oil return speed and ensure that the oil level in the reduction gearbox 400 is at a certain height, which is beneficial to oil stirring lubrication.
[0051] When the vehicle is running at high speed, the gear in the reduction gearbox 400 generates high heat, and the oil pump outputs a large amount of oil to cool and lubricate the gear meshing part. The oil level in the reduction gearbox 400 is higher than the first window portion 110, and then the oil can return to the oil pan through the second window portion 120 with a larger opening, so as to increase the oil return speed, reduce the oil stirring loss in the reduction gearbox 400, and improve the efficiency.
[0052] Therefore, the variable cross-section oil return window 100 provided by the application balances the heat dissipation, lubrication and efficiency of the reduction gearbox 400, and is particularly beneficial for lubrication at low speed and efficiency at high speed of the vehicle. Moreover, different oil return requirements under large and small flow are achieved by a simple oil return window design, the structure is simple, the technical effect is easy to achieve, and the cost is low.
[0053] It should be understood that the positional relationship of the second window part 120 and the first window part 110 defined in the application is the positional relationship of the second window part 120 and the first window part 110 when the variable cross-section oil return window 100 and the electric axle system are in use.
[0054] Referring to Figures 2 to 5 In the first embodiment, the first window part 110 and the second window part 120 are both formed in a rectangular shape, and the width of the first window part 110 is smaller than the width of the second window part 120, so that the variable cross-section oil return window 100 is formed in a T shape.
[0055] Referring to Figures 6 to 8 In the second embodiment, the first window part 110 is formed in a trapezoidal shape with the top being wider than the bottom, and the second window part 120 is formed in a rectangular shape, and the width of the second window part 120 is equal to the width of the top of the first window part 110.
[0056] Referring to Figure 9 In the third embodiment, the variable cross-section oil return window 100 is formed in a trapezoidal shape with the top being wider than the bottom.
[0057] Referring to Figure 10 In the fourth embodiment, the first window part 110 is formed in a semicircular shape or an arc shape (the part with an area smaller than a semicircle after a circle is cut into two parts by a straight line not along the diameter of the circle), and the second window part 120 is formed in a rectangular shape, and the width of the second window part 120 is equal to the width of the top of the first window part 110.
[0058] Referring to Figure 11 In the fifth embodiment, the variable cross-section oil return window 100 is formed in a semicircular shape or an arc shape.
[0059] In the application, the variable cross-section oil return window 100 can also be formed in the form of multiple holes. For example, the variable cross-section oil return window 100 includes the first window part 110 and the second window part 120, and in the vertical direction, the second window part 120 is located above the first window part 110.
[0060] Referring to Figure 12In the sixth embodiment, the first window portion 110 includes a plurality of layers of first holes 111 arranged in an array, and the sum of the cross-sectional areas of the first holes 111 of each layer is equal or increases from the lower layer to the upper layer. The second window portion 120 includes a plurality of layers of second holes 121 arranged in an array, and the sum of the cross-sectional areas of the second holes 121 of each layer is equal or increases from the lower layer to the upper layer. The sum of the cross-sectional areas of the first holes 111 of the uppermost layer of the first window portion 110 is smaller than the sum of the cross-sectional areas of the second holes 121 of the lowermost layer of the second window portion 120.
[0061] Alternatively, the first window portion 110 can include one layer of first holes 111, and the second window portion 120 can include one layer of second holes 121, and the sum of the cross-sectional areas of the second holes 121 of the second window portion 120 is larger than the sum of the cross-sectional areas of the first holes 111 of the first window portion 110.
[0062] Of course, the diameters of the first holes 111 and the second holes 121 can be made the same, and the relationship between the cross-sectional areas of the first window portion 110 and the second window portion 120 can be controlled by controlling the number of holes.
[0063] It should be understood that the corners of the variable cross-section oil return window in each of the foregoing embodiments can also be chamfered.
[0064] The variable cross-section oil return window 100 is located at the bottom of the side wall of the housing 200, and the variable cross-section oil return window 100 communicates the inside of the reduction gearbox 400 and the oil storage space of the oil pan of the reduction gearbox.
[0065] The electric bridge system provided in the present application can include the foregoing variable cross-section oil return window 100. Referring to Figure 2 The electric bridge system can also include the motor 300 and the reduction gearbox 400 installed side by side. The housing 200 can be formed as the housing of the reduction gearbox 400 or as part of the housing of the reduction gearbox 400, and the reduction gearbox 400 is installed on one side of the motor 300, so that the motor 300 and the reduction gearbox 400 can share the housing 200, and the side wall of the housing of the reduction gearbox 400 is formed as the side wall of the housing of the motor 300.
[0066] It should be understood that in the housing of the electric bridge system including the reduction gearbox and the motor, the housing is usually divided into a motor cavity accommodating the motor and a reduction mechanism cavity accommodating the reduction mechanism, and a partition wall is arranged between the motor cavity and the reduction mechanism cavity, and the variable cross-section oil return window 100 of the present application can be formed in the partition wall. The form, shape, and division (assembly method of different parts) of the housing of the electric bridge system can be different. The housing 200 here can also be referred to as the housing of the motor 300.
[0067] The variable cross-section oil return window 100 is located at the bottom of the side wall, and the variable cross-section oil return window 100 is communicated with the inside of the reduction gearbox 400. The electric bridge system can further comprise an oil pan located below the variable cross-section oil return window 100, so that the oil in the reduction gearbox 400 can enter the oil pan through the variable cross-section oil return window 100.
[0068] The variable cross-section oil return window 100 can be located below the internal space of the motor 300. When the oil in the reduction gearbox 400 passes through the variable cross-section oil return window 100, the oil does not flow through the internal space of the motor 300.
[0069] The above is the preferred embodiment of the present application, it should be pointed out that, for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.
Claims
1. A housing for a gearbox, characterized in that, Includes a variable cross-section oil return window, which is formed as an opening connecting the inner and outer spaces of the housing. In the vertical direction, the width of at least a local area of the variable cross-section oil return window gradually increases from low to high. The width of the variable cross-section return oil window remains unchanged in the first height region and in the second height region. The width of the variable cross-section return oil window in the second height region is greater than the width of the variable cross-section return oil window in the first height region, and the second height region is higher than the first height region.
2. The housing of the gearbox according to claim 1, characterized in that, The variable cross-section return oil window includes a first window portion and a second window portion. The second window portion is located above the first window portion. The first window portion and the second window portion are connected to form an opening or are not connected to form two openings.
3. The housing of the gearbox according to claim 2, characterized in that, Both the first window portion and the second window portion are formed into rectangles, and the width of the first window portion is smaller than the width of the second window portion, so that the variable cross-section oil return window is formed into a T shape.
4. The housing of the gearbox according to claim 2, characterized in that, The first window portion is formed as a trapezoid that is wider at the top and narrower at the bottom, and the second window portion is formed as a rectangle, with the width of the second window portion being equal to the width of the top of the first window portion.
5. The housing of the gearbox according to claim 2, characterized in that, The first window portion is formed in a semi-circular or arc shape, and the second window portion is formed in a rectangular shape. The width of the second window portion is equal to the width of the top of the first window portion.
6. The housing of the gearbox according to claim 1, characterized in that, The variable cross-section oil return window forms a trapezoid that is wider at the top and narrower at the bottom, or The variable cross-section oil return window is formed in a semi-circular or arc shape.
7. The housing of the gearbox according to claim 1, characterized in that, The variable cross-section oil return window is located at the bottom of the side wall of the housing, and the variable cross-section oil return window connects the interior of the gearbox and the oil storage space of the oil pan.
8. A housing for a gearbox, characterized in that, The system includes a variable cross-section oil return window disposed on the housing, connecting the inner and outer spaces of the housing. The variable cross-section oil return window includes a first window portion and a second window portion, wherein, in the vertical direction, the second window portion is located above the first window portion. The first window portion includes a first hole, and the second window portion includes a second hole. The sum of the cross-sectional areas of the second holes in the second window portion is greater than the sum of the cross-sectional areas of the first holes in the first window portion, or The first window portion includes multiple layers of first holes arranged in an array, from low to high, the sum of the cross-sectional areas of the first holes in each layer is equal or increasing. The second window portion includes multiple layers of second holes arranged in an array, from low to high, the sum of the cross-sectional areas of the second holes in each layer is equal or increasing. The sum of the cross-sectional areas of the first holes in the highest layer of the first window portion is less than the sum of the cross-sectional areas of the second holes in the lowest layer of the second window portion.
9. A bridge system, characterized in that, The bridge system includes the housing of the gearbox as described in any one of claims 1 to 8.
10. The bridge system according to claim 9, characterized in that, The electric bridge system includes a motor and a gearbox installed in parallel, and the variable cross-section oil return window is located at the bottom of the partition wall between the motor cavity and the gearbox cavity in the electric bridge system.