Electric vehicle planetary reduction gearbox

Abstract

The present application provides an electric vehicle planetary reduction gearbox, which relates to the field of transmission technology. It includes a front housing, a rear housing, a ring gear and a baffle. The front housing is connected to the rear housing, and the two jointly define an accommodation cavity. The rear housing is provided with an exhaust hole communicating with the accommodation cavity; the baffle is connected to the front housing and extends into the accommodation cavity, and the baffle is provided with a ventilation structure communicating with the accommodation cavity; the ring gear is located in the accommodation cavity, one side of the ring gear abuts against the inner wall of the rear housing, and the other side abuts against the baffle; the baffle shields at least part of the area of the exhaust hole in the radial direction of the ring gear. The baffle integrates two functions, namely, the limitation of the inner ring gear and the oil blocking of the exhaust hole, simplifies the structure, reduces the assembly difficulty, and saves the manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the field of transmission technology, and more particularly, to an electric vehicle planetary reduction gearbox. Background Art

[0002] In the prior art, a planetary reduction gearbox includes a front housing, a rear housing, a breather cap, an internal gear ring, a snap ring, and an oil baffle structure. The front housing and the rear housing are connected to jointly define a receiving cavity. The breather cap is fixed to the rear housing and can discharge the internal high-pressure gas during the operation of the gearbox to ensure safety. The internal gear ring is fixed in the rear housing by a snap ring. The oil baffle structure is disposed in the receiving cavity and can block the oil splashing towards the breather cap.

[0003] The inventor has found through research that the planetary reduction gearbox of the prior art has the following disadvantages:

[0004] The fixation of the internal gear ring and the oil baffle of the breather cap are realized by two independent components, which not only increases the assembly difficulty but also increases the manufacturing cost. Summary of the Invention

[0005] The purpose of the present invention is to provide an electric vehicle planetary reduction gearbox, which can simplify the structure, reduce the assembly difficulty, and reduce the manufacturing cost.

[0006] The embodiments of the present invention are implemented as follows:

[0007] The present invention provides an electric vehicle planetary reduction gearbox, including:

[0008] A front housing, a rear housing, a gear ring, and a baffle. The front housing is connected to the rear housing and the two jointly define a receiving cavity. The rear housing is provided with an exhaust hole communicating with the receiving cavity. The baffle is connected to the front housing and extends into the receiving cavity. The baffle is provided with a ventilation structure communicating with the receiving cavity. The gear ring is located in the receiving cavity. One side of the gear ring abuts against the inner wall of the rear housing, and the other side abuts against the baffle. The baffle shields at least a part of the area of the exhaust hole in the radial direction of the gear ring.

[0009] In an alternative embodiment, the baffle is provided as an annular member, and the ventilation structure is provided as a through hole penetrating the baffle.

[0010] In an alternative embodiment, an exhaust groove is provided on the outer peripheral surface of the baffle. The ventilation structure is provided as a through hole penetrating the bottom wall of the exhaust groove. The outer peripheral surface of the baffle contacts the inner wall of the rear housing to define an exhaust cavity at the exhaust groove.

[0011] In an alternative embodiment, the exhaust groove is provided as an annular groove.

[0012] In an alternative embodiment, the ventilation structure and the exhaust hole are spaced apart in the circumferential direction of the ring gear.

[0013] In an alternative embodiment, a bearing seat is provided on the front housing, the bearing seat is located on a side of the stopper closer to the center of the front housing, and an oil inlet is provided on the bearing seat.

[0014] In an alternative embodiment, a first guiding inclined surface is provided on the inner circumferential surface of the stopper, and the cross-sectional area of the first guiding inclined surface gradually increases from the side closer to the front housing to the other side. The first guiding inclined surface is used to guide the oil to the wall of the front housing so that the oil enters the bearing seat through the oil inlet.

[0015] In an alternative embodiment, an oil retaining structure is provided between the stopper and the bearing seat. The oil retaining structure has a second guiding inclined surface. The height of the second guiding inclined surface on the side closer to the stopper is higher than the height of the side closer to the bearing seat. The side of the second guiding inclined surface closer to the bearing seat is located at the oil inlet. The second guiding inclined surface is used to guide the oil from the high side to the low side under the action of gravity so that the oil enters the oil inlet.

[0016] In an alternative embodiment, the front housing is provided with a front housing oil storage area, the rear housing is provided with a rear housing oil storage area, the front housing oil storage area communicates with the rear housing oil storage area, and the ventilation structure is located above the front housing oil storage area.

[0017] In an alternative embodiment, an annular limiting platform is provided on the inner wall of the rear housing, and one annular end face of the ring gear away from the front housing abuts against the annular limiting platform; an oil through groove is further provided on the inner wall of the rear housing and is located in the rear housing oil storage area. The oil through groove penetrates through the annular limiting platform; an oil through hole located in the front housing oil storage area is provided on the stopper, and the oil through groove communicates with the oil through hole.

[0018] The beneficial effects of the embodiments of the present invention are:

[0019] In summary, for the planetary reduction gearbox of the electric vehicle provided in this embodiment, the front housing is connected to the rear housing, the blocking member is provided on the front housing, the ring gear is assembled into the rear housing, one side of which abuts against the inner wall of the rear housing, and the other side abuts against the blocking member on the front housing. In this way, the ring gear is limited by both the inner wall of the rear housing and the blocking member, and the position of the ring gear in its axial direction is firm. There is no need to set a snap ring for limiting the ring gear, and thus there is no need to set an annular groove for assembling the snap ring on the inner wall of the rear housing, which reduces the manufacturing difficulty of the rear housing, reduces the manufacturing cost, and there is no need to locally thicken the rear housing to strengthen the strength at the position where the annular groove is provided. The rear housing is light in weight and small in size, which is convenient for assembly. The blocking member blocks at least part of the area of the exhaust hole in the radial direction of the ring gear. During the operation of the reduction gearbox, when the oil moves towards the position where the exhaust hole is located under the action of centrifugal force, it can be effectively blocked by the blocking member, thereby preventing the oil from leaking directly from the exhaust hole and improving safety. At the same time, since there is a ventilation structure provided on the blocking member, the high-pressure gas in the accommodation cavity can smoothly enter the exhaust hole from the ventilation structure and be discharged from the exhaust hole, reducing the internal air pressure of the reduction gearbox and improving safety. In this way, the blocking member integrates two functions of limiting the inner ring gear and blocking the oil of the exhaust hole, simplifies the structure, reduces the assembly difficulty, and saves the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic cross-sectional structure view of a perspective of the planetary reduction gearbox of the electric vehicle according to an embodiment of the present invention;

[0022] Figure 2 is Figure 1 a partial enlarged structure view in;

[0023] Figure 3 It is a schematic cross-sectional structure view of another perspective of the planetary reduction gearbox of the electric vehicle according to an embodiment of the present invention;

[0024] Figure 4 It is a schematic three-dimensional structure view of the cooperation between the front housing and the blocking member according to an embodiment of the present invention;

[0025] Figure 5 It is a schematic cross-sectional structure view of the cooperation between the front housing and the blocking member according to an embodiment of the present invention;

[0026] Figure 6 It is a schematic plan structure view of the cooperation between the front housing and the blocking member according to an embodiment of the present invention;

[0027] Figure 7 This is a schematic structural diagram of the rear box body of the embodiment of the present invention.

[0028] Icon:

[0029] 001 - Accommodation cavity; 002 - Horizontal center line; 003 - Exhaust cavity; 004 - Counterclockwise direction; 100 - Front box body; 101 - Front box oil storage area; 110 - Fixing hole; 120 - Bearing seat; 121 - Oil inlet; 200 - Rear box body; 201 - Rear box oil storage area; 210 - Exhaust hole; 220 - Breather cap; 230 - Annular limiting platform; 240 - Oil through groove; 300 - Ring gear; 400 - Stopper; 410 - Ventilation structure; 420 - Exhaust groove; 430 - First guiding inclined surface; 440 - Oil through port; 500 - Oil retaining structure; 510 - Second guiding inclined surface. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0032] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0034] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0035] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "arranged", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] Currently, in order to assemble the internal gear ring, an annular groove needs to be provided on the inner wall of the rear housing. After the internal gear ring is inserted into the rear housing, a snap ring is arranged in the annular groove, so as to use the combined action of the snap ring and the rear housing to limit the position of the internal gear ring. And, a breather cap is provided on the rear housing, and the breather cap can discharge high-pressure gas during the operation of the gearbox. Since there is oil in the gearbox, in order to prevent the oil from directly acting on the breather cap and leaking from the breather cap, an oil baffle is provided at the breather cap. In the prior art, since an annular groove is provided on the rear housing to assemble the snap ring, the wall thickness of the rear housing at the annular groove is relatively thin. In order to meet the structural strength requirements, an annular reinforcing rib needs to be provided on the outside of the rear housing corresponding to the annular groove. In this way, the weight is increased, and the volume of the rear housing is increased, which is inconvenient for assembly. Moreover, the snap ring and the oil baffle are independent structures and need to be assembled separately, which increases the assembly difficulty and raises the manufacturing cost.

[0037] Please refer to Figures 1-7 , in view of this, the designer designed an electric vehicle planetary reduction gearbox, which integrates the position-limiting function of the internal gear ring 300 and the oil baffle structure 500 of the breather cap 220, simplifies the structure, reduces the assembly difficulty, and reduces the manufacturing cost. Moreover, the rear housing 200 does not need to be modified redundantly, has strong versatility, and is light in weight.

[0038] Please refer to Figure 1 and Figure 4, in this embodiment, the planetary reduction gearbox of the electric vehicle includes a front housing 100, a rear housing 200, a ring gear 300, and a baffle 400. The front housing 100 is connected to the rear housing 200, and the two jointly define an accommodation cavity 001. The rear housing 200 is provided with an exhaust hole 210 communicating with the accommodation cavity 001, and a breather cap 220 is installed at the exhaust hole 210; the baffle 400 is connected to the front housing 100 and extends into the accommodation cavity 001, and a ventilation structure 410 communicating with the accommodation cavity 001 is provided on the baffle 400; the ring gear 300 is located in the accommodation cavity 001, one side of the ring gear 300 abuts against the inner wall of the rear housing 200, and the other side abuts against the baffle 400; the baffle 400 shields at least a part of the area of the exhaust hole 210 in the radial direction of the ring gear 300.

[0039] The planetary reduction gearbox of the electric vehicle provided in this embodiment has at least the following advantages:

[0040] The ring gear 300 is clamped between the inner wall of the rear housing 200 and the baffle 400. The baffle 400 is directly inserted into the rear housing 200, there is no need to set an annular groove in the rear housing 200, and there is no need to modify the rear housing 200. The rear housing 200 is light in weight and has strong versatility. Moreover, the baffle 400 is provided with a ventilation structure 410, and the baffle 400 can block the oil splashing towards the exhaust hole 210 during the operation of the gearbox, thereby avoiding oil leakage from the exhaust hole 210. And the high-pressure gas in the accommodation cavity 001 can smoothly enter the exhaust hole 210 from the ventilation structure 410, effectively reducing the internal air pressure of the accommodation cavity 001 and ensuring the safety of operation. In this way, the baffle 400 integrates two functions of limiting the inner ring gear 300 and blocking oil at the exhaust hole 210, simplifies the structure, reduces the assembly difficulty, and saves the manufacturing cost.

[0041] Please refer to Figures 4-6 , in this embodiment, optionally, the front housing 100 is a disc structure. A plurality of fixing holes 110 are uniformly arranged at intervals near the outer edge of the front housing 100. The fixing holes 110 are used for passing bolts, and the bolts can be screwed with the rear housing 200 to realize the fixed connection between the front housing 100 and the rear housing 200. A through hole for passing the motor shaft is provided at the middle position of the front housing 100. The front housing 100 has a first plate surface and a second plate surface arranged oppositely. The first plate surface is attached to the rear housing 200. A bearing seat 120 is provided on the first plate surface. The bearing seat 120 is coaxially arranged with the through hole, and the through hole is located in the area surrounded by the bearing seat 120. A bearing connected to the planet carrier is installed in the bearing seat 120. At the same time, an oil inlet 121 is provided on the bearing seat 120. The oil inlet 121 is located above the horizontal center line 002 of the front housing 100, where the horizontal center line 002 takes Figure 1 the perspective as a reference.

[0042] Optionally, the stopper 400 is an annular member. The stopper 400 is disposed on the first surface, and the bearing seat 120 is located within the area surrounded by the stopper 400. The stopper 400 is coaxially arranged with the front housing 100. Since the stopper 400 is an annular member, the contact area between the stopper 400 and the gear ring 300 is large, and the limiting effect of the stopper 400 on the gear ring 300 is better.

[0043] Please refer to Figure 1 , Figure 2 and Figure 4 , furthermore, an exhaust groove 420 is provided on the outer peripheral surface of the stopper 400. The exhaust groove 420 is an annular groove, and the ventilation structure 410 is provided as a through hole. The through hole is disposed at the bottom wall of the annular groove. The through hole is a circular hole and is arranged along the radial direction of the stopper 400. And, after the front housing 100 and the rear housing 200 are assembled, the ventilation structure 410 has a spacing from the exhaust hole 210 in the circumferential direction of the gear ring 300, or, the ventilation structure 410 can also have a spacing from the exhaust hole 210 in the axial direction of the gear ring 300, or, the ventilation structure 410 has a spacing from the exhaust hole 210 both in the axial direction and the circumferential direction of the gear ring 300. A oil through hole 440 is also provided on the stopper 400. When the stopper 400 is inserted into the rear housing 200, the oil through hole is located below the oil inlet 121. The outer peripheral surface of the stopper 400 contacts the inner wall surface of the rear housing 200. The stopper 400 and the rear housing 200 form an annular exhaust cavity 003 at the position where the annular groove is located. When the gas in the accommodation cavity 001 enters the annular groove from the ventilation structure 410 and then enters the exhaust hole 210 to be discharged, the pressure of the gas decreases after entering the annular groove, thereby reducing the impact force on the breather cap 220 at the exhaust hole 210, and the breather cap 220 is not easily damaged. At the same time, during the operation of the speed reducer, since some oil will be carried to the ventilation structure 410 along with the gas, the gas and oil mixture passing through the ventilation structure 410 enters the annular groove together. Since the ventilation structure 410 has a spacing from the exhaust hole 210, the oil will not directly splash to the breather cap 220 and is not easily leaked from the breather cap 220. And, since the pressure of the gas-liquid mixture decreases after entering the annular groove from the ventilation structure 410, the oil is not easily moved to the position where the breather cap 220 is located along with the air flow, which also serves the purpose of reducing oil leakage. The oil entering the annular groove flows along the annular groove to the lower place under the action of gravity and enters the front box oil storage area 101 from the oil through hole 440 at the bottom of the stopper 400. The oil is not easily accumulated between the stopper 400 and the breather cap 220, thereby further avoiding oil leakage from the breather cap 220.

[0044] Please refer to Figure 6, Further, a first guiding inclined surface 430 is provided on the inner circumferential surface of the blocking member 400. The cross-sectional area of the first guiding inclined surface 430 gradually increases from the side close to the front box body 100 to the other side. The first guiding inclined surface 430 is used to guide the oil to the box wall of the front box body 100, so that the oil enters the bearing seat 120 through the oil inlet 121 to lubricate the bearing in the bearing seat 120. During the operation of the speed reducer, driven by components such as the planet carrier, the oil makes a corresponding rotational movement. In order to facilitate the oil to enter the oil inlet 121, an oil blocking structure 500 is provided between the blocking member 400 and the bearing seat 120. The oil blocking structure 500 is an oil blocking rib. One end of the oil blocking rib is attached to the blocking member 400, and the other end is attached to the bearing seat 120. And the oil blocking rib is located at the oil inlet 121, and the oil blocking rib has a second guiding inclined surface 510. When the speed reducer is in the normal operating position, the height of the side of the second guiding inclined surface 510 close to the blocking member 400 is higher than the height of the side of the second guiding inclined surface 510 close to the bearing seat 120, and the oil blocking rib is located in front of the oil inlet 121 in the counterclockwise direction 004, and the ventilation structure 410 is located in front of the oil blocking rib in the counterclockwise direction 004. When the oil rotates counterclockwise, it can be blocked by the oil blocking rib and then guided to the oil inlet 121 through the second guiding inclined surface 510, so that more oil enters the bearing seat 120, improving the lubrication effect. It should be understood that during the forward movement of the vehicle, the planet carrier in the gearbox rotates counterclockwise, and a large amount of oil rotates counterclockwise driven by the planet carrier, so it is blocked by the second guiding inclined surface 510 and guided from the oil inlet 121 into the bearing seat 120. A large amount of oil is blocked by the oil blocking rib and will not enter the ventilation structure 410.

[0045] In this embodiment, it should be noted that the front box body 100, the blocking member 400, the bearing seat 120 and the oil blocking structure 500 can be of an integral structure.

[0046] Please refer to Figure 7 , In this embodiment, optionally, an annular limiting platform 230 is provided inside the rear box body 200. After the ring gear 300 is embedded in the rear box body 200, it abuts against the annular limiting platform 230. In this way, the annular limiting platform 230 and the blocking member 400 cooperate together to realize the assembly of the ring gear 300.

[0047] Please refer to Figure 1 or Figure 3, Further, the rear housing 200 has a rear housing oil storage area 201, and an oil passage groove 240 located in the rear housing oil storage area 201 is further provided on the inner wall of the rear housing 200. The oil passage groove 240 penetrates through the annular limiting platform 230. After the front housing 100 and the rear housing 200 are assembled, the front housing oil storage area 101 is communicated with the rear housing oil storage area 201. Specifically, the front housing oil storage area 101 is communicated with the rear housing oil storage area 201 through an oil passage port 440 and the oil passage groove 240. When the vehicle moves forward or backward, the lubricating oil inside the gearbox continuously splashes towards one side along the axial direction (i.e., splashes towards the front housing 100 or towards the rear housing 200), resulting in the lubricating oil quantity on the axial splashing side being much larger than that on the axial non-splashing side; at the same time, the working oil level on the axial non-splashing side is too low, far lower than that on the axial splashing side, forming an oil level difference, which easily causes the axial non-splashing side to be unable to fully stir the oil for splash lubrication. In this embodiment, by communicating the front housing oil storage area 101 and the rear housing oil storage area 201, the working oil levels on the axial splashing side and the axial non-splashing side are communicated, avoiding the situation that the working oil level on the axial non-splashing side is too low, resulting in the axial non-splashing side being unable to fully stir the oil for splash lubrication, and making the gearbox operate more stably and reliably.

[0048] The planetary reduction gearbox for electric vehicles provided in this embodiment integrates the limiting of the internal gear ring 300 and the oil retaining structure 500 of the breather cap 220, simplifies the structure, reduces the assembly difficulty, and reduces the manufacturing cost. Moreover, the rear housing 200 does not need to be modified redundantly, has strong versatility, and is light in weight.

[0049] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electric vehicle planetary reduction gearbox, characterized in that, Comprising: A front box body, a rear box body, a gear ring and a baffle. The front box body is connected to the rear box body and the two jointly define an accommodation cavity. The rear box body is provided with an exhaust hole communicating with the accommodation cavity. The baffle is connected to the front box body and extends into the accommodation cavity. The baffle is provided with a ventilation structure communicating with the accommodation cavity. The gear ring is located in the accommodation cavity. One side of the gear ring abuts against the inner wall of the rear box body, and the other side abuts against the baffle. The baffle shields at least a part of the area of the exhaust hole in the radial direction of the gear ring. The baffle is arranged as an annular member, and the ventilation structure is arranged as a through hole penetrating the baffle. An exhaust groove is arranged on the outer peripheral surface of the baffle. The ventilation structure is arranged as a through hole penetrating the bottom wall of the exhaust groove. The outer peripheral surface of the baffle contacts the inner wall of the rear box body to define an exhaust cavity at the exhaust groove. A bearing seat is arranged on the front box body. The bearing seat is located on one side of the baffle close to the center of the front box body, and an oil inlet is arranged on the bearing seat.

2. The electric vehicle planetary reduction gearbox according to claim 1, characterized in that: The exhaust groove is arranged as an annular groove.

3. The electric vehicle planetary reduction gearbox according to claim 1 or 2, characterized in that: The ventilation structure and the exhaust hole have a spacing in the axial direction of the gear ring.

4. The electric vehicle planetary reduction gearbox according to claim 1, characterized in that: A first guiding inclined surface is arranged on the inner peripheral surface of the baffle. The cross-sectional area of the first guiding inclined surface gradually increases from one side close to the front box body to the other side. The first guiding inclined surface is used to guide the oil to the box wall of the front box body so that the oil enters the bearing seat through the oil inlet.

5. The electric vehicle planetary reduction gearbox according to claim 4, characterized in that: An oil blocking structure is arranged between the baffle and the bearing seat. The oil blocking structure has a second guiding inclined surface. The height of the second guiding inclined surface on the side close to the baffle is higher than the height of the side close to the bearing seat. The side of the second guiding inclined surface close to the bearing seat is located at the oil inlet. The second guiding inclined surface is used to guide the oil from the high side to the low side under the action of gravity so that the oil enters the oil inlet.

6. The electric vehicle planetary reduction gearbox according to claim 1, characterized in that: The front box body is provided with a front box oil storage area, and the rear box body is provided with a rear box oil storage area. The front box oil storage area communicates with the rear box oil storage area, and the ventilation structure is located above the front box oil storage area.

7. The electric vehicle planetary reduction gearbox according to claim 6, characterized in that: An annular limiting platform is arranged on the inner wall of the rear box body. One side of the gear ring away from the front box body abuts against an annular end face of the annular limiting platform. An oil through groove is also arranged on the inner wall of the rear box body and is located in the rear box oil storage area. The oil through groove penetrates the annular limiting platform. An oil through hole located in the front box oil storage area is arranged on the baffle, and the oil through groove communicates with the oil through hole.

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