Differential mechanism

Abstract

The utility model provides a differential mechanism. The differential mechanism comprises an input gear, two shells and an output gear. The two shells are welded to the two axial sides of the input gear respectively and jointly form a working cavity. The shell is provided with an opening communicated with the working cavity. The output gear is rotatably supported to the housing and is configured to be able to enter and exit the working chamber via the opening. In this way, the differential mechanism can have low production and after-sales maintenance costs.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of transmission mechanisms, and more particularly to a differential. BACKGROUND

[0002] According to the structure of the housing, the existing differential can be divided into two types: integrated differential and split differential.

[0003] For the integrated differential, for example, Chinese patent application for invention CN111051738A discloses a manufacturing method of a differential device. The differential housing is a hollow cylindrical housing with a built-in differential mechanism, and the upper part has an opening part that can assemble the differential mechanism. Due to the complex structure of the differential housing, the differential housing needs to be cast by, for example, sand casting process. Although the differential mechanism can be repeatedly disassembled through the opening part, the manufacturing of the differential housing requires complex molds and pouring systems. On the one hand, the precision of the cast differential housing is poor, and casting defects are easy to occur. On the other hand, the cast differential housing needs to be measured and adjusted for dynamic balance. In addition, the material of the differential housing is generally low-strength ductile cast iron, which makes the size of the differential housing larger and the weight heavier. Moreover, the differential housing and the differential gear ring are usually made of different materials, for example, the differential gear ring can be made of steel. The weldability between different materials is poor, which makes the differential housing and the differential gear ring prone to welding failure due to insufficient welding strength.

[0004] For the split differential, for example, Chinese utility model patent CN216975699U discloses a differential assembly and a vehicle. The differential housing includes a first housing and a second housing arranged on both sides of the power output gear. The outer circumferential surface of the first housing and the second housing is respectively limited and can be welded and fixed in the positioning stop. Such design makes the structure of the differential housing simple, and the differential housing can be processed by stamping or forging using steel such as 40Cr, so that the differential housing can have better strength and smaller size and weight. However, due to the limitation of the processing technology, the differential housing cannot be provided with the above-mentioned opening part. After the differential housing and the power output gear are welded, the planetary gear and the half shaft gear cannot be disassembled. In addition, the heat and deformation generated during welding will affect the precision of the gears, which will affect the yield of the differential assembly. In such a case, once the differential assembly fails to pass the EOL test or fails in use, the entire differential assembly can only be scrapped, thereby bringing high production and after-sales maintenance costs. SUMMARY

[0005] The present disclosure is made in view of the above state of the art. The purpose of the present disclosure is to provide a differential that can overcome or alleviate at least one of the disadvantages described in the background.

[0006] To achieve the above object, the present disclosure can adopt the technical scheme as follows.

[0007] The present disclosure provides a differential gear comprising: an input gear; two housings respectively welded on axial two sides of the input gear and jointly configured to form a working cavity, the housing being provided with an opening in communication with the working cavity; and an output gear rotatably supported on the housing and configured to be capable of entering and leaving the working cavity via the opening.

[0008] In an optional scheme, the housing is coaxially arranged with the input gear, and the opening is arranged at an axial end of the housing away from the input gear.

[0009] In another optional scheme, the differential gear further comprises: a plurality of planetary gear shafts separated from each other, the planetary gear shafts being limited by the housings and the input gear; and a plurality of planetary gears respectively mounted to the plurality of planetary gear shafts, the planetary gears being engaged with the output gear in the working cavity and being configured to be capable of entering and leaving the working cavity via the opening.

[0010] In another optional scheme, a distal end of the planetary gear shaft is provided with two protrusions respectively protruding to axial two sides of the differential gear, the protrusions being clamped between the housings and the input gear in the axial direction of the differential gear, and the planetary gear shaft being clamped between the two housings in the axial direction of the differential gear.

[0011] In another optional scheme, the plurality of planetary gear shafts comprises a pair of planetary gear shafts oppositely arranged in the radial direction of the differential gear, and the minimum spacing between the pair of planetary gear shafts is greater than the maximum axial dimension of the planetary gears.

[0012] In another optional scheme, the differential gear further comprises a bearing supporting the housing to rotate in the working cavity.

[0013] In another optional scheme, the bearing is configured to be capable of entering and leaving the working cavity via the opening.

[0014] In another optional scheme, the differential gear further comprises a support element separating the housing and the output gear, and the housing is rotatably connected to the output gear via the support element.

[0015] In another optional scheme, the support element is provided with an oil guide groove configured to supply lubricating oil to a rotating pair composed of the output gear and the support element.

[0016] In another alternative, the support element is configured to be able to enter and exit the working cavity via the opening.

[0017] With the above technical solution, the output gear can be repeatedly installed and disassembled after the input gear is welded to the housing, so that the differential can have lower production and after-sales maintenance costs. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic view of a differential according to one embodiment of the present disclosure.

[0019] Figure 2 is an exploded view of the differential in Figure 1

[0020] Figures 3 to 5 is a cross-sectional view of the differential in Figure 1

[0021] Figure 6 is a schematic view of an input gear of the differential in Figure 1

[0022] Figure 7 and Figure 8 is a schematic view of a planet gear shaft of the differential in Figure 1

[0023] Figure 9 and Figure 10 is a schematic view of a housing of the differential in Figure 1

[0024] Figure 11 and Figure 12 is a schematic view of a support element of the differential in Figure 1

[0025] REFERENCE NUMERALS

[0026] 30 differential

[0027] 32 input gear

[0028] 34 housing

[0029] 36 output gear

[0030] 38 working cavity

[0031] 40 opening

[0032] 42 planet gear

[0033] 44 bearing

[0034] 46 support element

[0035] 48 oil guide groove​​​​​​

[0036] 50 planetary gear shaft

[0037] 51 bulge

[0038] 52 Large diameter end

[0039] 54 Small diameter end

[0040] 56 end face

[0041] 58 mounting slots

[0042] 60 gasket

[0043] 62 oil guide hole

[0044] 64 load-bearing plane

[0045] 66 spline

[0046] 68 ribs DETAILED DESCRIPTION

[0047] like Figure 1 As shown, an embodiment of the present disclosure provides a differential 30 .

[0048] like Figures 2 to 5 As shown, the differential 30 includes an input gear 32, two housings 34, and an output gear 36. The two housings 34 are welded to either axial side of the input gear 32 and together define a working chamber 38. The housings 34 are provided with openings 40 that communicate with the working chamber 38. The output gear 36 is rotatably supported by the housings 34 and is configured to enter and exit the working chamber 38 through the openings 40.

[0049] In the above technical solution provided by the embodiment of the present disclosure, the output gear 36 can be repeatedly installed and disassembled after the input gear 32 is welded to the housing 34, so that the differential 30 can have lower production and after-sales maintenance costs.

[0050] In some examples, housing 34 is a forging.

[0051] In some examples, the housing 34 is made of steel, such as 40Cr steel.

[0052] In some examples, output gear 36 is a bevel gear.

[0053] In some examples, such as Figures 2 to 4 As shown, the output gear 36 is arranged coaxially with the input gear 32 .

[0054] In some examples, such as Figure 3 and Figure 4As shown, the output gear 36 is provided with splines 66 for splined connection of the output gear 36 with the half shafts. For example, the splines 66 can be internal splines.

[0055] In some examples, as shown in Figure 3 , Figure 4 , Figure 9 and Figure 10 , the housing 34 is provided with oil guide holes 62 configured to allow lubricating oil to enter the working cavity 38.

[0056] In some examples, as shown in Figure 9 and Figure 10 , the plurality of oil guide holes 62 are evenly spaced in the circumferential direction of the housing 34.

[0057] In some examples, as shown in Figures 2 to 4 , Figure 9 and Figure 10 , the housing 34 is arranged coaxially with the input gear 32, and the opening 40 is provided at an axial end of the housing 34 away from the input gear 32, i.e. at an axially outer end away from the center of the differential. In this way, an existing end opening on the housing 34 can be used as the opening 40, without the need for additional processing steps when machining the housing 34, thereby further reducing the production cost of the differential 30.

[0058] In some examples, as shown in Figures 2 to 4 , Figure 9 and Figure 10 , the housing 34 is substantially cylindrical. One axial end (axially inner end) of the housing 34 is a large-diameter end 52, and the other axial end (axially outer end) of the housing 34 is a small-diameter end 54. The large-diameter end 52 is joined to the input gear 32, and the axial opening of the small-diameter end 54 is formed as the opening 40.

[0059] In some examples, as shown in Figures 2 to 5 , the differential 30 further comprises a planetary gear 42. The planetary gear 42 is engaged with the output gear 36 within the working cavity 38, and is configured to be able to enter and exit the working cavity 38 via the opening 40. In this way, the planetary gear 42 can be repeatedly installed and removed after the input gear 32 is welded to the housing 34, thereby further reducing the cost of the differential 30.

[0060] In some examples, as shown in Figures 2 to 5 , the planetary gear 42 is a bevel gear.

[0061] In some examples, as shown in Figures 2 to 5 , the axial direction of the planetary gear 42 is orthogonal to the axial direction of the output gear 36.

[0062] In some examples, as shown in Figure 3 and Figure 4As shown, the differential 30 further includes a bearing 44. The bearing 44 supports the housing 34 for rotation within the working cavity 38. In this way, the housing 34 can have a larger size, given a size of the differential 30, so that a larger opening 40 can be provided for facilitating the access of parts to and from the working cavity 38 via the opening 40.

[0063] In some examples, an outer ring of the bearing 44 is fixedly connected to the housing 34, and an inner ring of the bearing 44 is fixedly connected to a housing of a gear box, for example.

[0064] In some examples, as shown in Figure 3 and Figure 4 , the bearing 44 is configured to be accessible to and from the working cavity 38 via the opening 40. In this way, the bearing 44 can be repeatedly installed and removed after the input gear 32 is welded to the housing 34, so that the cost of the differential 30 is further reduced.

[0065] In some examples, as shown in Figures 2 to 4 , Figure 11 and Figure 12 , the differential 30 further includes a support element 46. The support element 46 separates the housing 34 and the output gear 36, and the housing 34 is rotationally connected to the output gear 36 via the support element 46. In this way, the output gear 36 can be supported on the housing 34 with a smaller size, so that the output gear 36 can easily pass through the opening 40.

[0066] In some examples, as shown in Figures 2 to 4 , Figure 11 and Figure 12 , the support element 46 is annular, and coaxially sleeved on the output gear 36.

[0067] In some examples, as shown in Figure 3 and Figure 4 , the support element 46 is disposed between the output gear 36 and the bearing 44. An inner circumferential portion of the support element 46 abuts against the output gear 36, and supports the output gear 36 in the axial and radial directions of the differential 30. An outer circumferential portion of the support element 46 abuts against the housing 34 and the bearing 44, and is limited by the housing 34 and the bearing 44 in the axial direction, and abuts against the housing 34 in the radial direction.

[0068] In some examples, the support element 46 is a stamped part.

[0069] In some examples, the support element 46 is made of steel, for example, can be made of steel with a grade of DC01. In this way, the support element 46 can have sufficient hardness, and no gasket can be provided between the output gear 36 and the support element 46, so that the number of parts of the differential 30 is not increased due to the provision of the support element 46.

[0070] In some examples, as shown in Figure 4 and Figure 12 , the support element 46 is provided with an oil guide groove 48. The oil guide groove 48 is configured to supply lubricating oil to the rotating pair composed of the output gear 36 and the support element 46. In this way, the rotating pair composed of the output gear 36 and the support element 46 can be sufficiently lubricated.

[0071] In some examples, the oil guide groove 48 is configured to be constructed in a stamped manner.

[0072] In some examples, as shown in Figure 3 , Figure 4 and Figure 12 , an end face 56 of the support element abuts against the output gear 36, and the oil guide groove is provided on the end face 56.

[0073] In some examples, as shown in Figure 12 , the oil guide groove 48 extends in the radial direction of the support element 46, and a plurality of oil guide grooves 48 are arranged uniformly in the circumferential direction of the support element 46.

[0074] In some examples, as shown in Figure 3 and Figure 4 , the support element 46 is configured to be able to enter and exit the working cavity 38 via the opening 40. In this way, the support element 46 can be repeatedly installed and disassembled after the input gear 32 and the housing 34 are welded, thereby further reducing the cost of the differential 30.

[0075] In some examples, as shown in Figures 2 to 4 , Figure 7 and Figure 8 , the differential 30 further comprises a planetary gear shaft 50. The planetary gear shaft 50 is disposed between the two housings 34. The distal end (outer end in the radial direction of the differential) of the planetary gear shaft 50 is provided with two protrusions 51. The two protrusions 51 respectively protrude to both sides of the axial direction of the differential, and the housing 34 abuts against the protrusions 51 in the radial direction of the differential. In the axial direction of the planetary gear shaft 50 (radial direction of the differential), the protrusions 51 also abut against the bottom wall (outer wall) of the mounting groove 58 of the input gear 32 described below, so that the planetary gear shaft 50 is positioned in its axial direction (radial direction of the differential) and the axial direction of the differential. In this way, the differential 30 does not need to additionally provide parts for positioning the planetary gear shaft 50, so that the differential 30 can have a smaller number of parts, thereby reducing the weight of the differential 30 and simplifying the assembly process of the differential 30.

[0076] In some examples, as shown in Figures 3 to 5 , the planetary gear 42 is rotatably supported on the planetary gear shaft 50, for example, the planetary gear 42 can be sleeved on the planetary gear shaft 50.

[0077] In some examples, asFigures 3 to 5 As shown, the planetary gear shaft 50 is at least partially located within the working chamber 38.

[0078] In some examples, as shown in FIG. 1, the input gear 32 is ring-shaped, and the planetary gear shaft 50 is disposed radially inward of the input gear 32. Figures 3 to 5 As shown, the two planetary gear shafts 50 are oppositely arranged in the radial direction of the input gear 32 and spaced apart from each other, and the minimum spacing between the two planetary gear shafts 50 is greater than the maximum axial dimension of the planetary gear 42 (here, referring to the dimension in the axial direction of the planetary gear 42 / two planetary gear shafts 50). In this way, the planetary gear 42 can be mounted to the planetary gear shaft 50 via the space between the two planetary gear shafts 50.

[0079] Of course, the number of planetary gear shafts 50 and planetary gears 42 is not limited to two, but can also be three or four or other numbers.

[0080] In some examples, as shown in FIG. 1, the input gear 32 is ring-shaped, and the planetary gear shaft 50 is disposed radially inward of the input gear 32. Figures 3 to 6 As shown, the two planetary gear shafts 50 are oppositely arranged in the radial direction of the input gear 32 and spaced apart from each other, and the minimum spacing between the two planetary gear shafts 50 is greater than the maximum axial dimension of the planetary gear 42 (here, referring to the dimension in the axial direction of the planetary gear 42 / two planetary gear shafts 50). In this way, the planetary gear 42 can be mounted to the planetary gear shaft 50 via the space between the two planetary gear shafts 50.

[0081] In some examples, as shown in FIG. 1, the input gear 32 is ring-shaped, and the planetary gear shaft 50 is disposed radially inward of the input gear 32. Figures 3 to 6 As shown, the inner peripheral portion of the input gear 32 is provided with a mounting groove 58 that receives the planetary gear shaft 50.

[0082] In some examples, as shown in FIG. 1, the input gear 32 is ring-shaped, and the planetary gear shaft 50 is disposed radially inward of the input gear 32. Figure 6 As shown, the mounting groove 58 penetrates the input gear 32 in the axial direction of the input gear 32.

[0083] In some examples, as shown in FIG. 1, the input gear 32 is ring-shaped, and the planetary gear shaft 50 is disposed radially inward of the input gear 32. Figure 5 , Figure 7 and Figure 8 As shown, the outer periphery of the planetary gear shaft 50 is provided with a bearing plane 64. The bearing plane 64 is perpendicular to the circumferential direction of the input gear 32 and abuts against the circumferential wall surface of the mounting groove 58.

[0084] As shown in FIG. 1, the input housing 32 can include annular protrusions 68 that protrude axially to both sides thereof, which can support the housing 34. At the mounting groove 58, the protrusions 68 protrude radially outward, and the protrusions 51 of the planetary gear shaft 50 and the protrusions 68 at other positions are located on the same circumferential surface. In this way, the large-diameter end 52 of the housing 34 is circular and can support the planetary gear shaft 50 via the protrusions 51. When welding, the housing 34 can be welded to the input housing 32. The housing 34 can or can not be welded to the planetary gear shaft 50. Figure 3 Figure 6 In some examples, as shown in FIG. 1, the differential 30 further includes a gasket 60 that separates the housing 34 and the planetary gear 42.

[0085] In some examples, as shown in FIG. 1, the differential 30 further includes a gasket 60 that separates the housing 34 and the planetary gear 42. Figures 2 to 4

[0086] ​​In some examples, as shown in FIG. 1, the differential 30 is assembled on the input gear 32. Figure 3 and Figure 4 The washer 60 is sleeved on the planetary gear shaft 50.

[0087] In some examples, as shown in FIG. 1, the differential 30 is assembled on the input gear 32. Figure 4 Here, the cross section refers to a cross section perpendicular to the axial direction of the input gear 32. In this way, the differential 30 is simple in structure, and some parts in the differential 30 can share a mold, thereby further reducing the cost of the differential 30.

[0088] The differential 30 is assembled by the following steps.

[0089] (i) Positioning the planetary gear shaft 50 on the input gear 32.

[0090] (ii) Welding the housing 34 to the input gear 32, thereby forming the working cavity 38.

[0091] (iii) Placing the washer 60 in the working cavity 38 via the opening 40 and mounting the washer 60 to the planetary gear shaft 50.

[0092] (iv) Placing the planetary gear 42 in the working cavity 38 via the opening 40 and mounting the planetary gear 42 to the planetary gear shaft 50.

[0093] (v) Placing the output gear 36 in the working cavity 38 via the opening 40 and engaging the output gear 36 with the planetary gear 42.

[0094] (vi) Placing the support element 46 in the working cavity 38 via the opening 40.

[0095] (vii) Placing the bearing 44 in the working cavity 38 via the opening 40.

[0096] It should be understood that the above assembly method is a method for assembling the differential 30 for the first time. For the case of assembling the differential 30 for the second time, i.e., the case of assembling the differential 30 after the differential 30 is disassembled, the assembly method of the differential 30 can not include the above steps (i) and (ii).

[0097] In some examples, some of the above steps can be performed simultaneously, for example, steps (iii) and (iv) can be performed simultaneously, or steps (v) and (vi) can be performed simultaneously.

[0098] The order of the above steps is not limited to the given sequence number. For example, in one example, after the washer 60 and the planetary gear 42 are mounted to the planetary gear shaft 50 to form an assembly, the assembly is mounted on the input gear 32, and then the housing 34 is welded to the input gear 32.

[0099] In some examples, the above steps can be performed sequentially in the order given. Of course, some steps can still be performed simultaneously.

[0100] The present disclosure also provides a method of disassembly of a differential 30, the method comprising the steps of:

[0101] (i) removing the bearing 44 from the working chamber 38 via the opening 40.

[0102] (ii) removing the support element 46 from the working chamber 38 via the opening 40.

[0103] (iii) removing the output gear 36 from the working chamber 38 via the opening 40.

[0104] (iv) removing the planet gear 42 from the working chamber 38 via the opening 40.

[0105] (v) removing the spacer 60 from the working chamber 38 via the opening 40.

[0106] In some examples, some steps can be performed simultaneously, for example steps (i), (ii) and (iii) can be performed simultaneously, or steps (iv) and (v) can be performed simultaneously.

[0107] In some examples, the above steps can be performed sequentially in the order given. Of course, some steps can still be performed simultaneously.

[0108] The terminology used by the embodiments of the present disclosure is for the purpose of describing the embodiments of the present disclosure only and is not intended to be limiting of the present disclosure. Unless otherwise defined, technical terms or scientific terms used in the embodiments of the present disclosure shall have the same meaning as is commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first", "second", and similar terms are used herein to describe various elements in the disclosure, and are not intended to denote an order or importance of the elements. Also, the terms "one" and "another" are not intended to denote a quantity of the elements. The terms "comprising", "including", and similar terms are meant to encompass the elements listed thereafter and other elements not specifically listed. The terms "upper", "lower", "left", "right", and similar terms are used to describe relative positions of the elements, and can be changed when the absolute positions of the elements are changed. The term "plurality" means two or more, unless otherwise specified.

[0109] The above merely describes optional embodiments of the present disclosure, and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A differential characterized in that, The differential further comprises: a plurality of planetary gear shafts separated from each other, the planetary gear shafts being limited by the housings and the input gear; and a plurality of planetary gears respectively mounted to the plurality of planetary gear shafts, the planetary gears being engaged with the output gear within the working cavity and being configured to be able to enter and exit the working cavity via the opening. The distal end of the planetary gear shaft is provided with two protrusions, the two protrusions respectively extending to the axial two sides of the differential, the protrusions being clamped between the housings and the input gear in the axial direction of the planetary gear shaft, the planetary gear shaft being clamped between the two housings in the axial direction of the differential. The plurality of planetary gear shafts comprises a pair of planetary gear shafts arranged opposite in the radial direction of the differential, the minimum spacing between the pair of planetary gear shafts being greater than the maximum axial dimension of the planetary gears.

2. The differential of claim 1, wherein The differential further comprises a bearing supporting the housings to rotate within the working cavity.

3. The differential of claim 1 wherein, The bearing is configured to be able to enter and exit the working cavity via the opening. The differential further comprises a support element separating the housings and the output gear, the housings being rotationally connected to the output gear via the support element. The support element is provided with an oil guide groove configured to supply lubricating oil to the rotating pair consisting of the output gear and the support element.

4. The differential of claim 3, wherein, The support element is configured to be able to enter and exit the working cavity via the opening.

5. The differential of claim 3 wherein, ​ 6. The differential according to any one of claims 1 to 5, characterized in that, ​ 7. The differential of claim 6 wherein, ​ 8. The differential according to any one of claims 1 to 5, characterized in that, ​ 9. The differential of claim 8, wherein, ​ 10. The differential of claim 8 wherein, ​

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