Differential with auxiliary gear
By designing a second gear overlapping with the pinion shaft in the differential, the problem of the existing differential being uncontrolled when dealing with different wheel rotation rates is solved, achieving a more stable and simplified assembly process.
Patent Information
- Application Number
- CN202411785498.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-12-20
- Filing Date
- 2024-12-06
- Publication Date
- 2025-06-20
AI Technical Summary
When existing differentials deal with different wheel rotation rates, it is difficult to effectively limit the movement of pinion shafts, resulting in increased structural stability and assembly complexity.
By designing the second gear in the differential housing, it overlaps with the portion of the pinion shaft and overlaps with the inner surface of the second gear by the gear mounting surface, the retaining of the pinion shaft is achieved without additional connectors.
This design reduces the cost and complexity of maintaining pinion shafts, and improves the structural stability and assembly efficiency of the differential.
Smart Images
Figure CN120175818A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure generally relates to a differential with an auxiliary gear. Background Art
[0002] During normal operation of a motor vehicle, it is common for all four wheels not to rotate at the same speed rate. Different wheel rotation rates are most commonly encountered when the vehicle is turning, but can also be caused by braking or uneven road surface conditions. A differential is used to accommodate different wheel rotation rates and has various gears, including a pinion mounted on a pinion shaft. The pinion shaft is coupled to the differential housing by a clip or fastener installed during assembly of the differential. Summary of the Invention
[0003] In at least some embodiments, a vehicle differential includes: a housing; an input gear mounted to the housing such that the housing and the input gear rotate together; a pinion shaft mounted in the housing; a first pinion and a second pinion mounted on the pinion shaft; a first side gear and a second side gear within the housing and engaging the pinions; and a second gear mounted to the housing such that the second gear and the housing rotate together. A portion of the second gear overlaps at least a portion of the pinion shaft and restricts movement of the pinion shaft relative to the housing.
[0004] In at least some embodiments, the housing includes at least one pinion shaft opening through which the pinion shaft is received into the housing, and wherein the second gear overlaps at least a portion of the at least one pinion shaft opening. In at least some embodiments, the housing includes two pinion shaft openings, and each end of the pinion shaft is received in a respective one of the pinion shaft openings, and the second gear overlaps at least a portion of each end of the pinion shaft.
[0005] In at least some embodiments, the housing includes a gear mounting surface, and the second gear includes an inner surface received on at least a portion of the gear mounting surface. In at least some embodiments, the second gear has a rotational axis, and the inner surface axially overlaps the pinion shaft by at least 0.5 mm. In at least some embodiments, the inner surface overlaps the pinion shaft by at least 10% of the diameter of the pinion shaft. In at least some embodiments, the housing includes two pinion shaft openings, and each end of the pinion shaft is received in a respective one of the pinion shaft openings, and wherein the gear mounting surface has a central axis, and the gear mounting surface has a smaller axial extent in the region of the pinion shaft opening than in at least some regions circumferentially spaced apart from the pinion shaft opening. In at least some embodiments, the inner surface has a diameter that is 3 mm or less greater than the axial length of the pinion shaft.
[0006] In at least some embodiments, the gear mounting surface extends circumferentially around the exterior of the housing and extends parallel to the axis of rotation of the input gear.
[0007] In at least some embodiments, the input gear and the second gear are coaxial.
[0008] In at least some embodiments, the second gear has an axis of rotation and includes teeth extending radially outwardly, and at least a portion of the teeth axially overlap the pinion shaft.
[0009] In at least some embodiments, the second gear has an axis of rotation and outwardly extending teeth, and the teeth are axially centered on the second gear. In at least some embodiments, the second gear is symmetric about the axis of the second gear.
[0010] In at least some embodiments, the pinion shaft is held by the second gear relative to the housing without being connected to either the housing or another holding member of the pinion shaft.
[0011] In at least some embodiments, the input gear and the second gear are coaxial and the second gear is axially offset from the input gear.
[0012] In at least some embodiments, the housing includes at least one window that opens into the interior of the housing, and one or more gears are mounted into the interior through the at least one window, and the second gear overlaps a portion of the at least one window. Description of the Drawings
[0013] The following detailed description of the preferred embodiments and best mode will be set forth with reference to the drawings, in which:
[0014] Figure 1 is a perspective view of a differential including an input gear and an auxiliary or second gear;
[0015] Figure 2 is Figure 1 another perspective view of the differential of
[0016] Figure 3 is a side view of the differential;
[0017] Figure 4 is an end view of the differential;
[0018] Figure 5 is generally along Figure 4 sectional view taken along line 5-5 of
[0019] Figure 6 is generally along Figure 4Cross-sectional view taken along line 6-6. DETAILED DESCRIPTION
[0020] Referring more particularly to the drawings, automotive differential 10 may be disposed in an automotive driveline, for example, between side axles of a front axle, between side axles of a rear axle, or between a front axle and a rear axle. Generally, differential 10 may have different designs and configurations, depending on the architecture of the larger AWD automotive driveline, upstream and downstream driveline components, packaging requirements, torque output requirements, and other possible influences. In the embodiment presented in the drawings, differential 10 includes a housing 12, a first pinion 14, a second pinion 16, a first side gear 18, and a second side gear 20; additionally, more, fewer, and / or different components may be included in other embodiments. For example, differential 10 may have more than two pinions and may have three or four or more pinions. Input gear 22 (shown as a hypoid ring gear) is fixed to the exterior 24 of the housing such that it is engaged in use by an upstream output gear, such as an output gear of a transmission in a front axle layout or an output gear of a propeller shaft of an automotive driveline. When driven, housing 12 rotates about axis 26. Inside 28, housing 12 defines a cavity adapted to receive pinions 14, 16 and side gears 18, 20 therein.
[0021] First pinion 14 and second pinion 16, and first side gear 18 and second side gear 20 interact with each other to achieve the function of an automotive differential. Each of gears 14, 16, 18, 20 has teeth formed around its exterior. In this embodiment, in the assembly and use of automotive differential 10, the teeth of first pinion 14 engage the teeth of first side gear 18 and second side gear 20, and similarly, the teeth of second pinion 16 engage the teeth of first side gear 18 and second side gear 20. As Figure 5 shown, first pinion 14 and second pinion 16 include channels defining inner surfaces 30 of pinions 14, 16 through which pinion shafts 32 extend. Pinion shafts 32 have central axes 34 and are mounted in pinion shaft openings 36 in opposite side portions of differential housing 12. First side gear 18 has a set of internal splines 38 for connection to a first side axle, the ends of which are received in opening 40 of housing 12, and second side gear 20 has a set of internal splines 42 for connection to a second side axle, the ends of which are received in openings 44 in housing 12 that are generally opposite. As Figure 1 and Figure 2 shown, pinion washers 45 may be seated between housing 12 and first pinion 14 and second pinion 16, and side gear washers 46 may be located between housing 12 and first side gear 18 and second side gear 20.
[0022] The differential housing 12 may include a gear mounting surface 48 for an auxiliary or second gear 50 of the differential 10. In at least some embodiments, the gear mounting surface 48 extends circumferentially and axially and may be a cylindrical surface arranged parallel to the axis 26 and axially offset from and coaxial with the input gear 22. As for example by comparing Figure 5 and Figure 6 shown, the axial extent or length of the gear mounting surface 48 may vary along its circumferential length due to, for example, an opening or window 52 through which its gears 14 - 20 may be inserted into the housing 12 and a pinion shaft opening 36 extending through the exterior of the differential housing 12. The gear mounting surface 48 includes a first axial end 54 which, in at least some embodiments, may be circumferentially continuous and positioned axially spaced from the pinion shaft opening 36. A radially extending stop surface 56 may be located at or adjacent to the first axial end 54 of the gear mounting surface 48 and may be arranged to engage the second gear 50 when fully installed, as pointed out in more detail below. As Figure 6 shown, in at least some embodiments, a portion of the gear mounting surface 48 axially extends a distance sufficient to be completely below or to support the radially inner surface 58 of the second gear 50. That is, if desired, the distance between the first axial end 54 and the second axial end 60 of the gear mounting surface 48 may be equal to or greater than the axial extent of the inner surface 58 of the second gear 50. As noted, the second axial end 60 of the gear mounting surface 48 may be circumferentially discontinuous and interrupted by the pinion shaft opening 36 and one or more windows 52 of the differential housing 12. Although shown parallel to the axis 26, the gear mounting surface 48 may be oriented as needed to receive at least a portion of the second gear 50 and facilitate connection of the second gear 50 to the differential housing 12.
[0023] As Figure 1 and Figures 3 to 6 shown, the auxiliary or second gear 50 is carried by the differential 10 and may be fixed to the differential housing 12 for rotation therewith without relative rotation therebetween. In at least some embodiments, the second gear 50 is concentric with the input gear 22 about the axis 26 and at least a portion of the radially inner surface 58 of the second gear 50 axially overlaps the gear mounting surface 48 of the differential housing 12. In at least some embodiments, the second gear 50 is coupled to the differential housing 12 by a friction or interference fit between the inner surface 58 and the gear mounting surface 48, although the second gear 50 may be fixed to the housing 12 in other ways, such as but not limited to welding, fasteners (clips, bolts or others), adhesives, hot riveting, etc. In this way, the second gear 50 rotates with the differential housing 12.
[0024] In the illustrated example, the second gear 50 is a spur gear having circumferentially spaced teeth 62 and a tooth line 68 parallel to axis 26( Figure 5 ), the teeth 62 extending radially or substantially radially outward from a base 64 to a free end or tip 66 located radially outside the base 64. The face 70 of each tooth 62 extends radially and axially and is circumferentially spaced from the face of an adjacent tooth 62. The free end 66 may define the radially outermost portion of the second gear 50, with the gap between adjacent teeth 62 opening to the radially outer portion of the second gear 50. Of course, other gear types, such as helical gears or bevel gears, may be used by way of several non-limiting examples.
[0025] As Figure 5 and Figure 6 best shown in, the inner surface 58 of the second gear 50 may extend to a first side 74 and a second side 76 axially spaced from the first side 74. The inner surface 58 may be cylindrical and may be a right circular cylinder at a constant radius from axis 26. At least a portion of the inner surface 58 including the first side 74 axially overlaps and may be connected to the gear mounting surface 48. In addition, at least a portion of the inner surface 58 radially overlaps the pinion shaft opening 36 and the pinion shaft 32 and may overlap a portion of one or more of the windows 52. In at least some embodiments, a portion of the inner surface 58 of the second gear 50 is located radially outside and axially overlaps the two ends 78, 80( Figure 5 ) of the pinion shaft 32. Thus, the pinion shaft 32 may be held in the differential housing 12 by the overlapping second gear 50.
[0026] In at least some embodiments, the inner surface 58 axially overlaps the pinion shaft 32 by at least 0.5 mm, may axially overlap the entire pinion shaft 32, and in at least some embodiments, the inner surface 58 overlaps the pinion shaft 32 by at least 10% of the diameter of the pinion shaft 32, the pinion shaft 32 may include chamfers at its ends. In at least some embodiments, the diameter of the inner surface 58 of the second gear 50 is no more than 3 mm greater than the axial length between the ends 78, 80 of the pinion shaft 32, thereby allowing limited movement of the pinion shaft 32 along its axis 34 and relative to the differential housing 12 and the second gear 50. In at least some embodiments, the inner surface diameter of the pinion shaft 32 and the cross length 81( Figure 5) The difference therebetween is 0.5 mm or less, and in at least some embodiments, the difference is 0.3 mm or less. Some of these embodiments include a friction fit between the inner surface 58 and the pinion shaft ends 78, 80. The spanning length 81 is defined by a straight line extending through the center 83 of the pinion shaft 32 to diametrically opposite positions at the opposite ends 78, 80 of the shaft.
[0027] In at least some embodiments, no other couplings or connectors are required between the pinion shaft 32 and the differential housing 12. For example, some pinion shafts are held in the differential housing 12 by pins that extend radially into openings in the pinion shaft, and / or C-shaped or similar clips are received in grooves formed in one or both of the pinion shaft and the housing 12, and / or the ends of the pinion shaft are pressed or otherwise frictionally fit into the pinion shaft openings of the differential housing 12. In this way, the pinion shaft 32 can be a simple shaft such as a straight cylindrical shaft without any openings or grooves to receive components (e.g., pins / clips / fasteners) for holding the position of the pinion shaft, and thus, the pinion shaft 32 can be manufactured in less time and at lower cost. Although these connection modes or means are not required, one or more of them can be used in combination with the second gear 50 as the main retainer of the pinion shaft 32 if needed. For example, to facilitate holding the position of the pinion shaft in the housing 12 prior to assembling the second gear 50 to the differential housing 12, if needed, the ends 78 or 80 of the pinion shaft 32 can be frictionally fit into the pinion shaft opening 36, even if the friction fit is minimal and is only effective during the assembly of the differential 10 and does not always prevent movement of the pinion shaft 32 when the differential 10 is in use.
[0028] As Figure 5 and Figure 6As shown, the beveled or inclined transition surface 82 may extend axially and radially outwardly from one or both of the inner surfaces 58 such that the second gear 50 has a greater inner diameter at the first axial end 83 and the second axial end 85 of the gear 50 than at the inner surface 58. This may facilitate fitting the second gear 50 onto the mounting surface 48 and aligning it with the mounting surface 48. Additionally, the interior of the second gear 50 (e.g., including the inner surface 58 and any transition surfaces or other surfaces) may be axially symmetric such that the gear 50 may be connected to the differential housing 12 in either orientation. Similarly, the exterior of the second gear 50 may be axially symmetric such that when mounted to the differential housing 12, the gear teeth 62 are in the same axial position in either orientation of the second gear 50. In the example shown, the gear teeth 62 of the second gear 50 only partially extend along the axial extent of the second gear 50 and are located intermediate / centered between the first and second axial ends, with axially and circumferentially extending flanges 84 axially outside of the teeth 62. In at least some embodiments, one of the flanges 84 axially overlaps the pinion shaft 32 and, if desired, may overlap the axis 34 of the pinion shaft 32. In at least some embodiments, if desired, at least a portion of the teeth 62 may axially overlap the pinion shaft 32 and, if desired, the axial centerline of the second gear 50 may overlap the pinion shaft 32.
[0029] Thus, in at least some embodiments, the only retention of the pinion shaft 32 relative to the housing 12 is provided by the overlapping second gear 50. This may significantly reduce the cost and complexity of retaining the pinion shaft 32 and assembling the pinion shaft 32 into the differential 10, etc. For example, when clips or fasteners are required to retain the pinion shaft, the pinion shaft opening 36 is typically surrounded by a recess that provides access to the end of the pinion shaft 32 for mounting the clip or fastener.
[0030] Additionally, if desired, at least where the inner surface 58 overlaps the pinion shaft 32, a coating or insert may be applied to one or both of the end of the pinion shaft 32 and the inner surface 58 of the second gear 50. The coating may provide an interference fit between these components, damp vibrations or further restrict movement of the pinion shaft 32 relative to the housing 12, and / or the coating may have a desired hardness or toughness and durability to reduce wear at the interface between the pinion shaft 32 and the second gear 50. Such a coating or insert is optional and at least some embodiments do not include any such coating or insert.
[0031] The forms of the invention disclosed herein constitute presently preferred embodiments, and many other forms and embodiments are possible. It is not intended herein to refer to all possible equivalent forms or derivatives of the invention. It is understood that the terms used herein are merely descriptive and not restrictive, and that various changes may be made without departing from the spirit or scope of the invention.
[0032] Unless expressly indicated to the contrary herein, all terms used in the claims are intended to be given their broadest reasonable construction and their ordinary meaning as understood by those skilled in the art. In particular, the use of the singular articles such as "a," "the," and "said" should be understood to recite one or more of the indicated elements unless the claim recites a contrary express limitation.
Claims
1. A vehicle differential, comprising: case; an input gear mounted to the housing such that the housing and the input gear rotate together; a pinion shaft mounted in the housing; a first pinion gear and a second pinion gear, both of which are mounted on the pinion gear shaft; a first side gear within the housing and engaged with the first pinion gear and the second pinion gear; a second side gear within the housing and engaged with the first pinion gear and the second pinion gear; as well as A second gear is mounted to the housing so that the second gear and the housing rotate together, wherein a portion of the second gear overlaps at least a portion of the pinion shaft and restricts movement of the pinion shaft relative to the housing.
2. The vehicle differential according to claim 1, wherein: The housing includes at least one pinion shaft opening, the pinion shaft is received into the housing through the at least one pinion shaft opening, and wherein the second gear overlaps at least a portion of the at least one pinion shaft opening.
3. The vehicle differential according to claim 2, wherein: The housing includes two pinion shaft openings, and each end of the pinion shaft is received in a corresponding one of the pinion shaft openings, and the second gear overlaps at least a portion of each end of the pinion shaft.
4. The vehicle differential according to claim 1, wherein: The housing includes a gear mounting surface, and the second gear includes an inner surface received over at least a portion of the gear mounting surface.
5. The vehicle differential according to claim 4, wherein: The gear mounting surface extends circumferentially around an exterior of the housing, and the gear mounting surface extends parallel to an axis of rotation of the input gear.
6. The vehicle differential according to claim 1, wherein: The input gear and the second gear are coaxial.
7. The vehicle differential according to claim 4, wherein: The second gear has an axis of rotation, and the inner surface axially overlaps the pinion shaft by at least 0.5 mm.
8. The vehicle differential according to claim 7, wherein: The inner surface overlaps the pinion shaft by at least 10% of a diameter of the pinion shaft.
9. The vehicle differential according to claim 1, wherein: The second gear has an axis of rotation and includes teeth extending radially outwardly, and wherein at least a portion of the teeth axially overlap the pinion shaft.
10. The vehicle differential according to claim 1, wherein: The second gear has an axis of rotation and outwardly extending teeth, and wherein the teeth are axially centered on the second gear.
11. The vehicle differential according to claim 10, wherein: The second gear is symmetrical about the axis of the second gear.
12. The vehicle differential according to claim 4, wherein: The housing includes two pinion shaft openings, and each end of the pinion shaft is received in a corresponding one of the pinion shaft openings, and wherein the gear mounting surface has a central axis and the gear mounting surface has a smaller axial extent in the area of the pinion shaft opening than in at least some areas circumferentially spaced from the pinion shaft openings.
13. The vehicle differential according to claim 4, wherein: The inner surface has a diameter that is 3 mm or less than an axial length of the pinion shaft.
14. The vehicle differential according to claim 1, wherein: The pinion shaft is retained relative to the housing by the second gear without another retaining component connected to either the housing or the pinion shaft.
15. The vehicle differential according to claim 1, wherein: The input gear and the second gear are coaxial, and the second gear is axially offset from the input gear.
16. The vehicle differential according to claim 1, wherein: The housing includes at least one window that opens to an interior of the housing, and one or more gears are mounted into the interior through the at least one window, and wherein the second gear overlaps a portion of the at least one window.