A light-weight differential assembly for a vehicle

Abstract

Described herein is a differential assembly [100] for a vehicle. The differential assembly [100] comprises a ring gear member [102], and a cage member [104] of a cut-out bell-shaped structure. Ring gear member [102] comprises a rim portion [102a] defining a central bore section [102d], and a pair of cavities [102b, 102c] symmetrically defined on either side of central bore section [102d], Cage member [104] comprises a base plate portion [104e], a first flanged portion [104a] and a second flanged portion [104b], each extending from opposite sides of base plate portion [104e], First flanged portion [104a] and second flanged portion [104b] define a first extension section [104c] and a second extension section [104d] protruding therefrom, respectively. First extension section [104c] and second extension section [ 104d] are securely received within pair of cavities [102b, 102c], respectively, to join the ring gear member [102] and the cage member [104] in a manner.

Description

[0001] A LIGHT-WEIGHT DIFFERENTIAL ASSEMBLY FOR A VEHICLE TECHNICAL FIELD

[0002] The present invention relates to the field of vehicles, and more particularly, to a light-weight differential assembly for a vehicle.

[0003] BACKGROUND

[0004] This section is intended to provide information relating to the field of the invention and thus, any approach or functionality described below should not be assumed to be qualified as prior art merely by its inclusion in this section.

[0005] Differential assemblies are commonly known to be deployed in a vehicle to distribute power to wheels while allowing them to rotate at different speeds and facilitate smooth turning of the vehicle. A typical differential assembly comprises a ring gear member, a cage member, a first pinion gear, a second pinion gear, a pinion shaft, a first side gear, and a second side gear. A structure and arrangement of the ring gear member, the cage member, the first pinion gear, the second pinion gear, the pinion shaft, the first side gear, and the second side gear, is commonly known and is not repeated herein for the sake of brevity.

[0006] The ring gear member of the differential assembly generally includes a rim portion defining a central bore section. Additionally, the cage member is typically in the form of a bell-shaped structure having a base portion and a bell portion. The cage member is fixed to the ring gear member. Notably, the aforementioned configuration of the cage member leads to a bulky structure and requires a substantial amount of raw material for casting / forging and machining. As a result, the overall weight of the differential assembly increases. Moreover, the excessive material usage leads to higher costs, increased material waste, and lower casting / forging yield efficiency.

[0007] Additionally, in conventional differential assemblies, the cage member is required to be attached to the ring gear member. In one embodiment, the cage member is fixed to the ring gear member, by way of bolt-based connections, which suffers from a disadvantage of bolt loosening or backing out during operation, causing potential drivetrain failure.

[0008] Accordingly, considering the above drawbacks and various other limitations inherent in the existing art, there is a need to provide a low-cost, and light-weight differential assembly with a cut-out bell-shaped cage member to reduce weight and material usage, which the present disclosure aims to address.SUMMARY OF THE INVENTION

[0009] This section is intended to introduce certain aspects of the disclosed assembly in a simplified form and is not intended to identify the key advantages or features of the present disclosure.

[0010] The present disclosure relates to a differential assembly for a vehicle. The differential assembly comprises: a ring gear member and a cage member a cut-out bell-shaped structure. The ring gear member comprises: a rim portion defining a central bore section, and a pair of cavities symmetrically defined on either side of the central bore section. The cage member comprises: a base plate portion, and a first flanged portion and a second flanged portion, each extending from opposite sides of the base plate portion. The first flanged portion and the second flanged portion define a first extension section and a second extension section protruding therefrom, respectively. The first extension section, and the second extension section of the cage member, are adapted to be securely received within the pair of cavities, respectively, to join the ring gear member and the cage member in a manner.

[0011] According to an aspect of the present disclosure, a first pinion gear is rotatably supported within a first pinion-holding cavity defined in the first flanged portion of the cage member, and a second pinion gear is rotatably supported within a second pinion-holding cavity defined in the second flanged portion of the cage member.

[0012] According to another aspect of the present disclosure, a first side gear is meshed with the first and second pinion gear, and connected to a first axle shaft of a first wheel, and a second side gear is meshed with the first and second pinion gear, and connected to a second axle shaft of a second wheel.

[0013] According to another aspect of the present disclosure, a main pinion gear is meshed with the ring gear member and power the differential assembly. The main pinion gear is getting the power from power supply unit either directly or through some geartrain

[0014] According to another aspect of the present disclosure, the differential assembly operates in an equal power distribution mode, and an unequal power distribution mode. In the equal power distribution mode, rotation of the main pinion gear corresponds to rotation of the ring gear member about a longitudinal axis, further corresponds to rotation of the cage member about the longitudinal axis, further corresponds to revolution of the first and second pinion gears about the longitudinal axis, and further corresponds to rotation of the first and second side gears about the longitudinal axis. In the unequal power distribution mode, rotation of the main bevel pinion gear corresponds to rotation of the ring gear member about the longitudinal axis, further corresponds to rotation of the cage member about the longitudinal axis, further corresponds to revolution of the first andsecond pinion gears about the longitudinal axis, corresponds to rotation of the first and second pinion gears, and further corresponds to rotation of the first side gear and the second side gear. According to another aspect of the present disclosure, the first pinion gear rotates in direction different from the second pinion gear, and thus the first side gear rotates at a rotational speed different from the second side gear.

[0015] According to another aspect of the present disclosure, the first extension section and the second extension section of the cage member, are adapted to be secured with the pair of cavities, respectively, of the ring gear member, by laser welding technique.

[0016] According to another aspect of the present disclosure, each of the pair of cavities of the ring gear member, have an arc-shaped cross-section adapted to receive a corresponding arc-shaped sections of the first extension section and the second extension section of the cage member.

[0017] According to another aspect of the present disclosure, the cut-out bell-shaped structure of the cage member defines a yoke-shaped configuration. The yoke-shaped configuration is formed by a cutout between the first flanged portion and the second flanged portion, such that the flanged portions extend in a spaced-apart manner from opposite sides of the base plate portion,

[0018] The aforementioned aspects of the present invention may be better understood when read in conjunction with the detailed description of the present invention, which follows later in the present disclosure.

[0019] BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to explain the technical solution in the embodiments of the present application more clearly, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only some embodiments of the application. Forthose skilled in the art, without any creative work, other drawings can be obtained based on these drawings.

[0021] Figure 1 illustrates a sectional view of the differential assembly, in accordance with the concepts of the present disclosure.

[0022] Figure 2 illustrates an exploded view of an arrangement of a ring gear member and a cage member of the differential assembly, in accordance with the concepts of the present disclosure.

[0023] Figure 3a illustrates a first perspective view of the cage member of the differential assembly, in accordance with the concepts of the present disclosure.Figure 3b illustrates a second perspective view of the cage member of Figure 3a, in accordance with the concepts of the present disclosure.

[0024] Figure 4a illustrates a first perspective view of the ring gear member of the differential assembly, in accordance with the concepts of the present disclosure.

[0025] FIG. 4b illustrates a second perspective view of the ring gear member of Figure 4a, in accordance with the concepts of the present disclosure.

[0026] Figure 5 illustrates a bottom view of the differential assembly of Figure 1, in accordance with the concepts of the present disclosure.

[0027] DETAILED DESCRIPTION

[0028] In the following description, for the purpose of explanation, various specific details are set forth in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent, however, that the embodiments of the present invention may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address any of the problems discussed above or might address only one of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein. Exemplified embodiments of the present invention are described below, as illustrated in various drawings in which reference numerals refer to the same parts throughout the different drawings.

[0029] Figures 1-5 are to be viewed in conjunction with each other, in order to better understand the concepts of the present disclosure.

[0030] In accordance with the concepts of the present disclosure, a differential assembly

[0100] for a vehicle is shown. The vehicle can be a three -wheeler, four-wheeler, or any other heavy-duty vehicle. A type of vehicle does not limit a scope of the present disclosure.

[0031] The differential assembly

[0100] is a conventionally known component in vehicles to distribute power to wheels while allowing them to rotate at different speeds and facilitate smooth turning of the vehicle. The differential assembly

[0100] (as shown in Figures 1 and 5) comprises a ring gear member

[0102] , a cage member

[0104] , a first pinion gear [106a], a second pinion gear [106b], a first side gear [108a], a second side gear [108b], a pinion shaft

[0110] Details of each of the ring gear member

[0102] , the cage member

[0104] , the first pinion gear [106a], the second pinion gear [106b],the first side gear [108a], the second side gear [108b], a pinion shaft

[0110] , and their arrangement with each other, will now be discussed in detail.

[0032] The ring gear member

[0102] (as shown in Figures 1, 2, 4a and 4b) comprises a rim portion [102a], and a pair of cavities [102b, 102c], The rim portion [102a] is a circular annular structure defining a toothed outer periphery configured to mesh with the main pinion gear. The rim portion [102a] defines a central bore section [102d], which extends axially through the center of the ring gear member

[0102] , providing access for housing the cage member

[0104] and the associated pinion gears [106a, 106b] and the side gears [108a, 108b], The pair of cavities [102b, 102c] are symmetrically defined on either side of the central bore section [102d], Each of the pair of cavities [102b, 102c] of the ring gear member

[0102] have an arc-shaped cross-section adapted to receive a corresponding arc-shaped sections of a first extension section [104c] and a second extension section [104d] of the cage member

[0104] ,

[0033] The cage member

[0104] (as shown in Figures 1, 2, 3a and 3b) is a cut-out bell-shaped structure comprising of a base plate portion [104e], and a first flanged portion [104a] and a second flanged portion [104b], The base plate portion [104e] of the cage member

[0104] comprises a plurality of curved ribs extending radially outward from a central region of the base plate portion [104e], Each of the first flanged portion [104a], and the second flanged portion [104b] extend from the base plate portion [104e] in the form of radially extending curved arms configured to form lateral boundaries of an internal cavity of the cut-out bell-shaped structure of the cage member

[0104] , The cut-out bell-shaped structure of the cage member

[0104] defines a yoke-shaped configuration. The yoke-shaped configuration is formed by the cut-out between the first flanged portion [104a], and the second flanged portion [104b], such that the flanged portions [104a, 104b] extend in a spacedapart manner from opposite sides of the base plate portion. The first flanged portion [104a] and the second flanged portion [104b] define the first extension section [104c] and the second extension section [104d], each protruding laterally outward, and shaped with an arc-shaped crosssection complementary to the pair of cavities [102b, 102c] of the ring gear member

[0102] (as shown in Figure 5). The first extension section [104c] and the second extension section [104d] of the cage member

[0104] , are adapted to be securely received within the pair of cavities [102b, 102c], respectively, to join the ring gear member

[0102] and the cage member

[0104] to form the differential assembly

[0100] by laser welding technique. The mating interface between the arc-shaped cavities [102b, 102c] and the corresponding extending sections [104c, 104d] ensures a self-locating and continuous connection between the ring gear member

[0102] and the cage member

[0104] , Each of the first flanged portion [104a], and the second flanged portion [104b] define a first pinionholding cavity [112a], and a second pinion-holding cavity [112b], respectively (as shown inFigures 2 and 3b). The first pinion gear [106a] is rotatably supported within the first pinionholding cavity [112a] defined in the first flanged portion [104a], and the second pinion gear [106b] is rotatably supported within the second pinion-holding cavity [112b] defined in the second flanged portion [104b], The first pinion-holding cavity [112a] and the second pinion-holding cavity [112b] are circular recesses rotatably supporting the first pinion gear [106a] and the second pinion gear [106b], The first pinion gear [106a] and the second pinion gear [106b] are mounted on the pinion shaft

[0110] and are configured to revolve within the cage member

[0104] while meshing with the side gears [108a, 108b], The pinion shaft

[0110] extends laterally across the internal cavity of the cage member

[0104] , and is supported at opposite ends with the first flanged portion [104a], and the second flanged portion [104b], enabling stable rotation of the pinion gears [106a, 106b], The first side gear [108a] and the second side gear [108b] are provided within the cage and ring gear member

[0102] , each positioned coaxially along a longitudinal axis. The first side gear [108a] is meshed with the first pinion gear [106a] as well as second pinion gear [106b], and is connected to a first axle shaft of a first wheel of the vehicle. The second side gear [108b] is meshed with the second pinion gear [106b] as well as first pinion gear [106a], and is connected to a second axle shaft of a second wheel of the vehicle (as shown in Figure 1). The gear teeth of the pinion gears [106a, 106b] and the side gears [108a, 108b] are beveled to allow angled engagement, enabling torque to be transmitted transversely from the rotating cage member

[0104] to the first and the second axle shafts via the side gears [108a, 108b],

[0034] The main pinion gear (not shown) is meshed with outer teeth of the rim portion [102a] of the ring gear member

[0102] , The main pinion gear is further connected to the geartrain, and is powered by a power supply unit, such as an engine or an electric motor. As the geartrain rotates, the main pinion gear rotates the ring gear member

[0102] , thereby rotating the cage member

[0104] and initiating torque transfer to the first axle shaft and the second axle shaft via the side gears [108a, 108b],

[0035] The differential assembly

[0100] operates in two modes: an equal power distribution mode, and an unequal power distribution mode. In the equal power distribution mode, rotation of the main pinion gear rotates the ring gear member

[0102] about the longitudinal axis, which in turn rotates the cage member

[0104] about the longitudinal axis. This rotation of the main pinion gear, the ring gear member

[0102] and the cage member

[0104] causes revolution of the first pinion gear [106a] and the second pinion gear [106b] about the longitudinal axis, which results in rotation of the first and second side gears [108a, 108b] about the longitudinal axis. In the unequal power distribution mode, when the vehicle is cornering or when the wheels undergo different traction conditions, the cage member

[0104] continues to rotate, but the first pinion gear [106a], and the second pinion gear[106b] rotate on their own axes in addition to revolving about the longitudinal axis. This dual rotation causes the first side gear [108a], and the second side gear [108b] to rotate at different speeds, enabling smooth cornering. Particularly, the first pinion gear [106a] may rotate at a different speed from the second pinion gear [106b], thereby causing the side gears [108a, 108b] to deliver torque independently to each wheel based on resistance encountered.

[0036] Advantageously, by virtue of the present invention, the overall weight of the differential assembly

[0100] is substantially reduced, which directly improves the performance of powertrain of the vehicle. Moreover, minimizing the amount of material used to create the cage member

[0104] further aids in reduction of overall weight of the differential assembly

[0100] , thereby allowing more efficient power transmission and improved fuel economy or battery mileage. This reduction in weight also leads to better handling and responsiveness, making it attractive feature for vehicle manufacturers. Furthermore, the present invention leads to improvement in material yield, as less material is required to produce the cage member

[0104] , This reduced material usage not only results in cost savings but also minimizes waste and environmental impact. Additionally, the elimination of excess material reduces the likelihood of imperfections or defects in the final product. The present invention also leads to improvement in the ring gear member

[0102] yield, as there is less wastage of raw material from input material to finished part. One of the most significant advantages of the present invention is the elimination of bolt backing up during operation. By eliminating the need for bolts, the risk of mechanical failure due to back-up is significantly reduced, ensuring a smoother and more reliable powertrain experience. Finally, the present invention enables gear finishing to be done in an assembled condition, which reduces noise, vibration, and harshness (NVH). This feature ensures that the gears are properly aligned and fitted during assembly, resulting in improved performance and a quitter ride.

[0037] It may be understood that the above-listed advantages are merely exemplary and not exhaustive. Those skilled in the art may contemplate additional advantages of the present invention, in light of the concepts of the present disclosure.

[0038] While the preferred embodiments of the present invention have been described hereinabove, it should be understood that various changes, adaptations, and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims. It will be obvious to a person skilled in the art that the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.LIST OF COMPONENTS

[0039] 100 - Differential assembly

[0040] 102 - Ring gear member

[0041] 102a - Rim portion

[0042] 102b, 102c - Pair of cavities

[0043] 102d - Central bore section

[0044] 104 - Cage member

[0045] 104a - First flanged portion

[0046] 104b - Second flanged portion 104c - First extension section 104d - Second extension section 104e - Base plate portion

[0047] 106a - First pinion gear

[0048] 106b - Second pinion gear

[0049] 108a - First side gear

[0050] 108b - Second side gear

[0051] 110 - Pinion shaft

[0052] 112a - First pinion-holding cavity 112b - Second pinion-holding cavity

Claims

I / We Claim:

1. A differential assembly [100] for a vehicle, the differential assembly [100] comprising:a ring gear member [102] comprising a rim portion [102a], the rim portion [102a] defining a central bore section [102d], and a pair of cavities [102b, 102c] symmetrically defined on either side of the central bore section [102d]; anda cage member [104] of a cut-out bell-shaped structure, the cage member [104] comprising:a base plate portion [104e]; anda first flanged portion [104a] and a second flanged portion [104b], each extending from opposite sides of the base plate portion [104e], the first flanged portion [104a] and the second flanged portion [104b] defining a first extension section [104c] and a second extension section [104d] protruding therefrom, respectively;wherein the first extension section [104c] and the second extension section [104d] of the cage member [104], are adapted to be securely received within the pair of cavities [102b, 102c], respectively, to join the ring gear member [102] and the cage member [104] in a manner.

2. The differential assembly [100] as claimed in claim 1, comprises a first pinion gear [106a] rotatably supported within a first pinion-holding cavity [112a] defined in the first flanged portion [104a] of the cage member [104], and a second pinion gear [106b] rotatably supported within a second pinion-holding cavity [112b] defined in the second flanged portion [104b] of the cage member [104],3. The differential assembly [100] as claimed in claim 2, comprises a first side gear [108a] meshed with the first pinion gear [106a], and connected to a first axle shaft of a first wheel, and a second side gear [108b] meshed with the second pinion gear [106b], and connected to a second axle shaft of a second wheel.

4. The differential assembly [100] as claimed in claim 2, comprises a ring gear member [102], and cage member [104], connected to a pinion shaft [110]5. The differential assembly [100] as claimed in any of the preceding claims, wherein the main pinion gear is powered by a power supply unit either directly or through a gear train.

6. The differential assembly [100] as claimed in any of the preceding claims, operates in an equal power distribution mode, and an unequal power distribution mode, such that, in the equal power distribution mode, rotation of the main pinion gear corresponds to rotation of the ring gear member [102] about a longitudinal axis, further corresponds to rotation of the cage member [104] about the longitudinal axis, further corresponds to revolution of the first and second pinion gears [106a, 106b] about the longitudinal axis, and further corresponds to revolution of the first and second side gears [108a, 108b] about the longitudinal axis; andin the unequal power distribution mode, rotation of the main pinion gear, corresponds to rotation of the ring gear member [102] about the longitudinal axis, further corresponds to rotation of the cage member [104] about the longitudinal axis, further corresponds to revolution of the first and second pinion gears [106a, 106b] about the longitudinal axis, corresponds to revolution of the first and second pinion gears [106a, 106b], and further corresponds to rotation of the first side gear [108a] and the second side gear [108b] respective gear axis.

7. The differential assembly [100] as claimed in claim 6, wherein the first pinion gear [106a] rotates in direction different from the second pinion gear [106b], and thus the first side gear [108a] rotates at a rotational speed different from the second side gear [108b],8. The differential assembly [100] as claimed in claim 1, wherein the first extension section [104c] and the second extension section [104d] of the cage member [104], are adapted to be secured with the pair of cavities [102b, 102c], respectively, of the ring gear member [102], by laser welding technique.

9. The differential assembly [100] as claimed in claim 1, wherein each of the pair of cavities [102b, 102c] of the ring gear member [102] have an arc-shaped cross-section adapted to receive a corresponding arc-shaped sections of the first extension section [104c] and the second extension section [104d] of the cage member [104],10. The differential assembly [100] as claimed in claim 1, wherein the cut-out bell-shaped structure of the cage member [104] defines a yoke-shaped configuration, the yoke-shaped configuration being formed by a cut-out between the first flanged portion [104a], and the second flanged portion [104b], such that the flanged portions [104a, 104b] extend in a spaced-apart manner from opposite sides of the base plate portion [104e],

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