DESC:TECHNICAL FIELD
The present disclosure generally relates to Automobiles. Particularly, but not exclusively, the present disclosure relates to transmission mechanism in Automobiles. Further, embodiments of the present disclosure disclose a semi-float axle differential assembly for automobiles.

BACKGROUND OF THE DISCLOSURE
Vehicles including but not limiting to passenger vehicles, Sport utility vehicles, heavy duty vehicle, and light duty vehicles are equipped with differentials or differential gear assemblies (or simply differentials). The differential gear assemblies are generally known to perform three functions in drive trains. Firstly, they transmit torque (or power) from the engine to drive wheels of the vehicle through propeller shaft. Secondly, they transmit power from transmission shaft to wheel axles at right angles i.e. to direct power flow from propeller shaft to wheel axles at right angle. Thirdly, they provide differential angular speeds to left and right axles when vehicle takes turn, and maintains equal torque distribution between the axles when vehicle is moving along a straight path. The differential assembly, as mentioned earlier, is used to transmit and distribute torque (or power) from input shaft of the transmission system (drive train) to one or more pairs of output axles or shafts. The wheels of the vehicle are fixed to extreme ends of the axles and are provided with required torque and traction for rolling on ground surface. Generally, the input shaft (also referred to as transmission shaft or propeller shaft) takes power from vehicle gearbox, and is transversely connected to wheel axles via differential assembly. The entire assembly is mounted in a differential casing or housing, which supports gear drives, axles and other members constituting the differential assembly. In some cases, the differential assembly includes a differential casing which is rotatably supported within axle housing and a ring/annular gear coupled therewith to rotate which is driven by a pinion gear coupled to the input shaft. The differential casing rotates within the axle housing in response to rotation of the input shaft.

The axles that are assembled to differential assembly on one side and to drive wheels on the other side are broadly classified into three types, viz. semi-floating axle, full-floating axle and quarter floating axle. Of these three types, semi-floating axles and full floating axles are commonly used. In a semi-floating axle, the axle carries weight as well as transmits torque to turn the drive wheels. The wheels are directly coupled to the axle flange. Semi-float axle type differential assemblies can be found in vehicles with limited capacity such as cars and light duty trucks. On the other hand, in a full-float axle, weight of the vehicle is entirely supported by the axle housing and is not transmitted to axle shafts. More specifically, a bearing spindle attached to the axle housing and a set of bearings in a separate wheel hub are designed and incorporated in the differential assembly which take up the vehicle loads, and subsequently transmit them to housing. Therefore, in full-floating axles, the axle shafts only take part in transmitting torque to drive wheels of the vehicle, which consequently cause their rotation. Full-float axles are heavier and stronger and can be seen in almost all types of heavy duty trucks.

A major problem encountered in both semi-float axle type differential and full-float axle type differential is the transmission of torque to drive wheels. The axles must be designed so as to have enough strength to withstand torsional moments transmitted from the propeller shaft, which otherwise may lead to failure of these axles due to torsional stresses and vibrations. Further, in case of semi-float axles which also carry loads in addition to transmitting torque to drive wheels of the vehicle, the axles must be designed so that they withstand the loads acting on them. The loads acting on semi-float axles are basically axial loads (tensile and compressive) and bending loads. Both of these loads are exerted due to weight of the vehicle and their magnitudes continuously vary, particularly when vehicle takes a turn and when the vehicle encounters gradient. An increase in magnitudes of both these loads result in increased stresses in the axles, which may eventually lead to deformation of axles in forms including but not limiting to buckling and deflection. The deformations in axle shafts may progressively lead to failure, or may result directly in rupture of the axles. In addition, the bending loads cause excessive bending stresses in wheel end bearings which is not desirable. Another problem encountered during assembling associated components of differential assembly is proper spacing of the axles. Accurate spacing of the axles not only allows the axles to rotate freely about the bearings, but also allows the axles to freely move in longitudinal direction, so that bearing life is improved. However, existing spacer devices assembled in between the axles require frequent adjustments and maintenance for maintaining proper spacing between the axles. In addition, the spacer devices undergo deformation under frequent axial loadings, which arises the need for replacement of spacer devices on periodic basis. Replacing spacers on periodic basis is time consuming and expensive, and requires lot of manual intervention. Another limitation of semi-float axle differential assemblies with two pinions is limited torque transfer and power distribution between the axles, which results in limited traction control on the vehicle.
In light of foregoing discussion, it is necessary to develop an improved semi-float axle differential assembly to overcome one or more limitations stated above.

SUMMARY OF THE DISCLOSURE
One or more drawbacks of conventional semi-float axle differential assemblies for vehicles as described in the prior art are overcome and additional advantages are provided through the assembly as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure, there is provided a semi-float axle differential assembly for a vehicle. The differential assembly comprises a differential casing for supporting the semi-float axle differential assembly. A first axle and a second axle extend outwardly from the semi-float axle differential assembly, and at least one side gear is mounted on each of the first axle and the second axle. A thrust block is slidably disposed in between the first axle and the second axle. The thrust block comprises a first provision extending through the thrust block in a first direction, and the first provision accommodates at least a pair of first pinions through a first shaft. A plurality of second provisions is provided in the thrust block in a second direction, where each of the plurality of second provisions is configured to accommodate at least one second pinion through at least one second shaft. The first provision and the plurality of second provisions are configured with predetermined clearance to facilitate sliding movement of the thrust block relative to the first shaft and the at least one second shaft provided in the first provision and each of the plurality of second provisions respectively.

In an embodiment of the present disclosure, the first provision and the plurality of second provisions are at least one of slots, bores and holes. Further, cross-section of the first provision and the plurality of second provisions is at least one of rectangular and square.

In an embodiment of the present disclosure, cross-section of a portion of the first shaft and the at least one second shaft which resides in first provision and the plurality of second provisions respectively is at least one of square, circular and rectangular.

In an embodiment of the present disclosure, an axis A-A of the first provision and an axis B-B of the plurality of second provisions are configured at substantially right angles to one another in the thrust block.

In an embodiment of the disclosure, the first provision extends for entire depth of the thrust block in the first direction and the plurality of second provisions extend upto predetermined depth in the second direction in the thrust block. The predetermined depth of the plurality of second provisions is provided such that the plurality of second provisions is not in contact with the first provision.

In an embodiment of the present disclosure, the pair of first pinions are configured on either end of the first shaft and the at least one second pinion is mounted at an end of the at least one second shaft.

In an embodiment of the present disclosure, the pair of first pinions and the at least one second pinion are configured to be in meshing engagement with the at least one side gear.

In another non-limiting embodiment of the present disclosure, there is provided a device for transferring forces between axles in a semi-float axle differential assembly of a vehicle. The device comprises a block slidably disposable between the axles in the semi-float axle differential assembly. A first provision extends through the block in a first direction, and accommodates at least a pair of first pinions through a first shaft. A plurality of second provisions is provided in the block in a second direction, where each of the plurality of second provisions is configured to accommodate at least one second pinion through at least one second shaft. The first provision and the plurality of second provisions are configured with predetermined clearance to facilitate sliding movement of the block relative to the first shaft and the at least one second shaft provided in the first provision and each of the plurality of second provisions respectively.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent with reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The novel features and characteristics of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

FIG. 1 illustrates sectional top view of a semi-float axle differential assembly, according to an embodiment of the present disclosure.

FIG. 2 illustrates exploded perspective view of the semi-float axle differential assembly provided with a thrust block, according to an embodiment of the present disclosure.

FIG. 3 illustrates sectional front view of the thrust block of FIG. 2 comprising a first provision and at least one second provision accommodated with first shaft and second shafts respectively, according to an exemplary embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the assemblies and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its assembly and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

To overcome one or more limitations stated in the background, the present disclosure provides a semi-float axle differential assembly for a vehicle with a slidably disposed thrust block for transferring forces between the axles. As is well known in the art, a differential gear assembly is included in drive train of the vehicle to provide constant angular speed when vehicle moves along a straight path, as well as differential angular speed when vehicle takes a turn to drive wheels of the vehicle. The differential assembly is one which receives power directly from the transmission shaft of the gearbox, which is then transmitted to axle shafts. The differential assembly is therefore an intermediate gear train between the transmission shaft and the vehicle wheels, which take part in load distribution, torque transfer and speed regulation between the drive wheels. The differential assembly along with semi-float axles is enclosed in a differential casing. The differential casing is carried by main supporting structure of the vehicle and is intended to support the elements constituting the differential assembly. A semi-float axle differential is a type of differential in which the axles are imposed with necessary torque to rotate the drive wheels, in addition to carrying axial and bending loads. Each of the axles (first axle and second axle) disposed in the differential assembly is mounted with differential side gear (or simply side gear) on an end which resides inside the differential casing. The other end of axle is fixedly connected to wheel rim. To either axle, power (or torque) is transmitted via differential side gears.

The differential assembly further comprises a thrust block slidably disposed in between the first axle and the second axle. The term “slidably” denotes that the thrust block can slide along the co-inciding axis of axles for transmitting thrust forces to wheel end bearings. To achieve this, the thrust block is disposed in between the axles such that the longitudinal axis of the thrust block is co-axial or substantially co-axial with co-inciding axes of both the shafts. The thrust block comprises a first provision extending through the entire depth. The first provision is oriented in a first direction and accommodates at least one pair of first pinions through a first shaft. The first provision of the thrust block accommodates a first shaft whose ends are mounted with a pair of first pinions. The thrust block also comprises a plurality of second provisions which are oriented in second direction. The plurality of second provisions are configured to accommodate at least one second shaft, and each of the at least one second shaft is mounted with at least one second pinion. The first provision and the plurality of second provisions are configured with predetermined clearances so that the thrust block slides along the co-inciding axes of the axles relative to the first shaft and the at least one second shaft.

Further, the first provision and the plurality of second provisions configured in the thrust block are at least one of slots, holes and bores formed by appropriate machining process. The cross section of the first provision and the at least one second provision is at least one of square and rectangular. Also, the cross section of a portion of first shaft and at least one second shaft is at least one of square, circular and rectangular so that there are geometrical and dimensional conformities between the portions of first and second shafts with first and second provisions respectively. In addition, the first shaft and at least one second shaft are configured in the thrust block such that their axes are at right angles or substantially at right angles. The first shaft extends for entire depth of the thrust block, while the at least one second shaft extends only to a predetermined depth in the thrust block. This configuration prevents first shaft from coming in contact with the at least one second shaft in the thrust block. The pair of first pinions and at least one second pinion mounted on the first shaft and at least one second shaft respectively are in meshing engagement with both the side gears. The first and second pinions are carried on ring gear through plurality of carriers. The ring gear is in meshing engagement with the drive gear of transmission shaft which extends from vehicle gearbox. The rotation of ring gear by the drive gear of transmission shaft causes first and second pinions to orbit around the side gears for torque (or power) transmission.
In one embodiment of the present disclosure, the thrust block is configured to be retrofitted, and is adapted to act as a device for transferring forces between axles in a semi-float axle differential assembly.

Use of terms such as “comprises”, “comprising”, or any other variations thereof in the description, are intended to cover a non-exclusive inclusion, such that an assembly, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such assembly or device or method. In other words, one or more elements in a mechanism proceeded by “comprising… a” does not, without more constraints, preclude the existence of other elements or additional elements in the mechanism.

Reference will now be made to a differential assembly for semi-float axles in a vehicle, and is explained with the help of figures. The figures are for the purpose of illustration only and should not be construed as limitations on the differential assembly of the present disclosure. Further, the figures are illustrated without showing vehicle for the purpose of simplicity. One should note that any type of vehicle which can accommodate differential assembly is considered to be part of present disclosure. Wherever possible, referral numerals will be used to refer to the same or like parts.

FIG. 1 is an exemplary embodiment of the present disclosure which illustrates sectional top view of a semi-float axle differential assembly (100) with thrust block (106) axially disposed in between the first and second axles (101a, 101b). The differential assembly (100) comprises of semi-float axles (101a, 101b) which are intended to carry weight of the vehicle and transmit torque to drive wheels (not shown). In doing so, the semi-float axles (101a, 101b) transfer axial loads (thrust loads) to bearings, including but not limited to taper roller bearings installed in the differential casing (250). The differential casing (250) (interchangeably referred to as “housing” in the description) is supporting structure of the differential assembly (100) which houses all the components and members constituting the differential assembly (100) within it. The housing (250) in turn is supported by main supporting structure of the vehicle, including but not limited to vehicle chassis. Usually, in a semi-float axle type differential assembly (100), outer ends of the axles (101a, 101b) are mounted with flanges (not shown) which are fixedly connected to rims of drive wheels. In an embodiment of the present disclosure, the drive wheels are connected to flanges of the axles (101a, 101b) by processes including but not limiting to fastening. This fixed connection between flanges of axles (101a, 101b) and wheel rims allow wheels to rotate in unison with axles (101, 101b) to propel the vehicle. The axles (101a, 101b) are designed keeping in view the loads acting on them, and most importantly the magnitude of twisting moment and axial loads acting on them during vehicle propulsion.

As it can be seen in FIG. 1, the differential gears present in the differential assembly (100) are powered by transmission shaft (500) extending from gearbox (not shown) of the vehicle. The transmission shaft (500) is also referred to as “power shaft” or “propeller shaft”, and takes power from output shaft of the gearbox. The transmission shaft (500) is mounted with drive gear (501) which resides inside the differential casing (250). The drive gear (501) is intended to transmit power from transmission shaft (500) to differential gears, and takes part in diverting power at right angles from transmission shaft (500) to semi-float axles (101, 101b). Each of the semi-float axles (101a, 101b) are mounted with side gears (102a, 102b) which are positioned in the differential casing (250) such that the side gears (102a, 102b) are faced opposite to each other, with axes of the semi-float axles (101a, 101b) coinciding along X-X. In an embodiment of the present disclosure, the drive gear (501) and side gears (102a, 102b) include, but not limited to a straight bevel gear and a hypoid gear. In an embodiment of the present disclosure, the side gears (102a, 102b) are fixed to the axles (101a, 101b) by mechanical members including but not limiting to keys and splines. An annular gear (200), also called “crown gear” or “ring gear” is rotatably mounted adjacent to one of the side gears (102a, 102b) on one of the axles (101a, 101b). The annular gear (200) is not fixed to axles (102a, 102b), and can rotate independent of rotation of the axle (101a, 101b) on which it is mounted. The annular gear (200) meshes with the drive gear (501) mounted on the transmission shaft (500), and receives power from the transmission shaft (500) to drive the axles (101a, 101b) through side gears (102a, 102b) and pinions, which will be explained in greater detail in forthcoming paragraphs of detailed description. As it can be clearly seen from FIG. 1, the transmission shaft (500) is perpendicular to coinciding axes (X-X) of the axles (101a, 101b). In an embodiment of the present disclosure, the annular gear (200) includes but not limiting to bevel gears, such as but not limiting to straight bevel and hypoid gears. The annular gear (200) which is in meshing engagement with the drive gear (501) is rotated freely about the coinciding axes of axles (101a, 101b) without imparting any motion to the axles (101a, 101b) directly.

FIG. 2 is an exemplary embodiment of the present disclosure which illustrates exploded perspective view of the semi-float axle differential assembly (100) provided with a thrust block (106). Reference is now made to FIG. 2 in conjunction with FIG. 1. When vehicle moves along a straight path or takes a turn, the axles (101a, 101b) are subjected thrust forces (or axial forces) including but not limited to tensile and compressive loads along their longitudinal axis X-X. In addition, the axles (101a, 101b) may be subjected to bending loads which may induce bending stresses in them. Hence, axles (101a, 101b) are designed taking into consideration the combined loads (axial plus bending) along with twisting moment (or torque or torsional load) acting on them. However, the thrust loads acting on the axles (101a, 101b) have to be dissipated appropriately so that axial stresses are not amplified beyond safe working stresses in the axles (101a, 101b). To achieve this, the present disclosure provides a thrust block (106) disposed in between the axles (101a, 101b) for transferring axial (or thrust loads). The thrust block (106) is assembled such that its extreme ends (side faces) come in contact with axles (101a, 101b). In an embodiment of the present disclosure, the thrust block (106) includes but not limiting to cubical and cylindrical shaped thrust bearing member which carries axial loads. The thrust block (106) is slidably disposed between the semi-float axles (101a, 101b) so that it can reciprocate along the co-inciding axis (X-X) of the axles (101a, 101b). The sliding movement of the thrust block (106) allows thrust load to be transferred from one of the axles (101a, 101b) to bearing of other axle. In an embodiment of the present disclosure, the thrust block (106) transmits thrust load acting on the first axle (101a) to wheel end bearing of the second axle (101b), and conversely, transmits thrust load acting on the second axle (101b) to wheel end bearing of the first axle (101a). The dissipation of thrust loads to bearings increases durability of the axles (101a, 101b). Generally, the thrust loads are directed towards centre of differential assembly (100), and the thrust block (106) moves along the direction of thrust load for transmitting thrust load to other axle.

The thrust block (106), as shown in FIG. 2, comprises a first provision (301) extending in a first direction along A-A through the thrust block (106). In an embodiment of the present disclosure, the first provision (301) includes but not limited to a slot, a hole and a bore machined through the thrust block (106) by machining processes including but not limited to milling and drilling. In an embodiment, the cross-section of the first provision (301) is selected from at least one of rectangular and square with predetermined clearance (305a), so that portions of shafts which reside inside the first provision (301) can have close sliding fit with respect to the thrust block (106). In one embodiment of the present disclosure, the first provision (301) extends for entire depth of the thrust block (106) as a though hole, or a through bore, or a through slot. The thrust block (106) also comprises a plurality of second provisions (302) in second direction along the axis B-B. Similar to first provision (301), the plurality of second provisions (302) are at least one of slots milled through the thrust block (106) or bores/holes drilled in the thrust block (106). However, the second provisions (302) do not extend to entire depth of thrust block (106) and are configured only to predetermined depth. This prevents first provision (301) from coming in contact with plurality of second provisions (302). The second direction (along B-B) in which the plurality of second provisions (302) are configured is substantially perpendicular (or at right angle or transverse) to the first direction (along A-A) in which the first provision (301) is oriented. The term “substantially” herein above and below refers to magnitude of one quantity which is equal to, slightly lesser or slightly greater than the magnitude of other quantity that is considered for comparison. For example, first direction is substantially at right angle to second direction denotes that the first direction is exactly at right angle (90 degrees) to second direction, or at angles slightly more than or lesser than 90 degrees. The orientation of first provision (301) and the plurality of second provisions (302) at right angles and substantially right angles is not the only possible orientation of first and second provisions, and are not in any way limiting the scope of the present disclosure.

FIG. 3 is an exemplary embodiment of the present disclosure which illustrates sectional front view of a thrust block (106) showing predetermined clearances (305a, 305b) in the first provision (301) and the plurality of second provisions (302). The first provision (301) and the plurality of second provisions (302) as shown in FIG. 3 comprise of predetermined clearance (305a, 305b) to allow sliding movement of the thrust block (106) along the co-inciding axis (X-X) of the axles (101a, 101b). The predetermined clearances (305a, 305b) are configured such that they have predetermined cross-section with respect to first provision (301) and plurality of second provisions (302) so that the thrust block (106) can have sliding movement to transfer thrust forces between the axles (101a, 101b). In an embodiment of the present disclosure, the cross sections of predetermined clearances (305a, 305b) include but not limited to square, rectangular, elliptical and circular.

Further, as illustrated in FIG. 3, the first provision (301) and the plurality of second provisions (302) in the thrust block (106) are accommodated with first shaft (301a) and the at least one second shaft (105a, 105b) respectively along with differential pinions. More specifically, the first provision (301) accommodates a first shaft (301a) which carries one set of differential pinions at its ends, and the plurality of second provisions (302) are accommodated with second shafts (105a, 105b), and each of the second shafts (105a, 105b) carry another set of differential pinions at their ends.. A substantially central portion of the first shaft (105a) is configured to reside in the first provision (301), and ends of the second shafts (105a, 105b) are configured to reside in the second provisions (302) respectively. The substantially central portion of the first and end portions of the second shafts (105a, 105b) have predetermined cross-sections which conform to the cross-sections of first and second provisions (301, 302), so that the end portions have close sliding fit when they reside inside the provisions (301, 302). At the time of transferring forces between axles (101a, 101b) by the thrust block (106), the position of first shaft (301a) and the second shafts (105a, 105b) remains unchanged, and only the thrust block (106) can have displacement along the axis (X-X). The presence of predetermined clearance (305a, 305b) in the first and second provisions (301, 302) facilitates this axial displacement. In an embodiment of the present disclosure, the first shaft (301a) extends for entire depth of the thrust block (106) through the first provision (301), and the at least one second shaft (105a, 105b) extend only though predetermined depth inside the thrust block (106) in the plurality of second provisions (302). This prevents first shaft (301a) from coming in contact with at least one second shaft (105a, 105b). In an embodiment of the present disclosure, number of second shafts (105a, 105b) is two, wherein each of the second shafts (105a, 105b) are configured as half shafts. Each of the half shafts carries one pinion. The thrust block (106) as illustrated in FIGS. 2 and 3 showing one first shaft (301a) and two second shafts (105a, 105b) is only an exemplary embodiment of the present disclosure and is solely intended for the purpose of illustration. In an embodiment of the disclosure, the first shaft (105a) can be configured as two half shafts, having similar configuration as the plurality of second shafts. One can configure any number of second provisions and any number of second shafts in the thrust block and the above configuration of two second shafts should not be considered as limitation to the present disclosure.

The first shaft (301a) and the at least one second shaft (105a, 105b) are provided with one or more gears called differential pinions or spider gears or simply, pinions. More specifically, the first shaft (301a) [shown in FIG. 2] is provided with a pair of first pinions (103a) at its ends, and each of the at least one second shaft (105a, 105b) is provided with a second pinion (103b) [shown in FIGS. 2 and 3]. The first and second pinions (103a, 103b) are essentially planetary gears which can revolve or orbit around the differential side gears (102a, 102b). Each of the pair of first pinions (103a) and second pinions (103b) simultaneously mesh with both the side gears (102a, 102b), and aid in improved transmission of torque from transmission shaft (500) to axles (101a, 101b). The first and second differential pinions (103a, 103b) are oriented such that their axes are perpendicular to coinciding axes X-X of the axles (101a, 101b) (and therefore to the side gears (102a, 102b)). Usually, the differential pinions (103a) are pivotally connected to carrier arms (not shown) projecting from periphery of the annular gear (501). The carrier arms [not shown] are permanently fixed to the periphery of the annular gear (501) by processes including but not limiting to welding. The carrier arms are disposed on the annular gear (501) such that each of the first and second pinions (103a, 103b) is spaced apart by 90 degree from adjacent pinions measured along coinciding axis of the axles (101a, 101b). When the annular gear (501) rotates, the first and second pinions (103a, 103b) revolve around the side gears (102a, 102b). The revolution of first and second pinions (103a, 103b) drives the side gears (102a, 102b), and thereby transmits power to axles (101a, 101b). In addition to revolving motion, the first and second pinions (103a, 103b) can also rotate about their respective axes.

The working of differential gear assembly (100) is as follows. Firstly, the drive gear (501) rotates along with the transmission shaft (500) depending on the gear ratio selected by the operator. The rotation of drive gear (501) causes rotation of annular gear (200) with an angular velocity. The rotation of annular gear (200) in turn causes revolution of a pair of first and second pinions (103a, 103b) around the side gears (102a, 102b) about the coinciding axis X-X of the axles (101a, 101b). The side gears (102a, 102b) which are in meshing engagement with each of the pair of first and second pinion (103a, 103b) rotate with an angular velocity. The rotation of side gears (102a, 102b) subsequently provides driving torque to axles (101a, 101b), and thereby results in rotation of the drive wheels which propels the vehicle. When the vehicle moves along a straight line, the axles (101a, 101b) are imparted with equal torque by the pinions (103a, 103b) so that both axles (101a, 101b) rotate with same angular speed. But when vehicle takes a turn, say towards right, the left wheel of the vehicle has to trace a longer arcuate path than the right wheel, without hindering the movement of vehicle, i.e. without imparting any decelerating force to the vehicle. To accomplish this, the left wheel should turn or rotate at a faster speed than the right wheel, so that the axles (101a, 101b) remain in aligned condition. In other words, the axle carrying the left wheel is imparted with more twisting moment than the axle carrying right wheel so that both the axles rotate together in phase, and left wheel will successfully trace the arcuate path. Similarly, when vehicle takes a turn towards left, the axle carrying right wheel is imparted with more torque so that the vehicle takes the turn smoothly. The difference in torque (and hence the speed) is called differential torque (or differential speed) which is provided by the differential assembly (100). This is explained in greater detail as follows. When vehicle takes a turn, say towards right, the pinions (103a, 103b) which normally revolve around the side gears (102a, 102b) start rotating about their own axes. Since during right turn left wheel is to be rotated at more angular speed, the rotating and revolving pinions (103a, 103b) impart more torque on the side gear (102a) mounted on the left axle (101a). This causes the side gear (102a) on left axle (101a) to rotate at a speed greater than the speed of side gear (102b) mounted on right axle (101b), which enables it to overcome necessary rolling friction, thereby aiding the vehicle in successfully tracing the arcuate path. Similarly, during left turn, right wheel is to be rotated with more speed. To achieve this, the rotating and revolving pinions (103a, 103b) are configured to impart more torque on the side gear (102b) mounted on the right axle (101b). This causes the side gear (102b) on right axle (101b) to rotate at a speed greater than the speed of side gear (102a) mounted on left axle (101a), thereby enabling it to overcome necessary rolling friction to aid the vehicle in successfully tracing the arcuate path. The above example which is illustrated considering first axle (101a) as left axle and second axle (101b) as right axle is for the purpose of illustration only and is not in any way limiting the scope of present disclosure.

In exemplary embodiment of the present disclosure, the thrust block can be retrofitted, and is configured as a device (106) for transferring forces between axles (101a, 101b) in a semi-float axle differential assembly (100) of a vehicle. Referring to FIGS. 2 and 3, the device (106) comprises a block slidably disposable between the axles (101a, 101b) in the semi-float axle differential assembly (100). A first provision (301) extends through the block in a first direction (along A-A), and accommodates at least one pair of first pinions (103a) through a first shaft (301a). In addition, the block is provided with a plurality of second provisions (302) is provided in second direction (along B-B), where each of the plurality of second provisions (302) is configured to accommodate at least one second pinion (103b) through at least one second shaft (105a, 105b). The first provision (301) and the plurality of second provisions (302) are configured with predetermined clearance (305a, 305b) to facilitate sliding movement of the block relative to the first shaft (301a) and the at least one second shaft (105a, 105b) provided in the first provision (301) and each of the plurality of second provisions respectively (302).

It is to be understood that a person of ordinary skill in the art would design a semi-float axle differential assembly of any configuration without deviating from the scope of the present disclosure. Further, various modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.

Advantage(s):
The present disclosure provides a differential assembly for semi-float axles which can accommodate one or more pairs of pinions to transmit torque to the axles and therefore to drive wheels. The presence of plurality of pinions result in improved torque distribution in the differential and provides increased control over traction forces, particularly when vehicle takes a turn.
The present disclosure provides a differential assembly for semi-float axles which having a thrust block capable of floating or sliding between the axles to transfer thrust loads. The presence of thrust block increases the durability of axles and bearings of the wheel assembly in the differential casing.

The present disclosure provides a differential assembly for semi-float axles in which the first and second provisions in the thrust block is configured with clearances for close sliding fit between the pinions shafts and thrust block. This ensures smooth transmission of torque by pinions to axles and smooth transfer of thrust loads by thrust block to wheel end bearings without interference.

The present disclosure provides a differential assembly for semi-float axles in which the thrust block can be easily assembled and disassembled from the differential assembly. This makes the thrust block retro-fittable and allows easy maintenance and replaceability.

Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

TABLE OF REFERRAL NUMERALS

Referral Numerals Description
100 Semi-float axle differential assembly
101a and 101b First and second axles
102a, 102b Side gears
105a, 105b Second shafts
103a First pinions
103b Second pinions
106 Thrust Block
200 Annular gear
250 Differential casing
301 First provision
301a First shaft
302 Plurality of second provisions
305a Predetermined clearance in first provision
305b Predetermined clearance in second provision
500 Transmission shaft
501 Drive gear
X-X Co-inciding axes of axles
A-A Axis of first provision
B-B Axis of second provisions
,CLAIMS:We claim:
1. A semi-float axle differential assembly (100) for a vehicle, comprising:
a differential casing (250) for supporting the semi-float axle differential assembly (100);
a first axle (101a) and a second axle (101b) extending outwardly from the semi-float axle differential assembly (100), and at least one side gear (102a, 102b) is mounted on each of the first axle (101a) and the second axle (101b); and
a thrust block (106) slidably disposed in between the first axle (101a) and the second axle (101b), the thrust block (106) comprising:
a first provision (301) extending through the thrust block (106) in a first direction, wherein, the first provision (301) accommodates at least a pair of first pinions (103a) through a first shaft (301a); and
a plurality of second provisions (302) provided in the thrust block (106) in a second direction, wherein, each of the plurality of second provisions (302) is configured to accommodate at least one second pinion (103b) through at least one second shaft (105a, 105b);
wherein, the first provision (301) and the plurality of second provisions (302) are configured with predetermined clearance (305a, 305b) to facilitate sliding movement of the thrust block (106) relative to the first shaft (301a) and the at least one second shaft (105a, 105b) provided in the first provision (301) and each of the plurality of second provisions (302) respectively.

2. The assembly (100) as claimed in claim 1, wherein, the first provision (301) and the plurality of second provisions (302) are at least one of slots, bores and holes.

3. The assembly (100) as claimed in claim 2, wherein cross-section of the first provision (301) and the plurality of second provisions (302) is at least one of rectangular and square.

4. The assembly (100) as claimed in claim 3, wherein cross-section of a portion of the first shaft (301a) and the at least one second shaft (105a, 105b) which resides in first provision (301) and the plurality of second provisions (302) respectively is at least one of square, circular and rectangular.

5. The assembly (100) as claimed in claim 1, wherein an axis A-A of the first provision (301) and an axis B-B of the plurality of second provisions (302) are configured at substantially right angles to one another in the thrust block (106).

6. The assembly (100) as claimed in claim 1, wherein, the first provision (301) extends for entire depth of the thrust block (106) in the first direction.

7. The assembly (100) as claimed in claim 1, wherein the plurality of second provisions (302) extend upto predetermined depth in the second direction in the thrust block (106).

8. The assembly (100) as claimed in claim 7, wherein the predetermined depth of the plurality of second provisions (302) is provided such that the plurality of second provisions (302) are not in contact with the first provision (301).

9. The assembly (100) as claimed in claim 1, wherein the pair of first pinions (103a) are configured on either end of the first shaft (301a).

10. The assembly (100) as claimed in claim 1, wherein the at least one second pinion (103b) is mounted at an end of the at least one second shaft (105a, 105b).

11. The assembly (100) as claimed in claim 1, wherein, the pair of first pinions (103a) and the at least one second pinion (103b) are configured to be in meshing engagement with the at least one side gear (102a, 102b).

12. A device (400) for transferring forces between axles (101a, 101b) in a semi-float axle differential assembly (100) of a vehicle, the device (400) comprising:
a block (106) slidably disposable between the axles (101a, 101b) in the semi-float axle differential assembly (100);
a first provision (301) extending through the block (106) in a first direction, wherein, the first provision (301) accommodates at least a pair of first pinions (103a) through a first shaft (301a); and
a plurality of second provisions (302) provided in the block (106) in a second direction, wherein, each of the plurality of second provisions (302) is configured to accommodate at least one second pinion (103b) through at least one second shaft (105a, 105b);
wherein, the first provision (301) and the plurality of second provisions (302) are configured with predetermined clearance (305a, 305b) to facilitate sliding movement of the block (106) relative to the first shaft (301a) and the at least one second shaft (105a, 105b) provided in the first provision (301) and each of the plurality of second provisions (302) respectively.

13. A vehicle comprising a semi-float axle differential assembly (100) as claimed in claim