Description:TECHNICAL FIELD
[001] The embodiments herein relate generally to an arrangement for preloading of tapered roller bearings in a pinion shaft assembly and, more particularly to an arrangement for preloading of tapered roller bearings on a tail pinion shaft of a vehicle transmission system.
BACKGROUND
[002] A pinion shaft is an important component of a gear train assembly of a vehicle. The pinion shaft transmits power from gearbox to crown wheel through right angle drive to suit the tractor wheels and to reduce the speed of rotation. The constant movement/rotation of the pinion shaft causes friction resulting in wear and tear of the pinion shaft. Bearings are used on the pinion shaft assembly to reduce the friction and wear and tear caused by the movement/rotation of the pinion shaft. In differential gearboxes, tapered roller bearings are used on pinion shaft to support the movement/rotation pinion shaft and lower the friction caused during its movement/rotation. The continuous movement/rotation of the pinion shaft results in the radial and axial displacement of the tapered roller bearings. Such displacement may cause the loosening of the tapered roller bearings affecting the rotation/movement of the pinion shaft. Loosening of the tapered roller bearings is not desirable specially in systems which require high precision and speed such as automotives/vehicles. The loosening of the bearings causes noise in the vehicle while accelerating or decelerating the vehicle, affecting the performance of the vehicle.
[003] Therefore, to secure the tapered roller bearings tightly on a pinion shaft, a predetermined axial tolerance or load called as a preload is required which will prevent the loosening of the bearings. The preload increases the rigidity of the bearing, prevents sliding or wobbling of the bearing and assists in maintaining the relative position of bearing elements.
[004] Conventionally, an assembly consisting of a pair of lock nut and a washer is used to secure the position of the tapered roller bearings on the pinion shaft. The locknuts are tightened against the tapered roller bearing to achieve the desired preload, while a washer is inserted to avoid loosening of the nuts. This assembly of the lock nuts is not effective in case of smaller contact area with smaller module spline and small diameter shaft, as the locknuts loosens tendency of preloading over time due to the continuous movement of the pinion shaft and the lack of sufficient contact area with the pinion shaft, thereby resulting in the loosening of the tapered roller bearings.
[005] Therefore, there is a need for a preloading mechanism for tapered roller bearings on pinion shaft which does not loosen from the tail pinion shaft, and which eliminates the aforementioned drawbacks.
OBJECTS
[006] The principal object of an embodiment of this invention is to provide an arrangement for preloading of a tapered roller bearing of a tail pinion shaft of a vehicle transmission system.
[007] Another object of an embodiment of this invention is to provide the arrangement for preloading the tapered roller bearing of the tail pinion shaft which does not loosen over time and secures the tapered roller bearing to the tail pinion shaft.
[008] Yet another object of an embodiment of this invention is to provide the arrangement for preloading the tapered roller bearing of the tail pinion shaft which may be easily integrated with the existing tail pinion shaft assembly the vehicle transmission.
[009] Still another object of an embodiment of this invention is to provide the arrangement for preloading the tapered roller bearings of the tail pinion shaft which is cost effective and easy to manufacture.
[0010] Yet another object of an embodiment of this invention is to provide the arrangement for preloading the tapered roller bearings of the tail pinion shaft which increases the durability of the tail pinion shaft assembly by preventing loosening of the tapered roller bearings.
[0011] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0013] FIG. 1 depicts a conventional arrangement of preloading of tapered roller bearings on a tail pinion shaft assembly;
[0014] FIG. 2 depicts a perspective view of a crimping nut of the arrangement, according to an embodiment of the invention as disclosed herein;
[0015] FIG. 3 depicts a perspective view of a lock nut hub of the arrangement, according to an embodiment of the invention as disclosed herein;
[0016] FIG. 4a depicts an exploded view of the crimping nut engaging with the lock nut hub, according to an embodiment of the invention as disclosed herein;
[0017] FIG. 4b depicts a perspective view of the crimping nut assembled to the lock nut hub, according to an embodiment of the invention as disclosed herein;
[0018] FIG. 5 depicts a sectional view of the arrangement of the lock nut hub and crimping nut on the tail pinion shaft for preloading the tapered roller bearing, according to an embodiment of the invention as disclosed herein;
[0019] FIG. 6 is an exploded view of the arrangement for preloading the tapered roller bearings of the tail pinion shaft, according to an embodiment of the invention as disclosed herein; and
[0020] FIG. 7 is a flowchart depicting a method of providing an arrangement for preloading a taper roller bearing of the tail pinion shaft, according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0021] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0022] The embodiments herein achieve an arrangement for preloading of a tapered roller bearing of a tail pinion shaft of a vehicle transmission system. Further, the embodiments herein achieve the arrangement for preloading the tapered roller bearing of the tail pinion shaft which does not loosen over time and secures the tapered roller bearing to the tail pinion shaft. Furthermore, the embodiments herein achieve the arrangement for preloading the tapered roller bearing of the tail pinion shaft which may be easily integrated with the existing tail pinion shaft assembly the vehicle transmission. Additionally, the embodiments herein achieve the arrangement for preloading the tapered roller bearings of the tail pinion shaft which is cost effective and easy to manufacture. Moreover, the embodiments herein achieve the arrangement for preloading the tapered roller bearings of the tail pinion shaft which increases the durability of the tail pinion shaft assembly by preventing loosening of the tapered roller bearings. Referring now to the drawings, and more particularly to FIGS. 1 through 7, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0023] A tail pinion shaft is the main driver component of a gear train assembly of a vehicle transmission. The constant movement of the tail pinion shaft causes friction resulting in wear and tear. In differential gearboxes, tapered roller bearings are used on the tail pinion shaft to support the movement of the tail pinion shaft and lower the friction caused during its movement. The continuous movement of the tail pinion shaft results in the radial and axial displacement of the tapered roller bearings resulting in loosening of the bearings. Therefore, to secure the tapered roller bearings tightly on the tail pinion shaft, a predetermined axial tolerance or load is required which will prevent the loosening of the bearings.
[0024] The tail pinion shaft (104) includes a cylindrical body (104b) comprising of a first end and a second end. The tapered roller bearing (105) is connected towards the second end. The tail pinion shaft (104) includes a bevel gear (BG) at the second end. Further, the tail pinion shaft (104) includes a plurality of external splines (104a) defined between the first end and the second end. The tapered roller bearing (105) comprises of a head tapered roller bearing and a tail tapered roller bearing, constituting a tapered roller bearing pair. The tapered roller bearing pair is inserted on the tail pinion shaft (104) to reduce the friction caused due to the movement of the tail pinion shaft (104).
[0025] FIG.1 depicts the conventional arrangement of preloading of tapered roller bearings on a tail pinion shaft assembly. The arrangement includes a pair of lock nuts and a washer. The locknuts are tightened against the tapered roller bearings to provide preloading. The washer is inserted to avoid loosening of the lock nuts. This arrangement provides the desired preload to the tapered roller bearings. However, the lock nut loosens over time due to the constant radial and axial displacement/ motion of the tapered roller bearings and the rotation of the tail pinion shaft. The loosening of the lock nuts is primarily caused because of lack of sufficient contact area for the lock nuts with the tail pinion shaft.
[0026] FIG. 5 depicts a sectional view of the arrangement of the lock nut hub and crimping nut on the tail pinion shaft for preloading the tapered roller bearing, according to an embodiment of the invention as disclosed herein. In an embodiment, the arrangement (100) includes a lock-nut hub (101), a crimping nut (102), and a circlip (103). The arrangement (100) includes the lock nut hub (101) which includes a centrally defined bore (101b1) for receiving the tail pinion shaft (104) within the bore (101b1) and a first annular body (101b2) as shown in FIG. 3. Further, the lock nut hub (101) includes a plurality of external threads (not shown) which are defined on an outer region of the lock nut hub (101). The external threads (not shown) are defined so that the crimping nut (102) is engaged to the lock nut hub (101). Further, a plurality of internal splines (101a) are defined in an inner region of the lock nut hub (101) which are configured to engage with the external spines (ES) provided on the tail pinion shaft (104), thereby forming an interlock between the lock nut hub (101) and the tail pinion shaft (104). The internal splines extend from one side of the body (101b2) to the other of the body (101b2). The body (101b2) of the lock nut hub (101) also includes a crimping slot (101s) defined on an outer region of the lock nut hub (101) at a predetermined position. The locknut hub (101) is positioned adjacently to a tail tapered roller bearing (105a).
[0027] FIG. 2 depicts a perspective view of the crimping nut of the arrangement, according to an embodiment of the invention as disclosed herein. The arrangement includes the crimping nut (102) which has a centrally defined aperture (102a) and a plurality of internal threads (not shown) to engage with the external threads (not shown) of the lock-nut hub (101). A profile of the centrally defined aperture of the crimping nut (102) matches the profile of the outer region of the lock nut hub (101).
[0028] FIG. 4a depicts an exploded view of the crimping nut engaging with the lock nut hub, according to an embodiment of the invention as disclosed herein. FIG. 4b depicts a perspective view of the crimping nut assembled to the lock nut hub, according to an embodiment of the invention as disclosed herein. The bore (101b1) defined in the lock nut hub (101) includes an inner diameter d1 and an outer diameter d2. The bore (101b1) defined to receive the tail pinion shaft (104). The crimping nut (102) includes the centrally defined aperture (102a) which includes an inner diameter d3 and an outer diameter d4. The inner diameter d1 of the lock nut hub (101) is configured to receive the tail pinion shaft (104), while the inner diameter d3 of the crimping nut is adapted to receive the lock nut hub (101) i.e, the lock nut hub (101) and the crimping nut (102) are co-axial. Further, the crimping nut (102) is crimped to the lock nut hub (101) manually at the crimping slot (101b), whereby the crimping nut (102) is affixed to the lock nut hub (101). The tightening of the crimping nut (102) on the lock nut hub (101) provides the required preloading/load/force on the tapered roller bearing pair (105). The crimping of the crimping nut (102) on the lock nut hub (101) eliminates the relative movement of the crimping nut (102) and the lock nut hub (101). In an embodiment, the crimping nut is tightened using a special tool (conventional tool) such as wrench.
[0029] FIG. 6 is an exploded view of the arrangement for preloading the tapered roller bearings of the tail pinion shaft, according to an embodiment of the invention as disclosed herein. Further, the arrangement (100) includes the circlip (103) which is inserted within a slot defined on the tail pinion shaft (104). The circlip (103) is positioned adjacently to the lock nut hub (101) on the tail pinion shaft (104). The circlip (103) acts as a stopper and prevents the axial movement or displacement of the lock nut hub (101) relative to the tail pinion shaft (104).
[0030] The arrangement (100) provides an increased rigidity to the tapered roller bearings (105) by eliminating the possibility of loosening of the preloading arrangement. The use of the lock nut hub (101) provides an increased contact area for the crimping nut (102). In an embodiment, a preload value applied on the tapered roller bearings (105) is measured by a torque wrench meter.
[0031] FIG. 7 is a flowchart depicting a method of providing an arrangement for preloading a taper roller bearing of the tail pinion shaft, according to an embodiment of the invention as disclosed herein. The method (200) of providing an arrangement for preloading a taper roller bearing of the tail pinion shaft includes assembling a crimping nut (102) on a lock nut hub (102) (at step 202). Further, the method (200) includes installing said crimping nut (102) along with said lock nut hub (102) to a tail pinion shaft (at step 204). Furthermore, the method (200) includes disposing an external lug circlip (103) adjacent to said lock nut hub (101) on said tail pinion shaft (104) (at step 206). Additionally, the method (200) includes tightening said crimping nut (102) to preload said taper roller bearing (105) (At step 208). Moreover, the method (200) includes crimping the crimping nut (102) in both slots defined in the lock nut hub (101) to avoid loosening of said crimping nut (102) (At step 210).
[0032] The technical advantages achieved by the embodiments disclosed herein include effective preloading for tapered roller bearings on a tail pinion shaft, eliminating the possibility of loosening of the preloading arrangement and the tapered roller bearings, increased durability of preloading arrangement, cost effective and ease of integration with the tail pinion shaft assembly without affecting the length of the transmission of the vehicle.
[0033] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
, C , C , Claims:We Claim:
1. An arrangement (100) for preloading a tapered roller bearing (105) of a tail pinion shaft (104), said arrangement (100) comprising:
a lock nut hub (101) engaged to said tail pinion shaft (104), said lock nut hub (101) disposed adjacent to said tapered roller bearing (105);
a crimping nut (102) engaged to said lock nut hub (102); and
at least one circlip (103) disposed adjacent to said lock nut hub (101) on said tail pinion shaft (104),
wherein,
tightening of said crimping nut (102) on said lock nut hub (101) applies a predetermined load on said tapered roller bearing (105).
2. The arrangement (100) as claimed in claim 1, wherein said lock nut hub (101) includes:
a bore (101b1) defined centrally and a first annular body (101b2), said bore (101b1) having an inner diameter d1 and an outer diameter d2, said bore (101b1) adapted to receive said tail pinion shaft (104);
a plurality of internal splines (101a) defined in an inner region of said body (101b2), said plurality of internal splines (101a) extends from one side of said body (101b2) to the other side; and
a plurality of external threads (not shown) defined on an outer region of said body (101b2), and
a crimping slot (101s) defined in said outer region of said body (101b2) at a predetermined position.
3. The arrangement (100) as claimed in claim 2, wherein lock nut hub (101) receives the tail pinion shaft (104) such that the plurality of internal splines (101a) of said lock nut hub (101) receive a plurality of external splines (104a) of said tail pinion shaft (104), thereby forming an interlock between said lock nut hub (101) and said tail pinion shaft (104).
4. The arrangement (100) as claimed in claim 1, wherein said crimping nut (102) includes a centrally defined aperture (102a) and a second annular body (102b), said body (102b) having an inner diameter d3 and an outer diameter d4 and a plurality of internal threads (not shown) defined on an inner region of said body (102b).
5. The arrangement (100) as claimed in claim 1, wherein said internal threads of said crimping nut (102) is configured to engage with the external threads defined on said locknut hub (101), said crimping nut (102) is crimped to said lock nut hub (101) manually at said crimping slot (101s), whereby said crimping nut (102) is affixed to said lock nut hub (101).
6. The arrangement (100) as claimed in claim 1, wherein said tail pinion shaft (104) defines at least one slot at a predetermined location to receive said circlip (103), said circlip (103) is adapted to act as stopper for preventing axial movement of said lock nut hub (101) relative to said tail pinion shaft (104).
7. The arrangement (100) as claimed in claim 1, wherein said crimping nut (102) is tightened on said lock nut hub (101) with a predetermined torque to apply said predetermined load/force on said tapered roller bearing (105).
8. A method (200) of providing an arrangement for preloading a tapered roller bearing (105) of the tail pinion shaft (104), comprising:
assembling a crimping nut (102) on a lock nut hub (102);
installing said crimping nut (102) along with said lock nut hub (102) to a tail pinion shaft;
disposing an external lug circlip (103) adjacent to said lock nut hub (101) on said tail pinion shaft (104);
tightening said crimping nut (102) to preload said taper roller bearing (105); and
crimping the crimping nut (102) in both slots defined in the lock nut hub (101) to avoid loosening of said crimping nut (102).