DESC:FIELD
The present disclosure relates in general to roller bearings and in particular, it relates to preloaded taper roller bearings.
DEFINITION
Preloading: Preloading is the process of applying an external load to a component for various reasons. Preloading is performed in taper roller bearings to eliminate any internal clearance and produce an interference fit by pushing an inner race of the taper roller bearing towards an outer race of the taper roller bearing.
BACKGROUND
In conventional preloaded roller bearings, such as preloaded roller bearings 100 shown in Figure 1, inner races 115 are placed separately and are preloaded on an external member, such as a shaft 105. Such preloading is carried out by the use of dead weights, springs, or tightening nuts 125. Since the preloading is carried out on the shaft 105, the shaft 105 has to bear an additional load of the pre-loading arrangement used along with its functional load. Any kind of additional load acting on the shaft during the course of its operation may harm the shaft and reduce the life of the shaft. Moreover, apart from affecting the performance of the shaft, the additional load may even result in undesired vibrations, which also hinder the lifespan of the shaft.
Further, the separate placement of the inner races affects the rigidity of roller bearing 110 and may also cause unwanted vibrations. Again such vibrations have an adverse effect on the roller bearings 110 and may cause an untimely failure of the same. Further, separate outer races 120 as well as the housing 130 add not only to the cost of the whole assembly but also make it less rigid. Hence, there is a need for a preloaded taper roller bearing in which the above mentioned drawbacks are addressed.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as follows:
An object of the present disclosure is to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Another object of the present disclosure is to provide a new arrangement for arranging inner races of a preloaded taper roller bearing.
Yet another object of the present disclosure is to provide a pre-loading arrangement, wherein the inner races are not placed separately on the shaft.
Yet another object of the present disclosure is to provide a pre-loading arrangement that increases the rigidity of the subsystem consisting of the taper roller bearing.
Another object of the present disclosure is to provide an arrangement for pre-loading a preloaded taper roller bearing such that it does not involve the use of dead weights or springs.
Yet another object of the present disclosure is to provide an arrangement wherein the outer race for the preloaded taper roller bearing is integrated in the housing.
Still another object of the present disclosure is to provide a preloaded taper roller bearing which is a “ready to fit” solution.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
Described herein is a preloaded taper roller bearing comprising a first roller cage assembly having a first set of rollers and a second roller cage assembly having a second set of rollers, each set of rollers accommodated inside a cage element, the first set of rollers adapted to rotate within a first inner race, the second set of rollers adapted to rotate within a second extended inner race, the first inner race disposed on an inside of the second extended inner race and adapted to move in an axial direction on the second extended inner race, a spacer in the form of a ring placed in between the first inner race and the second extended inner race, and a tightening nut coupled to an extended portion of the second extended inner race to provide a pre-load to the roller bearings.
In an embodiment, the second extended inner race extends along an axial direction and has a profile resembling a hollow tube.
In an embodiment, one end of the second extended inner race is configured to receive the second roller cage assembly, while another end extends beyond the first inner race.
In an embodiment, the first inner race is disposed on the extended portion of the second extended inner race.
In an embodiment, an external threading is provided near a distal end of the extended portion of the second extended inner race to receive a complementary internal threading of the tightening nut.
In an embodiment, the first inner race has a profile complementary to the first taper roller bearing assembly.
In an embodiment, the first inner race receives the first roller cage assembly on its race surface and the tightening nut on an outer protruded surface.
In an embodiment, tightening of the tightening nut causes the second extended inner race and the first inner race to move towards one another.
In an embodiment, end faces of the spacer are in direct contact with the respective faces of the first inner race and the second extended inner race.
In an embodiment, a snap ring is mounted on a groove provided at a distal end of the extended portion of the second extended inner race to lock a movement of the tightening nut.
In an embodiment, an integrated housing with an in-built outer race portion acts as a common outer race for the first and second roller cage assemblies.
In an embodiment, the outer race portion of the integrated housing has a flange portion to facilitate assembly of the preloaded taper roller bearing.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
The present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a sectional view of a conventional preloading arrangement of tapered roller bearing; and
Figure 2 illustrates a sectional view of a preloaded tapered roller bearing, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
A preloaded taper roller bearing with a novel assembly will now be described with reference to the embodiments, which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration. The embodiment herein, the various features, and advantageous details thereof are explained with reference to the non-limiting embodiments 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.
The description hereinafter 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.
Figure 2 illustrates a sectional view of the preloaded taper roller bearing 200, in accordance with an embodiment of the present disclosure. The preloaded taper roller bearing 200 is shown mounted on a shaft 205. In an embodiment, the preloaded taper roller bearing 200 comprises a first and second set of rollers 210' and 210?, collectively referred to as rolling elements 210, accommodated inside respective cage element 215 (each set of the rolling elements 210 along with the respective cage element 215 being collectively referred to as the roller cage assembly), the first set of rollers 210' adapted to rotate within a first inner race 225 while the second set of rollers 210? adapted to rotate within a second extended inner race 230, the first inner race 225 disposed on an inside of the second extended inner race 230, in particular on an extended portion of the second extended inner race 230, and is adapted to move in an axial direction on the second extended inner race 230.
Further, a tightening nut 235 provides a pre-load to the rolling elements 210 and a snap ring 240 locks a movement of the tightening nut 235 in an axial direction. A spacer 220 in the form of a ring is placed in between the first inner race 225 and the second extended inner race 230 to increase the rigidity of the preloaded taper roller bearing 200.
In an embodiment, the second extended inner race 230 extends along an axial direction and has a profile resembling a hollow tube. One end of the second extended inner race 230 has a profile configured to receive a taper roller bearing assembly, while the other end extends beyond the first inner race 225. Further, an external threading 227 is provided near a distal end of the extended portion of the second extended inner race 230 to receive a complementary internal threading of the tightening nut 235.
Further, the first inner race 225 is disposed on the extended portion of the second extended inner race 230. As can be seen in Figure 2, the first inner race 225 is also configured to receive on its tapered profile a taper roller bearing assembly on its race surface and the tightening nut 235 on its outer protruded surface. Thus, the second extended inner race 230 and the first inner race 225 are placed in a strictly mating position, which does not allow any relative movement between the two. Such a disposition of the two races 225 and 230 increases the rigidity of the preloaded taper roller bearing 200, which in turn results in lesser vibrations and better performance.
As the tightening nut 235 is disposed on the external threading formed at the distal end of the extended portion of the second extended inner race 230 and not on an external member, such as the shaft 205, no additional load acts on the shaft 205. This leads to less wear and tear of the shaft 205. Further, as the tightening nut 235 is in direct contact with the first inner race 225, upon tightening of tightening nut 235, the first inner race 225 along with the respective cage element 215 and the first set of rollers 210' is assembled in an axial direction from one end of an integrated outer race with housing towards the second extended inner race 230. The second extended inner race 230 along with the respective cage element 215 and the second set of rollers 210? is assembled in a direction opposite to the direction in which the first inner race 225 is assembled. As such, the tightening causes the second extended inner race 230 and the first inner race 225 to move towards one another, thus inducing a pre-load in the roller bearings 210. In this way, a pre-loading arrangement is achieved.
Furthermore, the snap ring 240 is mounted on a groove provided at the distal end of the extended portion of the second extended inner race 230. The snap ring 240 locks a movement of the tightening nut 235 in the axial direction to maintain the pre-load provided by the tightening of the tightening nut 235.
Further, the spacer 220 is disposed between the second extended inner race 230 and the first inner race 225 such that its end faces are in direct contact with the respective faces of the inner races 225 and 230. The function of the spacer 220 is to provide additional rigidity to the preloaded taper roller bearing 200 as well as prolonged retention of the pre-load in the preloaded taper roller bearing 200.
Further, an integrated housing 245 having an in-built outer race accommodates the two inner races 225 and 230. The integrated housing 245 provides for a common outer race for the two rows of the rolling elements 210 and at the same time acts as an enclosure for the whole of the assembly. Such a construction results in the saves the manufacturing and assembly cost. In an embodiment, the outer race has a flange portion, which facilitates the insertion of the second extended inner race 230 with respective roller bearing and cage element from one side, and subsequently insertion of the spacer 220 and the first inner race 225 with respective roller bearings and cage element from the other side. Thus the construction of the integrated housing 245 also simplifies the installation of the preloaded taper roller bearing 200, thus making it a “ready to fit” solution. In an embodiment, the integrated housing 245 may be manufactured with two separate outer races, each covering separately the two inner races 225 and 230. Also, depending on the application requirements, the integrated housing 245 may not have the flange portion.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The preloaded taper roller bearing of the present disclosure described herein above has several technical advantages including but not limited to the realization of:
? A compact taper roller bearing structure having a simple pre-loading arrangement that does not involve the use of dead weight or springs;
? A roller bearing with increased rigidity, which results in prolonged pre-load retention in the bearing; and
? A “ready to fit” solution that can be accommodated into existing preloaded taper roller bearings.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. ,

CLAIMS:
1. A preloaded taper roller bearing (200) comprising:
a first roller cage assembly having a first set of rollers (210') and a second roller cage assembly having a second set of rollers (210?), each set of rollers accommodated inside a cage element (215), the first set of rollers (210') adapted to rotate within a first inner race (225), the second set of rollers (210?) adapted to rotate within a second extended inner race (230), the first inner race (225) disposed on an inside of the second extended inner race (230) and adapted to move in an axial direction on the second extended inner race (230);
a spacer (220) in the form of a ring placed in between the first inner race (225) and the second extended inner race (230); and
a tightening nut (235) coupled to an extended portion of the second extended inner race (230) to provide a pre-load to the roller bearings (210).
2. The preloaded taper roller bearing (200) as claimed in claim 1, wherein the second extended inner race (230) extends along an axial direction and has a profile resembling a hollow tube.
3. The preloaded taper roller bearing (200) as claimed in claim 1, wherein one end of the second extended inner race (230) is configured to receive the second roller cage assembly, while another end extends beyond the first inner race (225).
4. The preloaded taper roller bearing (200) as claimed in claim 1, wherein the first inner race (225) is disposed on the extended portion of the second extended inner race (230).
5. The preloaded taper roller bearing (200) as claimed in claim 1, wherein an external threading (227) is provided near a distal end of the extended portion of the second extended inner race (230) to receive a complementary internal threading of the tightening nut (235).
6. The preloaded taper roller bearing (200) as claimed in claim 1, wherein the first inner race (225) has a profile complementary to the first taper roller bearing assembly.
7. The preloaded taper roller bearing (200) as claimed in claim 1, wherein the first inner race (225) receives the first roller cage assembly on its race surface and the tightening nut (235) on an outer protruded surface.
8. The preloaded taper roller bearing (200) as claimed in claim 1, wherein tightening of the tightening nut (235) causes the second extended inner race (230) and the first inner race (225) to move towards one another.
9. The preloaded taper roller bearing (200) as claimed in claim 1, wherein end faces of the spacer (220) are in direct contact with the respective faces of the first inner race (225) and the second extended inner race (230).
10. The preloaded taper roller bearing (200) as claimed in claim 1 comprises a snap ring (240) mounted on a groove provided at a distal end of the extended portion of the second extended inner race (230) to lock a movement of the tightening nut (235).
11. The preloaded taper roller bearing (200) as claimed in claim 1 comprises an integrated housing (245) with an in-built outer race portion acting as a common outer race for the first and second roller cage assemblies.
12. The preloaded taper roller bearing (200) as claimed in claim 11, wherein the outer race portion of the integrated housing has a flange portion to facilitate assembly of the preloaded taper roller bearing (200).