Patent Application
20210239157
The present disclosure relates to tensioner having a roller assembly with a bearing and a roller having features for axially securing an outer bearing race of the bearing to the roller.
This section provides background information related to the present disclosure which is not necessarily prior art.
Tensioners of the type that are employed to tension belts commonly have a pivoting arm to which a roller assembly is rotatably mounted. The roller assembly is employed to engage the belt and commonly includes a roller and a bearing that supports the roller for rotation. The roller and the outer bearing race of the bearing can be coupled in various different manners. For example, the outer bearing race can be press-fit into the roller. As another example, the roller can be formed of a plastic material and can be overmolded onto the outer bearing race. In instances where the roller is formed out of a sheet metal, as when the roller is manufactured in a drawing operation, other more costly means of retention, such as snap rings or adhesives have been used. In the case of adhesives, care must also be taken to ensure that the adhesive is fully cured before axially directed loads can be applied to the roller assembly. Moreover, the aforementioned means of retaining the bearing to the roller are relatively sensitive to axially directed loads that can be applied to the roller assembly by the belt in some instances. In such cases, it is possible for the bearing to separate and move axially relative to the roller.
In view of the above drawbacks, there is a need in the art for a tensioner with an improved roller assembly that is easy to manufacture and assemble and is resistant to axially directed forces.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
In one form, the present disclosure provides a tensioner for tensioning a belt. The tensioner includes a base, an arm, which is coupled to the base for movement relative to a movement axis, and a roller assembly having a bearing and a roller. The bearing supports the roller relative to the arm for rotation about a roller axis that is spaced apart from the movement axis. The bearing has an outer bearing race, an inner bearing race, and a plurality of bearing elements that are disposed radially between the outer and inner bearing races. The roller has a wall member that defines a roller member, a bearing socket and one or more locking tabs. The roller member has an annular roller surface that is disposed concentrically about the roller axis and is configured to engage the belt. The bearing socket has an annular bearing surface, which is disposed concentrically within the annular roller surface, and a stop that is disposed radially inwardly from the annular bearing surface. Each of the locking tabs has a proximal end, which is resiliently coupled to an adjacent portion of the wall member, and a distal end that projects radially inward from the proximal end and the annular bearing surface. The bearing is received in the bearing socket such that the outer bearing race is disposed axially between the stop and the distal ends of each of the locking tabs. The one or more locking tabs limit axial movement of the outer bearing race along the roller axis in a direction away from the stop.
In another form, the present teachings provide a method for assembling a tensioner. The method includes: providing a bearing with an outer bearing race; inserting the bearing into a bearing socket in a roller along a roller axis such that distal ends of a plurality of locking tabs formed on the roller are urged in a radially outward direction by an outer circumferential surface of the outer bearing race; seating the bearing in the bearing socket such that the distal ends of the locking tabs release the outer circumferential surface of the outer bearing race and move radially inwardly to limit movement of the outer bearing race axially along the roller axis in a direction toward the distal ends of the locking tabs; securing the bearing to an arm member such that an annular roller surface of the roller is rotatable about the roller axis relative to the arm member; and coupling the arm member to a base for pivoting motion about a pivot axis.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
With reference to
With reference to
In
The bearing socket 46 can have an annular wall 56 and a stop 58. The annular wall 56 can have an annular bearing surface 60 that can be disposed concentrically within the annular roller surface 50. The stop 58 can be disposed radially inwardly from the annular bearing surface 60. In the example shown, the stop 58 is formed by a segment of the wall member 40 that extends radially inward from the annular bearing surface 60.
The bearing socket 46 can be fixedly coupled to the roller member 44 in any desired manner. In the example shown, a transition section 64 of the wall member 40 fixedly couples the bearing socket 46 to the roller member 44. A portion 66 of the transition section 64 is frustoconical in shape and diverges outwardly from a roller axis 68 with increasing radial distance from the annular wall 56. In the example provided, the transition section 64 includes fillet radii 70 at the radially outer and inner ends of the frustoconical portion 66 that couple the frustoconical portion 66 to the roller member 44 and the bearing socket 46 respectively. Configuration of the roller 32 in this manner permits the roller 32 to be fabricated in a deep drawing operation.
With reference to
With reference to
The locking tabs 48 are configured to limit axial movement of the outer bearing race 34 along the roller axis 68 in a direction away from the stop 58, while the stop 58 similarly limits axial movement of the outer bearing race 34 along the roller axis 68 in a direction away from the distal ends 82 of the locking tabs 48. Optionally, the distal ends 82 of the locking tabs 48 can abut an axial end of the outer bearing race 34 that is opposite the axial end of the outer bearing race 34 that abuts the stop 58. Alternatively, one or more spacing elements (not shown) can be disposed axially between the stop 58 and the outer bearing race 34 and/or between the distal ends 82 and the outer bearing race 34.
Returning to
Returning to
With reference to
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
