Patent Application
20170059011
The present disclosure relates to a hydraulic belt or chain tensioner with an oil reservoir for inverted installations to prevent leaking from the high-pressure chamber of the tensioner.
This section provides background information related to the present disclosure which is not necessarily prior art.
Hydraulic tensioners are used for applying tension against a chain or belt for preventing chain rattle or belt slippage in an auxiliary drive system of an engine or in other industrial machines. In a typical hydraulic tensioner 100, as shown in
According to the present disclosure, a hydraulic chain or belt tensioner is provided with an oil reservoir for inverted installations. The reservoir is added to the tensioner such that as oil is forced out of the high-pressure chamber the reservoir receives the oil and will hold oil within the high-pressure chamber during shutdown. The reservoir will maintain a sufficient level of oil in the high-pressure chamber to prevent startup chain rattle and inconsistent oil column stiffness.
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.
Example embodiments will now be described more fully with reference to the accompanying drawings.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.
With reference to
The tensioner device 20 can include a pivoting shoe 22 that engages the belt or chain 16 and is pivotable about a pivot 24. A housing or other support structure 26 defines a cavity 28. As best shown in
A seal 44 can be supported by the housing 26 in sliding engagement with the plunger 32 to seal in oil from leaking past the plunger 30. The hydraulic tensioner 20 is designed to be used in an inverted position where the plunger 30 is disposed vertically above the shoe 22 and maintains the pressing force against the shoe 22 in order to tension the belt or chain 16. The spring 32 within the cavity 28 maintains a force against the plunger 30 while the pressurized oil within the cavity damps movement of the plunger 30 to prevent chain or belt rattle or slip. The displacement of the plunger effectively pumps oil from a source and the resistance to flow around the plunger causes an increase in pressure which also creates a reaction force against the plunger that inhibits or damps its motion. The oil supply also includes a check valve 48 to prevent back flowing of oil due to plunger displacement.
Because the reservoir 38 provides oil at startup, there is no delay for maintaining the cavity 28 full so that there is reduced chain rattle at startup and improved chain control. Because the oil is maintained in the reservoir at startup, the damping is initiated right away. In addition, the oil reservoir renders the tensioner device 20 insensitive to being mounted in an inverted orientation.
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.
