Patent Application
20200400262
The present disclosure relates to an accumulator having a diaphragm or bladder with a metallized barrier film.
This section provides background information related to the present disclosure which is not necessarily prior art.
Accumulators are commonly used in hydraulic systems as a pressure storage reservoir in which a non-compressible hydraulic fluid is held under pressure by an external source. The external source can be a spring, a raised weight, or a compressed gas. When a compressed gas is used as a spring source, a diaphragm or bladder is typically used between the compressed gas and the hydraulic fluid. A concern with using compressed gas is that the gas can permeate through the diaphragm or bladder and the gas needs to be periodically recharged.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
A diaphragm for an accumulator includes a thermoplastic film formed in a dome shape. A metallic vapor deposition layer is disposed on at least one side of the dome shaped thermoplastic film to form a metallic coated dome shaped film. Inner and outer rubber layers are adhered on opposite sides of the metallic coated dome shaped film. The metallized thermoplastic film provides a barrier film to effectively slow the permeation of a gas such as nitrogen through the diaphragm.
According to a further aspect, a bladder for an accumulator includes a thermoplastic film formed in a bulbous shape. A metallic vapor deposition layer is disposed on at least one side of the bulbous shaped thermoplastic film to form a metallic coated predetermined shaped film. The film shape can be dome-shaped or shaped to correspond with other bladders or diaphragms. Inner and outer rubber layers are adhered on opposite sides of the metallic coated predetermined shaped film. The metallized thermoplastic film provides a barrier film to effectively slow the permeation of a gas such as nitrogen through the bladder.
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.
With reference to
With reference to
The thermoplastic film 24 can be between 4 and 8 mils thick and more particularly about 6 mils thick. The metallic vapor deposition layer 26 can include aluminum or another metal and can be between 1500 and 5000 angstroms thick. The inner and outer rubber layers 28, 30 can have an average thickness of be between 1 mm and 5 mm thick and more particularly about 2 mm thick. The inner and outer rubber layers 28, 30 can include inner and outer sealing beads or features 34 that aid in sealing the diaphragm 18 between the clamp ring 36 and an inner surface of the shell 12. The inner and outer rubber layers 28, 30 can include polyurethanes, HNBR, silicone rubber, fluorocarbon rubber and ECO rubbers.
The metallized thermoplastic film 24/26 provides a barrier film to effectively slow the permeation of a gas such as nitrogen through the diaphragm 18.
With reference to
With reference to
The thermoplastic film 124 can be between 4 and 8 mils thick and more particularly about 6 mils thick. The metallic vapor deposition layer 130 can include aluminum or another metal and can be between 1500 and 5000 angstroms thick. The inner and outer rubber layers 134, 136 can be between 1 mm and 10 mm thick and more particularly about 3 mm thick.
The metallized thermoplastic film 124/130 provides a barrier film to effectively slow the permeation of a gas such as nitrogen through the bladder 118.
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.
