Hydraulic chain tensioner with molded plastic body
AssigneeBorg-Warner Automotive, Inc.
InventorsRoger T. Simpson, Michael C. Duffield, Todd K. Preston
Life of this patent
Estimating the term…
Abstract
A hydraulic tensioner is designed for low cost and ease of manufacturing. A housing has a bore and a sleeve member received within the bore. A piston is slidably received within the sleeve member, forming a high pressure fluid chamber with the sleeve member. The housing can be constructed of inexpensive materials such as aluminum or plastic. The piston and sleeve member are constructed of drawn metal. The housing may be formed by injection molding. The sleeve member and other components of the tensioner may be assembled within the tensioner by inserting them into the mold during the injection molding process.
Claims10
A hydraulic tensioner comprising:
- a plastic housing having a bore formed along a central axis of said housing, said bore having a closed end and an open end;
- a generally cylindrical sleeve member having a first end and a second end, said sleeve member having a hollow cavity between said first end and said second end, said first end of said sleeve member being embedded within said bore and the second end protrudes from the bore, said sleeve member having an inner surface and an outer surface, said bore of said housing being plastic molded about at least a portion of said first end of said outer surface of said sleeve member;
- a hollow piston slidably received within said sleeve member along said inner surface of said second end of said sleeve member, said piston having an inner surface and an outer surface;
- a piston spring biasing said piston in a direction outward from said bore;
- said sleeve member inner surface and said piston inner surface positioned and configured to form a fluid filled chamber;
- said fluid filled chamber adapted to be in connection with a source of pressurized fluid;
- and
- a check valve fixedly located at said first end of said sleeve member, said check valve permitting the flow of fluid from said pressurized fluid source into said fluid filled chamber and restricting the flow of fluid in the reverse direction.
A method of manufacture of a hydraulic tensioner, said tensioner comprising a housing with a bore formed along a central axis of said housing, said bore having a closed end and an open end;
- a generally cylindrical sleeve member having a first end and a second end, said sleeve member having a hollow cavity between said first end and said second end, said first end of said sleeve member being embedded in said bore and the second end protrudes from the bore, said sleeve member having an inner surface and an outer surface;
- a hollow piston slidably received within said sleeve member along said inner surface of said second end of said sleeve member to define a fluid chamber connected with a source of pressurized fluid,
- a check valve fixedly located at said first end of said sleeve member, said check valve permitting the flow of fluid from said pressurized fluid source into said fluid filled chamber and restricting the flow of fluid in the reverse direction, and
- a piston spring biasing said piston in a protruding direction outward from said bore, said method comprising the steps of:
- placing the sleeve member in a mold configured to form the desired housing,
- forming the housing by injection molding, said bore of said housing being molded about at least a portion of said first end of said outer surface of said sleeve member, and
- assembling the piston and piston spring within the sleeve member.
Dependencies are inferred from the claim text.