A belt tensioner for a belt drive

Patent metadata

Field	Value
Publication number	US-2017002902-A1
Application number	US-201415104646-A
Country	US
Kind code	A1
Filing date	Dec 17, 2014
Priority date	Dec 17, 2013
Publication date	Jan 5, 2017
Grant date	—

Abstract

A belt tensioner for a belt drive of a motor vehicle engine, comprising: a fixed part configured to be fixed with respect to the engine and provided with a pivot defining a rotation axis; an arm having a connection portion hinged to the pivot and rotatable about the rotation axis and an opposite portion rotatably supporting a pulley configured to cooperate with a belt of the drive; a main spring interposed between the fixed part and the arm to exert thrust on the arm such as to rotate said arm towards the belt; and at least one rolling bearing interposed between the arm and the pivot to support the arm and ensure the alignment thereof.

First claim

1 . A belt tensioner for a belt drive of a motor vehicle engine, comprising:
a fixed part ( 2 ) configured to be fixed with respect to the engine and provided with a pivot ( 7 ) defining a rotation axis (A); an arm ( 3 ) having a connection portion ( 10 ) hinged to the pivot ( 7 ) and rotatable about the rotation axis (A) and an opposite portion ( 42 ) rotatably supporting a pulley ( 4 ) configured to cooperate with a belt of the drive; a main spring ( 5 ) interposed between the fixed part ( 2 ) and the arm ( 3 ) to exert thrust on said arm ( 3 ) such as to rotate said arm towards the belt; and at least one support member ( 14 , 15 ) interposed between the arm ( 3 ) and the pivot ( 7 ); characterized in that said support member ( 14 , 15 ) includes at least one rolling bearing.

2 . A tensioner according to claim 1 , further comprising two support members ( 14 , 15 ) constituted by respective ball bearings interposed between the connection portion ( 10 ) and said pivot ( 7 ).

3 . A tensioner according to claim 2 , wherein the connection portion ( 10 ) comprises an outer cylindrical wall ( 11 ) and an inner cylindrical wall ( 12 ) delimiting between them an annular cavity ( 13 ) housing said main spring ( 5 ), said support members constituted by respective ball bearings ( 14 , 15 ) being radially set between said pivot ( 7 ) and said inner cylindrical wall ( 12 ).

4 . A tensioner according to any of claim 1 , further comprising a damping device ( 34 ) for damping oscillations of the arm ( 3 ) with respect to the fixed part ( 2 ) arranged at least partially overlapping said at least one support member ( 14 , 15 ) in a radial direction.

5 . A tensioner according to claim 4 , wherein said damping device ( 34 ) acts radially.

6 . A tensioner according to claim 4 , wherein said damping device ( 34 ) has a damping intensity dependent on the direction of rotation of the arm ( 3 ).

7 . A tensioner according to claim 4 , wherein the damping device ( 34 ) comprises a bushing ( 35 ) rotationally integral with one of the fixed part( 2 ) and the connection portion ( 10 ) of the arm ( 3 ), and a cylindrical surface ( 11 ) carried by the other of the fixed part ( 2 ) and the connection portion ( 10 ) of the arm ( 3 ), said bushing ( 35 ) co-operating in an interference-fitted manner with said cylindrical surface ( 11 ).

8 . A tensioner according to claim 7 , wherein said bushing ( 35 ) has an open C-shape and in that said damping device ( 34 ) comprises a C-shaped blade spring ( 36 ) exerting a radial load on said bushing ( 35 ) to force it against said cylindrical surface ( 11 ).

9 . A tensioner according to claim 7 , wherein said fixed part ( 2 ) comprises a base plate ( 6 ) to which said pivot ( 7 ) is fastened, said bushing ( 35 ) and said blade spring ( 36 ) being anchored to said base plate ( 6 ).

10 . A tensioner according to claim 9 , wherein said base plate ( 6 ) has a first projection ( 39 ) for anchoring said bushing ( 35 ) and said blade spring ( 36 ) to said fixed part ( 2 ), and a second projection ( 40 ) for constraining one end of said main spring ( 5 ) to said fixed part ( 2 ).

11 . A tensioner according to claim 9 , wherein said base plate ( 6 ) comprises a projection ( 56 ) for constraining one end of said main spring ( 5 ) to said fixed part ( 2 ) and a slot ( 55 ) prismatically engaged by an end portion ( 54 ) of the blade spring ( 36 ).

12 . A tensioner according to claim 10 , further comprising a dust-protection ring ( 20 ) interposed between one of the bearings ( 15 ) and a shoulder ( 24 ) of the pivot ( 7 ) and forming a labyrinth seal with a cavity ( 27 ) of the connection portion ( 10 ).

13 . A tensioner according to claim 4 , wherein said at least one support member ( 14 , 15 ) supports the tilting loads on the arm ( 3 ), preventing said loads from interfering with said damping device ( 34 ).

Assignees

• Dayco Europe Srl

Inventors

• Cariccia Gianluca
• Cimino Antonino

Classifications

• F16H7/1209 Primary

  with vibration damping means · CPC title

• F16H2007/0865

  Pulleys · CPC title

• F16H2007/081

  Torsion springs · CPC title

• F16H2007/084

  having vibration damping characteristics dependent on the moving direction of the tensioner · CPC title

• F16H7/0829

  with vibration damping means · CPC title