Switchable hydrobushing
A switchable hydraulic bushing ( 10 ) is provided in which a secondary chamber ( 60 ) is sealed so as to be air-tight and is provided with a bleed passage ( 38 ) for allowing for the free flow of air into and out of the secondary air chamber ( 60 ). A closure device ( 40 ) is provided for closing off the bleed passage ( 38 ) for sealing off the air-tight secondary chamber ( 60 ) to alter the flexibility characteristics of the walls ( 58 ) of the compensation chambers ( 52 ) and effectively turn off the hydraulic damping function of the hydraulic bushing ( 10 ).
1 . A switchable hydraulic bushing mount, comprising:
a housing;
a core disposed in said housing;
an elastomeric member bonded to an outer surface of said core and disposed in said housing, said elastomeric member combining with said housing for defining a pumping chamber and at least one compensation chamber fluidly interconnected to one another by an inertia track extending along a periphery of said elastomeric member, said compensation chamber being defined by an interior wall surface of said housing and a flexible wall portion of said elastomeric member, said flexible wall portion of said compensation chamber defining a portion of a secondary chamber adjacent to said compensation chamber, said secondary chamber being air-tight and including a bleed passage communicating thereto; and
a closure device operable for closing said bleed passage.
2 . The switchable hydraulic bushing mount according to claim 1 , wherein said at least one compensation chamber includes a pair of fluidly interconnected compensation chambers.
3 . The switchable hydraulic bushing mount according to claim 1 , wherein said elastomeric member includes an inner support structure including:
a first ring having an annular wall, an outer end wall and an inner end wall;
a second ring having an annular wall, an outer end wall and an inner end wall; and
a plurality of legs formed between the first and second rings.
4 . The switchable hydraulic bushing according to claim 3 , wherein said plurality of legs of said inner support structure include a first pair of legs disposed on opposite sides of said pumping chamber.
5 . The switchable hydraulic bushing according to claim 4 , wherein said at least one compensation chamber includes a pair of fluidly interconnected compensation chambers and wherein said plurality of legs of said inner support structure include a leg disposed between said pair of compensation chambers.
6 . The switchable hydraulic bushing according to claim 3 , wherein said outer end wall and said inner end wall of said first ring are disposed on opposite sides of said inertia track.
7 . The switchable hydraulic bushing according to claim 1 , wherein said closure device is selectively closable.
8 . The switchable hydraulic bushing according to claim 1 , wherein said closure device includes an activation device for moving said closure device between an open and a closed position.
9 . A switchable hydraulic bushing mount, comprising:
a housing;
a core disposed in said housing;
an elastomeric member bonded to an outer surface of said core and disposed in said housing, said elastomeric member defining a pumping chamber and at least one compensation chamber fluidly interconnected to one another by a fluid passage, said compensation chamber being defined partially by a flexible wall portion of said elastomeric member, said flexible wall portion of said compensation chamber defining a portion of a secondary chamber adjacent to said compensation chamber, said secondary chamber being air-tight and including a bleed passage communicating thereto; and
a closure device operable for closing said bleed passage.
10 . The switchable hydraulic bushing mount according to claim 9 , wherein said at least one compensation chamber includes a pair of fluidly interconnected compensation chambers each having a flexible wall portion.
11 . The switchable hydraulic bushing mount according to claim 9 , wherein said elastomeric member includes an inner support structure including:
a first ring having an annular wall, an outer end wall and an inner end wall;
a second ring having an annular wall, an outer end wall and an inner end wall; and
a plurality of legs formed between the first and second rings.
12 . The switchable hydraulic bushing according to claim 11 , wherein said plurality of legs of said inner support structure include a first pair of legs disposed on opposite sides of said pumping chamber.
13 . The switchable hydraulic bushing according to claim 12 , wherein said at least one compensation chamber includes a pair of fluidly interconnected compensation chambers and wherein said plurality of legs of said inner support structure include a leg disposed between said pair of compensation chambers.
14 . The switchable hydraulic bushing according to claim 11 , wherein said outer end wall and said inner end wall of said first ring are disposed on opposite sides of said inertia track.
15 . The switchable hydraulic bushing according to claim 9 , wherein said closure device is selectively closable.
16 . The switchable hydraulic bushing according to claim 9 , wherein said closure device includes an activation device for moving said closure device between an open and a closed position.