Rotary actuator such as a hydraulic rotary actuator for a motor vehicle and a method of making a rotary actuator

• US 5,575,502 A
• Filed: 10/28/1994
• Issued: 11/19/1996
• Est. Priority Date: 11/05/1993
• Status: Expired due to Term

• Current Assignee: Fichtel & Sachs AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Fichtel & Sachs AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Schmitt, Bernhard, Oppitz, Horst, Schiffler, Stefan
• Primary Examiner(s): Culbreth, Eric D.
• Application Number:
  US08/331,042
• Time in Patent Office: 753 Days
• Field of Search: 280/689, 280/723, 280/741, 267/277, 267/276, 403/212, 403/279, 403/284
• US Class Current: 280/124.166
• CPC Class Codes: B60G 21/0555 including an actuator inducing vehicle roll
• CPC Class Codes: B60G 2202/135 Stabiliser bar and/or tube
• CPC Class Codes: B60G 2202/1522 of rotary type
• CPC Class Codes: B60G 2206/40 Constructional features of dampers and/or springs
• CPC Class Codes: B60G 2206/81 Shaping
• CPC Class Codes: B60G 2206/8107 by hydroforming
• CPC Class Codes: F04C 9/002 the piston oscillating around a fixed axis

Abstract

A rotary actuator for a divided stabilizer on a vehicle axle is taught. The rotary actuator has a cylinder, the ends of which are closed to form a working space. Ribs run axially on the inside diameter of the cylinder. In addition, vanes from a motor shaft have the same axial extension within the cylinder as the ribs of the cylinder. The vanes of the motor shaft and the ribs of the cylinder divide the working space into individual work chambers. The rotary actuator can also have a first and a second hydraulic connection for two separate work chambers, with an additional hydraulic connection system between at least pairs of work chambers. The orientation of the connected work chambers is such that the work chambers corresponding to the first hydraulic connection alternate with those which are connected to the second hydraulic connection. A first cap can be provided to close the end of the working chamber, and this cap can be fixed in place on the rotary actuator by means of a deformation connection to the cylinder.

Claims

1. A rotary actuator comprising:

housing means;

means for connecting said housing means to a first portion of a motor vehicle suspension;

shaft means, said shaft means defining a longitudinal axis;

at least a portion of said shaft means being rotatably disposed within said housing means;

means for connecting said shaft means to a second portion of a motor vehicle suspension;

means for rotatably mounting said at least a portion of said shaft means within said housing means for rotation of at least one of said shaft means and said housing means about said longitudinal axis with respect to the other of said shaft means and said housinq means;

said shaft means comprising an outer surface disposed towards said housing means;

said housing means comprising an inner surface disposed towards said outer surface of said shaft means, said inner surface of said housing means being spaced apart from said outer surface of said shaft means to define a chamber between said shaft means and said housing means, said chamber having a first axial end and a second axial end;

cap means for closing at least one of said first and second axial ends of said chamber;

means for connecting said cap means to said housing means;

said means for connecting comprising at least one radial deformation of said housing means;

said at least one radial deformation of said housing means being configured for engaging at least a portion of said cap means;

said housing means having a first axial end and a second axial end;

said cap means fitting within said inner surface of said housing means adjacent at least one of said first and second axial ends of said housing means;

said radial deformation comprising a radially inward deformation of said housing means for engaging at least a portion of said cap means;

said cap means comprising;

a first axial end surface being disposed within said housing;

a second axial end surface being opposite said first axial end surface; and

a cylindrical outer surface extending axially between said first and second axial end surfaces;

said radially inward deformation of said housing means engaging at least one of;

at least a portion of said second axial end surface of said cap means; and

at least a portion of said cylindrical outer surface of said cap means;

said housing means comprising a cylindrical flange forming said first end of said housing means;

said radially inward deformation comprising a radially inward deformation of at least a portion of said flange to axially engage said at least a portion of said flange with said at least a portion of said second axial end surface of said cap means;

said cap means comprising first and second cap means for closing both of said first and second axial ends of said chamber;

said means for connecting said first cap means to said housing means comprising said radially inward deformation;

said means for connecting said second cap means to said housing comprising a weld;

said second cap means comprising said means for connecting said housing means to said first portion of a motor vehicle suspension;

each of said outer surface of said shaft means, and said inner surface of said housing means, comprising at least two protections extending towards the other of;

said outer surface of said shaft means, and

said inner surface of said housing means;

said projections of said shaft means being disposed between said projections of said housing means;

each of said projections extending from said first axial end of said chamber to said second axial end of said chamber to axially divide said chamber into at least four chamber portions;

means for fluidly connecting together at least a first two of said chamber portions;

means for fluidly connecting together at least a second two of said chamber portions;

each of said at least a first two chamber portions being disposed between ones of said at least a second two chamber portions;

each of said at least a second two chamber portions being disposed between ones of said at least a first two chamber portions;

means for independently introducing fluid into each of;

said at least a first two chamber portions, and

said at least a second two chamber portions,

to relatively rotate said housing means and said shaft means with respect to one another;

said means for fluidly connecting together said at least a first two of said chamber portions comprising at least a first channel disposed circumferentially about said outer cylindrical surface of said first cap means between said first cap means and said inner surface of said housing means;

said means for fluidly connecting together said at least a second two of said chamber portions comprising at least a second channel disposed circumferentially about said outer cylindrical surface of said first cap means between said first cap means and said inner surface of said housing means;

said means for fluidly connecting together said at least a first two of said chamber portions additionally comprising;

first axial passages in said first cap means in fluid communication with each of said at least a first two of said chamber portions;

first radial passages in said first cap means extending radially between said first channel and said first axial passages;

said means for fluidly connecting together said at least a second two of said chamber portions additionally comprising;

second axial passages in said first cap means in fluid communication with each of said at least a second two of said chamber portions; and

second radial passages in said first cap means extending radially between said second channel and said second axial passages;

said means for introducing fluid comprising hydraulic connections for fluidly connecting said chamber portions to a fluid supply source;

said second cap means comprising said hydraulic connections;

said radially inward deformation comprising a radial inward deformation of all of said flange completely about the circumference of said housing;

said first and second channels being separated from one another axially on said outer cylindrical surface of said first cap means;

said cap means further comprising;

a third channel being disposed between said first channel and said first end surface of said cap means, said third channel being disposed circumferentially about said outer cylindrical, surface of said first cap means, and said third channel comprising a ring-shaped seal disposed therein to seal said outer cylindrical surface of said first cap means to said inner surface of said housing means;

a fourth channel being disposed between said first channel and said second channel, said fourth channel being disposed circumferentially about said outer cylindrical surface of said first cap means, and said fourth channel comprising a ring-shaped seal disposed therein to seal said outer cylindrical surface of said first cap means to said inner surface of said housing means; and

a fifth channel being disposed between said second channel and said second end surface of said first cap means, said fifth channel being disposed circumferentially about said outer cylindrical surface of said first cap means, and said fifth channel comprising a ring-shaped seal disposed therein to seal said outer cylindrical surface of said first cap means to said inner surface of said housing means;

each of said projections comprising;

a first side being disposed towards one of said first two chamber portions;

a second side being disposed opposite to said first side and adjacent one of said second two chamber portions;

a surface being disposed between said first side and said second side, said surface being disposed towards the other of;

said outer surface of said shaft means, and

said inner surface of said housing means; and

at least one seal means for sealing said surface of said at least one projection to the other of;

said outer surface of said shaft means, and

said inner surface of said housing means,

to minimize fluid flow from said first two chamber portions to said second two chamber portions;

said first and second cap means comprising gasket means for sealing said cap means about said shaft means;

said cap means further comprising bearing means for rotatably mounting said shaft means within said cap means;

said shaft means comprising a longitudinal hole therein disposed along said longitudinal axis of said shaft means;

at least a portion of said longitudinal hole having a non-round cross section;

said means for connecting said shaft means to a second portion of a motor vehicle suspension comprising said non-round cross-section of said longitudinal hole;

said housing comprising a cylinder, said cylinder having an outer surface; and

said weld of said second cap means being disposed circumferentially about said outer surface of said cylinder at said second axial end of said cylinder.

2. A rotary actuator comprising:

housing means;

means for connecting said housing means to a first portion of a motor vehicle suspension;

shaft means, said shaft means defining a lonqitudinal axis;

at least a portion of said shaft means being rotatably disposed within said housing means;

means for connecting said shaft means to a second portion of a motor vehicle suspension;

means for rotatably mounting said at least a portion of said shaft means within said housing means for rotation of at least one of said shaft means and said housing means about said longitudinal axis with respect to the other of said shaft means and said housing means;

said shaft means comprising an outer surface disposed towards said housing means;

said housing means comprising an inner surface disposed towards said outer surface of said shaft means, said inner surface of said housing means being spaced apart from said outer surface of said shaft means to define a chamber between said shaft means and said housing means, said chamber having a first axial end and a second axial end;

cap means for closing at least one of said first and second axial ends of said chamber;

means for connecting said cap means to said housing means;

said means for connecting comprising at least one radial deformation of said housing means;

said at least one radial deformation of said housing means being configured for engaging at least a portion of said cap means;

said housing means having a first axial end and a second axial end;

said cap means fitting within said inner surface of said housing means adjacent at least one of said first and second axial ends of said housing means;

said radial deformation comprising a radially inward deformation of said housing means for engaging at least a portion of said cap means;

said cap means comprising;

a first axial end surface being disposed within said housing;

a second axial end surface being Opposite said first axial end surface; and

a cylindrical outer surface extending axially between said first and second axial end surfaces;

said radially inward deformation of said housing means engaging at least one of;

at least a portion of said second axial end surface of said cap means; and

at least a portion of said cylindrical outer surface of said cap means;

said cap means comprising at least a first circumferential groove, portion disposed about said outer cylindrical surface and spaced apart from said first end surface; and

said radially inward deformation comprising a radially inward deformation of at least a portion of said housing means into said at least a first circumferential groove portion.

3. The rotary actuator according to claim 2 wherein:

said at least a first circumferential groove portion is disposed completely circumferentially about said outer cylindrical surface of said cap means; and

said radially inward deformation comprises a radially inward deformation completely about the circumference of said housing means into said circumferential groove of said cap means.

4. The rotary actuator according to claim 3, wherein:

said cap means comprises first and second cap means for closing both of said first and second axial ends of said chamber;

said means for connecting said first cap means to said housing means comprises said radially inward deformation;

said means for connecting said second cap means to said housing comprises a weld;

said second cap means comprises said means for connecting said housing means to said first portion of a motor vehicle suspension;

each of said outer surface of said shaft means, and said inner surface of said housing means, comprise at least two projections extending towards the other of;

said outer surface of said shaft means, and

said inner surface of said housing means;

said projections of said shaft means being disposed between said projections of said housing means;

each of said projections extending from said first axial end of said chamber to said second axial end of said chamber to axially divide said chamber into at least four chamber portions;

means for fluidly connecting together at least a first two of said chamber portions;

means for fluidly connecting together at least a second two of said chamber portions;

each of said at least a first two chamber portions is disposed between ones of said at least a second two chamber portions;

each of said at least a second two chamber portions is disposed between ones of said at least a first two chamber portions;

means for independently introducing fluid into each of;

said at least a first two chamber portions, and

said at least a second two chamber portions, to relatively rotate said housing means and said shaft means;

said means for fluidly connecting together said at least a first two of said chamber portions comprises at least a first channel disposed circumferentially about said outer cylindrical surface of said first cap means between said first cap means and said inner surface of said housing means; and

said means for fluidly connecting together said at least a second two of said chamber portions comprises at least a second channel disposed circumferentially about said outer cylindrical surface of said first cap means between said first cap means and said inner surface of said housing means.

5. The rotary actuator according to claim 4, wherein:

said means for fluidly connecting together said at least a first two of said chamber portions additionally comprises;

first axial passages in said first cap means in fluid communication with each of said at least a first two of said chamber portions; and

first radial passages in said first cap means extending radially between said first channel and said first axial passages;

said means for fluidly connecting together said at least a second two of said chamber portions additionally comprises;

second axial passages in said first cap means in fluid communication with each of said at least a second two of said chamber portions; and

second radial passages in said first cap means extending radially between said second channel and said second axial passages;

said means for introducing fluid comprises hydraulic connections for fluidly connecting said chamber portions to a fluid supply source;

said second cap means comprises said hydraulic connections;

said first and second channels are separated from one another axially on said outer cylindrical surface of said first cap means;

said cap means further comprises;

a third channel disposed between said first channel and said first end surface of said cap means, said third channel being disposed circumferentially about said outer cylindrical surface of said first cap means, and said third channel comprising a ring-shaped seal disposed therein to seal said outer cylindrical surface of said first cap means to said inner surface of said housing means;

a fourth channel disposed between said first channel and said second channel, said fourth channel being disposed circumferentially about said outer cylindrical surface of said first cap means, and said fourth channel comprising a ring-shaped seal disposed therein to seal said outer cylindrical surface of said first cap means to said inner surface of said housing means; and

a fifth channel disposed between said second channel and said second end surface of said first cap means, said fifth channel being disposed circumferentially about said outer cylindrical surface of said first cap means, and said fifth channel comprising a ring-shaped seal disposed therein to seal said outer cylindrical surface of said first cap means to said inner surface of said housing means;

each of said projections comprises;

a first side disposed towards one of said first two chamber portions;

a second side disposed opposite to said first side and adjacent one of said second two chamber portions;

a surface disposed between said first side and said second side, said surface being disposed towards the other of;

said outer surface of said shaft means, and

said inner surface of said housing means; and

at least one seal means for sealing said surface of said at least one projection to the other of;

said outer surface of said shaft means, and

said inner surface of said housing means,

to minimize fluid flow from said first two chamber portions to said second two chamber portion;

said first and second cap means comprise gasket means for sealing said cap means about said shaft means;

said cap means further comprises bearing means for rotatably mounting said shaft means within said cap means;

said shaft means comprises a longitudinal hole therein disposed along said longitudinal axis of said shaft means;

at least a portion of said longitudinal hole having a non-round cross section;

said means for connecting said shaft means to a second portion of a motor vehicle suspension comprises said non-round cross-section of said longitudinal hole;

said housing comprises a cylinder, said cylinder having an outer surface; and

said weld of said second cap means is disposed circumferentially about said outer surface of said cylinder at said second axial end of said cylinder.

6. A method for assembling a rotary actuator, the rotary actuator comprising:

housing means;

means for connecting said housing means to a first portion of a motor vehicle suspension;

shaft means, said shaft means defining a longitudinal axis;

at least a portion of said shaft means being rotatably disposed within said housing means;

means for connecting said shaft means to a second portion of a motor vehicle suspension;

means for rotatably mounting said at least a portion of said shaft means within said housing means for rotation of at least one of said shaft means and said housing means about said longitudinal axis with respect to the other of said shaft means and said housing means;

said shaft means comprising an outer surface disposed towards said housing means;

said housing means comprising an inner surface disposed towards said outer surface of said shaft means, said inner surface of said housing means being spaced apart from said outer surface of said shaft means to define a chamber between said shaft means and said housing means, said housing means havinq a first axial end portion and a second axial end portion;

first and second cap means for respectively closing each of said first and second axial end portions of said chamber;

said method comprising the steps of;

providing said housing means;

providing said second cap means;

fixedly disposing said second cap means at said second axial end portion of said housing means;

providing said shaft means;

disposing said shaft means at least partially within said housing means through said first axial end portion of said housing means;

disposing said first cap means within said first axial end portion, about said shaft means and within said inner surface of said housing means; and

radially inwardly deforming at least a portion of said first axial end portion of said housing means to engage at least a portion of said first cap means, to retain said first cap means within said housing means;

said first axial end portion having a terminal edge and an area adjacent said terminal edge, said terminal edge defining a periphery of said housing means about said shaft means;

said step of radially inwardly deforming comprising at least one of;

radially inwardly deforming said terminal edge of said first axial end portion about the entire periphery of said housing means to engage a substantial portion of said terminal edge with at least a portion of said first cap means;

radially inwardly deforming said terminal edge of said first axial end portion at spaced apart intervals about the periphery of said housing means to engage at least spaced apart portions of said terminal edge with portions of said first cap means; and

radially inwardly deforming at least spaced apart portions of said area adjacent said terminal edge to form at least one radially inwardly protruding bead at a distance from said terminal edge, and engaging the at least one radially inwardly protruding bead with at least one groove of said first cap means;

said fixedly disposing of said second cap means at said second axial end portion comprising welding said second cap means to said second axial end portion, and during said welding forming a weld seam;

said method further comprising the steps of;

after said welding, pressure testing said weld seam for leaks prior to further assembly of said rotary actuator;

configuring each of said inner surface of said housing means and said outer surface of said shaft means to have at least two projections thereon, each of said at least two projections extending in the axial direction of said rotary actuator along said outer surface of said shaft means and said inner surface of said housing means, each of said projections comprising sealing means for sealing said projections to the other of said outer surface of said shaft means and the inner surface of said housing means;

during said inserting of said shaft means into said housing means, dividing said chamber into four spaced apart chamber portions, said four spaced apart chamber portions each being disposed adjacent others of said four chamber portions and opposite one of said four chamber portions, and during said inserting, axially sealing said four chamber portions from the adjacent ones of said four chamber portions;

configuring said first cap means to comprise at least two separate passages for interconnecting said opposite ones of said four chamber portions, each of said passages being configured for connecting one pair of opposite chamber portions; and

inserting said first cap means into said housing to provide said at least two interconnecting passages;

said shaft means having a first end for being disposed adjacent said first axial end portion of said housing and a second end for being inserted into said housing adjacent said second axial end portion of said housing;

said method further comprising the steps of;

disposing at least one sealing element in said second cap means after welding said second cap means to said second axial end portion of said housing means and prior to disposing said shaft means within said housing means to provide a seal about said second end of said shaft means between said second end of said shaft means and said second cap means;

inserting said second end of said shaft means through said seal to seal about said second end of said shaft means between said second end of said shaft means and said second cap means;

inserting at least one additional seal about said first end of said shaft means, prior to disposing said first cap means about said first end of said shaft means to seal between said first end of said shaft means and said first cap means; and

inserting said first cap means about said seal on said first end of said shaft means to seal about said first end of said shaft means between said first end of said shaft means and said first cap means.

7. The method according to claim 6, further comprising:

providing first and second fluid connection means on said first cap means for independently connecting at least one chamber of each pair of oppositely disposed chambers to an external fluid supply;

after said radial deformation, connecting said connection means to a fluid supply, and introducing fluid into said chambers through said connection means from said fluid supply;

providing bearing means about each of said first and second ends of said shaft means between said first and second ends of said shaft means and said first and second cap means;

providing said two passages for interconnecting opposite chamber portions about a circumference of said first cap means, and spaced axially separated from one another, said passages being bordered by said inner surface of said housing means; and

said radially inwardly deforming comprising at least one of;

radially striking said housing means adjacent said first axial end portion from radially outside of said housing means in a radially inward direction to deform said at least a portion of said first axial end portion radially inwardly; and

radially pushing said housing means adjacent said first axial end portion from radially outside of said housing means in a radially inward direction to deform said at least a portion of said first axial end portion radially inwardly.