Active fluid mounting

• US 5,957,440 A
• Filed: 04/08/1997
• Issued: 09/28/1999
• Est. Priority Date: 04/08/1997
• Status: Expired due to Term

• Current Assignee: Lord Corporation (Parker-Hannifin Corporation)
• Original Assignee: Lord Corporation (Parker-Hannifin Corporation)
• Inventors: Whiteford, Gerald P., Jones, Peter J., Ivers, Douglas E., Cooney, Kevin C.
• Primary Examiner(s): Schwartz, Chris
• Application Number:
  US08/835,433
• Time in Patent Office: 903 Days
• Field of Search: 267/136, 267/140.11, 267/140.13-140.15, 267/219, 267/299, 188/379, 188/380, 248/550, 248/562, 244/54, 702/56
• US Class Current: 267/140.14
• CPC Class Codes: F16F 13/06 the damper being a fluid damper, e.g. the plastics spring not forming a part of the wall of the fluid chamber of the damper F16F13/26 takes precedence
• CPC Class Codes: F16F 13/22 characterised by comprising also a dynamic damper dampers using inertia effect per se F16F7/10
• CPC Class Codes: F16F 13/26 characterised by adjusting or regulating devices responsive to exterior conditions F16F13/101 takes precedence
• CPC Class Codes: F16F 2228/00 Functional characteristics, e.g. variability, frequency-dependence
• CPC Class Codes: F16F 7/1005 characterised by active control of the mass

Abstract

An active fluid mounting for isolating vibration between a vibrating member (21) and a structure (23). In one aspect, the active fluid mounting (20) includes an inner member (22), an outer member (24), a first flexible element (26), and an cartridge-like active fluid element (28) which is unitary and readily detachable, attached between the inner and outer members, (22) and (24). The cartridge-like active fluid element (28) preferably includes a first housing member (30) for attachment to inner member (22), a second housing member (32) for attachment to outer member (24), a second flexible element (34) for flexibly interconnecting first housing member (30) to second housing member (32), at least one fluid chamber (36) having a volume stiffness, a fluid (40) contained within, a moveable piston (42) interacting with fluid (40) in the fluid chamber (36) to cause pressure variations and produce dynamic forces which act between the inner and outer member, (22) and (24), and a preferable coil-and-magnet assembly (44) for driving piston (42) housed internally within active fluid element (28). In another aspect, a piston (42a) which is inductively driven is described. In yet another, an interchangeable motor unit including a magnet (68), coil (70), and pole pieces (66) is received within the inner member (22).

Claims

1. An active fluid mounting, comprising:

(a) an inner member,

(b) an outer member,

(c) a flexible element for flexibly suspending said inner member relative to said outer member, and

(d) a unitary active fluid element which is readily detachable, capable of providing active forces between said inner member and said outer member, said active fluid element including at least one fluid chamber exhibiting a volume stiffness, wherein said active fluid element further comprises;

a first housing member for interconnection to one of said inner member and said outer member,

a second housing member for interconnection to another of said inner member and said outer member,

a second flexible element for flexibly suspending said first housing member relative to said second housing member and for accommodating motion therebetween,

a first fluid chamber within said active fluid element having a volume stiffness associated therewith, wherein said first fluid chamber does not derive any of said volume stiffness from said first flexible element,

a fluid contained within said first fluid chamber;

a piston within said active fluid element interacting with said first fluid chamber to cause dynamic pressure variations resultantly producing active dynamic forces which act between said inner member and said outer member, and

means for driving said piston.

2. The active fluid mounting of claim 1 wherein said means for driving said piston is a coil and magnet assembly within said active fluid element further comprising a wound coil and a permanent magnet.

3. The active fluid mounting of claim 2 wherein said coil and magnet assembly, said piston, and pole piece means are included within a motor unit received within said active fluid element.

4. The active fluid mounting of claim 2 wherein a spring flexibly suspends said piston.

5. The active fluid mounting of claim 2 wherein said piston is slidably received in a bore interconnecting with said first fluid chamber and said piston is directly connected to said wound coil and always moves axially therewith.

6. The active fluid mounting of claim 2, wherein said wound coil and said permanent magnet are stationary relative to each other and said piston is inductively-driven due to inductive coupling between said piston and said coil and magnet assembly.

7. The active fluid mounting of claim 1 wherein said piston is an assembly including a nonmagnetic bobbin having a wire circumferentially wound about said bobbin forming a wound coil, and whereby a terminal end portion of said piston dynamically interacts with said fluid in said first fluid chamber upon energizing said wound coil.

8. The active fluid mounting of claim 1 further including a third flexible element which acts to decouple lateral loads acting upon said active fluid element.

9. The active fluid mounting of claim 1 wherein said piston also dynamically interacts with a second fluid chamber within said active fluid element.

10. The active fluid mounting of claim 1 wherein said active fluid element is received within a hollow formed in said inner member and rigidly secured to said inner member and said outer member.

11. The active fluid mounting of claim 1 wherein said piston is contained within an intermediate fluid chamber also containing fluid, said intermediate fluid chamber being interactive with said first and second fluid chambers by ports.

12. The active fluid mounting of claim 1 wherein said inner member, said outer member, and said flexible element for flexibly suspending said inner member relative to said outer member comprise a passive mounting.

13. An active fluid mounting for controlling dynamic vibration between a vibrating member and a structure, comprising:

(a) a passive mounting having and inner member for attachment to one of said vibrating member and said structure, said inner member including a hollow therein, an outer member for attachment to another of said vibrating member and said structure, and a first flexible element for interconnecting said inner and outer members,

(b) an active fluid element which is detachable from said passive mounting and received within said hollow, and which does not derive any volume stiffness from said first flexible element, said cartridge-like active fluid element interconnected between said inner member and said outer member of said passive mounting, said active fluid element further comprising;

(i) a first housing for interconnection to said inner member,

(ii) a second housing for interconnection to said outer member,

(iii) a second flexible element for flexibly suspending said first housing relative to said second housing,

(iv) first and second fluid chambers within said active fluid element each having a volume stiffness,

(v) a fluid contained in said first and second fluid chambers;

(vi) a piston interacting with said first and second fluid chambers to cause pressure variations producing active dynamic forces which act between said inner and outer members of said passive mounting, and

(vii) means for driving said piston which include a coil and magnet assembly having a wound coil and a permanent magnet, which is capable of actively driving said piston upon applying oscillating electrical current to said wound coil.

14. An active fluid mounting having an inner member, an outer member, a first flexible element for interconnecting said inner and outer members, at least one fluid chamber associated with said active fluid mounting having a volume stiffness, a fluid contained within said at least one fluid chamber, the improvement comprising:

(a) a nonmagnetic piston interacting with said fluid capable of being inductively driven to produce a dynamic pressure variation in said at least one fluid chamber causing dynamic forces between said inner and outer members,

(b) a permanent magnet for generating a static magnetic field, and

(c) a coil for inducing a oscillating electrical current within said nonmagnetic piston which generates a dynamic magnetic field which interacts with said static magnetic field to inductively drive said nonmagnetic piston.

15. An active fluid mounting, comprising:

an inner member,

an outer member,

a flexible element flexibly intervened between said inner and outer members,

an active fluid element directly connected between said inner and said outer members, said active fluid element further comprising;

a first element mounted to said inner member,

a second element mounted to said outer member,

a first fluid chamber including a first volume stiffness,

a second fluid chamber including a second volume stiffness,

an intermediate fluid chamber communicating with said first and second fluid chambers by ports,

a fluid contained in said fluid chambers,

a moveable piston within said intermediate chamber,

a spring flexibly suspending said moveable piston,

a permanent magnet generating a static magnetic field,

pole piece means directing said static magnetic field towards said movable piston, and

a coil which when electrically energized with oscillating electrical current creates a dynamically-varying magnetic field which interacts with said static magnetic field to oscillate said moveable piston resultantly pumping said fluid through said ports and into and out of said first and second fluid chambers.

16. An active fluid mounting, comprising:

an inner member including a first linkage depending therefrom in a first direction,

an outer member including a second linkage depending therefrom in a second direction opposed to said first direction,

a flexible element intervening between said inner and outer members,

first and second fluid chambers associated with said active fluid mounting,

a fluid contained within said fluid chambers,

a motor unit received within a pocket formed in said inner member, said motor unit including;

a moveable piston which is adapted to pump said fluid to and from said first and second fluid chambers,

a spring flexibly suspending said moveable piston,

a permanent magnet generating a static magnetic field,

pole piece means for directing said static magnetic field towards said piston, and

a coil, which when energized, causes said moveable piston to oscillate.

17. The active fluid mounting of claim 16 wherein said active fluid mounting is an active pylon isolator.

18. The active fluid mounting of claim 16 which functions as an active force producing linkage, in that it is adapted for attaching between a vibrating member and a structure by pin joints interconnecting to said inner and outer members.

19. An active fluid mounting, comprising:

an inner member,

an outer member,

a flexible element flexibly interconnecting said inner and outer members,

an active fluid element intervening between said inner and outer members, said active fluid element including;

a first housing member mounted to said inner member,

a second housing member mounted to said outer member,

a first fluid chamber having a first volume stiffness and a first pumping area,

a second fluid chamber having a second volume stiffness and a second pumping area,

a fluid passageway interconnecting said first and second fluid chambers,

a fluid contained in said first and second fluid chambers and said fluid passageway,

a moveable piston having a third pumping area moveable within said fluid passageway to pump said fluid, said third pumping area being one tenth the size of said first pumping area and said second pumping area or smaller,

spring means attached to and flexibly suspending said moveable piston relative to said inner member,

a permanent magnet generating a static magnetic field,

pole piece means directing said static magnetic field towards said movable piston, and

a coil which when electrically energized with oscillating electrical current creates a dynamically-varying magnetic field which interacts with said static magnetic field to oscillate said moveable piston resultantly pumping said fluid into and out of said first and second fluid chambers.