Mount assembly and method of adjusting stiffness

Patent metadata

Field	Value
Publication number	US-10060494-B2
Application number	US-201615352943-A
Country	US
Kind code	B2
Filing date	Nov 16, 2016
Priority date	Dec 10, 2015
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A method and mount assembly comprising a screw mechanism including a sleeve rotatable relative to the first housing and defining an internal screw-thread for adjusting the stiffness in the mount assembly in a vehicle. A collar non-rotatably secured to the plate and extends axially into the sleeve and defines an external screw-thread engaging the internal screw-thread of the sleeve. The internal screw-thread and the external screw-thread are self-locking in a static condition and prevent relative rotation between the sleeve and the collar below a predetermined force therebetween. A fluid pressure in the first housing overcomes the predetermined force and causes the sleeve to rotate from the static condition for moving the collar and the plate axially to change the stiffness of the pad.

First claim

What is claimed is:

1. A mount assembly comprising:
a first housing extending around and along a center axis and defining a first cavity,
a second housing extending around and along said center axis from said first housing to a cap to define a second cavity,
a plate disposed on said center axis in said second cavity,
a pad of an elastomeric material having a stiffness and being disposed on said center axis in said second cavity between said plate and said cap,
an actuator disposed on said center axis in said first cavity and extending along said center axis into said second cavity and coupled to said plate,
said actuator being a screw mechanism including a sleeve being rotatable about said center axis relative to said first housing and defining an internal screw-thread facing said center axis,
said screw mechanism including a collar disposed along said center axis and extending axially into said sleeve from and non-rotatably secured to said plate,
said collar defining an external screw-thread facing away from said center axis and engaging said internal screw-thread of said sleeve for causing axial movement of said collar and said plate in response to relative rotation between said sleeve and said collar,
said external screw-thread and said internal screw-thread having a coefficient of friction therebetween and a lead angle with the tangent of said lead angle being less than said coefficient of friction for providing self-locking between said screw-threads and said screw-threads preventing relative rotation between said sleeve and said collar below a predetermined force therebetween, and
whereby a fluid pressure in said first housing overcomes said predetermined force and causes said sleeve to rotate around said center axis for moving said collar and said plate axially along said center axis to change the stiffness of said pad and whereby an absence of the fluid pressure results in said self-locking between said screw-threads.

2. An assembly as set forth in claim 1 wherein said first housing further includes a plurality of partitions disposed in said first cavity to define a plurality of chambers between said partitions for enclosing a fluid in each of said chambers.

3. An assembly as set forth in claim 2 wherein said screw mechanism further includes a plurality of vanes with each coupled to and extending radially from said sleeve into respective ones of said chambers with each one of said vanes being spaced from and between two of said partitions to divide each one of said chambers into a first volume and a second volume and said vanes being rotatable with said sleeve in said chambers around said center axis to vary the ratio between said volumes and whereby a difference in fluid pressure between said volumes overcomes said predetermined force between said screw-threads and rotates said vanes around said center axis with said sleeve for moving said collar and said plate axially along said center axis for changing the stiffness of said pad and whereby an absence of the difference in fluid pressure between said volumes results in said self-locking between said screw-threads.

4. An assembly as set forth in claim 1 wherein said second housing further includes a plurality of ribs that are semi-circular in cross section and extend inwardly towards said center axis.

5. An assembly as set forth in claim 4 further including said plate having a plurality of grooves with each being semi-circular and sized to receive and slidably engage one of said ribs for preventing said plate and said collar from rotating about said center axis while allowing axial movement of said collar and said plate in response to rotation of said sleeve.

6. An assembly as set forth in claim 3 wherein said first housing further includes a sidewall extending annularly around and along said center axis between a first periphery and a second periphery and a base disposed at said first periphery and a first port and a second port extending radially through said sidewall at said first periphery.

7. An assembly as set forth in claim 6 wherein said first housing further includes a first conduit extending from said first port and annularly around said center axis in said base.

8. An assembly as set forth in claim 7 wherein said first conduit includes a plurality of first apertures establishing fluid communication between said first conduit and each of said first volumes and being spaced adjacent to and on the side of and counterclockwise from each one of said partitions for supplying the fluid through said first port and said first conduit into each one of said first volumes.

9. An assembly as set forth in claim 8 wherein said first housing further includes a second conduit extending from said second port and annularly around said center axis in said base.

10. An assembly as set forth in claim 9 wherein said second conduit includes a plurality of second apertures establishing fluid communication between said second conduit and each of said second volumes and being spaced adjacent to and on the side of and clockwise from each one of said partitions for supplying the fluid through said second port and said second conduit into each one of said second volumes.

11. A method of adjusting stiffness in a mount in a vehicle in response to real time operating conditions of the vehicle, the mount including a pad of an elastomeric material and a screw mechanism disposed on a center axis to compress the pad and being self-locking in a static state, said method comprising the steps of;
compressing the pad of an elastomeric material of the mount to establish a predetermined stiffness of the mount,
sensing external and gravitational forces being applied to the vehicle,
combining the external and gravitational forces to establish a plurality of both variable and instantaneous operating conditions of the vehicle,
multiplying hydraulic fluid pressure from a vehicle hydraulic system in response to various ones of the operating conditions of the vehicle,
rotating the screw mechanism in response to the multiplied hydraulic pressure in response to various ones of the operating conditions of the vehicle to compress and adjust the stiffness of the pad and to establish a predetermined stiffness position,
terminating the multiplied hydraulic pressure to establish a static condition of the screw mechanism and the self-locking to hold the predetermined stiffness position of the pad.

12. A method as set forth in claim 11 wherein said step of rotating the screw mechanism includes rotating vanes extending radially from the center axis in response to the multiplied hydraulic pressure to rotate the screw mechanism between the predetermined stiffness positions.

Assignees

• Beijingwest Ind Co Ltd
• Beijingwest Ind Co Ltd

Inventors

• Battek Wojciech
• Szostek Tomasz

Classifications

• F16F1/3615 Primary

  with means for modifying the spring characteristic (F16F1/371 takes precedence) · CPC title

• F16F13/00 Primary

  Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs (F16F5/00, {F16F6/00, F16F9/003} take precedence) · CPC title

• F16F2228/066

  Variable stiffness · CPC title

• F16F1/445

  the spring material being contained in a generally closed space (F16F1/393 takes precedence) · CPC title

• F16H25/2454

  Brakes; Rotational locks · CPC title