US 12,269,310 B2
Variable suspension spring rates using magnetorheological fluid
Brian K. Saylor, South Lyon, MI (US); Robert Patrick Marble, White Lake, MI (US); and Christopher J. Mettrick, Whitby (CA)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on May 5, 2023, as Appl. No. 18/312,823.
Prior Publication US 2024/0367473 A1, Nov. 7, 2024
Int. Cl. B60G 17/02 (2006.01); B60G 11/58 (2006.01); B60G 17/0165 (2006.01)
CPC B60G 17/021 (2013.01) [B60G 11/58 (2013.01); B60G 17/0165 (2013.01); B60G 2204/62 (2013.01); B60G 2206/42 (2013.01); B60G 2400/821 (2013.01); B60G 2500/22 (2013.01); B60G 2600/182 (2013.01); B60G 2600/20 (2013.01); B60G 2600/26 (2013.01); B60G 2800/162 (2013.01); B60G 2800/916 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A vehicle suspension control system comprising:
a central suspension spring core;
a first suspension spring surrounding an upper portion of the central suspension spring core;
a second suspension spring surrounding a lower portion of the central suspension spring core, the first suspension spring and the second suspension spring coupled between a wheel and a fixed structure of a vehicle to inhibit movement of the wheel;
a spring seat surrounding the central suspension spring core and coupled between the first suspension spring and the second suspension spring, the spring seat including an outer sleeve and multiple seals for retaining magnetorheological fluid between the outer sleeve and the central suspension spring core;
one or more electromagnets adjacent the spring seat; and
a suspension control module configured to energize the one or more electromagnets to selectively modify a viscosity of the magnetorheological fluid to inhibit movement of at least one of the first suspension spring and the second suspension spring,
wherein the suspension control module is configured to selectively energize the one or more electromagnets at a specified first energization value where the viscosity of the magnetorheological fluid is sufficient to generate friction between the central suspension spring core and the outer sleeve of the spring seat to lock the outer sleeve of the spring seat in place along the central suspension spring core via friction.