Methods and systems for hydraulic vehicle suspension are provided. A hydraulic suspension system, in one example, includes a first manifold including a piston-side interface and a rod-side interface fluidically coupled to a piston chamber and a rod chamber, respectively, for each of a first hydraulic cylinder and a second hydraulic cylinder. In the system, the first manifold includes a first electrically activated valve fluidically coupled to the piston-side interfaces, a first damping device, and a second damping device, the first electrically activated valve is configured to lock and unlock vertical motion of the first and second hydraulic cylinders and, while vertical motion of the first and second hydraulic cylinders is locked, the first electrically activated valve permits fluidic communication between the first and second hydraulic cylinders to permit free roll motion in the hydraulic suspension system.

This specification relates to a snowmobile. Each of the right suspension and the left suspension includes a damper capable of expanding and contracting according to the vertical movement of the lower arm and a spring that exerts spring force in the expansion/contraction direction of the damper. The cylinder of the right damper and the cylinder of the left damper are connected to each other through a hydraulic fluid channel so that the hydraulic fluid flows between the cylinder of the right damper and the cylinder of the left damper. This snowmobile can reduce the difference in contact pressure on snow surface between the left ski and the right ski, when the vehicle turns.

A hydraulic system includes a hydraulic pump. A first hydraulic shock is coupled to a first port of the hydraulic pump. A second hydraulic shock is coupled to a second port of the hydraulic pump. A first hydraulic cylinder is coupled to the first port of the hydraulic pump. A second hydraulic cylinder is coupled to the second port of the hydraulic pump. A first valve is coupled between the first hydraulic cylinder and second hydraulic cylinder. The first valve can be actuated by a computer system or can be a ball and spring check valve. A second valve is coupled between the first hydraulic cylinder and second hydraulic cylinder. A flow direction of the second valve is opposite a flow direction of the first valve. A first piston is disposed in the first hydraulic cylinder, and a second piston is disposed in the second hydraulic cylinder.

A damper assembly for a vehicle suspension system includes a primary damper and a secondary damper. The secondary damper includes a housing having a wall that at least partially surrounds at least a portion of the primary damper, the volume between the wall and the primary damper defining a chamber, and the wall defines an aperture. The secondary damper also includes a piston positioned within the chamber, a conduit defining a flow path that includes the aperture, and a valve disposed along the flow path. The primary damper is configured to provide a base damping force and the secondary damper is configured to provide a supplemental damping force that varies based on the position of the piston within the chamber.

A damper assembly for a vehicle suspension system includes a primary damper and a secondary damper. The secondary damper includes a housing having a wall that at least partially surrounds at least a portion of the primary damper, the volume between the wall and the primary damper defining a chamber, and the wall defines an aperture. The secondary damper also includes a piston positioned within the chamber, a conduit defining a flow path that includes the aperture, and a valve disposed along the flow path. The primary damper is configured to provide a base damping force and the secondary damper is configured to provide a supplemental damping force that varies based on the position of the piston within the chamber.

A damper assembly includes a tubular member, an outer cylinder positioned at least partially within the tubular member, an inner cylinder positioned at least partially within the outer cylinder, a cap coupled to the inner cylinder, a plunger received within the inner cylinder and coupled to an end of a rod extending at least partially within the inner cylinder, an annular piston fixed to the inner cylinder where the annular piston extends between the inner cylinder and the outer cylinder, and a barrier extending between the inner cylinder and the outer cylinder. The rod has an outer diameter that is smaller than an inner diameter of the inner cylinder. The plunger, the cap, and an interior of the inner cylinder at least partially define a first chamber. The barrier, the annular piston, an exterior surface of the inner cylinder, and the outer cylinder at least partially define a second chamber.

A damper assembly includes a tubular member, an outer cylinder positioned at least partially within the tubular member, an inner cylinder positioned at least partially within the outer cylinder, a cap coupled to the inner cylinder, a plunger received within the inner cylinder and coupled to an end of a rod extending at least partially within the inner cylinder, an annular piston fixed to the inner cylinder where the annular piston extends between the inner cylinder and the outer cylinder, and a barrier extending between the inner cylinder and the outer cylinder. The rod has an outer diameter that is smaller than an inner diameter of the inner cylinder. The plunger, the cap, and an interior of the inner cylinder at least partially define a first chamber. The barrier, the annular piston, an exterior surface of the inner cylinder, and the outer cylinder at least partially define a second chamber.

A damper assembly includes an outer cylinder, an inner cylinder positioned at least partially within the outer cylinder, a cap coupled to the inner cylinder, and a plunger positioned radially inward from the inner cylinder and coupled to a rod. The plunger, the cap, and an interior of the inner cylinder at least partially define a first chamber. The suspension system further includes a passage extending through the rod and fluidly coupled with the first chamber, a piston coupled to the inner cylinder and extending radially outward toward the outer cylinder, a first port in fluid communication with the plunger through the passage, and a second port in fluid communication with the piston. The piston, an exterior surface of the inner cylinder, and the outer cylinder at least partially define a second chamber.

A damper assembly includes an outer cylinder, an inner cylinder positioned at least partially within the outer cylinder, a cap coupled to the inner cylinder, and a plunger positioned radially inward from the inner cylinder and coupled to a rod. The plunger, the cap, and an interior of the inner cylinder at least partially define a first chamber. The suspension system further includes a passage extending through the rod and fluidly coupled with the first chamber, a piston coupled to the inner cylinder and extending radially outward toward the outer cylinder, a first port in fluid communication with the plunger through the passage, and a second port in fluid communication with the piston. The piston, an exterior surface of the inner cylinder, and the outer cylinder at least partially define a second chamber.

A damper assembly for a vehicle suspension system includes a first damper and a second damper. The second damper includes a housing including a wall that defines an aperture, the wall and the first damper at least partially defining a chamber. The second damper also includes a piston positioned within the chamber, a conduit defining a flow path that includes the aperture, and a flow control device disposed along the flow path. The second damper is configured to provide a damping force that varies based on the position of the piston within the chamber.