Progressive damping system for a track system

Patent metadata

Field	Value
Publication number	US-10640160-B2
Application number	US-201615565440-A
Country	US
Kind code	B2
Filing date	Apr 11, 2016
Priority date	Sep 29, 2014
Publication date	May 5, 2020
Grant date	May 5, 2020

Abstract

The present invention generally relates to vehicle and machinery in agriculture, construction, forestry, mining and powersport. It further generally relates to track systems and traction assemblies used with such vehicles. The track system comprises a drive wheel and a plurality of idler wheels mounted on a support frame. At least one of the plurality of wheels is operatively mounted on the support frame via a damping system adapted to provide a damping value dynamically varying as a function of the load applied. Track systems do not benefit from the damping provided by the layer of air within the tires. The disclosed damping system has the objective to overcome one this drawback by providing a smooth ride for tracked vehicles. The damping system comprises a cylinder fluidly connected to a reservoir. Damping ratio is varied by varying a flow circulating area between the cylinder and the reservoir.

First claim

The invention claimed is:

1. A method for varying the damping value of a damping system of a track system having a multi-member frame assembly including a first frame member and a second frame member, the first frame member being movable with respect to the second frame member, the damping system including:
a damper operatively connected between the first and second frame members of the track system for damping relative movement between the first and second frame members, the damper including:
a cylinder having a length and a cylindrical sidewall extending along the length of the cylinder; and
a piston that is reciprocally movable within the cylinder between an extended position and a retracted position, the piston sealingly engaging the cylinder for forming a variable volume chamber containing a liquid, the piston being movable between the extended position and the retracted position in a plurality of intermediate positions by changing a volume of the liquid contained within the chamber of the cylinder;

a reservoir fluidly connected to the chamber of the cylinder of the damper, the reservoir simultaneously containing the liquid and a gas; and
a plurality of conduits fluidly connecting the damper to the reservoir, each of the conduits being fluidly connected to the reservoir for allowing the liquid to flow between the chamber of the cylinder and the reservoir to change the volume of liquid within the chamber of the cylinder to move the piston within the chamber of the cylinder, the gas in the reservoir being under pressure and applying hydrostatic pressure to the liquid, tending towards an increase in the volume of liquid within the chamber of the cylinder, biasing the piston toward the extended position, the plurality of conduits being fluidly connected to the longitudinal sidewall of the cylinder and being spaced-apart from one another along the length of the cylinder;
the method comprising varying the liquid flow between the chamber of the cylinder and the reservoir in relation to movement of the piston within the chamber of the cylinder such that:
when the piston is in the extended position, the liquid flow between the chamber of the cylinder and the reservoir is permitted by all of the plurality of conduits and the damping system has a first predetermined damping value;
when the piston is in one of the plurality of intermediate positions, the liquid flow between the chamber of the cylinder and the reservoir is permitted by one or more of the plurality of conduits and the damping system has a second predetermined damping value; and
when the piston is in the retracted position, the liquid flow between the chamber of the cylinder and the reservoir is permitted by one of the plurality of conduits and the damping system has a third predetermined damping value.

2. The method as claimed in claim 1 , the method further comprising:
measuring the position of the piston in relation to the length of the cylinder; and
modifying the liquid flow based on the measured position of the piston.

3. The method as claimed in claim 2 , the method further comprising communicating a control signal to an active fluid flow control means configured to vary the liquid flow based on the control signal.

4. The method as claimed in claim 3 , the method further comprising communicating the measured position to a controller configured to communicate the control signal to the active fluid flow control means.

5. The method as claimed in claim 3 , wherein the active fluid flow control means is one or more solenoid valves, the method further comprising controlling the one or more solenoid valves to vary the liquid flow between the chamber of the cylinder and the reservoir.

6. A method for varying the damping value of a damping system of a track system having a multi-member frame assembly including a first frame member and a second frame member, the first frame member being movable with respect to the second frame member, the damping system comprising:
a damper operatively connected between the first and second frame members of the track system for damping relative movement between the first and second frame members, the damper including:
a cylinder; and
a piston that is reciprocally movable within the cylinder between an extended position and a retracted position, the piston sealingly engaging the cylinder for forming a variable volume chamber containing a liquid, the piston being movable between the extended position and the retracted position in a plurality of intermediate positions by changing a volume of the liquid contained within the chamber of the cylinder;

a reservoir fluidly connected to the chamber of the cylinder of the damper, the reservoir simultaneously containing the liquid and a gas;
at least one conduit fluidly connecting the damper to the reservoir for allowing the liquid to flow between the chamber of the cylinder and the reservoir to change the volume of liquid within the chamber of the cylinder to move the piston within the chamber of the cylinder, the gas in the reservoir being under pressure and applying hydrostatic pressure to the liquid, tending towards an increase in the volume of liquid within the chamber of the cylinder, biasing the piston toward the extended position; and
at least one valve disposed along the at least one conduit for controlling the flow of the liquid between the chamber of the cylinder and the reservoir, the at least one valve being movable between:
an open position in which the liquid is permitted to flow between the chamber of the cylinder and the reservoir, rendering the piston movable within the chamber for allowing relative movement between the first and second frame members; and
a closed position in which the liquid is prevented from flowing between the chamber of the cylinder and the reservoir, rendering the piston effectively immovable within the chamber for effectively preventing relative movement between the first and second frame members;

the at least one valve being movable between the open and closed positions in a plurality of intermediate positions so as to provide a plurality of flow rates of the liquid within the at least one conduit, rendering the piston movable between the retracted position and the extended position within the chamber of the cylinder at different speeds;

the method comprising varying the liquid flow between the chamber of the cylinder and the reservoir in relation to movement of the piston within the chamber of the cylinder such that:
when the at least one valve is in the open position, the damping system has a first predetermined damping value; and
when the at least one valve is in one of the plurality of intermediate positions, the damping system has a second predetermined damping value.

7. The method as claimed in claim 6 , the method further comprising:
measuring the position of the piston in relation to a length of the chamber of the cylinder; and
modifying the liquid flow based on the measured position of the piston.

8. The method as claimed in claim 7 , the method further comprising communicating the measured position to a controller configured to communicate with the at least one valve.

Assignees

• Soucy Int Inc

Inventors

• Sauvageau Yves
• Pellerin Jonathan

Classifications

• B62D55/04

  with tracks and alternative ground wheels, e.g. changeable from endless track vehicle into wheeled vehicle and vice versa {(for multi-purpose tractors B62D49/0635)} · CPC title

• F16F9/512

  Means responsive to load action, {i.e. static load} on the damper or {dynamic} fluid pressure {changes} in the damper, {e.g. due to changes in velocity (F16F9/504, F16F9/516 take precedence; non-automatic damper adjustment from a distance using servo control, the servo pressure being created by the flow of damping fluid F16F9/465; self-pumping fluid springs in vehicle suspensions B60G17/044)} · CPC title

• B60G17/056

  Regulating distributors or valves {for hydropneumatic systems}(B60G17/044 - B60G17/048, {B60G17/0416} take precedence; {Fluid interconnection systems to control vehicle inclination B60G21/06, B60G21/10}; valves per se F16K) · CPC title

• B60G2400/25

  Stroke; Height; Displacement · CPC title

• B60G17/08

  Characteristics of fluid dampers (adjusting fluid dampers in general F16F9/44 - F16F9/53) · CPC title