Damping system for an endless track system

Patent metadata

Field	Value
Publication number	US-10526027-B2
Application number	US-201715784024-A
Country	US
Kind code	B2
Filing date	Oct 13, 2017
Priority date	Sep 29, 2014
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

Damping system for an endless track system, comprising: Damper operatively connectable between frame members for damping relative movement therebetween, including: cylinder and piston movable therewithin forming variable volume chamber containing liquid. Reservoir containing liquid and gas connected to chamber. Conduits connecting chamber to reservoir for allowing liquid to flow therebetween to move the piston. Gas in reservoir applying hydrostatic pressure to liquid, biasing piston toward an extended position and causing piston to move theretowards when load on endless track system is decreased, and causing piston to move toward a retracted position when load on endless track system is increased. Conduits connected spaced-apart to longitudinal sidewall of cylinder such that when piston moves toward retracted position, piston prevents liquid from flowing within a conduit, and liquid is permitted to flow within a conduit, causing liquid to flow at different rates between chamber and reservoir as piston moves toward retracted position.

First claim

The invention claimed is:

1. A damping system for an endless track system, the endless 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 connectable between the first and second frame members of the endless 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;
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 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 damping system of claim 1 , wherein the plurality of conduits have a same internal volume.

3. The damping system of claim 1 , wherein the plurality of conduits have a same diameter.

4. The damping system of claim 1 , further comprising a plurality of valves, each valve being fluidly connected to one of the plurality of conduits, each valve having an open position in which the liquid is permitted to flow between the chamber of the cylinder and the reservoir, and a closed position in which the liquid is prevented to flow between the chamber of the cylinder and the reservoir.

5. The damping system of claim 4 , wherein each valve is movable in a plurality of intermediate positions so as to provide a plurality of flow rates within the conduit.

6. A damping system for an endless track system, the endless 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 connectable between the first and second frame members of the endless track system for damping relative movement between the first and second frame members, the damper including:
a cylinder;
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, wherein
the damping system has a first predetermined damping value when the at least one valve is in the open position; and
the damping system has a second predetermined damping value when the at least one valve is in one of the plurality of intermediate positions.

7. The damping system of claim 6 , further comprising:
a positioning device operatively connected to the damper for determining a position of the piston within the chamber of the cylinder; and
an electronic controller operatively connected to the positioning device and to the at least one valve, and wherein the at least one valve is movable between the open, intermediate and closed positions upon reception of an electronic signal triggered by the electronic controller based on at least one of (i) the positioning of the piston within the cylinder and (ii) a load applied to the endless track system.

8. The damping system of claim 7 , wherein the positioning device includes a linear variable differential transformer.

9. The damping system of claim 8 , wherein the at least one valve is a proportional valve.

10. The damping system of claim 9 , wherein:
the at least one conduit is four conduits disposed in parallel arrangement, each one of the four conduits fluidly connecting the damper to the reservoir; and
the at least one valve is four valves, each one of the four valves being disposed along one of the four conduits.

Assignees

• Soucy Int Inc

Inventors

• Sauvageau Yves
• Pellerin Jonathan

Classifications

• F16F9/48

  Arrangements for providing different damping effects at different parts of the stroke ({F16F9/346, F16F9/516} , F16F9/53 take precedence) · CPC title

• F16F9/3292

  Sensor arrangements · CPC title

• F16F9/50

  Special means providing automatic damping adjustment, {i.e. self-adjustment of damping by particular sliding movements of a valve element, other than flexions or displacement of valve discs}(F16F9/53 takes precedence); {Special means providing self-adjustment of spring characteristics} · CPC title

• F16F9/065

  Expansion chamber provided on the upper or lower end of a damper, separately there from or laterally on the damper · CPC title

• B62D55/112 Primary

  with fluid springs, e.g. hydraulic pneumatic · CPC title