Westport Research Inc.

Westport Power Inc.

Westport Fuel Systems Canada Inc.

Stephen Duncan Noble

Anker Gram

Thomas Brook

Gregory Charles Harper

Thomas Currie Brook

Alain Michel Touchette

S Michael Baker

Brad Douville

Bradley D Douville

Valerie Nadia LeBlanc

Greg Harper

Minh Tran

Bruce Muehlchen

Lance G Follett

Daniel J H Brennan

Lance Garner Follett

Valerie Nadia Leblanc

Daniel James Brennan

Gregory W Harper

Daniel James Hubbert Brennan

A hydraulic drive system comprises a hydraulic actuator comprising a piston reciprocable between two cylinder heads for actuating a machine. A flow switching device reverses the direction of hydraulic fluid flow to and from chambers on opposite sides of the piston. The piston stops at the end of each piston stroke when a shuttle valve associated with the piston opens to allow hydraulic fluid to flow between the chambers cancelling the differential pressure that acts on the piston to cause reciprocal movement. A controller is programmed to determine when the piston reaches the end of each stroke based upon at least one of hydraulic pump speed, hydraulic fluid pressure, or elapsed time, with each of these measured during each stroke. The controller then sends an electronic signal to command the flow switching device to reverse the direction of hydraulic fluid flow.

Hydraulic drive system and method of operating a hydraulic drive system

This invention relates to an apparatus for pressurizing a fluid and delivering a gas comprising a pump, an accumulator and a heater such that the pump pressurizes a quantity fluid received from a fluid store and delivers that pressurized fluid to an accumulator. The accumulator then delivers a quantity of the pressurized fluid to a heater that, in turn, warms the fluid to a gas within a specified temperature and pressure range to be delivered to the end user as required. The invention further relates to a method of delivering a gas at a desired pressure and temperature wherein a quantity of fluid is received, pressurized and stored as a fluid in an accumulator storage vessel at a desired pressure. The fluid is then delivered from the accumulator to a heater where it is warmed and delivered to the end user as a gas at specified temperature and pressure.

Method and apparatus for delivering pressurized gas

A cryogenic tank assembly has a pump which discharges into an accumulator which is located in the cryogenic storage area. This reduces the space required for the device as well as the functioning of the device. The high pressure fluid in the accumulator remains at a cryogenic temperature. The system may also include a heater to deliver high pressure gas form the liquid storage volume.

Method and apparatus for delivering a high pressure gas from a cryogenic storage tank

A storage tank for cryogenic liquids incorporates an ullage vessel that provides for an ullage space. The ullage vessel is in communication through an ullage line to a fill line that provides cryogen to a cryogen space. The junction where the ullage line and fill line meet is of a certain cross-sectional area. Downstream of the junction, the fill line is of a greater cross-sectional area than at the junction. This creates a pressure reduction at the junction during filling, which causes a net flow of material from the ullage space over the course of filling. Once the tank is liquid full, causing cryogen to be redirected down the ullage line, the smaller cross-sectional area of the ullage line compared to the fill line causes a reduction in flow of cryogen which is detected by the fill pump causing filling to stop.

Storage tank for cryogenic liquids

A medium and high pressure pump systems supplies a cryogenic fluid from a storage tank. The system comprises a pump that is operable to pump cryogenic liquid or a mixture of cryogenic liquid and vapor. The pump preferably comprises an inducer with at least two chambers and means for recycling excess fluid within the inducer instead of returning excess fluid to the storage tank. The reciprocating pump is preferably double acting such that fluid is discharged from the pump during both extension and retraction strokes.

High pressure pump system for supplying a cryogenic fluid from a storage tank

A method and apparatus is provided for supplying both cryogenic liquid and vapor from a storage tank to a pump to reduce the need for venting. The pump is operable to pump cryogenic liquid or a mixture of liquid and vapor. Different operating modes are selectable to control mass flow rate through the pump. With one operating mode a high flow rate is achieved by supplying only cryogenic liquid to the pump. By selecting another operating mode, a lower mass flow rate is achieved by simultaneously supplying liquid and vapor from the storage tank to the pump. The pump preferably has an inducer with at least two chambers and valves for recycling excess fluid within the inducer instead of returning it to the storage tank. The reciprocating pump is preferably double acting such that fluid is discharged from the pump during both extension and retraction strokes.

A seal assembly for providing sealing between a movable cylindrical body and a housing body comprises separate sealing mechanisms for providing static and dynamic sealing. The seal assembly is associated in fixed relationship with either the cylindrical body or the housing body and provides a static seal with the body it is associated with and a dynamic seal with the body that moves relative to the seal assembly. The static sealing mechanism is temperature-activated so that within the operating temperature range, a metallic member of the static seal mechanism is pressed tightly against the associated body to provide a fluid tight static seal. The temperature-activation is caused by the metallic member having a different thermal expansion coefficient than the associated body. The dynamic seal may employ known dynamic sealing mechanisms such as spring-energized seals, interference fit seals, and/or temperature-activated seals.

Seal assembly with two sealing mechanisms for providing static and dynamic sealing

A dynamic fluid sealing system for a fuel injection valve employs sealing-fluid to separate a gaseous fuel and a second fluid in the fuel injection valve, thereby preventing leakage of the gaseous fuel into the second fluid. A pressure-balancing system, which includes a pressure-balancing device, reduces the pressure differential between the sealing-fluid and the gaseous fuel used in the injection valve. At the same time, the pressure balancing system dynamically balances the sealing-fluid pressure such that the sealing-fluid pressure is equal to or slightly greater than the pressure of the gaseous fuel within the injection valve. The pressure differential between the gaseous fuel and the sealing-fluid may be maintained throughout the operating range of engine speeds, engine loads, and fuel cut-off conditions so as to prevent leakage of compressible gaseous fuel into the second fluid. The reduced pressure differential between the gaseous fuel and the sealing-fluid also reduces leakage of sealing-fluid into the gaseous fuel.

Fluid seal apparatus and method for dynamically controlling sealing-fluid pressure

This invention relates to a medium and high pressure liquid natural gas fuel system for internal combustion engines and for other cryogenic systems. A cryogenic pump comprising: (a) a vessel for containing compressed gas and liquid; (b) a first chamber in said vessel with an inlet therein for receiving gas and liquid; (c) a second chamber communicating with said first chamber for receiving and dispelling gas and liquid; (d) a third chamber communicating with said second chamber for receiving and dispelling gas and liquid; (e) a reciprocating means separating said first, second and third chambers from one another and for drawing and compressing gas and liquid in any one of the first, second and third chambers; (f) one-way inlet means for enabling gas and liquid to pass into the first chamber; (g) one-way means between said first and second chambers for enabling gas and liquid to pass from said first chamber to said second chamber; (h) one-way means for enabling gas and liquid to return from the second chamber to the first chamber; (i) one-way means between said second and third chambers for enabling gas and liquid to be passed from said second chamber to said third chamber; and (j) one-way means for enabling gas and liquid to be expelled from said third chamber to the exterior of the vessel. The invention also relates to a single action suction and double action discharge pump which can be readily removed from a confined space.

High pressure fuel supply system for natural gas vehicles

The invention relates to an apparatus and method for supplying high pressure gaseous fuel from a storage vessel to an internal combustion engine of a vehicle, or for other uses. A reverse cascade fuel supply apparatus for a vehicle comprising: (a) a storage tank for storing high pressure gaseous fuel; (b) an intermediate pressure accumulator for storing high pressure gaseous fuel, connected by a pipe to the storage tank; (c) a high pressure accumulator for storing high pressure gaseous fuel connected by a pipe to the intermediate accumulator and by a pipe to the storage tank; (d) a gaseous fuel compressing intensifier connected by a pipe to the storage tank, the intermediate pressure accumulator and the high pressure accumulator; and (e) a plurality of on-off pressure controlled valves located in the pipes connecting the storage tank, the intermediate accumulator, the high pressure accumulator and the intensifier, for enabling selective pumping to and withdrawal of high pressure gaseous fuel from the storage tank, the intermediate accumulator, the high pressure accumulator, the intensifier or the engine, according to a reverse cascade fuel supply program.

Growing community of inventors

Vancouver, Canada

Stephen Duncan Noble