Abstract: A mounting arrangement for attaching a pump arrangement to an exhaust pipe at a boss includes a delivery nozzle section and a remaining section including a pump body. The mounting arrangement includes a packing for supporting the pump body at the remaining section of the pump arrangement.

Abstract: A pumping assembly is provided which is suitable for use in a variety of dosing pumps. The pumping assembly comprises a pump body with a pump bore, and a sleeve fixed within the pump bore. The sleeve has a first end, a second end and a sleeve bore. A plunger is adapted to enter the first end of the sleeve and to reciprocate within the sleeve bore. The sleeve has at least one port to allow fluid flow through a wall of the sleeve. The, or each, port is elongated in a direction substantially orthogonal to a direction of reciprocation.

Abstract: A method for manufacturing a piezoelectric actuator, the method comprising: co-extruding alternating strips of a high permittivity material and a low permittivity material to form a green tape comprising said alternating strips of said high permittivity material and said low permittivity material; cutting said green tape to form a plurality of sheets, each sheet comprising a high permittivity region and at least two low permittivity regions adjacent to the high permittivity region; applying at least one conductive region to each one of two or more of the sheets to overly the high permittivity region and to leave exposed at least one low permittivity region; and stacking a plurality of sheets to form an actuator stack comprising adjacent sheets, wherein the or each conductive region on each sheet is offset with respect to a conductive region on a different sheet within the actuator stack.

Abstract: A fuel injector for use in an internal combustion engine comprises a first valve member and a second valve member, an injection control chamber for fuel, and a set of nozzle outlets; wherein actuation of the second valve member controls the fuel pressure within the injection control chamber, and actuation of the first valve member is regulated by the fuel pressure within the injection control chamber; and wherein the fuel injector is arranged such that actuation of the second valve member establishes a fuel flow path between the injection control chamber and the set of nozzle outlets. The first valve member may be provided with a first valve bore within which the second valve member is received. An injection nozzle and a method of operating a fuel injector are also described.

Abstract: A piezoelectric actuator comprises a stack of piezoelectric elements formed from piezoelectric material, a plurality of positive internal electrodes interdigitated with a plurality of negative internal electrodes to define active regions of the piezoelectric material which are responsive to a voltage being applied across the internal electrodes, in use. The active regions are responsive to voltage applied across the internal electrodes, in use. The piezoelectric actuator also comprises an external positive electrode for connection to the positive internal electrodes and an external negative electrode for connection to the negative internal electrodes.

Abstract: An armature for a solenoid actuator is disclosed. The armature comprises a first face comprising a recess suitable for receiving a biasing spring in use of the armature; a second face opposite the first face; and fluid communication means for providing a fluid flow path through the armature between the recess and the second face in use of the armature. The first face is uninterrupted by the fluid communication means. The invention reduces the risk of cavitation damage during operation of the actuator. In one application, the actuator is used in a fluid pump for a selective catalytic reduction system.

Abstract: A fuel injector for use in an internal combustion engine, comprising a nozzle body being provided with a nozzle bore and at least one set of one or more outlets for fluid, an outer valve member received within the nozzle bore and being engageable with a first seating region of the nozzle body to control the flow of a first fluid from a first delivery chamber, the outer valve member being provided with an outer valve bore, and an inner valve member received within the outer valve bore and being engageable with a second seating region of the nozzle body to control the flow of a second fluid from a second delivery chamber. In various embodiments, the fuel injector can be arranged to allow the first and second fluids to be injected separately and/or together. In one embodiment, the first and second fluids can be mixed within the injector before injection.

Abstract: A pump is provided for pumping two or more different fluids. The pump comprises a body having a longitudinal bore and at least first and second inlets selectively communicating with and providing passage to the bore via non-return valves. A plunger is mounted for reciprocation within the bore and at least one piston is also mounted for reciprocation within the bore so as to permit at least one type of fluid to pass into the bore through one or both inlets.

Abstract: A piezoelectric actuator comprises a co-fired stack of piezoelectric elements formed from a piezoelectric material and a plurality of positive internal electrodes interdigitated with a plurality of negative internal electrodes throughout the stack to define active regions of the piezoelectric material which are responsive to a voltage applied across the internal electrodes, in use. An external positive electrode connects with the positive internal electrodes and an external negative electrode connects with the negative internal electrodes. The actuator is characterised in that the stack further comprises means for deliberately creating artificial cracks within the stack at a location at which the artificial cracks do not give rise to a short circuit between the internal electrodes but serve to relieve stresses within the piezoelectric material.

Abstract: An injection nozzle for a compression ignition internal combustion engine, the injection nozzle comprising: a nozzle body provided with a bore, within which a unitary valve needle is movable along a primary valve needle axis, the valve needle being engageable with a valve seating defined by the bore to control fuel delivery through first and second outlets, and including a first valve region, a second valve region and a first seat region defined by a transition between the first and second valve regions that seats against the valve seating when the nozzle is in a non-injecting state, wherein the valve needle comprises a third valve region, a relieved region defined by a transition between said second and third valve regions, the relieved region defining a first exit volume between the valve needle and the bore adjacent to the first outlet when the valve needle is lifted from the valve seating into an injecting state, and a fourth valve region having at least a part in closer proximity to the bore than said re

Abstract: A fuel injection metering valve has a first fuel outlet for supplying fuel to a first accumulator volume, a second fuel outlet for supplying fuel to a second accumulator volume, valving for controlling fuel flow to the first and second fuel outlets, a first flow path for exposing the valving to fuel pressure representative of fuel pressure in the first accumulator volume and a second flow path for exposing the valving to fuel pressure representative of fuel pressure in the second accumulator volume. The valving is responsive to the representative fuel pressures to control the fuel supply from the second fuel outlet to the second accumulator volume as a function of the fuel pressure in the first accumulator volume. The fuel injection metering valve can be used in a dual-fuel fuel injection system to control the flow of one fuel such that it follows the controlled pressure of a different fuel, so that it is not necessary to provide duplication control components in the fuel injection system.

Abstract: Piezoelectric actuators of the type comprising a stack of layers of ferroelectric material and intervening electrodes which extend only part-way across the adjacent ferroelectric layers suffer differential remanent stress when electric fields are applied across the layers. To overcome this, a tensile stress is applied to the actuator along an axis substantially perpendicular to the layers of piezoelectric material in the actuator, which tensile stress is sufficient to mechanically align the dipoles, thus giving rise to a remanent strain which is uniform throughout the actuator. The actuator is advantageously heated while the tensile stress is applied, so as to increase the difference between the tensile strength of the material and the applied tensile stress. An alternative arrangement involves subjecting the actuator to a multidirectional stress and reducing the stress along the axis substantially perpendicular to the layers of piezoelectric material in the actuator.

Abstract: A pump for pumping a fluid is disclosed. The pump comprises an inlet, an outlet, an internal volume disposed between said inlet and said outlet, a first pumping arrangement operable to pump a first volume of fluid from the inlet means into the internal volume, and a second pumping arrangement operable to pump a second volume of fluid from the internal volume into the outlet. In a first mode of operation of the pump, the first volume of fluid is greater than the second volume of fluid such that, in use, the pressure of the fluid within the internal volume is elevated to a level above the pressure of the fluid at the inlet.

Abstract: A fuel injector comprising an injector body, a capnut, and a pressure sensor exposed to pressure changes in a combustion chamber in use, wherein the pressure sensor is accommodated within the capnut. Optionally, the fuel injector further comprises a signal cable external to the injector body to connect with the pressure sensor.

Abstract: A fuel injector for use in an internal combustion engine comprises a first valve member and a second valve member, an injection control chamber for fuel, and a set of nozzle outlets; wherein actuation of the second valve member controls the fuel pressure within the injection control chamber, and actuation of the first valve member is regulated by the fuel pressure within the injection control chamber; and wherein the fuel injector is arranged such that actuation of the second valve member establishes a fuel flow path between the injection control chamber and the set of nozzle outlets. The first valve member may be provided with a first valve bore within which the second valve member is received. An injection nozzle and a method of operating a fuel injector are also described.

Abstract: A method of operating a fuel injector having a piezoelectric actuator for controlling movement of an injector valve needle comprises: (a) prior to an initial fuel injection event, reducing the voltage across the actuator at an initial rate so as to de-energise the actuator; (b) increasing the voltage across the actuator at a first rate in order to initiate an initial fuel injection event of a first fuel injection sequence; and (c) reducing the voltage across the actuator at a second rate in order to terminate the initial fuel injection event. The method may further comprise the step of: (d) increasing the voltage across the actuator at a third rate, which is lower than the first rate, so as to de-energise the actuator but without initiating an injection event, once the initial fuel injection event has terminated and before a subsequent fuel injection event is initiated.

Abstract: A piezoelectric actuator for use in a diesel engine. The actuator comprises a piezoelectric element which is encapsulated such that a layer of gas at a pressure above atmospheric pressure surrounds the piezoelectric element. The presence of the gas within the encapsulation around the element avoids the need to passivate electrodes exposed on the surface of the element.

Abstract: An injection nozzle for a compression ignition internal combustion engine, the injection nozzle comprising: a nozzle body provided with a bore, within which a unitary valve needle is movable along a primary valve needle axis, the valve needle being engageable with a valve seating defined by the bore to control fuel delivery through first and second outlets, and including a first valve region, a second valve region and a first seat region defined by a transition between the first and second valve regions that seats against the valve seating when the nozzle is in a non-injecting state, wherein the valve needle comprises a third valve region, a relieved region defined by a transition between said second and third valve regions, the relieved region defining a first exit volume between the valve needle and the bore adjacent to the first outlet when the valve needle is lifted from the valve seating into an injecting state, and a fourth valve region having at least a part in closer proximity to the bore than said re

Abstract: A fuel injector for use in an internal combustion engine, comprising a nozzle body being provided with a nozzle bore and at least one set of one or more outlets for fluid, an outer valve member received within the nozzle bore and being engageable with a first seating region of the nozzle body to control the flow of a first fluid from a first delivery chamber, the outer valve member being provided with an outer valve bore, and an inner valve member received within the outer valve bore and being engageable with a second seating region of the nozzle body to control the flow of a second fluid from a second delivery chamber. In various embodiments, the fuel injector can be arranged to allow the first and second fluids to be injected separately and/or together. In one embodiment, the first and second fluids can be mixed within the injector before injection.

Abstract: A pump is provided for pumping two or more different fluids. The pump comprises a body having a longitudinal bore and at least first and second inlets selectively communicating with and providing passage to the bore via non-return valves. A plunger is mounted for reciprocation within the bore and at least one piston is also mounted for reciprocation within the bore so as to permit at least one type of fluid to pass into the bore through one or both inlets.