A cooling system and method for using the cooling system are described. The cooling system includes a plurality of individual piezoelectric cooling elements spatially arranged in an array extending in at least two dimensions, a communications interface and driving circuitry. The communications interface is associated with the individual piezoelectric cooling elements such that selected individual piezoelectric cooling elements within the array can be activated based at least in part on heat energy generated in the vicinity of the selected individual piezoelectric cooling elements. The driving circuitry is associated with the individual piezoelectric cooling elements and is configured to drive the selected individual piezoelectric cooling elements.

Disclosed herein is an integrated pump system in which a motor is directly coupled to a pump, preferably using a modular connection. The integrated pump system may operate in a uni-directional or bi-directional mode. The integrated pump system incorporates an internal cooling channel which directs the returning low pressure hydraulic fluid past the controller and the motor for cooling purposes. The low pressure hydraulic fluid is also directly fed into the coupling between the motor and the pump to provide both cooling and lubrication.

A cam ring of a supply pump revolves around a camshaft without rotating. A tappet reciprocates in a direction perpendicular to the camshaft in response to revolution of the cam ring such that the tappet slides along a cam ring sliding surface. A plunger reciprocates together with the tappet to pressurize and deliver fuel. The cam ring sliding surface is shaped in a convex form that has a curved contour line which is non-circular. A height of an inside of the cam ring sliding surface is higher than a height of a periphery of the cam ring sliding surface. Specifically, an ellipsoidal surface portion is formed at the cam ring sliding surface, and an axial direction of a major axis of the ellipsoidal surface portion is set to coincide with a direction perpendicular to a sliding direction of the cam ring sliding surface.

A cam ring of a supply pump revolves around a camshaft without rotating. A tappet reciprocates in a direction perpendicular to the camshaft in response to revolution of the cam ring such that the tappet slides along a cam ring sliding surface. A plunger reciprocates together with the tappet to pressurize and deliver fuel. The cam ring sliding surface is shaped in a convex form that has a curved contour line which is non-circular. A height of an inside of the cam ring sliding surface is higher than a height of a periphery of the cam ring sliding surface. Specifically, an ellipsoidal surface portion is formed at the cam ring sliding surface, and an axial direction of a major axis of the ellipsoidal surface portion is set to coincide with a direction perpendicular to a sliding direction of the cam ring sliding surface.

A fluid control device includes a fluid conveying element formed by a pump and a valve, and an outer housing containing the fluid conveying element. The outer housing includes a first outer wall forming an internal space closer to the pump, and a second outer wall forming an internal space closer to the valve. The second outer wall includes an outer-wall main plate having a part overlapping, in plan view, a through hole that is a discharge hole of the valve. A thermal conductivity of the part of the outer-wall main plate overlapping the discharge hole is higher than a thermal conductivity of the first outer wall.

An exhaust energy recovery system (EERS) and associated methods for an engine are disclosed. An embodiment of an EERS, for example, includes an inlet duct that is configured to divert exhaust gas from an exhaust duct of the engine into the recovery system and an outlet duct configured to return the exhaust gas to the exhaust duct downstream of the inlet duct. The recovery system is configured to heat components or fluids associated with engine to operating temperatures. The recovery system may be part of a mobile power system that is mounted to a single trailer and includes an engine and a power unit such as a high pressure pump or generator mounted to the trailer. Methods of operating and purging recovery systems are also disclosed.

A compressor includes a compression mechanism, a motor, a drive shaft, and a motor cooler. The compressor is configured to compress a working fluid. The motor dives the compression mechanism and is housed within a motor housing. The drive shaft is engaged with the motor and the compression mechanism and is configured to drive operation of the compression mechanism. The motor cooler is disposed adjacent the motor and is configured to pump a cooling working fluid around the motor. The motor cooler includes a pump that pumps the cooling working fluid into the motor housing based on a rotational speed of the drive shaft.

Disclosed herein are devices, systems, and methods relating to high-pressure fuel pump designs and features. A high-pressure fuel pump assembly includes a body, a camshaft, and an embossment. The body has a forward end and a rearward end opposite thereof and configured to couple to a low-pressure fuel pump. The camshaft is received and secured within a central bore of the body so as to be rotationally movable within the central bore. A coupler end of the camshaft is configured to couple to a drive shaft of the low-pressure fuel pump. The embossment includes at least one fastener boss configured to receive a fastener to couple the low-pressure fuel pump to the high-pressure fuel pump assembly. The embossment is formed at the rearward end of the body such that thermal stresses that cause geometrical deformations at the embossment are reduced through a range of engine temperature operating conditions.

Disclosed embodiments include a reconfigurable multi-stage gas compressor having a first-stage compression cylinder, a second-stage compression cylinder, and two stepped cylinders. Each of the stepped cylinders include first and second compression cylinders. The gas flow paths through the stepped cylinders are configured in a user-selectable configuration to be in series or in parallel so that the reconfigurable multi-stage gas compressor functions as one of: a three-stage compressor, as a four-stage compressor, and as a hybrid three/four stage compressor. In first and second configurations, the system generates four stages of compression and outputs 4-stage compressed gas through a single exit port, and through dual exit ports, respectively. In a third configuration, the system outputs hot and cooled 3-stage compressed gas through first and second ports and 4-stage compressed gas through a third port. In a fourth configuration, the system outputs hot and cooled 3-stage compressed gas with no 4-stage compressed gas.

Disclosed embodiments include a reconfigurable multi-stage gas compressor having a first-stage compression cylinder, a second-stage compression cylinder, and two stepped cylinders. Each of the stepped cylinders include first and second compression cylinders. The gas flow paths through the stepped cylinders are configured in a user-selectable configuration to be in series or in parallel so that the reconfigurable multi-stage gas compressor functions as one of: a three-stage compressor, as a four-stage compressor, and as a hybrid three/four stage compressor. In first and second configurations, the system generates four stages of compression and outputs 4-stage compressed gas through a single exit port, and through dual exit ports, respectively. In a third configuration, the system outputs hot and cooled 3-stage compressed gas through first and second ports and 4-stage compressed gas through a third port. In a fourth configuration, the system outputs hot and cooled 3-stage compressed gas with no 4-stage compressed gas.