There is provided a wobble plate piston water pump for use in a pressure washer and driven by a driving source, the water pump includes a pump body, a wobble plate, four or more pistons and a water passage defined by a water inlet and a water outlet. The driving source being electric powered and having a power consumption of less than or equal to a 15 ampere draw at 120 volts or 220 volts or the driving source being gas powered and having an engine displacement of less than or equal to 250 cubic centimetres.

A device for controlling a compressor of vehicles may include a sensor module including a cabin temperature sensor, an outdoor temperature sensor, an evaporator temperature sensor detecting a temperature of cooling medium in an evaporator, a vehicle speed sensor, and a brake sensor, an injector, an air conditioning system including a condenser, an evaporator, the compressor, a temperature control door controlling a temperature of air flowing into a cabin, an intake door selectively distributing an inner air or an outer air into the cabin, and a blower blowing the air to the intake door, and a controller controlling the injector and the air conditioning system, wherein the controller accumulates a cold air energy by increasing an operation of the compressor if a speed-reducing condition occurs, and the air conditioning system uses the accumulated cold air energy by decreasing the operation of the compressor if a release condition occurs.

Systems and methods for operating hydraulic fracturing units, each including a hydraulic fracturing pump to pump fracturing fluid into a wellhead and an internal combustion engine to drive the hydraulic fracturing pump, may include receiving signals indicative of operational parameters. The systems and methods also may include determining an amount of required fracturing power sufficient to perform the hydraulic fracturing operation, determining an available power to perform the hydraulic fracturing operation and a difference between the available power and the required power, and controlling operation of the hydraulic fracturing units based at least in part on the power difference. When the power difference is indicative of excess power available, the system and methods may include causing at least one of the hydraulic fracturing units to idle, and when the power difference is indicative of a power deficit, increasing a power output of at least one of the hydraulic fracturing units.

A device for controlling a compressor of vehicles may include a sensor module including a cabin temperature sensor, an outdoor temperature sensor, an evaporator temperature sensor detecting a temperature of cooling medium in an evaporator, a vehicle speed sensor, and a brake sensor, an injector, an air conditioning system including a condenser, an evaporator, the compressor, a temperature control door controlling a temperature of air flowing into a cabin, an intake door selectively distributing an inner air or an outer air into the cabin, and a blower blowing the air to the intake door, and a controller controlling the injector and the air conditioning system, wherein the controller accumulates a cold air energy by increasing an operation of the compressor if a speed-reducing condition occurs, and the air conditioning system uses the accumulated cold air energy by decreasing the operation of the compressor if a release condition occurs.

There is provided a wobble plate piston water pump including: a pump body defining a plurality of channels; a rotatable wobble plate disposed in the pump body; a plurality of pistons each located in a respective one of the plurality of channels, the pistons being reciprocatable within the channel along a piston axis; a water passage defined by a water inlet and a water outlet; and a plurality of inlet check valves, each associated with one of the channels, and positioned between the water inlet and the associated channel, the inlet check valves reciprocate along an axis parallel to the piston axis to transition between closed states and open states.

There is provided a wobble plate piston water pump including: a pump body defining a plurality of channels; a rotatable wobble plate disposed in the pump body; a plurality of pistons each located in a respective one of the plurality of channels, the pistons being reciprocatable within the channel along a piston axis; a water passage defined by a water inlet and a water outlet; and a plurality of inlet check valves, each associated with one of the channels, and positioned between the water inlet and the associated channel, the inlet check valves reciprocate along an axis parallel to the piston axis to transition between closed states and open states.