A watertight pump having a plunger used to causing air to be expelled from a nozzle of the pump. The plunger forms an interior compartment accessible by removal of a cap of the pump.

A floor pump includes a main body and a supporting device. The supporting device includes a base and a first leg. The base is fixed to the main body and has a first stopping flange and a second stopping flange. The first leg is pivotally connected to the base to approach or move away from the base. The first leg has a front end and a rear end. When the first leg is approached to the base, the first leg is limited by the first and second stopping flanges to a folded position or an unfolded position. When the first leg is in the folded position, the front end is approached to the main body. When the first leg is in the unfolded position, the front end is distal away from the main body.

A floor pump includes a main body and a supporting device. The supporting device includes a base and a first leg. The base is fixed to the main body and has a first stopping flange and a second stopping flange. The first leg is pivotally connected to the base to approach or move away from the base. The first leg has a front end and a rear end. When the first leg is approached to the base, the first leg is limited by the first and second stopping flanges to a folded position or an unfolded position. When the first leg is in the folded position, the front end is approached to the main body. When the first leg is in the unfolded position, the front end is distal away from the main body.

The present disclosure relates to an electric compressor capable of fixing a shaft seal without a retainer for fixing the shaft seal, and includes a shaft which is rotatably coupled inside a main housing, and a shaft seal which is press-fitted between the shaft and the main housing, seals between the shaft and the main housing by an elastic structure, prevents deformation in the elastic structure with a rigid structure formed integrally with the elastic structure, and maintains the coupled position by a frictional force of the elastic structure.

An air compressor contains a piston actuated by a motor to move in a cylinder. The piston includes an air stop sheet mounted on a top support plate thereof. The air stop sheet includes a bending section having a positioning zone and an acting zone located opposite to the positioning zone and configured to cover an air channel of the piston. The bending section is a boundary axis of the acting area and the positioning zone of the air stop sheet so that a top of the air stop sheet facing the cylinder forms an obtuse angle less than 180 degrees, and a back surface of the acting zone of the air stop sheet backing a top of the cylinder turns on relative to a plane of a top of the top support plate at an open angle θ, thus producing an air flowing space.

An air compressor contains a piston actuated by a motor to move in a cylinder. The piston includes an air stop sheet mounted on a top support plate thereof. The air stop sheet includes a bending section having a positioning zone and an acting zone located opposite to the positioning zone and configured to cover an air channel of the piston. The bending section is a boundary axis of the acting area and the positioning zone of the air stop sheet so that a top of the air stop sheet facing the cylinder forms an obtuse angle less than 180 degrees, and a back surface of the acting zone of the air stop sheet backing a top of the cylinder turns on relative to a plane of a top of the top support plate at an open angle θ, thus producing an air flowing space.

A piston of an air compressor, the air compressor including the piston actuated by a motor to move upward and downward in a cylinder. The piston contains a head accommodating an air stop sheet which has a first bending section being a boundary line of an acting area and a positioning zone of the air stop sheet. The acting zone has a noncircular spacing groove configured to separate an external portion and a circular portion, a neck, and a second bending section, such that an axial line between the circular portion and the external portion is the second bending section at an obtuse angle less than 180 degrees, and the second bending section is defined between a bottom of the circular portion and a top of the external portion at an acute angle θ2.

A piston of an air compressor, the air compressor including the piston actuated by a motor to move upward and downward in a cylinder. The piston contains a head accommodating an air stop sheet which has a first bending section being a boundary line of an acting area and a positioning zone of the air stop sheet. The acting zone has a noncircular spacing groove configured to separate an external portion and a circular portion, a neck, and a second bending section, such that an axial line between the circular portion and the external portion is the second bending section at an obtuse angle less than 180 degrees, and the second bending section is defined between a bottom of the circular portion and a top of the external portion at an acute angle θ2.

Systems and methods to enhance the flow of fracturing fluid into a wellhead during a high-pressure fracturing operation may include providing a pump frame and a crankshaft. A plurality of first plungers may be connected to the crankshaft and may reciprocate in a first plane. The hydraulic fracturing pump also may include a plurality of second plungers connected to the crankshaft and positioned to reciprocate in a second plane. The first plane and the second plane may define a non-zero offset angle between the first plane and the second plane. The crankshaft may include a plurality of crankpins, and each of the crankpins may be connected to one of the first plungers and one of the second plungers. The first plungers may pump a first fracturing fluid and the second plungers may pump a second fracturing fluid different from the first fracturing fluid.

Systems and methods to enhance the flow of fracturing fluid into a wellhead during a high-pressure fracturing operation may include providing a pump frame and a crankshaft. A plurality of first plungers may be connected to the crankshaft and may reciprocate in a first plane. The hydraulic fracturing pump also may include a plurality of second plungers connected to the crankshaft and positioned to reciprocate in a second plane. The first plane and the second plane may define a non-zero offset angle between the first plane and the second plane. The crankshaft may include a plurality of crankpins, and each of the crankpins may be connected to one of the first plungers and one of the second plungers. The first plungers may pump a first fracturing fluid and the second plungers may pump a second fracturing fluid different from the first fracturing fluid.