An eccentric screw pump for delivering solid-laden liquids includes a rotor and a stator within which the rotor is rotatably arranged. The rotor and stator are arranged and designed with respect to one another in such a way that at least one chamber is formed, which serves to transport the liquid. The eccentric screw pump has a drive motor for rotating the rotor, a control device for controlling the drive motor at least in a working state, in which the rotor is rotated, and an idle state, in which the rotor does not rotate, and an engagement unit, which is designed to set an engagement between the rotor and stator to an idle engagement in the idle state and to a working engagement in the working state. The idle engagement is less than the working engagement. A method for operating the eccentric screw pump is also disclosed.

A device usable as an impeller has a plurality of vanes rotating eccentrically about a shaft. Eccentric rotation is enabled by a cam mounted on the shaft. The vanes are received within slots in a rotor which surrounds the shaft and rotates about an axis coaxial with the shaft. The rotor rotates within a housing having a cylindrical surface facing the rotor. The surface is eccentric to the shaft. The vanes execute reciprocal motion upon rotation of the rotor. The vane motion is constrained so that the edges of the vanes remain proximate to the cylindrical surface during rotation.

A pump device is configured so that a first drive shaft 20 for driving a first pump element E1 and a second drive shaft 40 for driving a second pump element E2 are connected through a third drive shaft 50, and a first joint 51 and a second joint 52 are respectively connected between the first drive shaft 20 and the third drive shaft 50, and between the second drive shaft 40 and the third drive shaft 50, each of the first joint and the second joint being configured to permit a joining angle change or a change in an amount of eccentricity between the corresponding drive shafts. As a result of this configuration, a flexural deformation produced in the first and second drive shafts 20, 40 can be absorbed by means of the first and second joints 51, 52, and thus it is possible to suppress the problem of the flexural deformation of one of the first and second drive shafts 20, 40 affecting the other.

An inner rotor (a drive side) includes a plurality of slots. An outer rotor (a driven side) includes a plurality of pendulum retaining grooves. Each of pendulums includes a head section swingably fitted into a corresponding one of the pendulum retaining grooves and a body section slidably fitted into the corresponding one of the slots. A torque transmission surface of the body section includes a straight line section and a curved section. At a reference angle position at which a perpendicular line orthogonal to an eccentric direction becomes parallel to the corresponding one of the slots, the straight line section makes a surface contact on a torque-transmission-side side surface to start a torque transmission. Until a torque transmission end point, the curved section contacts on opening edge of the corresponding one of the slots. A curved section profile is set to make mutually equal angular velocities between the two rotors.

Techniques relate to a moving cavity motor or pump, such as a mud motor, including a rotor, a stator, and one or more apparatus for constraining (i.e., controlling or limiting) the movement of the rotor relative to the stator, where the apparatus for constraining is operable with the rotor catch. The motor may include a top sub, power section having a progressive cavity motor with a stator and rotor, a rotor catch, and an apparatus between a proximal and distal end of the rotor catch shaft. The apparatus may constrain the radial and/or tangential movement of the rotor catch shaft and the rotor.

A fuel pump includes an inner rotor, an outer rotor, a casing, and a housing. The inner rotor includes outward teeth. The outer rotor includes inward teeth geared with the outward teeth. The casing houses the inner rotor and the outer rotor, and forms a variable capacity pump chamber between the inward teeth and the outward teeth. The housing is formed in a cylindrical shape and includes a cylindrical inner portion, the casing being press fit into the cylindrical inner portion. A recessed portion is formed at a predetermined position in a circumferential direction of an outer circumferential surface of the casing, the recessed portion being recessed toward a radial direction center of the outer circumferential surface.

Disclosed are a transmission method and a device for coaxially outputting autorotation and revolution. The axis of a power output shaft (17) and the axis of a crank of a power input shaft (1) are coincided with each other. The power output shaft (17) revolves around the axis of a main shaft of the power input shaft (1), and the revolution speed equals to the rotation speed of the power input shaft (1). After the superposition of a transition gear train (A) and a K-H-V few-tooth-difference planetary gear train (B), a driving force of the power input shaft (1) enables the power output shaft (17) to generate the autorotation which has the same speed as that of the power input shaft (1) but in the opposite direction, and at the same time, a thrust bearing (19) coaxial with the power output shaft (17) is connected to a thrust bearing (18) coaxial with the main shaft of the power input shaft (1) in series to bear axial loads. The transmission device for coaxially outputting autorotation and revolution is mainly formed by the power input shaft (1), the transition gear train (A), the K-H-V few-tooth-difference planetary gear train (B), the thrust bearings (18, 19) connected in series, and the power output shaft (17), etc. The device can be combined with a plasticizing delivery device using an eccentric rotor and having pulsed volume deformation to form an extruder.

The present application discloses a high-precision electric oil pump, which relates to the technical field of new energy vehicles. The electric oil pump includes a pump housing connected with an outer gear and an inner gear engaged with each other, the pump housing is internally connected to a fixed shaft concentrically arranged with the pump housing, the outer gear is connected to the fixed shaft and concentrically arranged with the pump housing, the fixed shaft includes a connecting section, an eccentric calibrator is provided on an outer circumferential wall of the connecting section, the eccentric calibrator and the connecting section form an eccentric assembly, the inner gear is rotated around a geometric central axis of the eccentric assembly, and the eccentric assembly is non-concentrically arranged with the pump housing.

In a variable displacement oil pump (VP1) according to the present invention, a coil spring (SP) as an urging member is arranged at a position that does not overlap a first suction port (114), a first discharge port (115) and an inlet (124a) which correspond to a suction portion when viewed from an axial direction along a drive shaft (2). Therefore, in the variable displacement oil pump (VP1), there is no risk that during pump operation, flow of oil introduced into the pump chambers 30 located in a suction region through the first suction port (114), the first discharge port (115) and the inlet (124a) corresponding to the suction portion will be interrupted by the coil spring (SP). With this, in the variable displacement oil pump (VP1), a suction resistance during the pump operation is reduced, then a suction performance of the pump can be improved.

A shaft (1) is shown comprising a shaft section (2) having an axis (3), a tooth geometry (4) at least at one end of said shaft section, said tooth geometry (4) having a first end (5) opposite said shaft section (2) and a second end (6) adjacent said shaft section (2), a number of teeth (7) distributed in circumferential direction around said axis (3), a bottom curve (9) between adjacent teeth (7), and an outer tooth curve (12), said bottom curve (9) having a positive slope from said first end (5) towards said shaft section (2) and a negative slope (14) at said second end (6). In such a shaft wear should be made as small as possible. To this end said bottom curve (9) comprises a section having a concave bottom curvature (15) between said positive slope and said negative slope.