Abstract: A crude oil production equipment includes a submersible pump coupled with a driving shaft, a linear motor, an oil pipe, a well casing, a filter pipe, an outer passage, an inner tube, an upper valve ball, a piston and a lower valve ball. During down stroke of the driving shaft, a suction force is produced to suck crude oil from the well casing into the upper chamber of the inner and the piston forces crude oil out of the lower chamber of the inner tube into the inner passage and then the outlet of the oil pipe. During up stroke of the driving shaft, the piston forces crude oil out of the upper chamber into the lower chamber, and the driving shaft enters the upper chamber and the lower chamber to force crude oil out of the lower chamber out of the oil outlet of the oil pipe.

Abstract: A crude oil production equipment includes a submersible pump coupled with a driving shaft, a linear motor, an oil pipe, a well casing, a filter pipe, an outer passage, an inner tube, an upper valve ball, a piston and a lower valve ball. During down stroke of the driving shaft, a suction force is produced to suck crude oil from the well casing into the upper chamber of the inner and the piston forces crude oil out of the lower chamber of the inner tube into the inner passage and then the outlet of the oil pipe. During up stroke of the driving shaft, the piston forces crude oil out of the upper chamber into the lower chamber, and the driving shaft enters the upper chamber and the lower chamber to force crude oil out of the lower chamber out of the oil outlet of the oil pipe.

Abstract: Connected to a 3-phase linear motor of a submersible oil pump of a crude oil production system, a linear motor automatic control circuit assembly is disclosed to include a linear motor power supply circuit, a CPU, an insulated gate bipolar transistor driving circuit, a current detection circuit, a temperature sensor, a fluid depth sensor, a function setting and status display circuit, and a circuit assembly power supply circuit for controlling the operation speed of the linear motor subject to the submergence depth of the linear motor in the oil well.

Abstract: A mover stabilizing and stator cooling arrangement includes an upper sleeve surrounding the mover of the linear motor, a lower sleeve, a thermoconducting sleeve surrounding the stator and axially connected between the upper sleeve and the lower sleeve. The arrangement further includes a thermal grease filled in the space defined between the upper sleeve and the mover, the space defined between the thermoconducting sleeve and the stator, and the space defined between the lower sleeve and the outer tube for quick dissipation of waste heat. A stabilizer ring is set between the upper sleeve and the mover to stabilize axial movement of the mover. A piston and multiple one-way valve sets are mounted in the space between the lower sleeve and the outer tube for allowing adjustment of the volume in the thermoconducting sleeve responsive to expansion/contraction of the thermal grease due to temperature changes.

Abstract: A mover stabilizing and stator cooling arrangement includes an upper sleeve surrounding the mover of the linear motor, a lower sleeve, a thermoconducting sleeve surrounding the stator and axially connected between the upper sleeve and the lower sleeve, a thermal grease filled in the space defined between the upper sleeve and the mover and the space defined between the thermoconducting sleeve and the stator and the space defined between the lower sleeve and the outer tube for quick dissipation of waste heat, a stabilizer ring set between the upper sleeve and the mover to stabilize axial movement of the mover, and a piston and multiple one-way valve sets mounted in the space between the lower sleeve and the outer tube for allowing adjustment of the volume in the thermoconducting sleeve subject expansion/contraction of the thermal grease during temperature change.

Abstract: A vibration machine includes a base, a vibration plate suspending above the base for supporting a person, a supplementary shaft fixedly mounted on the center of the bottom side of the vibration plate, a plurality of axle housing elements fixedly mounted on the base around the supplementary shaft, a plurality of spring members vertically connected between the vibration plate and the base and spaced around the axle housing elements, and a DC linear motor surrounded by the axle housing elements on the base for moving the supplementary shaft and the vibration plate alternatively up and down relative to the base.

Abstract: Connected to a 3-phase linear motor of a submersible oil pump of a crude oil production system, a linear motor automatic control circuit assembly is disclosed to include a linear motor power supply circuit, a CPU, an insulated gate bipolar transistor driving circuit, a current detection circuit, a temperature sensor, a fluid depth sensor, a function setting and status display circuit, and a circuit assembly power supply circuit for controlling the operation speed of the linear motor subject to the submergence depth of the linear motor in the oil well.

Abstract: The present invention provides a brightness remote control system for LED lighting device. There are two control modes, namely automatic mode and manual mode. At automatic mode, the brightness of the LED lighting device changes as the brightness of the environment changes to maintain preset constant brightness. At manual mode, the brightness of the LED lighting device can be changed instantaneously or at preset time or times.

Abstract: A swivel glide bar rail table for stringing racquets in which glide bars and clamps are mounted on a rotatable table to permit a change in clamp orientation without the need for removing the clamps and glide bars. Glide bar rails are mounted on a disk which pivots and can be secured in a variety of positions depending on the desired string orientation. The rotatable table is retained in stringing position by screws with stepped heads which are positioned beneath a fixing plate.

Abstract: Athletic racket string construction consisting of a seven strand core and an outer layer of wrapping fibers.