| 摘要 |
1. A device for directly actuating a rod of a sucker rod pump assembly, the device comprising: an electric linear motor, the motor including an armature, stators and a base and positioned about the axis of operation of the sucker rod pump, wherein the motor armature is connected to the top end of the rod; and a counterbalance in contact with the armature. 2. The device of Claim 1, wherein at least a portion of the counterbalance is positioned between the armature and the base of the linear motor. 3. The device of Claim 2, wherein the counterbalance includes a mechanical spring. 4. The device of Claim 3, wherein one end of the spring contacts the armature and the other end contacts the base. 5. The device of Claim 1, wherein the counterbalance includes a pneumatic cylinder. 6. The device of Claim 1, wherein the counterbalance includes a hydraulic cylinder. 7. The device of Claim 1, wherein the counterbalance includes a rocker arm counterweight. 8. The device of Claim 1, wherein the counterbalance includes a flexible cable, one end of which is connected to the armature, an idler pulley which supports the cable and a counterweight fixed to the other end of the flexible cable. 9. The device of Claim 1, wherein the linear motor is computer controlled. 10. A device for pumping fluid, the device comprising a sucker rod pump assembly, the assembly including a rod, an electric linear motor, the motor including an armature, stators and a base, and positioned such that it operates on substantially the same axis as the rod traverses, wherein the armature is connected to the rod and a counterbalance positioned such that it counterbalances the weight of the sucker rod assembly and the liquid being pumped. 11. The device of Claim 10, wherein the linear motor is computer controlled. 12. The device of Claim 10, wherein at least a portion of the counterbalance is positioned between the armature and the base of the linear motor. 13. The device of Claim 10, wherein the counterbalance is positioned below the linear motor. 14. A method for pumping a fluid utilizing a sucker rod assembly including a rod and the electric linear motor including an armature, stators and a base and the counterbalance, the method comprising: positioning the sucker rod assembly such that the pump contacts a fluid reservoir; positioning the linear motor such that its axis of operation is substantially the same as the axis of moment of the sucker rod; attaching the top end of the sucker rod to the armature of the linear motor such that when operable the armature directly drives the rod; providing a counterbalance positioned such that it alleviates the load imposed on the linear motor by the sucker rod and the column of fluid to be pumped; and operating the motor such that the pump acquires fluid on its down stroke and transports fluid on its up stroke. 15. The method of Claim 14, wherein the fluid is oil. 16. The method of Claim 14, wherein at least a portion of the sucker rod assembly is substructure. |
