Self-Balanced Double Horse Head and Rack-And-Pinion Driven Pumping Unit Based on Intermittent Power Supply Control

Abstract

Considering the shortcomings of beam pumping unit, a kind of mainstream equipment serving in oilfields of China today, also known as “Kowtow Machine”, such as high energy consumption, low efficiency and disturbance caused to grid, a self-balanced double horse head rack-and-pinion driven pumping unit based on intermittent power supply control is put forward by combining the rack and pinion drive with offset crank slider with intermittent power supply motor control. This unit has the following features: (1) having the quick-return characteristics compared with the existing centric mechanism, i.e. slow move during travel under heavy load, and quick return during travel under light load, which are suitable for pumping unit; (2) utilizing the stable drive through rack and pinion, and employing the double horse head structure to keep the vertical downward force applied by counterweight to beam. Moreover, the counterweight is self-balanced, and receives no additional torque at both ends, so as to improve the force applied to beam; (3) using the microcontroller to control the start and stop of motor, which lowers the loss of motor and its power supply system, so as to reduce the consumption of electric power and enhance the utilization rate of equipment. Additionally, pumping unit is disconnected from grid when it is under no load, in order to reduce the impact on and disturbance caused to grid. We have: (1) completed the structural design of this product, which realizes the energy conservation by around 49.52% compared to the conventional beam pumping unit; (2) finished the prototype of the product after conducting a lot of work including mechanical analysis and design, Solidworks 3D modelling and AutoCAD 2D drafting, Simulink simulation, fabrication, assembly and commissioning; (3) performed the test to verify that the power of the prototype is basically consistent with that in the theoretical analysis, which preliminarily meets the expectation; (4) generalized the prospects on the future application and improvement scheme of this product.