Direct drive permanent magnet synchronous motor for screw pump

Abstract

The invention relates to a direct-drive permanent magnet synchronous motor for a screw pump, which belongs to ground-driven mechanical oil production equipment. The present invention adopts a permanent magnet synchronous motor, and also includes a matching device with a screw pump. connection device. The belt drive and gear reducer are omitted, and it can provide a short-term overload torque multiple of 4 times, which is conducive to the full-load start of the screw pump, high efficiency, energy saving and power saving of 25%, effectively solving accidents such as pump rod breakage, and preventing disc failure. Root leakage oil, thereby improving the reliability of the screw pump at full load, maintenance-free, increasing operating time and reducing oil production costs. The equipment is more compact and light in weight.

Description

technical field [0001] The invention relates to a direct-drive permanent-magnet synchronous motor for a screw pump, a drive device for a ground-driven screw pump, and belongs to mechanical oil recovery equipment. Background technique [0002] There are usually two driving methods for the screw pump oil production equipment driven by the ground: 1. The traditional screw pump pumping unit driven by a horizontal asynchronous motor, which uses 90° bevel gears to reduce the direction and drive the belt to increase the torque. The disadvantages of this structure are: 1. The transmission efficiency is low and the energy consumption is high. This is because the screw pump generally belongs to the full-load start-up and light-load operation state. In order to overcome the mechanical loss in belt transmission or gear transmission and ensure a sufficient torque when starting, people usually adopt the method of increasing the motor capacity, thus causing a waste of resources for large h...

AI Technical Summary

Problems solved by technology

The disadvantages of this structure are: 1. Low transmission efficiency and high energy consumption. This is because the screw pump generally starts at full load and operates at light load.

In order to overcome the mechanical loss in belt transmission or gear transmission and ensure a sufficient torque when starting, people usually adopt the method of increasing the motor capacity, thus causing a waste of resources for large horse-drawn carts

2. It is impossible to prevent mechanical accidents from breaking the pump rod. This is because the equipped motor is generally controlled by asynchronous constant frequency and constant pressure, and the torque cannot be adjusted. Faults such as breakage of the pump rod and breakage of the gearbox gear

3. The oil leakage of the packing is serious. Due to the use of medium and high-speed asynchronous motors and belt drives, the mechanical vibration is large, and the reduction box is driven by one-sided asymmetry, resulting in a large amplitude of the mechanical swing of the drive system. As a result, It is the packing of the screw pump that is subjected to excessive mechanical swing force, which will cause serious oil leakage problems.

2. The rotor shaft of the screw pump pumping unit driven by a vertical motor is generally a hollow structure, and the power polished rod passes through the rotor shaft in a coaxial drive mode. Although this can overcome some defects of the aforementioned horizontal drive mode , but this structure still has certain defects, such as: because the weight of the downhole screw pump and the pump rod and all act on the bearing at the bottom of the vertical motor shaft, and the screw pump pumping unit works continuously for 24 hours, the result It is bound to cause premature damage and failure of the bearing. If the damaged and failed bearing cannot be found in time, it will cause serious mechanical and safety accidents; and frequent shutdowns for inspection and maintenance will affect oil production.

These patented technologies also cannot overcome the defects in the prior art mentioned above

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