CN204327078U - A kind of mud pulse generator brshless DC motor transmission mechanism - Google Patents

Abstract

The utility model discloses a brushless DC motor transmission mechanism for a mud pulse generator, which is composed of a brushless DC motor and a control system, a flexible coupling, a ball screw, a main shaft and a limit device. DC brushless motor and control system are composed of driver module, brushless DC motor and reducer; elastic coupling is composed of fastening shaft shell and elastic body; ball screw is composed of ball nut and screw rod; ball screw The rotation of the motor is converted into linear motion. The direction of the linear motion of the main shaft is provided with a limit device at an appropriate position. After reaching the limit device, the brushless DC motor stalls and the current rises. The driver judges the position of the main shaft according to the detected current. Control the rotation direction of the motor, so as to realize the pilot control of the pulser main valve. The utility model has the advantages of simple structure, reliable operation and power saving, is suitable for a wireless measurement system while drilling, and solves the problems of high failure rate and complicated control of a mud pulse generator.

Description

A mud pulse generator brushless DC motor transmission mechanism

technical field

The utility model belongs to the field of petroleum drilling engineering, in particular to a brushless DC motor transmission mechanism for a mud pulse generator.

Background technique

In the process of oil drilling, especially in the drilling process of complex structure wells such as horizontal wells, extended-reach wells and lateral wells, various downhole parameters that the well site personnel need to know in real time are completed by the measurement while drilling MWD and logging while drilling LWD systems of.

There are four main information transmission methods for measurement while drilling: cable method, mud pulse method, acoustic wave method, and electromagnetic wave method. Each method has its limitations and scope of application. Among them, the mud pulse method is the most widely used and reliable. The mud pulse method is divided into three transmission modes: negative pulse, positive pulse and continuous wave, and the positive pulse transmission mode is the most widely used at present.

Among them, the hydraulically driven reciprocating signal generator with pilot control is the most common form of mud positive pulse transmission. It is driven by the hydraulic control circuit to reciprocate the main throttle valve to generate a pressure pulse signal. The medium of the hydraulic control circuit can be drilling fluid or hydraulic oil. Among them, the hydraulic control circuit structure of the reciprocating throttling signal generator with drilling fluid as the medium is relatively simple, but due to the serious pollution of the drilling fluid, the flow has non-Newtonian characteristics, and its properties change with the drilling conditions. , resulting in very low operating frequency, which can only generate discrete pressure pulse signals; the reciprocating throttling signal generator with hydraulic oil as the medium needs to establish a hydraulic power system, the structure is very complicated, due to the narrow space and harsh environment restrictions The application of high performance hydraulic components.

Utility model content

The purpose of the utility model is to provide a brushless DC motor transmission mechanism of a mud pulse generator, which is used to drive a pilot valve in a wireless measurement-while-drilling system. When the system needs to generate a pulse signal, the brushless DC motor transmission mechanism drives the pilot valve to act, and then controls the main valve to generate a mud positive pulse signal.

The technical solution adopted by the utility model is: a mud pulse generator brushless DC motor transmission mechanism, including a brushless DC motor and a control system, a flexible coupling, a ball screw, a main shaft and a limit device, a DC brushless motor and The control system is at the top, and the flexible coupling, ball screw, and main shaft are connected in sequence, and the limit device is installed at the bottom; the brushless DC motor and the control system are composed of the driver module, the brushless DC motor and the reducer; the flexible coupling consists of The fastening shaft housing is composed of an elastic body; the ball screw is composed of a ball nut and a screw rod.

The brushless DC motor, reducer, flexible coupling, and ball screw are immersed in hydraulic oil, the main shaft is partially immersed in hydraulic pressure, and the other part is immersed in mud.

The ball screw is connected with the rotating shaft of the brushless DC motor, and the rotation is converted into a linear motion, and the end of the main shaft is provided with a limit device.

The spindle is welded together with the ball nut.

Compared with the prior art, the utility model has the advantages that the brushless DC motor is completely submerged in the hydraulic oil because of its brushless characteristics, which will neither damage the explosion-proof characteristics of the instrument, but also meet the requirements of the instrument's internal and external pressure balance . A brushless DC motor spins, and a ball screw converts the rotary motion into linear motion. The transmission efficiency of the ball screw is high, and it is completely immersed in the hydraulic oil, so the mechanical wear is smaller, and it can be maintenance-free under its reasonable service life. The flexible coupling can buffer the instantaneous large torque generated by the acceleration and deceleration of the motor, and protect the subsequent transmission components and the brushless DC motor itself. The linear movement direction of the main shaft is provided with a limit device at an appropriate position. After reaching the limit device, the brushless DC motor is blocked and the current rises. Pilot control of the main valve of the device. The utility model has the advantages of simple structure, reliable operation and power saving, and is suitable for the wireless measurement while drilling system, and solves the problems of high failure rate and complicated control of the mud pulse generator.

Description of drawings

Fig. 1 is the structural representation of the utility model.

In the figure: 1 is a limit device, 2 is a main shaft, 3 is a screw, 4 is a ball nut, 5 is a flexible coupling, 6 is a reducer, and 7 is a brushless DC motor.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

As shown in Figure 1, a mud pulse generator brushless DC motor transmission mechanism includes a brushless DC motor 7 and a control system, a flexible coupling 5, a ball screw, a main shaft 2 and a limit device 1, and the DC brushless The motor 7 and the control system are on the top, the flexible coupling 5, the ball screw, and the main shaft 2 are connected in sequence, and the limit device 1 is installed at the bottom; The flexible coupling 5 is composed of a fastening shaft shell and an elastic body; the ball screw is composed of a ball nut 4 and a screw rod 3 . When the whole mechanism is working in the well, it is installed in the pressure-resistant outer cylinder, and the mud pressure outside the pressure-resistant outer cylinder is kept consistent with the internal hydraulic oil pressure under the action of the corresponding balance device.

Brushless DC motor 7, reducer 6, flexible coupling 5, and ball screw are immersed in hydraulic oil, part of main shaft 2 is immersed in hydraulic pressure, and the other part is immersed in mud.

The ball screw is connected with the rotating shaft of the brushless DC motor 7, and the rotation is converted into linear motion, and the end of the main shaft 2 is provided with a limiting device 1.

The main shaft 2 and the ball nut 4 are welded together. The pressures on both ends of them are basically the same, so the driving force on the main shaft 2 all comes from the axial force of the ball screw.

When the pilot valve needs to operate, the driver module controls the brushless DC motor 7 to rotate forward, and drives the screw 3 to rotate forward through the flexible coupling 5, and then drives the ball nut 4 to move to the right. After moving a certain distance, the end surface of the screw 3 and the main shaft 2 end face contact, the brushless DC motor 7 stalls, and the current rises. After the driver module detects that the current rises, it controls the brushless DC motor 7 to stop rotating, and adjusts the next rotation direction of the brushless DC motor 7 to reverse . After maintaining this state for a period of time, the driver module controls the reverse rotation of the brushless DC motor 7, drives the screw rod 3 to reverse through the flexible coupling 5, and then drives the ball nut 4 to move to the left as shown in Figure 1. After moving a certain distance, the main shaft 2. The end face is in contact with the limit device 1, the brushless DC motor 7 is locked, and the current rises. After the driver module detects that the current rises, it controls the brushless DC motor 7 to stop rotating, and the next step of the brushless DC motor 7's rotation Adjust the direction to forward rotation, keep it for a period of time, and complete one action of the pilot valve.

When the utility model is applied, it needs to work together with other modules of the wireless measurement-while-drilling system. Mud pressure fluctuations are generated, and the surface system decodes them according to the detected pressure fluctuations to obtain measurement-while-drilling and well logging data.

Claims (4)

1. A mud pulse generator brushless DC motor transmission mechanism, including a brushless DC motor and a control system, a flexible coupling, a ball screw, a main shaft and a limit device, characterized in that: a brushless DC motor and a control system At the top, the flexible coupling, ball screw, and main shaft are connected in sequence, and the limit device is installed at the bottom; the brushless DC motor and the control system are composed of the driver module, the brushless DC motor and the reducer; the flexible coupling consists of fastening The shaft shell is composed of elastic body; the ball screw is composed of ball nut and screw rod. 2. A mud pulse generator brushless DC motor transmission mechanism according to claim 1, characterized in that: the brushless DC motor, reducer, flexible coupling, and ball screw are immersed in hydraulic oil, and the main shaft part Submerged in hydraulic pressure, the other submerged in mud. 3. A mud pulse generator brushless DC motor transmission mechanism according to claim 1, characterized in that: the ball screw is connected with the brushless DC motor shaft, the rotation is converted into linear motion, and the end of the main shaft is provided with a limit device . 4. A brushless DC motor transmission mechanism for a mud pulse generator according to claim 1, characterized in that: the main shaft and the ball nut are welded together.