TBM auxiliary hydraulic drive

TBM integrates a variety of equipment into one, and has advanced technology in hydraulics and control. This article only analyzes the TBM auxiliary drive hydraulic system in order to understand the host's hydraulic control.

1 set the purpose of the auxiliary drive In the normal driving process, TBM cutter plate is driven by the motor, then the cutter plate has two kinds of speed: high speed is 5.4r/min, low speed is 2.7r/min, the maximum torque is 8700kNm. During the tool change process, an auxiliary hydraulic drive is provided in the IBM drive due to the need for the cutter head to rotate slowly. Another purpose of setting up the auxiliary hydraulic drive is that the hydraulically driven torque is greater, facilitating the cutter head to be freed from difficulties and excavation when the rock is soft or the cutter head is jammed.

2 auxiliary drive hydraulic circuit (see) drive hydraulic motor, p5 pump and pump in parallel to the 302 valve for oil, used to control the brake. The brake is operated by a three-position four-way solenoid valve on the 302 valve block, and the pressure is set to 5.0. The pressure is set to about 2.7 MPa, which is controlled by a two-position four-way solenoid valve on the 302 valve. P5 chestnut maximum flow = dead body coffee = 25, is a constant power pump, dead body 31 pump = 401/min, psS.OMPa, is a pressure control pump. The two pumps are fed in parallel on the valve 302 because the safety factor of the brake and the clutch is high in the driving. In the main motor drive, if the clutch pressure is not reached, the clutch is easily damaged. In the auxiliary drive of the hydraulic motor, the brake cannot be opened, which will cause damage to other motors. Therefore, this is a safe design. A speed-limiting valve (301) is installed on the inlet and outlet ports of the motor. After this valve is set, the pressure relief valve cannot be opened because of no pressure at point B, rendering the oil return path unusable. The role is that when the auxiliary motor is driven, if one brake is damaged and cannot be braked, all the brakes will be braked and the pressure oil will pass through the motor, causing the motor to be damaged by overspeed. In this case, the speed limit valve is An orifice is provided on the return oil to allow the motor to be limited in speed. The 305 valve is a proportional relief valve that, by means of remote control, changes the displacement of the motor and forms a volumetric speed control loop with Pl and 2 pumps. The principle of speed regulation is as follows: (see) The first step through the proportional relief valve to maximize the motor displacement, if the load is unchanged, the motor output torque A / unchanged. Since the output power TV = M/974 (kw), then; v and a linear relationship, change the pump displacement (realized by the proportional relief valve 100), the motor speed changes, yv with the change, this part is constant torque adjustment speed. In the second step, keep the pump at maximum displacement, change the displacement of the motor, and adjust the speed. Because the pump maintains the maximum displacement, the motor is a constant voltage motor. At this time, the output power of the pump is constant. From V = M/974, M and n are in a hyperbolic relationship, that is, the motor speed changes automatically with the load. It is called the constant power speed regulation stage.

3 Auxiliary hydraulic pressure to calculate the speed and torque of the cutterhead is the main parameter of the full-face tunnelling machine, which restricts the tunneling speed. In order to understand the ability of the cutterhead when the auxiliary hydraulic drive is used and the cutterhead rotates when the cutter is changed, Calculate the speed and torque of the auxiliary hydraulically driven cutterhead.

3.1 Hydraulic motor-driven cutterhead torque calculation = 0.0551/r. If mechanical efficiency is not taken into consideration, the output torque is: regardless of pressure loss, and by the P2 pump, ZP = 34MPa. There are 8 hydraulic motors on the TBM, the total drive Ratio i = 5375, the total output torque is: x5375x297 = 12793kNm If you consider the pressure loss and the efficiency factor 7 = 0.83, then the cutter head torque is 12793 = 10618kN.m In this hydraulic circuit, the motor oil is from Pl, p2 Pumps provided in parallel, P, p2 pump models are A4VS0250HD, the maximum flow rate Gmax = 3701 / min maximum pressure = 34.0MPa, flow and pressure after confluence.

3.2 Cutter speed calculation 37x0.97 = 3601/min, Q total effective = 2x360 = 7201/min. Since Q is valid = q motor n motor, when the motor is at its minimum, the motor is at its maximum. The total minimum displacement for 1,8 motors l/r = 5625r/min. Consider the mechanical efficiency n motor = 5625x0.97 2 5460r/min, at this time the speed of the cutterhead n cutterhead max = auxiliary hydraulic drive circuit of TBM , Focused on the proportion of technology, parallel circuit technology, mechanical and hydraulic braking technology, volume control and other technology, to provide the maximum reliability and sensitivity for the operation of the equipment.

According to Shi Xuan, TBM is responsible for the maintenance of TBM from the construction in the Qinling Mountains. 726309 China Railway Tunnel (TBM) Company, Qingyouhe Town, Shangnan County, Shaanxi Province, China (On page 53). After passing the inspection, the work platform can only be dismantled. Move the TBM forward and dismantle the fixed parts of the stirrup and the bucket according to the technical requirements and install the bucket and the cutter head. After running the TBM and following the inspection, the TBM may be tested according to the technical documents of the normal operation of the TBM, the main bearing, the lubrication system, and the labyrinth seal.