The problem is to propose a modification scheme for the main valve block of hydraulic winch with a diameter of more than two meters.
The brake and main power system of the KY2/1.8B explosion-proof hydraulic winch are all hydraulically driven. Our mine uses the equipment for -200 level to -625 horizontal inclined well extract with a length of 1 222m and an inclination of 18°. When the winch was installed, the hydraulic oil temperature was normal due to the small amount of work. As the lifting amount of the winch gradually increases, the oil temperature of the main oil passage is becoming more and more prominent. By August 1997, the winch continuously operated 2~3 hooks, and the oil temperature reached 80~90, which could not meet the normal lifting. Claim. After two months of maintenance by the engineers and technicians of the winch and main valve group manufacturers, it still could not be solved. After studying and analyzing the structure of the valve block, we believe that there are certain problems in the design of the oil circuit. The heat exchange back pressure circuit cannot realize the heat exchange function and needs to be modified.
First, the main oil circuit hydraulic system working principle The pressure motor 2 constitutes a closed circuit. The pressure oil from the pump pushes the hydraulic motor to rotate.
Replenishment circuit. The pressure oil output from the charge pump 6 is sucked from the strainer 8 and passed through the ball valve 7 through the fine filter check valve 5 to the 3-2 check valve on the main valve group to be replenished into the main circuit. The relief valve 3-1 is used for replenishing oil overflow. The excess oil is returned to the fuel tank through the cooler 4. The replenishing pressure is 8~11.3-8, which is the replenishing pressure relay. When the replenishing pressure is low, the performance of the lifting brake is improved. The old model of the comparison table and the manufacturer Z160Ed201/6 Germany KRUPPYP2-2000 Shanghai Zhenhua main technical parameters Torque: 650~6 compensation device realizes the brake clearance compensation by interlocking pin, cam and chain. The disadvantage is that the transmission link is more Long stroke, large drag resistance, poor compensation of brake clearance through the compensation head, compensation sleeve and one-way bearing to achieve clearance compensation, which is characterized by short stroke, compact structure, small resistance during clearance compensation, flexible compensation for brake clearance The timely opening and closing transmission device drives the triangular wedge-shaped push arm to advance and retreat through the thruster to realize the braking, which is a wedge-shaped push-opening opening and closing form.
The disadvantage is that there is no manual opening and automatic lubrication function. The push arm is subject to large resistance and is easy to wear. The inconvenient maintenance adopts the opening and closing mode of the four-link rocker arm (power is still used with the thruster), which is characterized in that each movable pin is made of stainless steel. With automatic lubrication and manual opening. Basically, it will not be rusted and worn, and the resistance is small. It is easy to repair and brake. The braking torque and clearance adjustment device can adjust the braking torque and clearance by adjusting the screw, the cymbal and the circular concave spring piece. There is no torque scale, and the torque is difficult to grasp when adjusting. The reliability is poor. The braking torque is adjusted by the slewing spring, the adjusting bolt and the shackle. The torque scale is provided for easy adjustment and reliability. The parts are common parts, and the brake lining is easy to purchase.Wire-fastened brake linings are difficult to assemble and disassemble, and the replacement brakes are easy to replace. The replacement is simple and quick. The Chinese equipment management 2000.5 new brake-compatible chassis is welded on the original base to ensure the modified brake. The brake center is on the same level as the brake disc center line and has good braking performance. The working principle of the new brake is shown in the modified hoisting brake system. From the perspective of more than half a year of use, it completely solves the problem that the spreader slips due to mechanical reasons. Moreover, the new brake is obviously superior to the original brake in terms of technical performance and maintenance. The specific comparative analysis is shown in Table 1. After the hoisting brake system is modified, it not only has the advantages of convenient adjustment and maintenance, flexible and timely compensation of brake clearance, etc. Moreover, the adjustment period is long, the brake is stable, safe and reliable, the labor intensity of the mechanics is reduced, the repair cost is reduced, and the overall effect of the transformation is satisfactory.
Company communication address: When the hydraulic principle diagram of the main oil road of Huangpu New Port in Guangzhou is at the specified value, the main control circuit will not start.
High voltage safety circuit. The check valve 3-6 and the high pressure safety valve 3-7 form a high pressure safety circuit. When one side of the main circuit is high pressure and the other side is back pressure, if the load is too large, the pre-adjustment pressure is exceeded, the high-pressure safety valve acts, overflows to the low-pressure side, the hoist drum will stand still, and the safety pressure is pressed. Adjust to 20 MPa (ie 1.25 times the rated working pressure).
Heat exchange back pressure loop. It consists of a heat exchange three-position three-way hydraulic control reversing valve 3-9 and a back pressure relief valve 3-10. When one side is high pressure, the control oil taken out from the high pressure side pushes the spool of 3-9 to make the back pressure and the relief valve 3-10 connected. When the back pressure is adjusted to a certain pressure value, it comes from the charge pump. The oil is displaced through the main circuit and a portion of the hot oil is returned to the tank through the cooler 4. The back pressure is between 0.7 and 1 MPa to ensure back pressure.
Median bypass circuit. It consists of a 3-1 two-position two-way hydraulic control valve and a throttle valve 3-4. When there is no control oil, that is, when the operating handle is in the neutral position, the main circuit is high and low pressure collusion. The control oil is generated when the operating handle is operated, and the high and low pressure are cut off, and the main circuit can work normally.
When lifting (the solid line in the figure below represents the oil passage, the arrow represents the flow direction of the hydraulic oil) (1) Schematic diagram of the oil exchange heat exchange circuit before the transformation (see). Schematic diagram of the charge oil exchange oil circuit from the low pressure side of the motor to the heat exchange valve to the oil suction side of the main oil pump to the charge pump (2) (see). Schematic diagram of the charge exchange heat exchange circuit from the low pressure side of the motor to the heat exchange valve to the oil suction side of the main oil pump to the charge pump (1). Schematic diagram of the charge heat exchange oil circuit from the low pressure side of the motor to the heat exchange valve to the oil suction side of the main oil pump to the charge pump (2) (see). Before the low pressure side of the motor to the heat exchange valve to the oil suction side of the main oil pump to the charge pump, the hot oil returning from the motor to the valve group directly enters the oil suction side of the main oil pump, and the pressure oil of the main oil circuit is supplemented by the charge pump. It is impossible to enter the heat exchange valve and return to the fuel tank, so the heat exchange oil circuit basically does not work, thereby causing the hydraulic oil of the main oil passage of the winch to overheat.
After the modification, a part of the hot oil returned from the motor to the valve block to the suction side of the main oil pump, and a part of which is returned from the heat exchange valve to the oil tank, thereby achieving the heat exchange function.
The main valve block is compact in structure, and it is difficult to block and penetrate the oil passage.
The plugging and the eccentric bushing are respectively used to separate the oil filling and heat exchange oil passages; two 030mm high-pressure hoses are used for passing through, and the hot oil returning the motor to the valve group is directly in front of the main valve group. Through the heat exchange valve.
Third, the application of the main valve group after the transformation of the KY2/1.8B explosion-proof hydraulic winch main valve group after the transformation of the effect is very satisfactory. Under the condition of full load continuous operation, the oil temperature is 40~ China equipment management 2000.5 earthen oil tank brick, stone oil tank and concrete oil tank. The oil tanks in China are mostly built in the historical period of steel shortage. The temperature difference inside the tank is small, the evaporation loss is low, and it can play a good heat preservation function. So far, many oil depots are still in use throughout the country. However, due to its design flaws, maintenance is difficult.
The heating pipe in the earth oil tank is composed of a condensation pipe, a steam heating inlet pipe and a heating coil. Heating pipe perforation is one of the common failures, which can cause the following hazards.
The oil is drained from the condensing pipe in the tank to the trap at the sand well outside the tank. The bow, the trap is blocked, and the condensed water cannot flow smoothly to the sand well, thereby reducing the heating speed of the oil and even heating. .
The oil is heated from the tank to the steam pipe and slowly enters the main steam pipe, and flows to the drain through the heat pipe on the plurality of oil pipelines, causing pollution to the river.
The perforation of the heating pipe in the earth oil tank often appears in the bend position of the condensation pipe in the collecting tank. The reason is that the diameter of the condensation pipe is small, the pipe wall is thin, the pipe is heated and bent by the external force to the 90° bend position due to the oxide scale falling off. And the outer wall of the tension tube wall becomes thinner; at the same time, the place is immersed in the oil moisture boundary for a long time, between 50 and 50, ensuring safe and reliable improvement.
