Characteristics of hydraulic winch equipment
Balance control panel
The panel controls the boom and its two winches for lifting a light load, usually less than 5000 pounds, on a stand-alone unit. There are only limited controls and instruments on this panel, but operation is very important for successful hydraulic drilling.
The number of meters usually depends on the number of functions operated by this panel. There is usually at least one pressure gauge to measure the system power fluid pressure (i.e. the fluid pressure available in the circuit on the panel), winch motor pressure, jib rotary motor pressure (if equipped) and weight indicator. Another pressure gauge is also included to balance the loop pressure or tension (sometimes both). Depending on the manufacturer, there may be other instruments.
Main winch in / out control
The main winch is usually equipped with two lines and a moving block to lift the heavy load. Winch is directly driven by hydraulic motor. It shall be located so that the upper pulley does not interfere with the balance winch line.
The winch control of the main winch is usually a three position control lever, which has the function of retracting the wire rope or releasing the winch to an important neutral position in the control circuit. Pull the handle backward to roll up the winch, and the end of the whip of the hoist should also be raised. Push forward to pull it down from the winch and the load drops.
The main winch usually has friction brakes controlled by the operator. It is usually used when lifting or lowering the equipment and installing some equipment (such as electric tongs and other heavy objects) in the basket. During lifting, there is no need to stop and suspend the load.
The circuit can be directly operated or pilot operated. For any one, the control lever can control the speed and direction of the winch. Push the lever forward, a small amount will cause the winch to discharge slowly. If the lever is pushed forward further, more fluid will be transmitted to the winch motor, and the oil delivery speed of the pipeline will be faster. The same is true when the line is occupied.
Balance winch control
The balance winch is a single line direct lifting system for light loads, such as picking up a single joint of tubing or drill pipe. It does not have the dual functions of two-line main winch system and its travel stop.
Balance winch control is also a control lever or lever type control to control direction and speed. It is usually a pilot circuit and the lever is spring loaded to return to the neutral position so that the load can be suspended without the use of a static brake (although the winch can be equipped with one as a backup).
It is called balance circuit because it contains a hydraulic brake as balance valve. It consists of a check valve and a pilot control spool valve. The check valve allows oil to flow freely to the motor in the tension direction. When the control valve is in neutral, the spool valve can prevent oil from flowing out of the motor.
When the control valve is placed in the release position, the spool remains closed until sufficient pilot pressure is applied to the end of the spool to displace it against the preset pressure and open the channel. When the spool valve splits, the pilot pressure depends on the flow rate, and the opening of the spool valve is adjusted to control the descending speed.
There are two types of hydraulic balance valves, lift type and spring type. Each one is adjustable. The control lever is used to operate the winch, so that the winch can move the load into and out of the basket when it is suspended in the hoisting process, and the load will not fall on the personnel below.