1. Hitachi excavator rotary buffer valve
When the rotary joystick is pulled to the neutral position to stop the operation, the oil return line of the rotary motor is blocked and the oil pressure of the oil return line rises.At this time, the inertial force of the upper rotary platform is still driving The concave rotary motor is called Zonaida to suck oil from the oil inlet to reduce the pressure of the oil inlet. Then, the motor stops rotating, and the high oil pressure at the oil return port pushes the motor back from the stop position until the pressure of the oil inlet and return port tends to balance.The rotary motor repeats the same clockwise and counterclockwise Rotation: The function of the co-rotation buffer valve is to enable the motor to realize this rotation action conversion as soon as possible so that the upper intermediate rotation platform can smoothly rotate. The principle is shown in the figure
Rotary buffer valve is composed of valve 1, valve 2, valve 3 and solenoid valve 4. Pilot pressure oil from the ports AM and BM connected to the rotary motor and entering the valve 1 is sent to port PS. The signal from the PVC causes the solenoid valve 4 to operate.
When the rotary joystick is in the neutral position (the rotary pressure switch is in the OF position) and the temperature of the hydraulic oil detected by the T sensor is higher than 20°C (68F), the engine controller (EC) does not emit any signal to energize the solenoid valve 4, Therefore, the solenoid valve 4 is closed. Then, the valve 1 is opened to realize the function of its swing buffer.
When the rotary joystick is in the operating position (the rotary pressure switch is in the ON position) or the temperature of the hydraulic oil detected by the T sensor is lower than 20°C (68 degrees), the engine controller (EC) sends a signal to energize the solenoid valve 4 The solenoid valve 4 is activated. Then, the pilot oil flows from the oil port to the valve 1. It is closed, eliminating the function of the rotary buffer valve, and the normal rotary operation is resumed.
Rotary buffer valve is composed of valve 1, valve 2, valve 3 and solenoid valve 4. The ports AM and BM are connected to the rotary motor. The pilot pressure oil entering the valve 1 is sent to the port PS. The signal from the PVC causes the solenoid valve 4 to operate.
When the rotary joystick is in the neutral position (the rotary pressure switch is in the OF position), and the temperature of the hydraulic oil detected by the T sensor is higher than 20 ℃ (68F), the engine controller (EC) does not emit any signal to energize the solenoid valve 4 Therefore, the solenoid valve 4 is closed. Then, valve 1 is opened to realize its function of swing buffer
When the rotary joystick is in the operating position (the rotary pressure switch is in the ON position) or the temperature of the hydraulic oil detected by the T sensor is lower than 20°C (68F), the engine controller (EC) sends a signal to energize the solenoid valve 4, so that The solenoid valve 4 is activated. Then the pilot oil flows from the oil port to the four-flow valve 1. It is closed, eliminating the function of the rotary buffer valve and restoring the normal rotary operation
2. Rotary reducer
Reduction gearbox is a two-stage planetary gearbox, its structure is shown in Figure 5-11. The first-stage ring gear 2 and the second-stage ring gear 4 are installed in the housing. The housing is bolted to the main frame, so the ring gears 2 and 4 are fixed. The output shaft 10 of the rotary motor drives the power of the first-stage sun gear 9 to pass to the second-stage sun gear 7 through the first-stage planet gear 1 and the planet carrier 8. The second-stage sun gear drives the transmission shaft 5 through the second-stage planetary gear 3 and the planet carrier 6.
The drive shaft 5 is meshed with the ring gear of the slewing bearing through a gear, and the slewing bearing is bolted to the base to drive the upper slewing platform to rotate.
