Analysis Of Internal Flow Field And Research Base On Novel Rotary High Speed On/Off Valve

In the hydraulic control system, high-speed on/off valve is a new type of digital electro-hydraulic control components developed in the1980s. It only works in two states, high control precision, fast response, less energy loss and easy for computer connection by providing digital interface and it have a wide range of applications. However, due to the characteristics of the high-speed on/off valve itself, the conflict between high flow and fast response are unable to meet the demand for high-power hydraulic system.This paper presents a new type of rotary speed valve on/off without external drive, acceleration and deceleration operation commutation, spool gained momentum rotation by using the kinetic energy of the fluid itself to impact the helical blade of the spool sandwich section. With the spool rotating, the interwoven structure made of helical blade selectively channel the flow in for application or back into the tank. The PWM output is adjusted by changing the axial position of the spool. PWM is adjustable from0to100%. The flow rate is up to40L/M and the on/off speed is3.4ms. Axial control system is composed of cycloid pump and the H-bridge circuit. In order to control the flow rate output, the PWM is controlled by pumping the hydraulic oil from one side to the other side to change the axial position of the spool. By analyzing the principle and the geometric relationship of the valve, the two parts (spool and sleeve) are used to design new rotary high speed valve on/off by using Proe software. The sleeve have fluid inlet, three nozzles and four holes feature. Spools have sandwich section and two output-oriented sections (for applications or back to the tank). The main designs in the sandwich section are six helical blades. The tracks of blades are designed by analysing the spool rotary power. In order to improve the on/off speed, this paper proposes two ways to optimize the rotary valve to improve the speed of spool rotation, reduce the nozzle area and slots in the guide section, combined with the Fluid Flow (Fluent) model in ANSYS/WORKBENCH to simulate the internal flow field of the valve. The simulation results shows that slots in the guide section of the spool increases rotary power by using the kinetic energy of the fluid itself to improve the spool rotation speed, thereby increasing the on/off frequency of the valve. After it is optimized, the loss of pressure on the nozzle is0.36Mpa, the pressure loss of the output-oriented is0.2Mpa, and the spool rotation speed is upgraded from51Hz to81Hz and response speed decreases from5.4ms to3.4ms. The Virtually Variable Displacement Pumps system (VVDP) have been designed according to the simulation results and study the energy loss of the system. Results show that VVDP based on the new rotary high speed on/off valve is better than the proportional valve throttle control system.