Research On Influence Of Inner Curver To The Output Capacity Of Radial Piston Hydraulic Motor

Motor is one of the key components of hydroulic system which transforms the hydraulic energy of the system into mechanical energy to output the torque, so the motor's output performance reflects the hydroulic system's performance. The inner curver radial piston hydraulic motor is particularly applicable to low speed and high torque applications, which can be connected to the driving devices directly without deceleration device for the advantage of small volume, compact structure, large displacement and so on ,and it is widely used in hydrostatic transmission system. The inner curve radial piston motor's output performance mainly depends on the form of the inner curve, so the design and improvement of inner curve is always of great importance in motor designing.First, the working principle of the motor is introduced. The influence of inner curver to the piston motion is analyzed.The geometric property required to form a motor cueve is analyzed too. The influence factors to the radial force of motor shaft and to motor's output performance are analyzed. By the analysis of the circular curve and the modified heart-shaped curve, considering the impact of the acceleration change of the constant acceleration-deceleration curve, a modified ellipse curve is presented. The modified curve is choosed as inner curve ,optimized for small size and big displacement and compared with the modified heart-shaped curve at the same size.Then oil distribution form for motor is choosed for the modified ellipse curve. The axial force of the oil distribution disc is analysised without overturning moment. The influencing factors to the internal leakage of the motor is analyzed. The oil-trap of the motor caused by the curve is analylized too. Considering the compressibility of the oil, the change of pressure in piston when the piston is sealed is anaylised. The actual inner curver form is deduced. A serialized program is design according to the previous analysis. A motor is designed using the program, and 3d modeling and movement simulation is done on the motor.Comprehensive the analysis to the motor's plusation rate, output torque and stress condition, it indicates that the modified ellipse curve is of good output performance as inner curve of radial piston motor.