In this study's first report, the effects of the dynamic characteristics of a tilt angle supporting element on the operating moment of a swash-plate type variable delivery axial piston pump has been investigated, and a method for predicting the operating moment, that combines a calculation of the dynamic behavior of the tilt angle supporting element and the conventional calculation method for cylinder pressure, has been obtained.
The values calculated by this method coincided well with the actual observed experimental values of a pump in which a valve plate with wide, short and deep knotches was used. The calculated and experimental values, however, did not always coincide in the case of the pump in which a valve plate with narrow, long and shallow knotches was used. The authors found that this disagreement was due to an inaccuracy in the calculation of the cylinder pressure.
In this report, the efffects of the dynamic characteristics of the tilt angle supporting system on cylinder pressure were investigated.
From the re sults, a new method for predicting the cylinder pressure and the operating moment was developed.
Both the cylinder pressure and the operating moment calculated by the new method agreed well with the experimental values with no distinction between the valve plate configurations of the pump.

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Dynamic characteristics of pneumatic RC circuits is the basis for many fundamental pneumatic circuit dynamics. This paper describes dynamic pressure response of pneumatic RC circuits with nondimen sional equations, considering the heat transfer effect. Pressure response of pneumatic RC circuits is affected by the heat transfer effects between the air in the chamber and chamber wall. From this viewpoint, thermal-time constant and pressure-time constant are derived. With nondimensional parameter, which is the ratio of two time constants, pressure and temperature responses can be analyzed. The experimental data are in satisfactory agreement with the calculated pressure and temperature responses.

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This report describes the results of a numerical simulation of a method to provide a riding comfort in a hydraulic elevator equipped with a variable displacement pump.
The equations of motion and fluid flow for the hydraulic system were derived first. The main components of the hydraulic elevator system were the hydraulic pump, line, check valve, accumulator, hydraulic cylinder and cage. In deriving the equations, consideration was given to hydraulic pump leakage, fluid compressibility and friction on the hydraulic cylinder packings. The digital simulation program was developed to compute the cage acceleration and deceleration of the elevator from start to stop, based on the Runge -Kutter method. The parameters in computing acceleration and deceleration were the resistance of the choke, which was built into the accumlator intake, the coefficient of fluid viscosity and the weight of the load placed in the cage. The effects of each were examined to yield the results given below.
(1) Despite the rectangular waveform of the pump's flow rate derivative, the use of the accumlator induced a time lag in the hydraulic system resulting in a trapezoidal acceleration-deceleration waveform con sidered ideal for elevator operation.
(2) Appropriate use of the accumlator's damping capacity allowed the absorption of the transient vibration of the cage.
(3) The resistance values of the accumlator intake's choke changed the elevator system's damping ratio. As a result optimum resistance value was achieved to obtain the maximum damping ratio.
(4) Bringing the damping ratio of the numerically simulated hydraulic elevator up to 0.4 or higher reduced the transient vibration in the first wave only.

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