Comparative Study on Dynamic Characteristics of Hydraulic, Pneumatic and Electric Motors

Abstract

Hydraulic or pneumatic motors are replacing electromagnetic servomotors in many applications. It is important for engineers and designers to select adequate actuators in given servo applications. In a previous paper, Nakano had predicted the performance of future electric or hydraulic motors after that there have been many advances in actuators. In this paper the performance of hydraulic and pneumatic motors, and electric AC servo and DC motors has been calculated, surveyed, and evaluated on the basis of specifications listed for them in current catalogs and nonpublic data. We selected 765 different kinds of electric motors and 404 different kinds of fluid power motors available in the market. Power density, torque–inertia ratio, power rate, and power rate density were selected as the performance indexes for comparison. Rated power and torque were found to be nearly proportional to motor mass and moment of inertia, respectively. The electromagnetic motors have developed high performance with large rated torque and a smaller moment of inertia. The newly developed small-size hydraulic motor was also included in the performance index, and its characteristics were plotted. The compact size of fluid power actuators has great potential for power rating or quick response.

Characteristics of Hydraulic and Electric Servo Motors

“…We divided the electric motors into AC, AC direct, brushless DC, and brushed DC motors and hydraulic motors into swash plate-type axial piston, bent axis-type axial piston, crank-type radial piston, and multistroke-type radial piston motors. Among these, the brushless DC motor data were added relative to our previous study [32]. Moreover, we collected data on motors of various sizes and from different years.…”

“…W. Durfee et al, in 2011, considered whether hydraulic systems are appropriate for powered orthotics and compared the weights of hydraulic systems, which were found to be smaller than commonly used electromechanical systems [31]. In 2013, Y. Tanaka and S. Sakama et al surveyed and compared the performances of electric, hydraulic, and pneumatic motors [32] based on the work of Nakano [29]. T. Kazama, in 2019, unlike many previous studies, focused on power transmission elements (hoses in hydraulic systems, tubes in pneumatic systems, and wires in electric drive systems) and conducted a comparison of the relationship between their weight and transmission power [33].…”

A new type of bladeless turbine for compressed gas energy storage system

“…However, the pneumatic motor needs regular maintenance and low energy efficiency (less than 65%). Therefore, there are still many restrictions on the use of pneumatic motors ( Stoianovici et al, 2007 ; Tanaka et al, 2013 ; Deaconescu and Deaconescu, 2022 ).…”

Transmitted Power of Piping and Wiring in Hydraulic, Pneumatic, and Electric Drive Systems

“…Actuators, motors, and pumps have been mainly studied [6][7][8] because they constitute the greater part of these systems.…”