Pneumatic cylinders
or hydraulic cylinders
Single acting pneumatic
cylinder or cylinder
Double acting pneumatic
cylinder or cylinder
Motor
Gear motor
Vane motor
Piston motor
Swing pneumatic cylinder or cylinder
Pneumatic cylinders
or hydraulic cylinders
Pneumatic cylinder or hydraulic cylinder can also be divided into single acting
cylinder and double acting cylinder according to the following ways.
(1) Single acting cylinder: Structurally, only one side of the piston is supplied with
fluid with a certain pressure. The single acting cylinder relies on the fluid force
in one direction to control the movement in that direction, and the return
process relies on the action of external forces such as spring force or gravity.
(2) Double acting cylinder: Structurally, both sides of the piston are supplied with a
certain working pressure of fluid, under the action of fluid force on both sides,
pneumatic cylinder or cylinder can move in the positive or negative direction.
Generally, if the asymmetry of pneumatic cylinder or cylinder can be neglected,
the initial position of piston is in the neutral position of cylinder, and both sides can
be regarded as symmetrical structure, then it is called symmetrical cylinder or
pneumatic cylinder. In fact, the cylinder or pneumatic cylinder moving in a straight
line, and actuator of rotary motion are often asymmetrical, or the initial position
works in a non-neutral position, which has strong nonlinear characteristics.
Approximate calculation is often inadequate for similar structures or applications.
Therefore, it is necessary to analyze the dynamic characteristics and control system
design strictly.
The high-performance and high-speed control performance of pneumatic or
hydraulic systems are directly affected by the volumetric elastic coefficient of fluids.
The natural frequencies of the fluid-controlled actuator with pressure depend on the
parameters of the actuator, the load mass of the movable part, the effective area of
the piston, the displacement, and the characteristics of the fluid. The natural frequencies play a dominant role in the performance of the fluid. This paper mainly
analyzes the characteristics of pneumatic cylinder and hydraulic cylinder, including
single acting cylinder and double acting cylinder.
8.1.2 Natural Frequency of Pneumatic Cylinder
8.1.2.1 Natural Frequency of Single Acting Cylinder
Figure 8.1 shows a typical load mass–spring system diagram, which shows the
system composed of load mass M and spring K. The natural frequency of the
system is
2
8 Pneumatic Actuators, Driving Elements and Accessories
or hydraulic cylinders
Single acting pneumatic
cylinder or cylinder
Double acting pneumatic
cylinder or cylinder
Motor
Gear motor
Vane motor
Piston motor
Swing pneumatic cylinder or cylinder
Pneumatic cylinders
or hydraulic cylinders
Pneumatic cylinder or hydraulic cylinder can also be divided into single acting
cylinder and double acting cylinder according to the following ways.
(1) Single acting cylinder: Structurally, only one side of the piston is supplied with
fluid with a certain pressure. The single acting cylinder relies on the fluid force
in one direction to control the movement in that direction, and the return
process relies on the action of external forces such as spring force or gravity.
(2) Double acting cylinder: Structurally, both sides of the piston are supplied with a
certain working pressure of fluid, under the action of fluid force on both sides,
pneumatic cylinder or cylinder can move in the positive or negative direction.
Generally, if the asymmetry of pneumatic cylinder or cylinder can be neglected,
the initial position of piston is in the neutral position of cylinder, and both sides can
be regarded as symmetrical structure, then it is called symmetrical cylinder or
pneumatic cylinder. In fact, the cylinder or pneumatic cylinder moving in a straight
line, and actuator of rotary motion are often asymmetrical, or the initial position
works in a non-neutral position, which has strong nonlinear characteristics.
Approximate calculation is often inadequate for similar structures or applications.
Therefore, it is necessary to analyze the dynamic characteristics and control system
design strictly.
The high-performance and high-speed control performance of pneumatic or
hydraulic systems are directly affected by the volumetric elastic coefficient of fluids.
The natural frequencies of the fluid-controlled actuator with pressure depend on the
parameters of the actuator, the load mass of the movable part, the effective area of
the piston, the displacement, and the characteristics of the fluid. The natural frequencies play a dominant role in the performance of the fluid. This paper mainly
analyzes the characteristics of pneumatic cylinder and hydraulic cylinder, including
single acting cylinder and double acting cylinder.
8.1.2 Natural Frequency of Pneumatic Cylinder
8.1.2.1 Natural Frequency of Single Acting Cylinder
Figure 8.1 shows a typical load mass–spring system diagram, which shows the
system composed of load mass M and spring K. The natural frequency of the
system is
2
8 Pneumatic Actuators, Driving Elements and Accessories