Spiral piston type, guide rod type and double spiral type are commonly used in the current spiral swing oil cylinder, and the working principle of each type of oil cylinder is different.
First, the spline piston swings the oil cylinder structure.
The inner surface of the rotating sleeve is also splined and meshes with the piston spline. When the piston moves linearly along the spiral rod under the action of hydraulic pressure, it also rotates at the same time. This rotary motion is output by the rotary sleeve and the flange. This structure is relatively simple, easy to process, and can transmit large torques. However, since the axial length of the rotating sleeve is greater than or equal to the length of the spline on the piston, and when the swing angle of the cylinder is greater than 360 °, this length is also greater than a lead. Therefore, this structure has a large axial dimension.
Second, the guide rod type spiral swing oil cylinder. The spiral rod is supported on the cylinder block by tapered bearings at both ends, and two guide rods are fixed on the cylinder block through the piston. When the piston moves along the spiral rod under the action of hydraulic pressure, a rotary motion is generated. If the cylinder is fixed, since the guide rod is also fixed, the piston can only move linearly along the spiral rod and the guide rod, and the rotary motion is output by the spiral rod. If the spiral rod is fixed, the piston drives the cylinder to rotate through the guide rod. However, from the perspective of sealing, the piston should not be rotated. This oil cylinder has a simple structure and is easy to process. However, since the guide rod passes through the piston, the effective area of the piston is reduced. Thus, the radial size of the cylinder increases when transmitting the same torque.
3. Double spiral swing cylinder: The spiral direction of the spiral sleeve and the spiral rod is opposite. The spiral sleeve is fixed to the cylinder. When the piston rotates along the spiral sleeve and moves linearly, the spiral pair inside the piston causes the spiral rod to rotate, and vice versa. Generally, the two helix leads are equal, and the helix rise angle of the spiral rod is larger than the helix rise angle of the spiral sleeve. If the two helix rise angles are equal, the lead of the spiral rod is smaller than the lead of the spiral sleeve. When the piston rotates for one revolution, the rotation range of the spiral rod is greater than one revolution. This oil cylinder has a compact structure and a large output torque.
The above is an introduction to the working principles of several common spiral swing oil cylinders, I hope to help everyone.