The planetary roller screw converts rotational motion into linear motion, and the transmission unit is the roller between the screw and the nut. The planetary roller screw is installed around the main threaded screw, with 6-8 small threaded roller screws arranged on the planet. The rotation of the motor is converted into linear motion of the screw or nut. The transmission between the screw, roller, and nut is achieved through threaded engagement. The lead screw is a multi head thread with a tooth angle of 90 °; Roller is a single head thread with the same tooth profile angle; A nut is an internal thread with the same number of heads and tooth profile as a lead screw. Planetary roller screws are superior to ball screws in terms of load-bearing capacity, stiffness, accuracy, and miniaturization. Due to the existence of threaded transmission structure, the planetary roller screw pair has the following advantages

(1) High load-bearing capacity and high stiffness. When the installation space is the same, due to the limitation of the ball diameter, the number of meshing points between the ball and the screw raceway in the ball screw pair is much smaller than the number of meshing points between the roller thread and the screw thread in the planetary roller screw pair. An increase in the number of meshing points will enhance the load-bearing capacity of the screw pair.

(2) Realize small lead precision transmission.

(3) The required workspace is small.

Partial Product Introduction 1

Specification and model: RV20 * 6-5

Dynamic load: 37.5KN

Static load: 55.6KN

Application of a certain research institute in aircraft actuator systems

Partial Product Introduction 2

Specification and model: RV20 * 6-5

Dynamic load: 37.5KN

Static load: 55.6KN

A customer of AVIC applied a servo system for a certain type of aircraft, which uses a two-stage screw. The first stage is an RV25 * 5-6 planetary roller screw pair, and the second stage is a TR45 * 5 trapezoidal screw pair.