Direct drive Linear Actuators
A linear stepper motor, also referred to as a linear actuator with direct drive, offers a simple solution for highly precise applications with low load. It functions without a gearhead and without an encoder. This makes it extremely compact, as well as especially easy to integrate. FAULHABER offers linear stepper motors with numerous equipment options for a wide range of operating conditions.
A linear stepper motor or linear actuator with direct drive is a combination of a rotating motor with a lead screw. The rotation of the lead screw is transferred by the nut to the application as a linear movement. This task can also be performed by a component of the application whose threaded hole is seated on the lead screw.
For linear actuators with direct drive, FAULHABER only uses stepper motors – hence the designation "linear stepper motor." The rotary movement of a stepper motor can be divided into small steps by the motor control. As a result, this drive can approach a predefined position very precisely without the use of an encoder.
At the same time, stepper motors accelerate very rapidly, they deliver full power with nearly no delay, and hold their position even with the power switched off. Thanks to these properties, they are very well suited for demanding positioning tasks. Because neither a gearhead nor an encoder is interconnected, this type of drive has an especially short overall length.
The lead screw of the linear actuator is directly connected to the output shaft of the motor. Lead screws are available with diameters of between 1.2 and 3 millimeters and with leads of between 0.2 and 0.5. The threads are metric. For the standard products, the length of the lead screws ranges from 7.5 to 120 millimeters, customer-specific versions are possible.
As an optional component, FAULHABER offers nuts made from a variety of materials. Their exterior features a surface that prevents them from rotating in the application. Instead of a nut, a threaded hole in the application can also hold the lead screw. As another option, ball bearings are available for a bearing tip with which the free end of the lead screw can be secured and stabilized.
Because motor and lead screw are directly coupled, the threaded rod performs the same rotary movement as the output shaft of the motor. The rotation sets the nut into linear movement. The interplay of lead screw and nut acts like a gearhead reduction. The smaller the selected lead, the lower the speed but the greater the force and the precision of the linear movement.
The devices are available with two types of stepper motors:
In addition, the linear actuators with direct drive from FAULHABER follow the same concept and differ from one another only with respect to size and features.
Linear stepper motors from FAULHABER are all designed for very compact applications with small loads in which a very high precision is required. As a rule, the key criteria are, thus:
In addition, consideration must be given to the required force, speed and service life. The standard combinations of motor with lead screw offer a wide range of product variants. A suitable drive can be found in this product range for most applications. You can enter the required parameters in the Drive Calculator. There, you will receive a selection of suitable linear stepper motor calculations from series production. FAULHABER also offers the bespoke manufacture of customized linear drives.
