Linear technology belongs to the technical sub-discipline of power transmission technology and deals with mechanical components or mechatronic systems for carrying out translational movements. The special feature of linear guides and drives is running with low friction and the ability to absorb transverse forces without noticeable deformation. Linear systems are used in various technical systems. These include building technology (sliding doors, sliding windows, ventilation flaps, skylights, etc.), in mechanical engineering (feed and advance movements), in handling systems (storage systems, placement) and in rail vehicles with linear motors (Transrapid, certain underground trains or roller coasters).
Guides can be differentiated according to the type of movements, the type of contact points and the principle of rolling element circulation. Movements on machines are only made possible by the guides. Depending on the type of guide, forces and torques can be transmitted in certain directions between moving and non-moving components. Guides are generally differentiated according to their respective type of movement.
With linear guides, the linear movement takes place in one axial direction. Ball guide rail or dovetail slides guides are the best-known examples of this. With rotary guides, on the other hand, the rotary movement takes place around an axis. These include, for example, deep groove ball bearings or radial plain bearings.
Linear guides, which are also referred to as guide systems, can be divided into sliding guides, rolling guides and magnetic guides. Sliding guides are usually based on several guide elements (e.g. guide rails) or on a tongue-and-groove system in which the tongue and groove are milled into the material. Rolling guides, on the other hand, are based on the principle of the circulation of rolling elements between two moving guide elements. As with the rolling bearing, balls, rollers, needles or other rolling elements serve as rolling elements, which are often kept apart by a rolling element cage. Guides with ball-bearing track rollers are also guided by rolling bearings. In magnetic guides, the moving and stationary machine parts are separated by magnetic force. The moving machine part floats and thus the guide is contactless.
Rolling guides without rolling element circulation
Rolling guides without rolling element circulation have the property that the rolling elements move at half the speed of the carriage and thus only cover half the stroke path. Therefore, they have a limited stroke path.
Rolling guides with rolling element circulation
In a rolling guide with rolling element recirculation, the rolling elements circulate in the carriage and move together with the carriage relative to the guide rail. The stroke is only limited by the rail length.
Learn more about linear guides at PACH Systems!
Linear actuators are described as drive systems that enable linear movement. They enable the movement of machine elements and plant components in a straight line or other predetermined course.
The following versions exist:
- Ball screw drives
- Roller screws (Roller screw with roller recirculation and planetary roller screw)
- Hydraulic cylinders
- Pneumatic cylinders
- Electro-mechanical linear actuators (Linear motors with electrodynamic operating principle and linear actuators)
The maximum travel of linear actuators can be increased by connecting several actuators in series, as in telescopic actuators. Likewise, non-linear movements can also be generated with linear actuators, which are made possible via crankshafts or with the help of a hexapod.