The guiding function is the basic mechanical function performed by one or more components that allow another element to move in a precise manner, either in a rotational or in a translational motion, or both at the same time.
In technical objects, some parts may be mobile and move according to one of the three existing types of motion. In order to ensure proper operation of the object, the motion of the mobile parts must be controlled. To do this, a guiding component will enable a precise type of motion and limit its amplitude.
The simplest guides enable a part to move in rotational or in a translational motion. The more complex ones, on the other hand, allow the parts to move in different axes and through different types of motion. The main types of guides are outlined below.
Regardless of the type of guide, there should be a slight gap between the parts. If the adhesion between moving parts is too great, the friction caused may damage the parts. To facilitate guiding and avoid friction, a lubricating component or intermediate materials can be added.
The choice of a guide therefore aims to reduce the friction between the parts. The space available for guiding and the presence of links (pivot or slide) can be used to determine the appropriate type of guiding depending on the technical object.
Rotational guiding allows parts to move by turning on themselves. Therefore only a rotational motion can be performed by a part.
Rotational guiding symbol
Rotational guiding is used in many technical objects, for instance in volume control knobs, door handles, car steering wheels, or bicycle wheels. The allowed rotation can be complete or even limited to a certain amplitude. The parts that form a rotational guiding control are usually cylindrical or spherical. Their translational motion is impeded by fixing them in place with a nut or a rivet.
The rotational motion of the adhesive tape dispenser wheel is guided by the hub holding it in place.
The axle that holds the steering wheel in place guides its rotational motion while preventing translation.
Translational guiding allows parts to move in a straight line. Therefore, it only allows a part to perform a translational (rectilinear) motion.
Translational guiding symbol
Translational guiding is used in many technical objects, for instance in sliding windows or in a drawer's opening mechanisms. The parts that form the translational guiding controls are usually prismatic in shape. Rails, slides, or grooves are particularly suitable for this type of guidance.
The rails on the sides of a drawer control opening and closing, only allowing a rectilinear translational motion.
The opening and closing of a sliding window undergo translational guiding.
Helical guiding enables parts to move in a translational motion when these parts are rotated. The resulting translation and rotation thus obtained take place around the same axis.
Helical guiding symbol
The helical guiding control ensures the combination of a circular and a rectilinear motion. Components with threads are particularly suitable for this type of guiding. The link between a screw and a nut or any other screw-nut motion transformation system are simple examples of helical guiding.
When adjusting the position of a c-clamp, the motion of the screw is controlled by a helical guiding control.
The motion of the valve is controlled by threads ensuring helical guiding.
