Mechanical articulation . (From Latin articulatĭo , -ōnis ). Union between two rigid pieces so that turning or displacement movements can be produced or transmitted between them, without losing the connection. In most cases these movements are angular, that is, the pieces form a variable angle to each other. In other cases, relative displacement occurs on the same axis.
Applications
In the mechanisms there are numerous cases in which it is necessary to transmit a movement between two axes that are at an angle to each other. The simplest case is when the angle is always in the same plane, as in a hinge, where only one turn occurs. However, when there are two axes between which a rotational movement is transmitted and which form an angle, or are not continuous, this can only be done with a mechanical joint.
Types of joints
From Holdham . It is used for rotational movement between two axes in the same plane , but separated from each other. The mechanism consists of three plate-shaped pieces, the outer ones with grooves, and the central one with a projection on each side, perpendicular to each other, that slide through the grooves. The combination allows a constant turn and the transmission of power between the axles.
Ball . It is a variant of the Holdham joint, in which the center piece is shaped like a ball.
Elastic . It consists of a rubber disc supported by alternate legs on each axis. Continuous bending on the disc compensates for the difference in angle between the shafts when they rotate.
Gimbal . If it is a simple joint, it allows movement between two axes at an angle. If it is double (called CV joint ), it also allows transmitting the movement on two parallel axes. See gimbal page .
Sliding . It enables the rotary movement of two separate pieces on the same axis, but which can be slightly separated from each other.
