Linear drive and linear drive arrangement

A linear drive, comprising:

• a lever element which has a through bore, a first portion spaced apart from the through bore and a second portion arranged between the first portion and the through bore,
• a rod element which extends along a rod axis and through the through bore,
• a bearing element which supports the rod element, the bearing element configured to allow a movement of the rod element along the rod axis and to block a movement perpendicular to the rod axis,
• a shape memory alloy element which extends along a first axis and length of which is adjustable by application of electrical power, wherein
• a first end of the shape memory alloy element is connected to the first portion of the lever element,
• a second end of the shape memory alloy element opposite the first end is stationarily connected to a first fixed bearing, and
• the shape memory alloy element is configured to exert a tensile force acting along the first axis on the lever element when electrical power is applied,
• a restoring element extending along a second axis, wherein
• a first end of the restoring element is connected to the second portion of the lever element,
• a second end of the restoring element opposite the first end is stationarily connected to a second fixed bearing, and
• the restoring element exerts a restoring force on the lever element acting along the second axis and counter to the tensile force, wherein
• in a first state, in which electrical power with a first power value is applied to the shape memory alloy element, the shape memory alloy element is shortened in such a way that the lever element is tilted owing to the tensile force exerted by the shape memory alloy element and, as a result, there is a non-positive connection between the lever element and the rod element,
• in a second state, in which electrical power with a second power value, which is greater than or equal to the first power value, is applied to the shape memory alloy element, the shape memory alloy element is further shortened in such a way that the tilted lever element is displaced parallel in the direction of the tensile force exerted by the shape memory alloy element and, as a result, brings about a movement of the rod element along the rod axis,
• in a third state, in which electrical power with a third power value, which is smaller than the first power value, is applied to the shape memory alloy element, the tilted lever element is at least partially tilted back and, as a result, the non-positive connection between the lever element and the rod element is released, and
• in a fourth state, in which electrical power with a fourth power value, which is smaller than or equal to the third power value, is applied to the shape memory alloy element, the at least partially tilted back lever element is displaced parallel in the direction of the restoring force exerted by the restoring element.