| 摘要 |
An actuator of the thermal type is described, which comprises: a body (2), wherein a chamber (5) is defined for containing a material (C) which expands in function of the temperature of said body (2); a shaft (5), having one end directly dipped into said material (C), said shaft being movable in function of the increase and decrease of volume of said material (C); closure and sealing means (8-11) for said chamber (4) and said shaft (5), comprising: at least a closure element (11), configured as a washer or similar element, which is apt to cooperate mechanically with said body (5), at least a first sealing element (10), such as a bushing or similar element, which is apt to perform a first sealing on said shaft (5), at least a second sealing element (9), such as a ring or similar element, which is apt to perform a second sealing on said shaft (5). According to the invention, said closure and sealing means (8-11) comprise lower-support means (8) for at least one of said first sealing element (10) and second sealing element (9), said lower-support means (8) being associated with said body (2) at a pre-defined point (6A) of the latter, said closure element (11) and said lower-support means (8) delimiting a precise housing zone (6,7) in said body (2) for said first and second sealing elements (9,10). <IMAGE> |
