Abstract: A fluid powered rotary actuator having a first member which is pivotally connected to a second member and which is includes at least one toroidal shaped spear or piston which acts within a correspondingly shaped toroidal shaped cylinder to move the first member relative to the second member. The or each toroidal shaped spear or piston and cylinder assembly includes seals mounted within a seal carrier and the configuration allows movement of the seals relative to the or each cylinder. This configuration allows the seals to continue to provide a leak resistant hydraulic seal between each toroidal shaped spear or piston and its associated cylinder even in cases where the toroidal shaped spears or pistons deflect relative to their associated cylinders. The cylinders are also mounted to the first or second members in a manner designed to reduce the chance of tensile cracking due to deflection of the cylinders.

Abstract: A fluid powered rotary actuator having a first member which is pivotally connected to a second member and which is includes at least one toroidal shaped spear or piston which acts within a correspondingly shaped toroidal shaped cylinder to move the first member relative to the second member. Each toroidal shaped spear or piston and cylinder assembly includes seals mounted within a seal carrier and the configuration allows movement of the seals relative to the or each cylinder. This configuration allows the seals to continue to provide a leak resistant hydraulic seal between each toroidal shaped spear or piston and its associated cylinder even in cases where the toroidal shaped spears or pistons deflect relative to their associated cylinders. The cylinders are also mounted to the first or second members in a manner designed to reduce the chance of tensile cracking due to deflection of the cylinders.

Abstract: A toroidal ram actuator comprising a part toroidal shaped cylinder mounted to a first member and a part toroidal piston reciprocally movable within the cylinder, a free end of the piston being mounted to a second member, wherein the first and second members are pivotally attached along an axis and the relative movement between the cylinder and piston produces rotary motion of the first or second member about the axis.

Abstract: A toroidal ram actuator comprising a part toroidal shaped cylinder mounted to a first member and a part toroidal piston reciprocally movable within the cylinder, a free end of the piston being mounted to a second member, wherein the first and second members are pivotally attached along an axis and the relative movement between the cylinder and piston produces rotary motion of the first or second member about the axis.