Electric actuator
AssigneeNabtesco Corporation
InventorMasanori Hirai
Life of this patent
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Abstract
An object of the present invention is to provide an electric actuator having a structure capable of reducing an external force or impact acting on a screw shaft when a piston rod is at a stretched position. An electric actuator 1 includes a first port 6, a second port 7, and a cylinder chamber connecting passage 9. The first port 6 is formed on an inner face of a rod-side cylinder chamber 5a of a cylinder body 2. The second port is formed on an inner face of a head-side cylinder chamber 5b of the cylinder body 2. the cylinder chamber connecting passage 9 connects the first port 6 and the second port 7. In the electric actuator 1, a piston part 4a of a piston rod 4 closes the first port 6 when the piston rod 4 advances.
Claims7
An electric actuator comprising:
- a cylinder body which stores therein a fluid;
- a screw shaft which is provided in the cylinder body, and is rotated by an electric motor;
- a piston rod which moves linearly in accordance with rotation of the screw shaft;
- a first port formed on an inner face of a rod-side cylinder chamber of the cylinder body, which cylinder chamber is located in a direction in which the piston rod advances;
- a second port formed on an inner face of a head-side cylinder chamber of the cylinder body, which cylinder chamber is located in a direction in which the piston rod retracts;
- and
- a cylinder chamber connecting passage connecting the first port and the second port,
- wherein the piston part of the piston rod closes the first port when the piston rod advances.
Dependencies are inferred from the claim text.