| 摘要 |
The present invention relates to a no-packing cylinder and a method for manufacturing a cylinder tube. A first airtightness maintaining coating layer is formed on the inner circumferential surface of a cover. A second airtightness maintaining coating layer and a third airtightness maintaining coating layer are formed on the outer circumferential surface of a piston coming in contact with the inner circumferential surface of a cylinder tube and the first airtightness maintaining coating layer, and the outer circumferential surface of a piston rod, respectively. Therefore, the first, second, and third airtightness maintaining coating layers with excellent oxidation resistance and abrasion resistance are coated on the outer circumferential surface of the piston rod, the outer circumferential surface of the piston, and the inner circumferential surface of the cover, so the present invention reliably maintains a sealing state of a contact portion of the cylinder tube and the piston and a contact portion of the piston rod and the cover, thereby preventing the contact portion from being worn over a long period of use, reducing maintenance costs, and improving reliability. |
