Rotary damper
[Problem] To provide a rotary damper wherein damping torque generated by rotation can be easily adjusted using a simple configuration. [Solution] A rotary damper 1 limits the movement of viscous fluid contained in a circular cylinder chamber 111 , thereby generating damping torque against applied rotational force. This rotary damper 1 is configured such that: a lid 15 is screwed into a case 11 ; and the gap g 1 between the lower surface 153 of the lid 15 and the upper surface 119 of a partition section 115 and the gap g 2 between the lower surface 153 of the lid 15 and the upper surface 129 of a vane 122 can be adjusted by adjusting the amount of screwing of the lid 15 into the case 11 . This means that adjusting the amount of movement of viscous fluid through the gaps g 1 , g 2 can adjust damping torque generated by rotation.
1. A rotary damper that generates damping torque against applied rotational force by limiting movement of viscous fluid, wherein:
the rotary damper comprises:
a case which is open at one end and has a circular cylinder chamber filled with the viscous fluid;
a rotor which is received in the circular cylinder chamber rotatably relative to the circular cylinder chamber; and
a lid which is fitted to an opening side of the circular cylinder chamber, to enclose the rotor together with the viscous fluid within the circular cylinder chamber;
the rotor comprises:
a rotor body of a circular cylinder shape; and
a vane which projects outward in radial direction from an outer peripheral surface of the rotor body, and an end surface of which comes close to a sidewall surface of the circular cylinder chamber so as to partition the circular cylinder chamber;
the case comprises:
a partition member which projects inward in a radial direction from the side wall surface of the circular cylinder chamber, and an end surface of which comes close to the outer peripheral surface of the rotor body so as to partition the circular cylinder chamber; and
a female screw portion formed in the sidewall surface of the circular cylinder chamber on the opening side of the circular cylinder chamber;
the lid comprises:
a male screw portion formed in an outer peripheral surface of the lid, to be engaged with the female screw portion formed in the sidewall surface of the circular cylinder chamber on the opening side of the circular cylinder chamber; and
a gap between a back surface of the lid and vanes' surface facing the back surface of the lid functions as a flow path that limit movement of the viscous fluid and can be adjusted by adjusting degree of screwing of the lid into the circular cylinder chamber; and
the rotary damper further comprises:
a first seal member attached the partition member, the first seal member filling both of a gap between the end surface of the partition member and the outer peripheral surface of the rotor body and a gap between the back surface of the lid and partition members' surface facing the back surface of the lid.
2. A rotary damper of claim 1 , further comprising:
a second seal member which fills a gap between the end surface of the vane and the sidewall surface of the circular cylinder chamber.
3. A rotary damper of claim 2 , wherein:
the rotary damper further comprises:
a flow path which is formed in the vanes, and runs through between both side surfaces of the vane along a rotational direction of the rotor; and
a second check valve which closes the flow path of the vane when the rotor rotates in a normal direction relative to the circular cylinder chamber, and opens the flow path of the vane when the rotor rotates in a reverse direction relative to the circular cylinder chamber; and
the second check valve is formed integrally with the second seal member.
4. A rotary damper of claim 2 , further comprising:
a flow path which is formed in the partition member, and runs through between the side surfaces of the partition member along a rotational direction of the rotor; and
a first check valve which closes the flow path of the partition member when the rotor rotates in a normal direction relative to the circular cylinder chamber, and opens the flow path of the partition member when the rotor rotates in a reverse direction relative to the circular cylinder chamber.
5. A rotary damper of claim 3 , further comprising:
a flow path which is formed in the partition member, and runs through between the side surfaces of the partition member along a rotational direction of the rotor; and
a first check valve which closes the flow path of the partition member when the rotor rotates in a normal direction relative to the circular cylinder chamber, and opens the flow path of the partition member when the rotor rotates in a reverse direction relative to the circular cylinder chamber.
6. A rotary damper of claim 2 , further comprising:
a flow path which is formed in the vane, and runs through between both side surfaces of the vane along a rotational direction of the rotor; and
a second check valve which closes the flow path of the vane when the rotor rotates in a normal direction relative to the circular cylinder chamber, and opens the flow path of the vane when the rotor rotates in a reverse direction relative to the circular cylinder chamber.
7. A rotary damper of claim 1 , further comprising:
a flow path which is formed in the partition member, and runs through between both side surfaces of the partition member along a rotational direction of the rotor; and
a first check valve which closes the flow path of the partition member when the rotor rotates in a normal direction relative to the circular cylinder chamber, and opens the flow path of the partition member when the rotor rotates in a reverse direction relative to the circular cylinder chamber; and
the first check valve is formed integrally with the first seal member.
8. A rotary damper of claim 7 , further comprising:
a flow path which is formed in the vane, and runs through between both side surfaces of the vane along a rotational direction of the rotor; and
a second check valve which closes the flow path of the vane when the rotor rotates in a normal direction relative to the circular cylinder chamber, and opens the flow path of the vane when the rotor rotates in a reverse direction relative to the circular cylinder chamber.
9. A rotary damper claim 1 , further comprising:
a flow path which is formed in the partition member, and runs through between the side surfaces of the partition member along a rotational direction of the rotor; and
a first check valve which closes the flow path of the partition member when the rotor rotates in a normal direction relative to the circular cylinder chamber, and opens the flow path of the partition member when the rotor rotates in a reverse direction relative to the circular cylinder chamber.
10. A rotary damper claim 1 , further comprising:
a flow path which is formed in the vane, and runs through between both side surfaces of the vane along a rotational direction of the rotor; and
a second check valve which closes the flow path of the vane when the rotor rotates in a normal direction relative to the circular cylinder chamber, and opens the flow path of the vane when the rotor rotates in a reverse direction relative to the circular cylinder chamber.