Rotary-body support structure

1. A rotary-body support structure comprising:

a rotary body including a rotary shaft and a flexible contact portion spirally wound around the rotary shaft; and

bearing parts that rotatably support the rotary body,

wherein the amount of engagement of the rotary body with a contact body that is in contact with the contact portion of the rotary body changes when the rotary body moves toward one side in a rotation axis direction.

2. The rotary-body support structure according to claim 1 , wherein

the bearing parts include contact members having a larger diameter than the rotary shaft and fitted on the rotary shaft of the rotary body, and inclined portions that are in contact with and support the contact members, and

the contact members are supported so as to be movable in a direction intersecting the rotation axis direction when the rotary body moves in the rotation axis direction.

3. The rotary-body support structure according to claim 2 , wherein the contact members have a ring shape with a circular outer circumference.

4. The rotary-body support structure according to claim 2 , wherein the contact members have a tapered shape with an outer circumference tapered in the rotation axis direction.

5. The rotary-body support structure according to claim 2 , wherein the contact members are ball bearings including outer races in contact with the inclined portions and inner races attached to the rotary shaft.

6. The rotary-body support structure according to claim 2 , wherein the contact member is fitted on one end of the rotary shaft.

7. The rotary-body support structure according to claim 3 , wherein the contact member is fitted on one end of the rotary shaft.

8. The rotary-body support structure according to claim 4 , wherein the contact member is fitted on one end of the rotary shaft.

9. The rotary-body support structure according to claim 5 , wherein the contact member is fitted on one end of the rotary shaft.

10. The rotary-body support structure according to claim 6 , wherein the inclined portion is formed on one side corresponding to the one end of the rotary shaft and is in contact with the rotary shaft, and the contact member having a tapered shape with an outer circumference tapered in the rotation axis direction is fitted on the other end of the rotary shaft.

11. The rotary-body support structure according to claim 7 , wherein the inclined portion is formed on one side corresponding to the one end of the rotary shaft and is in contact with the rotary shaft, and the contact member having a tapered shape with an outer circumference tapered in the rotation axis direction is fitted on the other end of the rotary shaft.

12. The rotary-body support structure according to claim 8 , wherein the inclined portion is formed on one side corresponding to the one end of the rotary shaft and is in contact with the rotary shaft, and the contact member having a tapered shape with an outer circumference tapered in the rotation axis direction is fitted on the other end of the rotary shaft.

13. The rotary-body support structure according to claim 9 , wherein the inclined portion is formed on one side corresponding to the one end of the rotary shaft and is in contact with the rotary shaft, and the contact member having a tapered shape with an outer circumference tapered in the rotation axis direction is fitted on the other end of the rotary shaft.

14. The rotary-body support structure according to claim 1 , wherein

the contact body is a charging roller that is in contact with and charges a photoconductor drum while rotating, and

the rotary body is a cleaning roller having the contact portion made of an elastic member spirally wound around the outer circumference of the rotary shaft, the cleaning roller being in contact with the charging roller and cleaning the surface of the charging roller while rotating.

15. The rotary-body support structure according to claim 2 , wherein

the contact body is a charging roller that is in contact with and charges a photoconductor drum while rotating, and

the rotary body is a cleaning roller having the contact portion made of an elastic member spirally wound around the outer circumference of the rotary shaft, the cleaning roller being in contact with the charging roller and cleaning the surface of the charging roller while rotating.

16. The rotary-body support structure according to claim 1 , wherein

the contact body is a photoconductor drum, and

the rotary body is a cleaning brush including the contact portion having a brush spirally wound around the outer circumference of the rotary shaft, the cleaning brush being in contact with the photoconductor drum and cleaning the surface of the photoconductor drum while rotating.

17. The rotary-body support structure according to claim 2 , wherein

the contact body is a photoconductor drum, and

the rotary body is a cleaning brush including the contact portion having a brush spirally wound around the outer circumference of the rotary shaft, the cleaning brush being in contact with the photoconductor drum and cleaning the surface of the photoconductor drum while rotating.

18. The rotary-body support structure according to claim 16 , wherein the cleaning brush is rotationally driven via a belt.

19. The rotary-body support structure according to claim 1 , wherein

the contact body is a floor, and

the rotary body is a vacuum-cleaner brush including the contact portion having a brush spirally wound around the outer circumference of the rotary shaft, the vacuum-cleaner brush being in contact with and cleaning the floor while being rotated by air suction.

20. The rotary-body support structure according to claim 2 , wherein

the contact body is a floor, and

the rotary body is a vacuum-cleaner brush including the contact portion having a brush spirally wound around the outer circumference of the rotary shaft, the vacuum-cleaner brush being in contact with and cleaning the floor while being rotated by air suction.