Photoreceptor drums, methods and apparatus for assembling the same, and image-forming apparatus employing the same

A method of assembling a photoreceptor drum which comprises a drum main body having a photosensitive layer formed on the outer circumferential surface thereof and a flange member to be attached to one lengthwise-direction end of the drum main body, the flange member having a shaft support part serving as the center of rotation of the flange member and a cylindrical part to be fitted into and fixed to a fitting hole formed in said one lengthwise-direction end of the drum main body, and in which the degree of radial deflection of the photoreceptor drum based on a central axis connecting the center of a shaft support part formed at the other end of the drum main body to the center of the shaft support part of the flange member is not larger than a given value,

• which method comprises:
• measuring or determining the degree and direction of radial deflection of the drum main body based on the shaft support part at said other end of the drum main body and on the fitting hole,
• measuring or determining the degree and direction of radial deflection of the outer circumferential surface of the cylindrical part of the flange member based on the shaft support part of the flange member,
• determining the difference between the degree of deflection of the drum main body and the degree of deflection of the outer circumferential surface of the cylindrical part of the flange member, and
• when the difference is not larger than that given value, then fitting and fixing the cylindrical part of the flange member into the fitting hole in the drum main body so that the direction of deflection of the outer circumferential surface of the cylindrical part is almost opposite to the direction of deflection of the drum main body.

A method of assembling a photoreceptor drum which comprises a drum main body having a photosensitive layer formed on the outer circumferential surface thereof and a flange member to be attached to one lengthwise-direction end of the drum main body, the flange member having a shaft support part serving as the center of rotation of the flange member and a cylindrical part to be fitted into and fixed to a fitting hole formed in said one lengthwise-direction end of the drum main body, and which rotates on a central axis connecting the center of a shaft support part formed at the other end of the drum main body to the center of the shaft support part of the flange member,

• which method comprises:
• measuring or determining the degree and direction of radial deflection of the drum main body based on the shaft support part at said other end of the drum main body and on the fitting hole,
• measuring or determining the degree and direction of radial deflection of the outer circumferential surface of the cylindrical part of the flange member based on the shaft support part of the flange member,
• determining the difference between the degree of deflection of the drum main body and the degree of deflection of the outer circumferential surface of the cylindrical part of the flange member, and
• when the difference is 15 μm or smaller, then fitting and fixing the cylindrical part of the flange member into the fitting hole in the drum main body so that the direction of deflection of the outer circumferential surface of the cylindrical part is almost opposite to the direction of deflection of the drum main body.

A method of assembling a photoreceptor drum which comprises a drum main body having a photosensitive layer formed on the outer circumferential surface thereof and flange members to be attached respectively to both lengthwise-direction ends of the drum main body, each flange member having a shaft support part serving as the center of rotation of the flange member and a cylindrical part to be fitted into and fixed to one of two fitting holes respectively formed in both lengthwise-direction ends of the drum main body, and in which the degree of radial deflection of the photoreceptor drum based on a central axis connecting the centers of the shaft support parts of the respective flange members at both ends is not larger than a given value,

• which method comprises:
• measuring or determining the degree and direction of radial deflection of the drum main body based on the fitting holes in both ends,
• measuring or determining the degree and direction of radial deflection of the outer circumferential surface of each flange member based on the shaft support part,
• determining the difference between the degree of deflection of the drum main body and the degree of deflection of the outer circumferential surface of the cylindrical part of each flange member, and
• when the difference is not larger than that given value, then fitting and fixing the cylindrical parts of the flange members into the fitting holes in the drum main body so that the direction of deflection of the outer circumferential surface of the cylindrical part of each flange member is almost opposite to the direction of deflection of the drum main body.

A method of assembling a photoreceptor drum which comprises a drum main body having a photosensitive layer formed on the outer circumferential surface thereof and flange members to be attached respectively to both lengthwise-direction ends of the drum main body, each flange member having a shaft support part serving as the center of rotation of the flange member and a cylindrical part to be fitted into and fixed to one of two fitting holes respectively formed in both lengthwise-direction ends of the drum main body,

• which method comprises:
• measuring or determining the degree and direction of radial deflection of the drum main body based on the fitting holes in both ends,
• measuring or determining the degree and direction of radial deflection of the outer circumferential surface of each flange member based on the shaft support part,
• determining the difference between the degree of deflection of the drum main body and the degree of deflection of the outer circumferential surface of the cylindrical part of each flange member, and
• when the difference in deflection is 15 μm or smaller, then fitting and fixing the cylindrical parts of the flange members into the fitting holes in the drum main body so that the direction of deflection of the outer circumferential surface of the cylindrical part of each flange member is almost opposite to the direction of deflection of the drum main body.

An assembling apparatus for assembling a photoreceptor drum which comprises a drum main body having fitting holes respectively formed in both lengthwise-direction ends thereof and a first flange member and a second flange member each having a cylindrical part capable of being fitted into the corresponding fitting hole, the first flange member and the second flange member having been attached respectively to both ends of the drum main body, with the cylindrical parts fitted in the fitting holes, and which rotates on a central axis connecting the centers of shaft support parts respectively formed in or on the first flange member and second flange member,

• which apparatus comprises:
• a table on which the drum main body is placed so that the direction of radial deflection of the drum main body as measured based on the fitting holes in both ends of the drum main body is faced in a given direction,
• a first and second supporting part which have been disposed on both sides of the table and removably support the first and second flange members almost coaxially with the drum main body placed on the table,
• a first and second rotating device which respectively rotate the first and second flange members supported by the first and second supporting parts,
• a moving device which moves one of the first and second supporting parts in directions in which the distance between the two parts increases and decreases,
• a measuring device which measures or determines the degree and direction of radial deflection of the outer circumferential surface of the cylindrical part of each of the first and second flange members supported by the first and second supporting parts, based on the shaft support part, and
• a control device which controls the rotating devices concerning rotation and the moving device concerning movement,
• wherein the control device is so designed as to perform the following procedures:
• operating the rotating devices to rotate the first and second supporting parts and simultaneously causing the measuring device to measure or determine the degree and direction of radial deflection of the outer circumferential surface of the cylindrical part of each of the first and second flange members based on the shaft support part;
• comparing the degree of deflection of the drum main body with the degree of deflection of each of the first and second flange members;
• and when the difference is not larger than a given value, operating the rotating devices so that the direction of deflection of each of the first and second flange members becomes almost opposite to that given direction and then operating the moving device to fit the cylindrical parts of the first and second flange members respectively into both ends of the drum main body.

A method of assembling a photoreceptor drum which comprises a drum main body having a photosensitive layer formed on the outer circumferential surface thereof and one or two flange members to be attached to one or both lengthwise-direction ends of the drum main body and in which the degree of radial deflection of the photoreceptor drum is 15 μm or less,

• which method comprises:
• forming a bearing fitting hole in each of both lengthwise-direction ends of the drum main body and forming a flange member fitting hole in one or both lengthwise-direction ends of the drum main body continuously outside the bearing fitting hole,
• fitting and fixing a bearing into each bearing fitting hole in the drum main body, and
• fitting and fixing a flange member having a shaft through-hole having an inner diameter larger than the bearing hole of the bearing into the flange member fitting hole formed outside the bearing fitted and fixed.

A method of assembling a photoreceptor drum which comprises a drum main body comprising a cylindrical body having a photosensitive layer formed on the outer circumferential surface thereof and flange members to be attached respectively to both lengthwise-direction ends of the drum main body, the flange members each having a shaft support part serving as the center of rotation of the flange member and a cylindrical part to be fitted into and fixed to one of fitting holes respectively formed in both lengthwise-direction ends of the drum main body, and in which the degree of radial deflection of the photoreceptor drum based on a central axis connecting the centers of the shaft support parts of the flange members at both ends is 15 μm or less,

• which method comprises:
• forming a fitting hole in each of both lengthwise-direction ends of the cylindrical body,
• attaching a first and second flange member by fitting and fixing the cylindrical parts thereof into the respective fitting holes,
• turning the outer circumferential surface of the cylindrical body using the shaft support parts of the first and second flange members as a base, and
• forming a photosensitive layer on the turned outer circumferential surface of the cylindrical body.