Vibration drive device, image forming apparatus, positioning stage, and medical system

A medical system including a multi-joint robot that performs a predetermined diagnosis or operation on a subject,

• wherein the multi-joint robot has a plurality of joint portions, and
• each of the joint portions incorporates a vibration drive device in which a vibration element and a driven element are brought into pressure contact with each other, and vibration is excited in the vibration element to thereby rotationally move the driven element relative to the vibration element, in order to enable each joint portion to perform rotational movement,
• the vibration drive device including a bearing rotatably supporting the driven element,
• the bearing comprising:
• a plurality of rolling elements;
• a first bearing portion that has a first raceway surface in contact with said plurality of the rolling elements;
• a second bearing portion that has a second raceway surface in contact with said plurality of the rolling elements;
• and
• a third bearing portion that has a third raceway surface in contact with said plurality of the rolling elements,
• wherein said second bearing portion and said third bearing portion are joined to the driven element, and said second bearing portion and said third bearing portion are pressed against each other via said plurality of the rolling elements in a direction along an axis of said bearing, whereby said plurality of the rolling elements are brought into pressure contact with the first raceway surface, the second raceway surface, and the third raceway surface, and
• wherein one of said second bearing portion and said third bearing portion is integrally formed with the driven element from a same material.

An image forming apparatus including:

• an image forming unit configured to form an image on a sheet using toner or ink, and
• a conveying unit configured to convey a sheet to said image forming unit or convey a sheet having a predetermined image formed thereon by the image forming unit,
• wherein the conveying unit is equipped with a vibration drive device which is connected to a roller driven for rotation for conveying a sheet and in which a vibration element and a driven element are brought into pressure contact with each other, and vibration is excited in the vibration element to thereby rotationally move the driven element relative to the vibration element,
• the vibration drive device including a bearing rotatably supporting the driven element,
• the bearing comprising:
• a plurality of rolling elements;
• a first bearing portion that has a first raceway surface in contact with said plurality of the rolling elements;
• a second bearing portion that has a second raceway surface in contact with said plurality of the rolling elements;
• and
• a third bearing portion that has a third raceway surface in contact with said plurality of the rolling elements,
• wherein said second bearing portion and said third bearing portion are joined to the driven element, and are pressed against each other via said plurality of the rolling elements in a direction along an axis of said bearing, whereby said plurality of the rolling elements are brought into pressure contact with the first raceway surface, the second raceway surface, and the third raceway surface, and
• wherein one of said second bearing portion and said third bearing portion is integrally formed with the driven element from a same material.

A positioning stage including:

• a vibration drive device in which a vibration element and a driven element are brought into pressure contact with each other, and vibration is excited in the vibration element to thereby rotationally move the driven element relative to the vibration element, and
• a stage that is moved in a predetermined direction by the vibration drive device,
• the vibration drive device including a bearing rotatably supporting the driven element,
• the bearing comprising:
• a plurality of rolling elements;
• a first bearing portion that has a first raceway surface in contact with said plurality of the rolling elements;
• a second bearing portion that has a second raceway surface in contact with said plurality of the rolling elements;
• and
• a third bearing portion that has a third raceway surface in contact with said plurality of the rolling elements,
• wherein said second bearing portion and said third bearing portion are joined to the driven element, and are pressed against each other via said plurality of the rolling elements in a direction along an axis of said bearing, whereby said plurality of the rolling elements are brought into pressure contact with the first raceway surface, the second raceway surface, and the third raceway surface, and
• wherein one of said second bearing portion and said third bearing portion is integrally formed with the driven element from a same material.