Industrial robot

• US 5,640,883 A
• Filed: 04/12/1995
• Issued: 06/24/1997
• Est. Priority Date: 04/21/1994
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Takizawa, Hiroshi
• Primary Examiner(s): Herrmann, Allan D.
• Application Number:
  US08/420,643
• Time in Patent Office: 804 Days
• Field of Search: 74/490.04, 901/15, 901/21, 414/744.5
• US Class Current: 74/490.04
• CPC Class Codes: B25J 9/044 with forearm providing vertical linear movement
• CPC Class Codes: B25J 9/106 with articulated links
• CPC Class Codes: Y10T 74/20323 including flaccid drive element

Abstract

An industrial robot provides precision control of a rotating axis without generating fluctuations in rotating axis direction during movement of the rotating axis due to positional movements of first and second robot arms in which the first arm is supported by a base as a center of rotation and the second arm is supported at its mid-point by the other end of the first arm. The robot includes a rotating axis, a second arm driving unit for rotating the second arm and installed at the center of rotation so that rotation relative to the base is prevented, a core shaft for supporting the first and second arms in such a way that the first and second arms can rotate relative to each other, a core shaft angle sustaining mechanism for sustaining the core shaft at constant angle of rotation relative to the base, a rotating base axis driving motor for driving the rotating axis, and a rotating axis angle driving sustaining mechanism for sustaining the angle of rotation of the rotating axis driving motor at the same value as the angle of rotation of the core shaft.

Claims

1. An industrial robot comprising:

a base defining a horizontal plane;

a first arm supported by said base and rotatable over the horizontal plane with a first end of said first arm in a first longitudinal direction taken as a center of rotation;

a second arm supported at substantially a longitudinal midpoint of said second arm by a second end of said first arm in a second longitudinal direction;

a rotating axis set in a vertical direction on a first end of said second arm in a longitudinal direction;

an arm driving unit for rotating said second arm and installed at approximately the center of rotation of said first arm so that rotation thereof relative to said base is prevented;

an axis core including a planet shaft for supporting said first and second arms for permitting said first and second arms to rotate relative to each other;

core shaft angle sustaining means including a planet pulley in said first arm connected to said planet shaft and arranged for sustaining said axis core at a constant angle of rotation relative to said base;

rotating axis driving means for driving said rotating axis and provided on said second arm; and

rotating axis driver angle sustaining means including an earth pulley and a Z-axis pulley connected to said earth pulley for sustaining an angle of rotation of said rotating axis driving means to a value equal to said angle of rotation of said axis core.

2. The industrial robot according to claim 1, wherein said core shaft angle sustaining means further includes:

a base-fixed pulley fixed to the base and having a center approximately coinciding with the center of rotation of said first arm; and

an earth belt wound around said base-fixed pulley and said planet pulley.

3. The industrial robot according to claim 1 wherein said rotating axis driver angle sustaining means further includes:

a rotating axis direction regulating pulley connected to said rotating axis driving means; and

a rotating axis direction regulating belt wound around said rotating axis direction regulating pulley and said earth pulley connected to said planet shaft.

4. An industrial robot comprising:

a base defining a horizontal plane;

a first arm supported by said base and rotatable over the horizontal plane with a first end of said first arm in a first longitudinal direction taken as a center of rotation;

a second arm supported by a second end of said first arm in a second longitudinal direction;

a rotating axis set in a vertical direction on a first end of said second arm in a longitudinal direction;

an arm driving unit for rotating said second arm and installed at approximately the center of rotation of said first arm so that rotation thereof relative to said base is prevented;

a planet shaft for supporting said first and second arms for permitting said first and second arms to rotate relative to each other;

core shaft angle sustaining means including a planet pulley connected to said planet shaft and arranged for sustaining said planet shaft at a constant angle of rotation relative to said base;

axial direction driving means including a Z-axis driving pulley for driving said rotating axis in its axial direction and provided on said second arm for permitting said rotating axis to rotate; and

axial direction driver angle sustaining means including a Z-axis pulley and an earth pulley connected to said planet shaft for sustaining an angle of rotation of said axial direction driving means at a value equal to said angle of rotation of said planet shaft.

5. The industrial robot according to claim 4, wherein said core shaft angle sustaining means comprises:

a base-fixed pulley having a center approximately coinciding with the center of rotation of said first arm over said base; and

an earth belt wound around said base-fixed pulley and said planet pulley.

6. An industrial robot comprising:

a base defining a horizontal plane;

a first arm supported by said base and rotatable over the horizontal plane with a first end of said first arm in a first longitudinal direction taken as a center of rotation;

a second arm supported by a second end of said first arm in a second longitudinal direction;

a rotating axis set in a vertical direction on a first end of said second arm in a longitudinal direction;

an arm driving unit for rotating said second arm and installed at approximately the center of rotation of said first arm so that rotation thereof relative to said base is prevented;

a planet shaft for supporting said first and second arms for permitting said first and second arms to rotate;

core shaft angle sustaining means including a planet pulley connected to said planet and arranged for sustaining said planet shaft at a constant angle of rotation relative to said base;

rotating axis driving means for rotating said rotating axis and provided on said second arm for permitting said rotating axis driving means to rotate;

rotating axis driver angle sustaining means including an earth pulley and a rotating axis pulley connected to said earth pulley and arranged for sustaining an angle of rotation of said rotating axis driving means at a value equal to said angle of rotation of said axis core;

axial direction driving means including a Z-axis driving pulley for driving said rotating axis in its axial direction and provided on said second arm for permitting said rotating axis to rotate; and

axial direction driver angle sustaining means including a Z-axis pulley connected to said earth pulley for sustaining an angle of rotation of said axial direction driving means at a value equal to said angle of rotation of said axis core.

7. The industrial robot according to claim 6, wherein said rotating axis driver angle sustaining means further includes:

a rotating axis direction regulating pulley connected to said rotating axis driving means; and

a rotating axis direction regulating belt wound around said rotating axis direction regulating pulley and said earth pulley; and

wherein said axial direction driver angle sustaining means further includes

an axial direction regulating belt wound around said earth pulley and said axial direction regulating pulley.