Claims
- 1. A robot comprising:
- a base;
- a rotatable first link connected to the base by a shoulder joint;
- a rotatable second link connected to the first link by an elbow joint;
- an end-effector connected to the second link by a wrist joint;
- a shoulder motor located in the base to rotate the first link about the shoulder joint;
- a shoulder drive shaft extending from the shoulder motor and non-rotatably secured to the first link;
- an elbow motor located in the base to rotate the second link about the elbow joint;
- a first pulley positioned in the elbow joint and non-rotatably secured to the first link; and
- a second pulley positioned in the wrist joint, the second pulley secured to the end effector and coupled to the first pulley by a first drive band, wherein a diameter of the first pulley and a diameter of the second pulley are related by a 1:2 ratio so that the end effector is constrained to maintain a radial alignment with respect to the shoulder joint;
- a third pulley positioned in the shoulder joint;
- an elbow drive shaft extending from the elbow motor and secured to the third pulley; and
- a fourth pulley positioned in the elbow joint and secured to the second link, the fourth pulley directly coupled to the third pulley by a second drive band and driven thereby.
- 2. The robot of claim 1, wherein the third and fourth pulleys have equal diameters.
- 3. The robot of claim 2, wherein each joint is sealed by a fluid seal.
- 4. The robot of claim 3, wherein each fluid seal is a ferro-fluid seal.
- 5. The robot of claim 1, wherein the elbow motor and shoulder motor are concentrically mounted in a base housing.
- 6. The robot of claim 5, further comprising a slip-ring assembly for communicating signals from within the housing to the first link.
- 7. The robot of claim 6, wherein the slip-ring assembly comprises a static member affixed to the housing and a moving member affixed to the first link, whereby the first link may rotate about the housing.
Parent Case Info
This is a continuation of application Ser. No. 08/500,428, filed Jul. 10, 1995 now abandoned.
US Referenced Citations (21)
Non-Patent Literature Citations (2)
Entry |
Ferrofluidics Corporation, "Ferrofluidic Metric Vacuum Rotary Feedthroughs," (Information Bulletin). |
Rigaku Corporation, "Rigaku/Magnetic Rotary Seal Unit--Rotary Feedthrough, RMS Seris," pp. 1-10. |
Continuations (1)
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Number |
Date |
Country |
Parent |
500428 |
Jul 1995 |
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