Flexible shaft assemblies

A flexible shaft assembly that couples a driver to a driven member for transferring torque to the driven member, the flexible shaft assembly comprising:

• a stub shaft comprising an elongated shaft portion having an elongated shaft axis and including a first stub shaft interface located at a first end of the shaft portion and a second stub shaft interface located at a second end of the shaft portion, the first stub shaft interface couples to the driver and the second stub shaft interface is coupled to a flexible coupling;
• the flexible coupling comprising:
• a first hub that is adjustably connected to a second hub, the first hub comprising a first coupling interface coupled to the second stub shaft interface of the stub shaft and the second hub comprising a second coupling interface that couples to the driven member and an external cylindrical interface;
• and
• a jaw coupling comprising a compliant spider element located between driving jaws extending from the first hub and driven jaws extending from the second hub;
• and
• a spacer comprising a spacer body, a shaft clearance hole that passes through the spacer body having a central axis extending therethrough, and a cylindrical guide surface concentric with the shaft clearance hole,
• wherein at least a portion of the external cylindrical interface of the flexible coupling is located inside the cylindrical guide surface of the spacer, and the first hub of the flexible coupling is positioned outside of the cylindrical guide surface of the spacer and the first hub adjusts relative to the second hub of the flexible coupling when the elongated shaft axis of the stub shaft is out of alignment with the central axis of the shaft clearance hole.

A robotic paint dispensing apparatus, comprising:

• a multi-axis robot comprising at least one repositionable arm;
• a motor coupled to the at least one repositionable arm of the multi-axis robot, the motor comprising an output shaft;
• a stub shaft comprising an elongated shaft portion comprising a first stub shaft interface located at a first end of the shaft portion and a second stub shaft interface located at a second end of the shaft portion, wherein the first stub shaft interface is coupled to the output shaft of the motor;
• a flexible coupling comprising a first coupling interface located along a first hub, a second coupling interface located along a second hub, and an external cylindrical interface extending along the second hub, wherein the first coupling interface is coupled to the second stub shaft interface of the stub shaft;
• a hydraulic pump coupled to the at least one repositionable arm of the multi-axis robot, the hydraulic pump comprising a pump housing and an input shaft protruding from the pump housing, wherein the input shaft of the hydraulic pump is coupled to the second coupling interface of the flexible coupling;
• and
• a spacer comprising a spacer body, a shaft clearance hole that passes through the spacer body, a cylindrical guide surface concentric with the shaft clearance hole, and a locating lip that is concentric with the shaft clearance hole and extends from the spacer body in a direction opposite to the cylindrical guide surface, wherein the locating lip is held within a seating surface of the hydraulic pump,
• wherein the spacer is statically mounted such that cylindrical guide surface is aligned with the input shaft of the hydraulic pump and at least a portion of the external cylindrical interface of the flexible coupling is located inside the cylindrical guide surface of the spacer and the first hub of the flexible coupling is positioned outside of the cylindrical guide surface of the spacer such that the first hub adjusts relative to the second hub of the flexible coupling when the elongated shaft portion of the stub shaft is out of alignment with a central axis of the shaft clearance hole.