ROBOTIC WRIST APPARATUS
Publication Date: 2014-Mar-14
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ROBOTIC WRIST APPARATUS
The present invention relates to a robotic wrist apparatus; more particularly, to a hydraulic wrist apparatus in a robotic arm assembly for use in a humanoid robot.
Currently, there are some problems and unmet needs with existing robotic arm assemblies which are useful in a variety of environments, including industrial, manufacturing, and medical applications. However, humanoid applications require that the robotic apparatus has the ability to cooperate with humans. In order to enable a robot to interact with humans, high standards are required for position sensors and control of its movements.
FIG. 1 is an exploded view of a robotic wrist apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view of the robotic wrist apparatus of FIG. 1.
FIG. 1 is an exploded view of a robotic wrist apparatus 100 according to an embodiment of the present invention. Referring now to FIG. 1, a robotic wrist apparatus 100 is illustrated. Apparatus 100 comprises a hydraulic cylinder housing 101 and a hydraulic cylinder 102. The housing 101 includes fluid ports 103, 104 for supplying and returning pressurized hydraulic fluid. The pressurized fluid enables the hydraulic cylinder 102 to extend and retract using techniques well known in the art. The hydraulic cylinder 102 comprises a cross post 105 and a linear position sensor 106 which will be explained in detail below.
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- 2 - The apparatus 100 further comprises a cylindrical bearing assembly 107 and a cylindrical guide 108. The cylindrical guide 108 includes a flange plate 109 for connecting the cylindrical guide 108 to the hydraulic cylinder housing 101. The cylindrical bearing assembly 107 and the cylindrical guide 108 are of hollow design and include a longitudinal slot 110. The longitudinal slot 110 acts as a guide for the cross post 105, preventing the hydraulic cylinder 102 from rotating during operation.
Still referring to FIG. 1, the cylindrical bearing assembly 107 includes spherical roller bearings 111 located at both ends of the cylinder. The roller bearings 111 aid in the rotation of a barrel cam 112. The cam 112 is allowed to freely rotate on the roller bearings 111, while the linear motion of the cam 112 is prohibited.
FIG. 2 illustrates a perspective view of the robotic apparatus 100 according to an embodiment of the present invention. Referring now to FIG. 2, the barrel cam 112 comprises a cap 114 and a helical slot 113. The cross post 105 is aligned inside the helical slot 113 during operation, such that the linear motion of the hydraulic cylinder 102 (shown in FIG. 1) is transferred into rotational movement of the cam 112, as the cross port 105 moves throughout helical slot 113. Specifically, as hydraulic fluid is s...