Changes between Version 21 and Version 22 of Hand/280/KinematicsJointRangesConversionFactors
- Timestamp:
- Jan 7, 2016, 11:23:20 PM (8 years ago)
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Hand/280/KinematicsJointRangesConversionFactors
v21 v22 13 13 14 14 15 Figure 2 is a close-up of the drive elements in the finger. During normal operation, the 16-tooth motor pinion (gray) drives both the 30-tooth distal (yellow) and 40-tooth proximal (blue) gears, which transmit power through their respective worms (red and green) and into two 50-tooth worm gears (orange and purple). The proximal worm gear (purple) is tied directly to the proximal link with six screws, whereas the distal gear (orange) connects to the distal link via mechanical cables. The net result is a motion ratio of 93.75:1 for the motor shaft to proximal joint position and a 125:1 reduction for the motor shaft to distal joint position. Also, note the two magnets (light blue) and their associated Hall-array sensors (black) at the ends of the motor shaft and worm shaft. The magnets are magnetized N/S radially, rather than axially, which allows the Puck to determine the position of both joints in the finger via the Hall-array sensors.15 Figure 2 is a close-up of the drive elements in the finger. During normal operation, the 16-tooth motor pinion (gray) drives both the 30-tooth distal (yellow) and 40-tooth proximal (blue) gears, which transmit power through their respective right-handed, single-start worms (red and green) and into two 50-tooth worm gears (orange and purple). The proximal worm gear (purple) is tied directly to the proximal link with six screws, whereas the distal gear (orange) connects to the distal link via mechanical cables. The net result is a motion ratio of 93.75:1 for the motor shaft to proximal joint position and a 125:1 reduction for the motor shaft to distal joint position. Also, note the two magnets (light blue) and their associated Hall-array sensors (black) at the ends of the motor shaft and worm shaft. The magnets are magnetized N/S radially, rather than axially, which allows the Puck to determine the position of both joints in the finger via the Hall-array sensors. 16 16 17 17 {{{ … … 30 30 [[Image(htdocs:bhand/282/PreBreakaway.png)]] 31 31 32 '''Figure 3 - The worm and proximal gear rotate together at first, linked across the belleville washers via Coulomb friction.''' 33 }}} 32 '''Figure 3 - Finger drivetrain pre-breakaway''' 33 }}} 34 35 The worm and proximal gear rotate together at first, linked across the belleville washers via Coulomb friction. 34 36 35 37 {{{ … … 37 39 [[Image(htdocs:bhand/282/Breakaway.png)]] 38 40 39 '''Figure 4 - When the proximal link encounters adequate resistance torque, the friction breaks away and the proximal gear winds off the belleville washers. From this point forward, the proximal link remains locked in place.''' 40 }}} 41 '''Figure 4 - Proximal gear winding off bellevilles''' 42 }}} 43 44 When the proximal link encounters adequate resistance torque, the friction breaks away and the proximal gear winds off the belleville washers. From this point forward, the proximal link remains locked in place. 41 45 42 46 {{{ … … 44 48 [[Image(htdocs:bhand/282/PostBreakaway.png)]] 45 49 46 '''Figure 5''' 47 48 '''The proximal gear then winds up the worm shaft, directing motor torque to drive the distal link.''' 49 50 '''The threaded shaft is long enough to allow full range-of-motion for the distal link in any scenario.''' 51 52 '''All motor torque is directed to the distal link until the bellevilles are re-engaged by reversing the motor.''' 53 }}} 50 '''Figure 5 - Finger drivetrain post-breakaway''' 51 }}} 52 53 The proximal gear then winds up the worm shaft, directing motor torque to drive the distal link. The threaded shaft is long enough to allow full range-of-motion for the distal link in any scenario. All motor torque is directed to the distal link until the bellevilles are re-engaged by reversing the motor. 54 54 55 55 The TorqueSwitch™ is reset by opening the finger. First, the distal link will open as the proximal gear winds along the shaft, then drive the proximal gear against the belleville washers, re-engaging the clutch and causing the proximal link to open with the distal link. When the proximal link encounters a resistive force, such as its joint stop, the proximal gear will compress the bellevilles, preloading the system to a programmable level (Puck parameter "OT").
