Talk:Torque amplifier
Add topic | A fact from Torque amplifier appeared on Wikipedia's Main Page in the Did you know column on 1 January 2013. The text of the entry was as follows:
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What cam?
[edit]Please justify this assertion:
Both end with a cam (obscured in the attached sketch), which via a follower and a rocking arm holds one end of each rope. If the input shaft rotates from the null position, its cam raises or lowers the input follower, which via the rocking input arm tensions the rope on one drum and slackens the other.
As far as I can determine there is no cam in that design nor any need for one. John G Hasler (talk) 13:56, 5 February 2021 (UTC)
- The image's description page links to a source which describes it as:
... a torque amplifier, working on the principle of the ship's capstan, but adapting it for continuous rotation. Fig. 3 is taken from his report (1931) and sufficiently indicates the principle. The friction drums are rotated in opposite directions by a continuously running motor of sufficient power. When the input shaft is turned, one of the cords attached to the input arm begins to tighten on the friction drum round which it is wrapped. Which cord tightens depends on the direction of rotation of the input shaft. A very small tightening, and hence a very small tension in the end of the cord attached to the input arm, is sufficient, in view of the friction of the rotating drum, to produce a large tension in the end attached to the output arm. A small torque applied to the input shaft is thus capable of producing a much larger torque in the output shaft.
- I think the authors of the current text have mistaken the reference to a crank in source 4 for a cam and assumed that details are missing when the only thing that really seems to be missing from the diagram are the bearings and support arrangements that allow the four coaxial shafts to rotate independently. -- Aamackie (talk) 16:46, 14 June 2026 (UTC)
- I have reverted much of the text of this section to a version of the text that didn't mention obscured cams and corrected the mention of the cam to a refer to them as crank arms. As the introductory paragraph to the article says that the "most widely known use is in power steering on automobiles" and those are described as being either hydraulic or electric in the referenced article I have changed the description of the illustrated device from "typical" to "an example". Further cleanup is probably required as the same device is essentially described three times in the same section.-- Aamackie (talk) 17:38, 14 June 2026 (UTC)
