Editing Torque density

{{refimprove |date=November 2024}}
'''Torque density''' is a measure of the [[torque]]-carrying capability of a mechanical component. It is the ratio of torque capability to [[volume]] and is expressed in units of [[torque per volume]].

Torque density is a system [[property]] since it depends on the design of each element of the component being examined and their interconnection.

While torque is a [[Pseudovector]], volume only by definition exists in [[Three-dimensional|three Euclidean dimensions]], must always be positive, and never can be negative.

==Examples and uses==

Torque density of magnetic [[gearboxes]], [[wind turbine]]s, [[magnetic train]]s, and [[mechanical train]]s are used to compare the [[Energy conversion efficiency|energy efficiency]] of [[machine]]s; 150 kilo-Newtons per [[cubic meter]] per stage is considered the highest attainable as of 2024.<ref name=Rahimpour>{{cite book|url= https://books.google.com/books?id=s8IAEQAAQBAJ&pg=RA2-PA609&dq=%22Torque+density%22+-wikipedia&hl=en&newbks=1&newbks_redir=0&source=gb_mobile_search&sa=X&ved=2ahUKEwiunNfR5PiJAxVoZ0EAHSUoNuYQ6AF6BAgNEAM#v=onepage&q=%22Torque%20density%22%20-wikipedia&f=false|page=609|title=Encyclopedia of Renewable Energy, Sustainability and the Environment|first= Mohammad Reza |last=Rahimpour |publisher=Elsevier|isbn=9780323939416|date=August 9, 2024|access-date=November 25, 2024}}</ref>

Torque density is useful during the [[concept]] evaluation stage of mechanical [[design]]s, especially in [[power train]] design problems. Typically, it will be one of many factors used to assign potential success measures to each concept. For example, in the upgrade of a drive train for a set of rolls in a [[rolling mill]], space is often dictated by the configuration of current components.  There may be several types of devices that can perform the function of an existing component that must be replaced. The relative torque densities of the devices may be an important determinant for which design is ultimately selected, although it will often compete with other factors such as cost, ease of maintenance, time to install, operating costs and potential failure modes.

==Units==
In [[SI|SI units]], torque density is expressed in [[joule]]s per [[cubic metre]] or equivalently [[newton (unit)|newton]]-[[metre]]s per [[cubic metre]].<ref name=Rahimpour />

Although dimensionally equivalent to the [[pascal (unit)|pascal]], that is usually not used for this purpose.

Small amounts can be expressed in newton-[[millimetre]]s per cubic millimetre. 

In [[U.S. customary units]], torque density is expressed in [[foot-pound force|foot-pounds force]] per cubic foot, or [[inch]]-pounds force per cubic inch or [[pound-force|ounce-force]] inches per cubic inch.

==See also==
* [[Angular momentum]]
* [[Automobile design]]
* [[Density]]
* [[Mechanical engineering]]
* [[Newton-meter]]
* [[Pressure]]
* [[Renewable energy]]
* [[Superconductivity]]
* [[Sustainability]]

==References==
{{reflist}}

{{DEFAULTSORT:Torque Density}}
[[Category:Mechanical engineering]]
[[Category:Density]]