Editing Lunar Roving Vehicle (section)

=== Wheels and power ===
[[File:Lunar Roving Vehicle wheel close-up.JPG|thumb|right|Close-up of wheel showing chevron treads]]

The wheels were designed and manufactured by General Motors Defense Research Laboratories in [[Santa Barbara, California]].<ref>"Lunar Rover", brochure, Delco Electronics, Santa Barbara Operations,1972</ref> [[Ferenc Pavlics]] was given special recognition by NASA for developing the "resilient wheel".<ref>[http://www.omikk.bme.hu/archivum/pavlics/dokumentumok/pavlicse0002-01.htm "NASA Certificate for Ferenc Pavlics for Inventing the Resilient Wheel"] (from Hungarian University of Engineering).</ref> They consisted of a [[spun aluminum]] hub and a {{convert|32|in|cm|adj=mid|-diameter}}, {{convert|9|in|cm|adj=mid|-wide}} tire made of zinc-coated woven {{convert|0.033|in|mm|adj=mid|-diameter}} steel strands attached to the rim. [[Titanium]] chevrons covered 50% of the contact area to provide traction. Inside the tire was a {{convert|25.5|in|cm|adj=mid|-diameter}} titanium bump stop frame to protect the hub. Dust guards were mounted above the wheels. Each wheel had its own electric drive made by Delco, a [[brushed DC electric motor]] capable of {{convert|0.25|hp|W}} at 10,000 rpm, attached to the wheel via an 80:1 [[harmonic drive]], and a mechanical brake unit. In the case of drive failure, astronauts could remove pins to disengage the drive from the wheel, allowing the wheel to spin freely.

Maneuvering capability was provided through the use of front and rear steering motors. Each series-wound DC steering motor was capable of {{convert|0.1|hp|W}}. The front and rear wheels could pivot in opposite directions to achieve a tight turning radius of {{convert|10|ft|m|0}}, or could be decoupled so only front or rear would be used for steering. The wheels were linked in [[Ackermann steering geometry]], where the inside tires have a greater turn angle than the outside tires, to avoid sideslip.

Power was provided by two 36-volt [[Silver-oxide battery|silver-zinc]] [[potassium hydroxide]] [[Primary cell|non-rechargeable batteries]] developed by [[Eagle-Picher]]<ref>{{Cite web |date=1971-07-15 |title=Press Kit Apollo 15|page=96 |url=https://www.nasa.gov/specials/apollo50th/pdf/A15_PressKit.pdf |access-date=2022-10-28}}</ref> with a charge capacity of 121 [[Ampere hour|A·h]] each (a total of 242 A·h), yielding a range of {{convert|57|mi|km}}.<ref>Young, Anthony; ''Lunar and planetary rovers: the wheels of Apollo and the quest for Mars''; Springer, 2007, p. 96; {{ISBN|0-387-30774-5}}</ref> These were used to power the drive and steering motors and also a 36-volt utility outlet mounted on the front of the LRV to power the communications relay unit or the TV camera. LRV batteries and electronics were passively cooled, using change-of-phase wax [[Thermal mass|thermal capacitor]] packages and reflective, upward-facing radiating surfaces. While driving, radiators were covered with mylar blankets to minimize dust accumulation. When stopped, the astronauts would open the blankets, and manually remove excess dust from the cooling surfaces with hand brushes.