Shaft carried on the rims of two pairs of wheels (anti-friction bearing) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/anti-friction-wheel-bearing-mechanism/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown No. 250 (1868)
Catalog version: 2026-10-20

Sizes: see table below
- Instead of turning in a plain bearing, the shaft lies in the angle between the rims of two wheels whose axles are parallel to it: as the shaft turns, the wheels turn with it, and the sliding friction of a journal becomes rolling friction at the rims plus a small journal friction at the wheels' axles, reduced in the ratio of their diameters.
- Here a Ø10 shaft on Ø40 wheels with axles 44 mm apart: the shaft's centre is 11.87 mm above the axles, touching each rim on a line. Two pairs, 70 mm apart along the shaft.
- Brown's No. 250 (anti-friction bearing: the shaft running on the circumferences of two wheels).
- Parts (each has its own page): anti-friction-wheel-40x10-bore8, linear-shafts-h6.
- Brown's movement No. 250 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

parameter  value
shaft  Ø10
wheels  4 × Ø40 × 10
axle spacing  44 mm
shaft height  11.87 mm

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala
- 507movements.com: Brown's movement No. 250: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_250.html

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/anti-friction-wheel-bearing-mechanism/index.json
API: https://xemstudio.com/api/geometry?object=anti-friction-wheel-bearing-mechanism