{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "anti-friction-wheel-bearing-mechanism",
 "name": "Shaft carried on the rims of two pairs of wheels (anti-friction bearing)",
 "kind": "hardware",
 "category": "Mechanisms",
 "group": "Belt and friction drives",
 "year": null,
 "question": "What is a friction-wheel bearing?",
 "tags": [
  "mechanism",
  "belt and friction drives",
  "kinematics",
  "507 mechanical movements"
 ],
 "aliases": [
  "friction wheel bearing",
  "anti friction rollers",
  "roller bearing (early)",
  "cojinete de ruedas antifricción",
  "Friktionsrollenlager"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/anti-friction-wheel-bearing-mechanism/",
 "sheet_txt": "https://xemstudio.com/objects/anti-friction-wheel-bearing-mechanism/sheet.txt",
 "sheet": {
  "basis": "Xem Studio design following Brown No. 250 (1868)",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "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."
  ],
  "table": {
   "columns": [
    "parameter",
    "value"
   ],
   "rows": [
    [
     "shaft",
     "Ø10"
    ],
    [
     "wheels",
     "4 × Ø40 × 10"
    ],
    [
     "axle spacing",
     "44 mm"
    ],
    [
     "shaft height",
     "11.87 mm"
    ]
   ]
  }
 },
 "sheet_text": "Shaft carried on the rims of two pairs of wheels (anti-friction bearing) — dimension sheet\nSource: 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/)\nBasis: Xem Studio design following Brown No. 250 (1868)\nCatalog version: 2026-10-20\n\nSizes: see table below\n- 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.\n- 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.\n- Brown's No. 250 (anti-friction bearing: the shaft running on the circumferences of two wheels).\n- Parts (each has its own page): anti-friction-wheel-40x10-bore8, linear-shafts-h6.\n- Brown's movement No. 250 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.\n\nparameter  value\nshaft  Ø10\nwheels  4 × Ø40 × 10\naxle spacing  44 mm\nshaft height  11.87 mm\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- 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\n- 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\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/anti-friction-wheel-bearing-mechanism/index.json\nAPI: https://xemstudio.com/api/geometry?object=anti-friction-wheel-bearing-mechanism\n",
 "sources": [
  {
   "publisher": "Henry T. Brown (1868, public domain)",
   "title": "Five Hundred and Seven Mechanical Movements — scan on archive.org",
   "url": "https://archive.org/details/fivehundredseven00browiala",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "507movements.com",
   "title": "Brown's movement No. 250: figure, his text and an animation",
   "url": "https://507movements.com/mm_250.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "anti-friction-wheel-40x10-bore8",
  "linear-shafts-h6"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "What is a friction-wheel bearing?",
   "a": "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."
  }
 ],
 "files_license": {
  "name": "Xem Studio Design License",
  "holder": "Xem Studio",
  "url": "https://xemstudio.com/license/",
  "note": "Xem Studio's own design: free to use, print, modify and sell things made from it; not to be republished or redistributed as files."
 },
 "offers": [
  {
   "file": "anti-friction-wheel-bearing-mechanism-assembly",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/anti-friction-wheel-bearing-mechanism/anti-friction-wheel-bearing-mechanism-assembly.step",
   "stl": "https://xemstudio.com/files/hardware/anti-friction-wheel-bearing-mechanism/anti-friction-wheel-bearing-mechanism-assembly.stl",
   "note": "Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/anti-friction-wheel-bearing-mechanism/index.md"
}