ISO 11687-1:2020

Overview

ISO 11687-1:2020 - Plain bearings - Pedestal plain bearings - Part 1: Pillow blocks specifies the design characteristics and dimensional requirements for pillow blocks (pedestal plain bearings) in size ranges 9 to 28 and 35 to 71. The standard covers bearing housings, shaft design, materials, tolerances, surface finish and lubrication/cooling options, and is intended primarily for use in the electrical and turbo engineering industries.

Key topics and technical requirements

• Types and designation
  • Classification by housing (G = without cooling fins, R = with cooling fins), heat dissipation (N, W, U, T, Z), bore shape and lubrication (C, L, Y, V), and thrust bearing type (Q, B, K, A).
  • Example designation format: Pillow block ISO 11687-1 - 14 - 125 - RZLK.
• Dimensions and interchangeability
  • Dimensional tables and figures define required dimensions for the two size ranges; conformance is required to specified dimensions rather than to illustrated shapes.
• Shaft and bearing geometry
  • Includes shaft dimensions (see tables) and recommendations for bore shapes (cylindrical, lobed) and split oil ring options.
• Materials
  • Housing: grade 300 grey cast iron (ISO 185) or by agreement.
  • Half‑bearing/backing and bearing materials: examples include S235 B, C10R/C15R, GE 200/GS 200 and tin-casting alloy bearing metal (ISO 4381).
  • Oil ring and seals: copper-zinc alloy (ASTM B124/B124M) and various copper/aluminum/plastic options by agreement.
• Surface finish and tolerances
  • Machined surfaces: ISO 2768-1/-2 tolerances (mH); unmachined castings: ISO 8062-3 grading.
  • Surface roughness per ISO 1302: mounted surfaces Ra = 3.2 µm, sliding surfaces Ra = 0.8 µm.
• Design and features
  • Housing protection against corrosion, oil‑resistant paint for internal surfaces, lifting/handling provisions, interconnected oil spaces for pressure compensation, and provisions for inspection plates and drain/connection points.
• Special conditions
  • Options for cooling (natural, water, circulation, external oil cooling) and design variants to suit space or application constraints; seals and some connections are by agreement.

Applications and users

• Targeted industries: electrical engineering, turbo machinery, power generation and any application using pedestal plain bearings.
• Primary users:
  • Bearing and machine designers, OEMs and component manufacturers
  • Maintenance and reliability engineers specifying replacements
  • Procurement and standards/quality managers preparing technical specifications
• Practical uses: specifying interchangeable pillow block housings and shafts, ensuring correct lubrication/cooling arrangements, and achieving consistent tolerances and finishes for long service life.

Related standards

Normative references in ISO 11687-1:2020 include:

• ISO 185 (grey cast iron), ISO 630-2 (structural steels), ISO 683-3 (case‑hardening steels)
• ISO 4381 (tin casting alloys for plain bearings), ISO 1302 (surface texture), ISO 2768 (general tolerances)
• ISO 8062-3 (casting tolerances), ISO 12129 series (plain bearing tolerances)
• ASTM B124/B124M (copper‑zinc alloys for oil rings)

Keywords: ISO 11687-1:2020, pillow blocks, pedestal plain bearings, bearing housing, shaft design, surface roughness, tolerances, lubrication, cooling, bearing materials.