We use cookies to provide you with a better experience. By continuing to browse the site you are agreeing to our use of cookies in accordance with our Privacy Policy.
  • TOPICS
    • Design
    • Manufacturing
    • Applications
    • Components
    • Industry
    • MRO
  • MAGAZINE
    • Current Issue
    • Departments
    • Archives
    • Subscribe
    • Advertise
  • NEWSLETTER
  • VIDEO
    • Power Transmission Engineering TV
    • Webinars
  • BLOGS
    • Revolutions
    • Editors Choice
    • Motor Matters with George Holling
    • Bearings with Norm
  • BUYER'S GUIDE
  • NEWS and EVENTS
    • Product News
    • Industry News
    • Events
  • Advertising
    • Brand Awareness
      • Print: Display Advertising
      • Print: Engineering Showcase
      • Online: Web Banners & Keyword Banners
      • Online: Sponsored Content (Native Advertising)
      • E-mail: Custom, White Papers & Webinars
      • Email: Sponsored Content (Native Advertising)
    • Response & Lead Generation
      • E-Mail: Sponsored Content (Native Advertising)
      • E-mail: Newsletters
      • E-mail: Custom, White Papers & Webinars
      • Online: Buyers Guide
      • Online: Sponsored Content (Native Advertising)
    • Print
      • Print: Display Advertising
      • Print: Engineering Showcase
      • Print: MPT Expo Showstoppers (October 2023)
      • Print: Buyers Guide
      • Print: Engineering sMart
      • Print: Specifications
      • MPT Expo Show Guide Advertising
    • Online
      • Online: Web Banners and Keyword Banners
      • Online: Buyers Guide
      • Online: Sponsored Content (Native Advertising)
      • Online: Specifications
    • E-Mail
      • E-mail: Newsletters
      • E-mail: Custom, White Papers & Webinars
      • E-mail: Sponsored Content (Native Advertising)
      • E-mail: Specifications
    • Special Promotions
      • Print: Engineering Showcase
      • Print: Showstoppers (MPT Expo)
      • Print: Buyers Guide
      • Print: Engineering sMart
      • MPT Expo Show Guide Advertising
  • Contact Us
  • AGMA
    • Membership
    • Events
    • Education
    • Emerging Technology
    • AGMA Media
      • Gear Technology
      • Gear Technology India
    • Standards
Subscribe
  • Sign In
  • Create Account
  • Sign Out
  • My Account
Home » Blogs » Bearings with Norm » Aluminum Housing Series: Cup Distortion after Installation

Bearings with Norm
Bearings with Norm RSS FeedRSS

Design / Applications / Components / Gear Design / Power / Temperature / Steel / Bearings / Controls

Aluminum Housing Series: Cup Distortion after Installation

February 20, 2015
No Comments
The next step in our aluminum housing series is to determine where the cup interference is going. If we press a cup with 100µm interference into a solid steel block, most of that interference is going to compress the cup. If we press the cup into a block of jello, the cup isn’t going to compress at all. This is important to understand because the amount of cup compression plays a large role in the amount of preload you will lose with increasing temperatures.

You can find several variations of a bearing hoop stress/strain formula. I like the NSK version from their Technical Report; everything is in one table with the variables defined for an easy one-page reference. This table contains surface pressure, maximum stress and actual ring contraction. This is a cumbersome formula, but well worth your time to set up in a spreadsheet in lieu of running a CAE analysis or guessing. Plan on a ½ day in a quiet spot to get this set up with an example bearing. My advice is to break this up into steps in a spreadsheet. My spreadsheet has 29 cells just for the formula and another 6 for bearing dimensions.


norm32

All bearings are a little different, but for an easy example, a 100mm cup with a 100µm interference with a 20mm thick wall will have ~ 20µm of compression with the remaining 80µm expanding the housing. For this example, you have a 1:5 ratio of cup compression vs. housing expansion. If you set your target to be line to line fit at 120C (from 25C), at the halfway point, 47.5C, your cup should have expanded by 10 microns with the remaining press fit of 50µm.

Last week we covered how to target your press fit. This week we talked about the methods to find how much of that press fit goes into the cup vs. the housing. Next week, we will discuss exactly how to convert the radial bore expansion into axial preload loss. That won’t be your only source of preload loss, don’t jump the gun just yet.

If you don’t have NSK’s Technical Report, download it here for free: http://www.jp.nsk.com/app01/en/ctrg/index.cgi?rm=pdfView&pno=e728g

Recent Comments

Good advice, so are the big majors rebranding...

Post a comment to this article

Report Abusive Comment

Free Power Transmission Engineering Subscriptions
Subscribe
Free Power Transmission Engineering Subscriptions
Subscribe
FEATURED VIDEO
  • Pcb camroller
    PBC Linear: Cam Roller Technology Overview
December 14, 2022
RECOMMENDED
  • Highlights of Turbomachinery & Pump Symposia 2022

    December 2, 2022
    Sundyne-Ansimag Pump.jpg
  • Bearing Design Considerations for the Food Processing Industry

    December 2, 2022
    pt1222_Page_24_Image_0001.jpg
  • 2022 PTE Buyers Guide

    December 2, 2022
    BuyersGuide-01.jpg
  • FVA Presents Transmission Design Considerations

    January 3, 2023
    FVA.jpg
  • Bearing Reinvention with Schaeffler

    December 23, 2022
    Bearing6.jpg
  • FVA Presents Transmission Design Considerations

    January 3, 2023
    FVA.jpg
  • Bearing Reinvention with Schaeffler

    December 23, 2022
    Bearing6.jpg
  • Highlights of Turbomachinery & Pump Symposia 2022

    December 2, 2022
    Sundyne-Ansimag Pump.jpg
  • Subscribe
  • Advertise
  • Contribute
  • Gear Technology
Powered byAGMA
Copyright © 2023 Power Transmission Engineering
  • Privacy Policy
  • Contact