-
我們的產品
GGB是高性能軸承解決方案的領導者，為全球各行業提供創新、可靠且專業的產品與服務。憑借在摩擦學、材料科學和精密工程領域逾百年的深厚積累，我們不斷開發先進的滑動軸承，幫助客戶提升產品性能、降低摩擦，并延長關鍵部件的使用壽命。
- 返回首頁
- 軸承知識
- Design Press Fit for Installation
Design Press Fit for Installation
An interference press fit is the preferred method of installation for sleeve bearings due to its simplicity and effectiveness. Below you can find a calculation method for the press fit force along with a method for estimating the bearing installed ID.
Press fit design considerations for sleeve bearings
Tools required will include:
- Arbor press to apply the required force
- Installation mandrel to guide the sleeve bearing into its housing
- Fixture, when necessary, to support and align the housing bore with the sleeve bearing
- Controls to control the speed and direction of the installation mandrel
Design calculations to determine required installation force based on:
- Bearing and housing dimensions
- Bearing: Go / NoGo Ring diameters, nominal ID, width
- Housing: Min / Max Bore ID, nominal OD, width
- Bearing and housing material properties
- Modulii of elasticity, E, for sleeve bearing and housing materials
- Poisson’s ratio, U, for sleeve bearing and housing materials
- Assumed coefficient of friction at the bearing / housing bore interface.
Determining force to press a sleeve bearing into its housing
- First, determine the contact surface interference pressure, p
Where:
δ = diametral interference fit
d = nominal contact surface diameter at bearing OD/housing bore interface
do = housing OD
di = bearing ID
Eo and Ei = modulii of elasticity for housing and sleeve bearing respectively
υo and υi = Poisson’s Ratios for housing and sleeve bearing respectively
- Next, calculate frictional force, F
F = p × A × μ
Where
p = calculated contact surface interference pressure
A = contact surface area of bearing / housing interface
μ = coefficient of friction at bearing / housing interface.
For GGB metal-polymer bearings, compensate for the bronze inner structure and polymer layers on the interference pressure calculation, adjustment to the ID should be made:
- For PTFE-based metal-polymer bearings, the ID of the bearing, di = dnom + 0.6 mm, where dnom = the nominal bearing ID
- For thermoplastic-based metal-polymer bearings, the ID of the bearing, di = dnom + 1.2 mm, where dnom = the nominal bearing ID
- For GGB metal-polymer bearings, the OD of the bearings can be defined by the specified GO/NOGO ring gages
The calculated value of the maximum frictional force is used to determine the capacity of the installation arbor press required to install the sleeve bearing. The maximum frictional force is based on the max interference fit, δmax = maximum bearing OD – minimum housing bore.
Estimating bearing installed ID
Another reason for calculating the contact surface interference pressure, p, is to estimate the elastic expansion of the housing due to the interference fit with the sleeve bearing and consequently estimating the installed bearing ID. This approach is especially helpful when the housing has a fairly thin cross section and/or has a low modulus of elasticity relative to the bearing material (for example, a metal sleeve bearing pressed into a plastic housing).
Where:
Δd = estimated elastic expansion of housing bore
p = calculated contact surface pressure, calculate both pmax and pmin
d = nominal contact surface diameter at bearing OD/housing bore interface
Eo = housing modulus of elasticity
do = housing OD
The simplified approach found above will provide an estimate of the housing elastic expansion from which the min/max installed ID can be calculated. However, this approach is not meant as a substitute for Finite Element Analysis or other advanced design programs.