Product category:
Bearings
News Release from: SKF UK | Subject: Self-aligning bearing arrangements
Edited by the Engineeringtalk Editorial
Team on 28 December 2000
Innovative products combine in
self-aligning units
The combination of a variety of SKF's latest products enables users to achieve a new standard for self-aligning bearing configurations.
The combination of a variety of SKF's latest products enables users to achieve a new standard for self-aligning bearing configurations In self-aligning bearing arrangements that are subject to axial displacement there has always been the problem that if spherical roller bearings are used at both ends of the shaft, they effectively fight each other when the axial movement takes place
This causes incorrect loading on the bearings and leads to premature wear.
One solution has been to allow one bearing to float within its housing to account for the axial movement, but this in turn can lead to fretting corrosion to the outer edge of the floating bearing and also cause judder in the machine.
This is a problem that every manufacturer of large fans, for example, is acutely aware.
By fitting an SKF CARB toroidal roller bearing at the floating end of the shaft, the performance of both the bearing system and of the spherical roller bearing at the fixed end, is improved dramatically.
In trials, SKF has proven that by employing a spherical roller bearing - such as the Explorer type - at one end of the shaft, a CARB bearing at the other, and then supporting them in a good quality housing - such as SKF's SNL split plummer block housings - an unprecedented level of performance and service life is achieved.
Indeed, life expectancy for the new standard is significantly more than that of conventional self-aligning bearing configurations! When designing the Explorer spherical roller bearing, SKF completely re-addressed bearing development.
Explorer changed the standards for products of their type - from the selection of the exceptionally clean and homogenous steels employed, to the advanced modelling techniques used in the mechanical design.
The bearings have an all steel construction and SKF patented self-guiding symmetrical rollers.
As a result, the bearings give the maximum service life under any conditions with the benefits of lower temperature, higher speeds, low noise, reduced maintenance, reduced size, greater strength and stiffness and reduced costs.
Indeed, the bearing delivers three times the life expectancy of others.
SKF's CARB toroidal roller bearing is the first fundamentally new bearing technology in decades.
The unique bearing offers greater shaft misalignment tolerance, elimination of fretting corrosion, reduced heat, lower maintenance costs and the elimination of the need for shaft coatings or sleeves.
SKF CARB bearings are designed to automatically adjust the roller position inside the bearing so that the load is distributed evenly along the roller contact length, irrespective of misalignment.
Axial movement is accommodated internally, as in a cylindrical or needle roller bearing, without any frictional resistance, so a loose fit of the bearing rings is unnecessary.
However well engineered a bearing may be, its performance and life expectancy is compromised significantly if a poor quality housing is used.
SKF's SNL split plummer block bearing housings were designed after consultation with customers who identified the features and benefits they wanted.
The resultant housings are stronger and stiffer, have an improved bearing seating, give longer service life, longer relubrication intervals and have better heat dissipation.
The casting has been designed to provide the rigidity and heat transfer, while assembly and dismantling arrangements have also been improved.
A range of sealing options are available and the housings are manufactured ready to accept SKF's lubrication and condition monitoring accessories.
System 24, SKF's automatic lubrication system, can be fitted directly to the SNL housings.
This lubrication device is a fit and forget accessory that enables the continuous supply of lubricant to the bearings.
The incorporation of SKF's TempGuard temperature monitor allows users to get an early warning that excessive heat is building within the housing - a reliable symptom that something is wrong with the machine. Request a free brochure from SKF UK ...
• SKF UK: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
