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plummer block
1.what is plummer block
A pillow block, also known as a plummer block or bearing housing, is a mounted plain or roller bearing used to provide support for a rotating shaft with the mounting surface on a parallel line with the axis of the shaft. Housing material for a pillow block is typically made of cast iron or pressed steel. Pillow blocks are extensively used in conveyor systems such as tube chain conveyors
2.how to select
Pillow blocks are usually referred to the housings which have a bearing fitted into them & thus the user need not purchase the bearings separately. Pillow blocks are usually mounted in cleaner environments & generally are meant for lesser loads of general industry. These differ from "plummer blocks" which are bearing housings supplied without any bearings & are usually meant for higher load ratings & corrosive industrial environments.
However fundamental application of both types is the same which is to primarily mount bearings safely enabling their outer ring to be stationary usually and allowing rotation of the inner ring. The housing is bolted to a foundation through the holes in the base. Bearing housings are either split type or unsplit type. Split type housings are usually two piece housings where the cap and base can be detached. While certain series are one single piece housings. Various seals are provided to prevent dust and other contaminants from entering the housing. Thus the housing provides a clean environment for the expensive bearings to freely rotate hence increasing their performance and duty cycle.
Large bearing housings are usually made of grey cast iron. However various different grades of metals can be used to manufacture the same. Small and low-cost housings are die-cast in zinc or aluminium alloys.
ISO 113 specifies standard dimensions for interchangeable plummer blocks.
Mounted Bearing Unit