FK Pillow blocks structure and material

1 STRUCTURE OF FK PILLOW BLOCKS

(A). Grease nipple for supplying lubricating grease.

(B). Grease hole..........Grease groove on outside of the outer race together with two grease holes provides efficient flow of grease to ball and raceways.

(C). Hollow set screw ............Two hollow set screws ensure easy and firm mounting on a shaft.

(D). One piece cast iron housing .........of rigid structure and fault-free.

(E). Steel plate slinger........Perfect sealing with steel slingers and synthetic rubber seals excludes dust efficiently. Centrifugal force generated by shaft rotation also prevents the grease from leaking out of bearing.

(F). Synthetic rubber seals.........Synthetic rubber seals placed between the inner ring and the outer ring prevent lubricating grease from leaking as well as preventing moisture and dust from entry.

(G). Self-aligning surface..........Self-aligning in any direction enable misaligned shaft to be centered and aligned without distorting seals.

2 COMBINATION TABLES OF INSERT BEARING AND BEARING HOUSINGS

A ball bearing unit consists of a insert bearing and a bearing housing. There are many different ball bearing units available. Following table shows some of the combinations of insert bearings and housings. Also, there are many kinds of insert bearings which are classified according to the method of mounting on the shaft, the bore diameter series, and the outer ring outside profiles, as well as the diameter series and the width series.

Table 1

3 MATERIALS OF BALL BEARING UNITS

3.1 Materials of Insert Bearings

The materials of the race and ball of bearing require enough hardness and the following qualities:

(1). Large fatigue strength against repeated stress due to fatigue fracture of the race surface which governs the life of the bearing.

(2). High limit of elasticity and high yield strength to prevent deformation when a large load is applied per unit area.

(3). Large abrasion resistance against sliding friction between the retainer and the ball.

(4). High strength against crack due to impact load and failure caused by improper fitting etc.

(5). Small secular change in dimension and shape due to change of structure or internal stress.

GCr15 Steel < GB/T 18254>(High carbon chromium bearing steel) satisfies the above comparatively well, and its chemical composition is shown in the following table.

Chemical composition of high carbon chromium bearing steel

Table 2

Chemical composition of stainless steel

Table 3

In order to maintain uniform quality of materials, FK keeps fully equipped installations and performs strict acceptance tests and inspections based on the strict acceptance standards in addition to GB- standards.

Kinds of test done at the FK are mainly chemical analysis, magnetic exploration, ultrasonic exploration, corrosion by strong acid, inspection of structure by naked eyes, inspection of structure by microscope, crusher test and hardness etc.

Materials of Insert Bearing Components

Table 4

*Nylon cage is available

3.2 Materials of Housings

The material of the housings is HT200 GB/T 9439(Cast iron) and the mechanical properties are shown in the following table.

Mechanical properties of cast iron HT200

Table 5

Other Materials of Housings

Table 6

3.3 Materials of Other Accessories

Table 7

2025 July 3rd Week FK Product Recommendation:

Pillow Block:

A pillow block bearing (or plummer block) is a mounting used to support a rotating shaft with the use of bearings and various accessories. The assembly consists of a mounting block which houses a bearing. The block is mounted to a foundation, and a shaft is inserted, allowing the inner part of the bearing/shaft to rotate. The inside of the bearing is typically 0.025 millimetres (0.001 in) larger diameter than the shaft to ensure a tight fit. Set screws, locking collars, or set collars are commonly used to secure the shaft. Housing material for a pillow block is typically made of cast iron or cast steel.

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