Product Details

Restricted Tolerances Precision Spindle Bearings: Ceramic balls HC7000E.T.P4S.UL

Characteristics of spindle bearings

Spindle bearings are single row angular contact ball bearings comprising solid inner and outer rings and ball and cage assemblies with solid window cages. They cannot be dismantled. The bearings are available in both open and sealed versions.

Spindle bearings have restricted tolerances. They are particularly suitable for where requires very high guidance accuracy and speed capacity, especially for slewing part of the main spindle of machine tool.

Angular contact ball bearings have raceways in the inner and outer rings that are displaced with respect to each other in the direction of the bearing axis. This means that they are designed to accommodate combined loads, i.e. simultaneous radial and axial acting loads.

The axial load carrying capacity of angular contact ball bearings increases with the enlarging of contact angle. The contact angle α is defined as the angle between the line joining contact point of the ball and the raceways in the radial plane, along which the load is transmitted from one raceway to another, and a line perpendicular to the bearing axis.

Single row angular contact ball bearings can accommodate axial loads acting in one direction only. Under radial loads a force acting in the axial direction is engendered in the bearing, and this force must be counteracted. Consequently the bearing is normally adjusted via a second bearing.

Single row angular contact ball bearings have one high and one low shoulder. Some bearings, particularly those of Diameter Series 8 and 9, have an inner ring with two high shoulders as a deep groove ball bearing. The low shoulder on one or both rings enables a large number of balls to be filled in the bearing, thus giving the bearings a relatively high load carrying capacity. They are of inseparable design.

The contact angle αis 15°(C) or 25°(E), designation suffix C.T.P4S or E.T.P4S.F, for the most common sizes, the cage is a solid window type cage made of textile-laminated phenolic resin(T) and the tolerance class is P4S. Single row angular contact ball bearings are produced in two versions.

-Bearings for universal matching-basic design bearings(not universally matchable) can be only be used for arrangements with single bearings

Bearing Tolerances

Bearing "tolerances" of dimensional and running accuracy, are regulated as ISO standard. For dimensional accuracy, these standards prescribe the necessary tolerances when installing bearings on shafts or in housings, consisting of the acceptable values for bore diameter, outer diameter, assembled bearing width, the permit chamfer, and tapered bore deviation. The geometry accuracy includs average bore diameter variation, outer diameter variation, average outer diameter parattelism, as well as raceway width and height variation(for thrust bearings).

Running accuracy is defined as the allowable limits for bearing runout during operation, consisting of the acceptable values for inner and outer ring radial and axial runout, inner ring side runout, and outer diameter perpendicular deviation.

Comparison of tolerance classifications of national standardsStandardApplicableStandardTolerance ClassBearing TypesChinese Industrial Standard(GB)GB 307.1P0P6P5P4P2All typesInternationalOrganizationfor Standardization(ISO)ISO 492Class 6xClass 6Class 5Class 4Radial bearingsISO 199Normal classClass 6Class 5Class 4Thrust ball bearingsISO 1224Class 5AClass 4APrecision instrument bearingsDeutsches institut for Normung(DIN)DIN 620P0P6P5P4P2All types

Criteria for selecting bearing internal clearance

A bearing's life is theoretically maximum when operating clearance is slighly negative at steady operation. In reality it however is difficult to constantly maintain this optimal condition.If the negative clearance becomes enlarged by fluctuant operating conditions, heat will be produced and bearing life will decrease dramatically. Under ordinary circumstances you should therefore select an initial internal clearance where the operating clearance is slightly larger than zero.

For ordinary operating conditions that use fitting for ordinary loads, running speed and operating temperature are ordinary, selecting normal clearance enables you to obtain the proper operating clearance.

Radial internal clearance for duplex angular contact ball bearingsUnit:µmNominal bore DiameterC2CNC3C4C5d mmover incl.minmaxminmaxminmaxminmaxminmax101838612815152430401830310612102020324055305031081414252540557550803111117173232507595801003131322224040609512010012031515303050507511014012015030161635355555801301701501803181835356060901502001802003202040406565100180240Note:The Clearance group in the table is applied only to contact angles in the table below

Contact angleNomial ContactApplicable clearance groupSymbolangleC15°C1C2A30°C2CNC3B40°CNC3C4

Designation bearing sets

Bearing sets consist of bearings with matched bore and outside diameters. The first letter refers to the number of bearings in a set.

D 2 bearings Duplex

T 3 bearings Triplex

Q 4 bearings Quadroplex

Ready-to-mount bearing sets feature a defined order of bearings. The second (and sometimes third) letter refers to the arrangement of the bearings within the set:

B back-to-back arrangement

F face-to-face arrangement

T tandern arrangement

Bearing Code	HC7000E.T.P4S.UL
Shaft	10
d	10
D	26
B	8
rsmin	0.3
a	8
Mass(Kg)	0.02
Cr_kN	1.8
Cor_kN	1.06
Attainable Speed Grease	75000
Oil Throwaway	120000
Abutment da h12 mm	15
dimensions Da H12	20.5
ramax	0.3