ABMA 25.2:1990(R1999) pdf download

ABMA 25.2:1990(R1999) pdf download.ROLLING BEARINGS LINEAR MOTION, RECIRCUL ATING BALL, SLEEVE TYPE-INCH SERIES
1. INTRODUCTION
Linear motion bearings provide for rec- tilinear motion as opposed to rotational mo- tion. The type of bearing described in this standard uses balls which circulate in a number of closed loops in the cylindrical bearing body which surrounds the shaft. See Figure 1. Linear bearings are typically applied to meet one or more of the following criteria: 3. Smooth antifriction motion, free from stick-slip or chatter. b. Low force required to produce rel- ative linear motion between the bear- ing and shaft. These requirements, as well as others, can be met by appropriate use of the var- ious linear bearing types (closed type, ad- justable type, open type). The appropriate selection of bearing type and specification should be established between the man- ufacturer and the user.
2. SCOPE
This Standard gives the general plan for boundary dimensions, tolerances and ter- minology for recirculating ball, sleeve type, : linear motion bearings. This standard applies only to the size range covered by Table 1, Boundary Di- mensions.
3. REFERENCES ANSI/AFBMA
Standard 1- -Terminology for Anti-Friction Ball and Roller Bearings ANSI/AFBMA Standard 4- Tolerance Definitions and Gauging Practices for Ball and Roller Bearings
4.TERMINOLOGY
4.1 Definitions For the purposes of this National Stan- dard, the following definitions apply: 4.1.1 Linear bearing- A basically cylin- drical sleeve with a number of closed loops of circulating balls which is designed to achieve linear rolling motion along a shaft. 4.1.2 Shaft- -The hardened cylindrical rod along which a linear bearing traverses. 4.1.3 Nominal outside diameter- _The di- ameter of the cylinder containing the the- oretical surface of a basically cylindrical outside surface. 4.1.4 Nominal ball complement bore di- ameter- -The diameter of the cylinder in- scribed inside the inner balls. 4.1.5 Nominal bearing width- _Distance between two theoretical end faces desig- nated to bound the width of the linear mo- tion rlling bearing. 4.1.6 Radial runout- -The difference be- tween the largest and the smallest radial distance between the outside surface of the cylindrical sleeve and the centerline of the ball complement bore diameter. 4.1.7 Closed type- -That type in which the outer sleeve is continuous, or virtually continuous, whereby adjustment of clear- ance between the ball complement bore and the shaft can be achieved only by se- lection of the housing fit, shaft precision class, and the bearing. 4.1.8 Adjustable type- -That type which has elastic features which permit mechan- ical adjustment of the clearance between the ball complement bore and the shaft. 4.1.9 Open type- -That type in which a longitudinal section is removed to provide clearance over shaft support rails. D – Nominal outside diameter. Dmp – Single plane mean outside diam- eter. ADmp – Single plane mean outside diam- eter deviation from the nominal outside diameter (difference be- tween Dmo and D). D，- Snap ring groove diameter. – -Nominal bearing width. C。一Single bearing width. 0C。一 Deviation of a single bearing width from nominal bearing width (dif- ference between C。and C). C，- – Nominal distance between the outer faces of the snap ring grooves. Symmetrical with re- spect to the bearing width. C1。- Single distance between the outer faces of the snap ring grooves. 0C1。- _Deviation of a single distance be- tween the outer faces of the snap ring grooves from the nominal snap ring groove distance (differ- ence between C1s and C).