Catalogue Ball Spline
36Pages

Ball Splines

HIWIN GmbH Brucklesbund 1 77654 Offenburg Deutschland Fon +49 781 93278-0 info@hiwin.de hiwin.de All rights reserved. Complete or partial reproduction is not permitted without our permission. Note: The technical data in this catalogue may be changed without prior notice.

Ball Splines Ball Splines Ball Splines are shaft guides used for precise guidance of linear movements. They consist of a shaft with multiple pairs of longitudinal grooves and a ball spline nut. The nut contains ball cages filled with steel balls. They roll along the longitudinal grooves of the ground shaft and thus enable precise linear movements. Due to the angular arrangement of the force-transmitting elements, Ball Splines can absorb both radial forces and torque loads. Assembly instructions and catalogue for download Here you can download the corresponding assembly instructions and the...

Ball Splines Contents

3.1 Linear Ball Splines 9 3.2 Ball Screw Splines (FBR type) 11 5.1 Strength design of spline shaft 13 6.2 Conditions and benchmarks for use in the selection of preload 23 7.1 HIWIN order code for Ball Splines RS, FS and FSR types 24 7.3 Product dimensions and specifications 28 8.1 HIWIN order code for Ball Splines FBR and FBL types 30 8.3 Product dimensions and specifications for compound Ball Splines 31 9.2 Material and surface treatment 32 10.1 FB type Ball Spline working mode 33

Ball Splines Product overview

Linear Ball Spline { { { { { Different nut types available Linearly freely movable Torque and radial load transmission With solid or hollow shaft Nominal diameter 13 – 32 mm Ball Screw Spline { { { { Driven flange nuts Shaft with Ball Spline nut and Ball Screw nut With solid or hollow shaft Nominal diameter 16 –

Ball Splines Features 2. Features The HIWIN Ball Spline is an anti-rotation shaft guide consisting mainly of a nut filled with steel balls and a shaft with several longitudinal grooves arranged in pairs. The steel balls roll in the raceways between the nut and shaft in a closed circuit and enable the nut to move along the shaft with low friction and high precision. The angular contact between the steel balls and the raceway in the nut and shaft enables radial forces and torques to be absorbed. Thanks to the integrated nut/bearing design, the Ball Spline can achieve high payloads with a...

3. Introduction of Ball Splines 3.1 Linear Ball Splines Cylinder type (RS type) Flange type (FS type) Rotary type (FSR type)

Ball Splines Introduction of Ball Splines 3.1.1 Technical structure RS Type Retainer Steel ball Spline shaft Retainer Steel ball Spline shaft Flange outer ring Bearing seal Spline shaft Spline shaft Spline nut Steel ball Retainer

3.2 Ball Screw Splines (FBR type) Flange outer ring Steel ball Retainer Steel ball (bearing) Flange outer ring Bearing seal Retainer Bearing seal Spline nut Retainer Spline shaft including thread End cap Steel ball

5. Calculation methods 5.1 Strength design of spline shaft The Ball Spline can absorb radial loads and torsions. Sufficient strength of the Ball Spline must be ensured by calculating the load-bearing capacity and structural safety, especially in the case of high combined loads. 5.1.1 Spline shaft subjected to bending When bending moments act on the spline shaft of the Ball Spline, the most suitable spline diameter can be calculated according to formula F 5.1: F 5.1 M Maximum torque acting on spline shaft [Nmm] σ Allowable bending stress of spline shaft (98 N/mm2) Z Axial section modulus of...

Ball Splines Calculation methods 5.1.3 Spline shaft subjected to bending and torsion simultaneously If the shaft is subjected to bending and torsional loads simultaneously, the required shaft diameter must be calculated separately for the equivalent bending moment (Me) and for the equivalent torsional moment (Te). The values must be compared and the larger of the two calculated shaft diameters must be used. Equivalent bending moment F 5.3 5.1.4 Rigidity of the spline shaft Rigidity of the spline shaft is indicated by the torsional angle of the spline shaft of length 1 m, which is limited to...

5.1.5 Bending and bending angle of the spline shaft The bending and bending angle of the ball spline shaft must be determined by calculation using the formulas corresponding to the actual load conditions. Table 5.1 Calculation of bending and bending angle Support method Both ends are free Calculation formula of bending Calculation formula of bending angle Both ends are fixed Both ends are free Both ends are fixed Both ends are fixed dmax Maximum bending [mm] I Geometric moment [mm4] P Concentrated load [N] Mo Torque [Nmm] i1 Bending angle at support point p Uniform load [N/mm] l Span moment...

Calculation methods Table 5.2 Characteristics of the spline shaft cross-section 5.1.7 Critical velocity of the spline shaft When the ball spline shaft is driven by a motor and the rotation speed of the spline shaft increases closely to the resonance frequency, the mechanical stress on the ball spline increases significantly and can lead to bad running performance, vibration and even mechanical failure Nc Critical velocity [min-1] lb Distance between installation surfaces [mm] E Modulus of longitudinal elasticity [2.06 x 105 N/mm2] I Minimal geometrical moment of inertia [mm4] Y Density...

Fig. 5.7 Schematic diagram of spline shaft: fixed - fixed 5.2 Predicting life 5.2.1 Rated life The life of a Ball Spline can vary considerably even if it is manufactured from the same batch and used under the same motion conditions. Therefore, as a basis for calculating the life of a linear motion system, use the rated life as defined below. The rated life is the total running distance that can be achieved by having a batch of identical linear motion systems moving separately under the same conditions, 90 % of which do not show metal fatigue. Fig. 5.8 Schematic diagram of the Ball Spline...

When subjected to both torsional and radial loads simultaneously, the equivalent radial toad can be calculated according to formula F 5.9 and then the life can be calculated. PE Equivalent radial load [N] cosa Constant angle (FBR type: a = 70°) i 3 rows of steel balls under load for specification 20 dp Ball center diameter [mm] Calculating life time After calculating the rated life (L) using the above formulas, the life time can be calculated according to formula F 5.9 when the number of strokes and times are fixed. 5.2.2 Temperature coefficient fT When using a Ball Spline in operating...