Schaublin - Unibal
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Spherical and rod-end bearings Swiss ISO 9001 – 2000 AECMA-EASE – EN 9100 www.schaublin.com www.rbcfrance.com

2 Ed. Jan.2006 Copyright © 2006 – Schaublin-SA – All rights reserved

Unibal products Standards In its standard programme, Schaublin offers a huge range of spherical bearings. The item reference gives the identity of the spherical bearing. ─ The shape ─ The nature of the slip contact ─ The series Our standard rod-end bearings comply with the dimensions of the ISO 12240–4 series K standard, so as to allow total interchangeability. Derivatives In order to supplement the standard programme, Schaublin makes spherical bearings to your requirements. ─ Special thread pitch ─ Specific thread length ─ High mechanical performance steel mounts ─ Specific slip surfaces...

Definitions Dimensional standards ISO 12240–4 The international standard sets the dimensions of rods with spherical bearing assembled. It also specifies tolerances relative to the dimensions. The diameter of the head d2 is sized at the lower value of the standard, which gives our rod-end bearings minimal size and weight, thus ensuring total interchangeability with any other rod-end bearing meeting the standard. European and American aerospace standards Schaublin SA manufactures and distributes spherical bearings and self-lubricated bushes to the following standards: EN2584, EN2585, EN3048,...

Standard programme SME 12.40 Description SCHAUBLIN Shape M: ML: F: FL: S: _: G: A: E: Rod-end bearing Male Rod-end bearing Male, left-hand thread Rod-end bearing Female Rod-end bearing Female, LH thread Spherical (to be fitted in a mount) Steel / Bronze, without Lubricator Steel / Bronze, with Lubricator Steel / Steel ® Steel / Uniflon (self-lubricating fabric) Nominal size Series _: .20: .40: .45: .50: Standard Special thread High tensile Stainless steel Competition (Derivatives) .30: Made according to Male spherical bearing drawing Type of Slip Size Series Mechanical industry Food and...

Slip Type Friction G Steel / Bronze Steel / Steel (Series 50) A Maintenance Regular lubrication Good radial and axial strength Special features The lubricator is available on male and female rods from size 8 Working temperature 150° C max (special lubrication) Regular lubrication Steel / Steel Excellent impact resistance Excellent radial strength Version not available on rodend bearings Without lubricator Working temperature 300° C max (special lubrication) Maintenance-free, self-lubricating fabric Excellent impact resistance Excellent radial strength The Uniflon® E selflubricating fabric...

Ed. Jan.2006 Copyright © 2006 – Schaublin-SA – All rights reserved 9

Calculations Static loading The basic static loading C0 is given in the tables of dimensions. For a rod-end bearing, it is limited by the strength of the mount. The values given in the Unibal standard programme tables are calculated from the elastic limit of the mount material (Cse) taking a safety factor into account: C0 = Cse 1.25 In the case of a spherical bearing, the basic static loading C0 is calculated using the following formula: C0 = dk x C x 0.85 x X dK: diameter of the inner bush sphere (mm) C: width of the mount (mm) -2 X: Stress admissible by the material (daN.mm ) Fatigue...

Checking the application Proceed as follows to check the choice of a spherical bearing: ─ Calculate and check whether the pressure is within the allowable limits ─ Calculate and check whether the velocity is within the allowable limits ─ Calculate the PV factor (Pressure x Velocity) and check the allowable limit Max. allowable pressure -2 (daN ⋅ mm ) Slip contact Series Int. bush Ext. bush Max. allowable velocity -1 (m ⋅ min ) Maximum allowable PV - Steel Bronze Steel Uniflon® E 5 10 15 5 4 4 3.5 3.5 4.5 .40 Steel Bronze Uniflon® E 5 15 2.5 4 3 4.5 .45 Stainless steel Bronze Stainless steel...

Calculating the slip velocity on contact Checking the maximum friction velocity between the inner bush and outer bush. dK x ß x f 114’600 V= V: dK: ß: f: -1 velocity (m.min ) diameter of the inner bush sphere (mm) angle of oscillation complete (degrees) frequency of oscillation (Hz) PV factor PxV PV = P: -2 pressure (daN.mm ) V: -1 velocity (m.min ) Calculating life If your application requires the play or torque of the spherical bearing to be controlled throughout its life, please ask us. Dh = D= Dh D C K F ß f c1 c2 c3 c4 c5 c6 c7 c8 X c1 ⋅ c2 ⋅ c3 ⋅ c4 ⋅ c5 ⋅ c6 ⋅ c7 ⋅ c8 ⋅ X ⋅ C ⋅ K ⋅...

Determining calculation coefficients The life of a spherical bearing or rod is the maximum number of running hours or oscillations before play appears that does not allow the spherical bearing to fulfil its function. The life is a function of the dynamic strain and of the various parameters of the application. ─ Pressure ─ Velocity (angle and frequency of oscillations) ─ Strain (continuous, pulsating, alternate loadings) ─ Temperature ─ Vibrations Calculation formulas, worked out from trials conducted on our test benches, enable you to determine the life in accordance with your application....

Examples of dynamic calculations Calculation n° Steel / Bronze 1: Calculation n° Steel / Steel 2: On a machine, an automatic loading system requires size You want to fit the tower of a crane with size 16 rod-end 12 rod-end bearings bearings. What will the life stress surfaces below be? 1) Data 1) Data Type and size wanted: Dynamic radial loading: Type of strain: Angle of oscillation: Frequency: Maintenance: Ambient temperature: Life wanted: SMG12 180 daN continuous ± 45° (ß = 180° ) 125 osc./min 1 lubrication / 18h 50° C 7,000,000 osc. Type and size wanted: Dynamic radial loading: Type of...

Calculation n° Steel / Uniflon E 3: An SF..30 rod-end bearing is going to be used for the transmission on a fairground ride. It must be able to run maintenance-free. What type should be used? Calculation n° Steel / Steel 4: Several type SSA 3.45 spherical bearings are fitted to scale models (model boats). Despite the corrosive environment and stresses, these Unibals must withstand 300,000 oscillations. 1) Data Type and size wanted: Dynamic radial loading: Type of strain: Angle of oscillation: Frequency: Maintenance: Ambient temperature: Life wanted: 1) Data Type and size wanted: Dynamic...