BK7
Metal Bellows Coupling with expanding shaft

15 - 300 Nm

BK7 METAL BELLOWS COUPLING WITH EXPANDING SHAFT

  • BK7
  • Specifications BK7

    BK7 Series
    Rated torque (Nm)TKN
    Overall length (mm)A-2
    Inside diameter possible from Ø to Ø H7 (mm)D1
    Outside diameter (mm)B
    Moment of inertia (10-3 kgm2)Jges.
    Approximate weight (kg)
    Torsional stiffness (10³ Nm/rad)CT
    Axial ± (mm))max.
    Lateral ± (mm)max.
    Angular ± (degree)max.
    Axial spring stiffness (N/mm)Ca
    Lateral spring stiffness (N/mm)Cr
    Fastening screw (ISO 4762)E1/2
    Tightening torque of the fastening screw (Nm)E1/2
    Distance between centerlines (mm)F
    Distance (mm)G
    Mounting length (mm)C1
    Fit length (mm)C2
    Shaft diameter from Ø to Ø h7 (mm)D2
    Hub material
    CAD Portal
    BK7 Serien15
    Rated torque (Nm)TKN15
    Overall length (mm)A-245 | 52
    Inside diameter possible from Ø to Ø H7 (mm)
    D18-28
    Outside diameter (mm)B49
    Moment of inertia (10-3 kgm2)Jges.0,07 | 0,08
    Approximate weight (kg)0,15
    Torsional stiffness (10³ Nm/rad)CT20 | 15
    Axial ± (mm))max.1 | 2
    Lateral ± (mm)max.0,15 | 0,2
    Angular ± (degree)max.1|1,5
    Axial spring stiffness (N/mm)Ca20 | 12
    Lateral spring stiffness (N/mm)Cr315 | 108
    Fastening screw (ISO 4762)E1/2M5
    Tightening torque of the fastening screw (Nm)E1/28
    Distance between centerlines (mm)F17
    Distance (mm)G6,5
    Mounting length (mm)C122
    Fit length (mm)C220
    Shaft diameter from Ø to Ø h7 (mm)D213-25
    Hub materialAluminium
    15
    CAD
    BK7 Series
    Rated torque (Nm)TKN
    Overall length (mm)A-2
    Inside diameter possible from Ø to Ø H7 (mm)D1
    Outside diameter (mm)B
    Moment of inertia (10-3 kgm2)Jges.
    Approximate weight (kg)
    Torsional stiffness (10³ Nm/rad)CT
    Axial ± (mm))max.
    Lateral ± (mm)max.
    Angular ± (degree)max.
    Axial spring stiffness (N/mm)Ca
    Lateral spring stiffness (N/mm)Cr
    Fastening screw (ISO 4762)E1/2
    Tightening torque of the fastening screw (Nm)E1/2
    Distance between centerlines (mm)F
    Distance (mm)G
    Mounting length (mm)C1
    Fit length (mm)C2
    Shaft diameter from Ø to Ø h7 (mm)D2
    Hub material
    CAD Portal
    BK7 Serien30
    Rated torque (Nm)TKN30
    Overall length (mm)A-253 | 61
    Inside diameter possible from Ø to Ø H7 (mm)
    D110-30
    Outside diameter (mm)B55
    Moment of inertia (10-3 kgm2)Jges.0,14 | 0,15
    Approximate weight (kg)0,3
    Torsional stiffness (10³ Nm/rad)CT39 | 28
    Axial ± (mm))max.1 | 2
    Lateral ± (mm)max.0,2 | 0,25
    Angular ± (degree)max.1|1,5
    Axial spring stiffness (N/mm)Ca50 | 30
    Lateral spring stiffness (N/mm)Cr730 | 230
    Fastening screw (ISO 4762)E1/2M6
    Tightening torque of the fastening screw (Nm)E1/214
    Distance between centerlines (mm)F19
    Distance (mm)G7,5
    Mounting length (mm)C127
    Fit length (mm)C225
    Shaft diameter from Ø to Ø h7 (mm)D214-30
    Hub materialAluminium
    30
    CAD
    BK7 Series
    Rated torque (Nm)TKN
    Overall length (mm)A-2
    Inside diameter possible from Ø to Ø H7 (mm)D1
    Outside diameter (mm)B
    Moment of inertia (10-3 kgm2)Jges.
    Approximate weight (kg)
    Torsional stiffness (10³ Nm/rad)CT
    Axial ± (mm))max.
    Lateral ± (mm)max.
    Angular ± (degree)max.
    Axial spring stiffness (N/mm)Ca
    Lateral spring stiffness (N/mm)Cr
    Fastening screw (ISO 4762)E1/2
    Tightening torque of the fastening screw (Nm)E1/2
    Distance between centerlines (mm)F
    Distance (mm)G
    Mounting length (mm)C1
    Fit length (mm)C2
    Shaft diameter from Ø to Ø h7 (mm)D2
    Hub material
    CAD Portal
    BK7 Serien60
    Rated torque (Nm)TKN60
    Overall length (mm)A-262 | 72
    Inside diameter possible from Ø to Ø H7 (mm)
    D112-35
    Outside diameter (mm)B66
    Moment of inertia (10-3 kgm2)Jges.0,23 | 0,26
    Approximate weight (kg)0,4
    Torsional stiffness (10³ Nm/rad)CT76 | 55
    Axial ± (mm))max.1,5 | 2
    Lateral ± (mm)max.0,2 | 0,25
    Angular ± (degree)max.1|1,5
    Axial spring stiffness (N/mm)Ca72 | 48
    Lateral spring stiffness (N/mm)Cr1200 | 380
    Fastening screw (ISO 4762)E1/2M8
    Tightening torque of the fastening screw (Nm)E1/238
    Distance between centerlines (mm)F23
    Distance (mm)G9,5
    Mounting length (mm)C131
    Fit length (mm)C227
    Shaft diameter from Ø to Ø h7 (mm)D223-38
    Hub materialAluminium
    60
    CAD
    BK7 Series
    Rated torque (Nm)TKN
    Overall length (mm)A-2
    Inside diameter possible from Ø to Ø H7 (mm)D1
    Outside diameter (mm)B
    Moment of inertia (10-3 kgm2)Jges.
    Approximate weight (kg)
    Torsional stiffness (10³ Nm/rad)CT
    Axial ± (mm))max.
    Lateral ± (mm)max.
    Angular ± (degree)max.
    Axial spring stiffness (N/mm)Ca
    Lateral spring stiffness (N/mm)Cr
    Fastening screw (ISO 4762)E1/2
    Tightening torque of the fastening screw (Nm)E1/2
    Distance between centerlines (mm)F
    Distance (mm)G
    Mounting length (mm)C1
    Fit length (mm)C2
    Shaft diameter from Ø to Ø h7 (mm)D2
    Hub material
    CAD Portal
    BK7 Serien150
    Rated torque (Nm)TKN150
    Overall length (mm)A-271 | 83
    Inside diameter possible from Ø to Ø H7 (mm)
    D119-42
    Outside diameter (mm)B81
    Moment of inertia (10-3 kgm2)Jges.2,2 | 2,4
    Approximate weight (kg)1,7
    Torsional stiffness (10³ Nm/rad)CT175 | 110
    Axial ± (mm))max.2 | 3
    Lateral ± (mm)max.0,2 | 0,25
    Angular ± (degree)max.1|1,5
    Axial spring stiffness (N/mm)Ca82 | 52
    Lateral spring stiffness (N/mm)Cr1550 | 435
    Fastening screw (ISO 4762)E1/2M10
    Tightening torque of the fastening screw (Nm)E1/265
    Distance between centerlines (mm)F27
    Distance (mm)G11
    Mounting length (mm)C136
    Fit length (mm)C232
    Shaft diameter from Ø to Ø h7 (mm)D226-42
    Hub materialStahl
    150
    CAD
    BK7 Series
    Rated torque (Nm)TKN
    Overall length (mm)A-2
    Inside diameter possible from Ø to Ø H7 (mm)D1
    Outside diameter (mm)B
    Moment of inertia (10-3 kgm2)Jges.
    Approximate weight (kg)
    Torsional stiffness (10³ Nm/rad)CT
    Axial ± (mm))max.
    Lateral ± (mm)max.
    Angular ± (degree)max.
    Axial spring stiffness (N/mm)Ca
    Lateral spring stiffness (N/mm)Cr
    Fastening screw (ISO 4762)E1/2
    Tightening torque of the fastening screw (Nm)E1/2
    Distance between centerlines (mm)F
    Distance (mm)G
    Mounting length (mm)C1
    Fit length (mm)C2
    Shaft diameter from Ø to Ø h7 (mm)D2
    Hub material
    CAD Portal
    BK7 Serien300
    Rated torque (Nm)TKN300
    Overall length (mm)A-284 | 98
    Inside diameter possible from Ø to Ø H7 (mm)
    D130-60
    Outside diameter (mm)B110
    Moment of inertia (10-3 kgm2)Jges.6,5 | 8,9
    Approximate weight (kg)4
    Torsional stiffness (10³ Nm/rad)CT450 | 350
    Axial ± (mm))max.2,5 | 3,5
    Lateral ± (mm)max.0,25 | 0,3
    Angular ± (degree)max.1|1,5
    Axial spring stiffness (N/mm)Ca105 | 71
    Lateral spring stiffness (N/mm)Cr3750 | 1050
    Fastening screw (ISO 4762)E1/2M12
    Tightening torque of the fastening screw (Nm)E1/2120
    Distance between centerlines (mm)F39
    Distance (mm)G13
    Mounting length (mm)C143
    Fit length (mm)C245
    Shaft diameter from Ø to Ø h7 (mm)D238-60
    Hub materialSteel
    300
    CAD

    Properties

    • Design:
      • On one side with a single radial clamping screw ISO 4762.
      • 
On one side an expanding shaft with tapered clamping element.
    • Temperature range: -30° C to +100° C (-22° F to +212° F)
    • Backlash: Absolutely backlash-free due to frictional clamp
connection.
    • Service life: These couplings have an infinite life and are maintenance-free if the technical ratings are not exceeded.
    • Tolerance: On the hub/shaft connection 0.01 to 0.05 mm
    • Material:
      • Bellows made of highly flexible high-grade
stainless steel
      • Hub material: see table
      • Expanding hub and cone (steel)
    • Brief overload: Acceptable up to 1.5 times the value specified.
    • Speeds: Up to 10,000 rpm, over 10,000 rpm available with a finely balanced version.
    • Custom designs: Custom designs with varied tolerances, keyways, non-standard material,
bellows and ATEX designs are available upon request.
    • Properties of Bellows Coupling model BK7:
      • compact design, conserves space while saving cost
      • easy mounting
      • low moment of inertia
      • backlash-free and torsionally rigid
      • compensation for misalignment


    Overview