BK7
Metal Bellows Coupling with expanding shaft

15 - 300 Nm

BK7 METAL BELLOWS COUPLING WITH EXPANDING SHAFT

BK7

Specifications BK7

BK7 Serien
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 4762E1/2
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 4762E1/2M5
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 Serien
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 4762E1/2
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 4762E1/2M5
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 Serien
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 4762E1/2
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 4762E1/2M5
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 Serien
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 4762E1/2
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 4762E1/2M5
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 materialAluminium
150
CAD
BK7 Serien
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 4762E1/2
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 4762E1/2M5
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