BK7
Metal Bellows Coupling with expanding shaft

15 - 300 Nm

BK7 METAL BELLOWS COUPLING WITH EXPANDING SHAFT

Specifications BK7

BK7 series 15 30 60 150 300
Rated torque (Nm) TKN 15 30 60 150 300
Overall length (inserted) (mm) A-2
4552
5361
6272
7183
8498
Outer diameter (mm) B 49 55 66 81 110
Fit length (mm) C1 22 27 31 36 43
Inner diameter possible from Ø to Ø H7 (mm)D1 8-28 10-30 12-35 19-42 30-60
Inner diameter possible from Ø to Ø H7 (inch) D1 0,375"-
1,000"
0,437"-
1,125"
0,500"-
1,375"
0,750"-
1,625"
1,250"-
2,250"
Fit length (mm) C2 20 25 27 32 45
Shaft Diameter possible from
Ø to Ø h7 (mm)
D2
13-25 14-30 23-38 26-42 38-60
Shaft Diameter possible from
Ø to Ø h7 (inch)
D2
0,625"-
0,875"
0,625"-
1,125"
1,000"-
1,375"
1,000"-
1,625"
1,500"-
2,250"
Fastening screws ISO 4762E1/2 M5 M6 M8 M10 M12
Tighting torque of the Fastening screws (Nm) E1/2 8 14 38 65 120
Distance between centers (mm) F 17 19 23 27 39
Distance (mm) G 6.5 7.5 9.5 11 13
Moment of inertia (10-3 kgm2) Jges
0.070.08
0.140.15
0.230.26
2.22.4
6.58.9
Hub material (standard) (steel on request)Al Al Al Steel Steel
Approx. weight (kg)0.15 0.3 0.4 1.7 4
Torsional stiffness (103 Nm/rad) CT
2015
3928
7655
175110
450350
Axial      (mm) max.
12
12
1.52
23
2.53.5
Lateral  (mm) max.
0.150.2
0.20.25
0.20.25
0.20.25
0.250.3
Axial spring stiffness (N/mm)Ca
2012
5030
7248
8252
10571
Angular  ± (grad) 
11.5
11.5
11.5
11.5
11.5
Lateral spring stiffness (N/mm)Cr
315108
730230
1200380
1550435
37501050
CAD Portal 15 30 60 150 300
2D/3D Data 

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