Metal Bellows Couplings BK- flexible Shaft Couplings

Please select a Metal Bellows Coupling:

MODEL SERIES BK	BK1	BK2 / BKC / BKL	BKH	BK3	BK4	BK5	BK6	BK7	BK8
	General \| Technical information \| 2D and 3D download

Bellows coupling model BK4 for Fanuc drives

Series from 15 - 150 Nm

Data table and downloads bellows coupling BK4 Series 15 - 150 Nm

Model BK4		Series
		15		30		60		150
Rated torque (Nm)	T_KN	15		30		60		150
Overall length (mm)	A	47	54	68	76	72	82	82	94
Outer diameter of bellow (mm)	B	49		55		66		81
Fit length (mm)	C	19		22		27		32
Inner diameter possible from Ø to Ø H7 (mm)	D	10-22		12-23		12-29		15-37
6 x Fastening screws ISO 4017	E	M4		M5		M5		M6
Tighting torque of the fastening screws (Nm)	E	4		6		8		12
3 x draw-off screw ISO 4017	F	M4		M4		M5		M5
Shaft diameter (mm)	G	20		27		30		30
Shaft length (mm)	H	8.5		22		18		20
Mass moment of inertia (10^-3 kgm²)	J_ges	0.10	0.12	0.22	0.27	0.58	0.61	1.1	1.4
approx. weight (kg)		0.25		0.4		0.8		1.35
Torsional stiffness (10³ Nm/rad)	C_T	20	15	39	28	76	55	175	110
axial (mm)	max.	1	2	1	2	1.5	2	2	3
lateral (mm)	max.	0.15	0.2	0.2	0.25	0.2	0.25	0.2	0.25
axial spring stiffness (N/mm)	C_a	25	15	50	30	72	48	82	52
lateral spring stiffness (N/mm)	C_r	475	137	900	270	1200	420	1500	435
Cone Ø (Fanuc-Motor) (mm)	I	11		16		16		16
Keyway wide (mm)	K	4		5		5		5
Downloads Short Version		15		30		60		150
2D-DXF (ZIP folder)
3D-EXE (Viewer)
3D-STEP (ZIP folder)
Downloads Long Version		15		30		60		150
2D-DXF (ZIP folder)
3D-EXE (Viewer)
3D-STEP (ZIP folder)

(1Nm = 8.85 in lbs), higher torques on request, max. angular misalignment see shaft coupling BK1

Ordering example

Order example for Bellows Coupling BK4 Required information for servo bellows coupling model BK4.

Technical instructions:

Before mounting the coupling, the concial sleeve (1) has to be removed.
After sliding the coupling on to the motor shaft (3) the nut (4) can be put on through the bellows body (4).

To tighten the nut a special DIN 896 B key is used. The bore (5) is used for holding the coupling while tightening the nut.