Flexible Couplings - BIPEX-S Series

BIPEX-S couplings are torsionally flexible and are free of backlash in the pretensioned state. They are characterized by their compact design and high power density. BIPEX-S couplings connect machine shafts and compensate for shaft misalignment that can occur during assembly or operation. The damping properties of the couplings can be varied by the use of cam rings made of elastomer of various degrees of hardness.

BIPEX-S couplings are suitable for all drive applications which require a coupling that offers positioning accuracy and vibration damping.

Область применения

BIPEX-S couplings within the standard catalog range are available in 10 sizes with torque ratings ranging from 0.5 to 655 Nm. The coupling is suitable for ambient temperatures of between -30 °C and +90 °C. Cam rings with alternative hardness grades can be supplied for ambient temperatures down to -50 °C or up to +120 °C.

BIPEX-S couplings are ideal for use in servo drives, linear axes or rotary encoders of the type typically deployed in machine tools, packaging machines or printing presses.

Дизайн

BIPEX-S couplings each comprise two hub parts connected by a cam ring made of polyurethane (PU).

The couplings can be axially plugged in during assembly. The hubs can be coupled to the shafts by many different methods including set screws, key joint, slotted clamping hubs, half-shell hubs, clamping hubs or expanding hubs.

BIPEX-S couplings are positive-locking and torsionally flexible thanks to the polyurethane cam ring. Misalignment between the connected shafts deforms the cam ring.

Coupling materials:

Hubs:
Up to size 38 aluminum
Sizes 42 and 48 steel

Cam ring:
PU 80 ShoreA -50 °C to +80 °C
PU 92 ShoreA -40 °C to +90 °C
PU 98 ShoreA -30 °C to +90 °C
(standard ring)
PU 64 ShoreD -50 °C to +120 °C

The coupling types can be combined from the available range of hub versions and different elastomer grades.

Hub versions:

N: Hub with set screw
G: Slotted clamping hub
C: Slotted clamping hub, compakt
H: Half-shell clamping hub
K: Clamping hub with external taper
S: Expanding hub

Versions N, G, C and H are optionally available with keyway.

BIPEX-S coupling versions

Type	Description
BNN ¹⁾	Hub with set screw on both sides
BGG ¹⁾	Clamping hub on both sides
BCC ¹⁾	Compact clamping hub on both sides
BHH ¹⁾	Half-shell clamping hubs on both sides
BKK ¹⁾	Clamping hub with external taper on both sides
BCS ¹⁾	Hub 1: Clamping hub/Hub 2: Expanding hub
BHH-W ¹⁾	Drive shaft with half-shell clamping hub
BNG	Hub 1: Set screw/Hub 2: Clamping hub
BNC	Hub 1: Set screw/Hub 2: Compact cl. hub
BNH	Hub 1: Set screw/Hub 2: Half-shell
BNK	Hub 1: Set screw/Hub 2: External taper
BGC	Hub 1: Clamping hub/Hub 2: Compact cl. hub
BGH	Hub 1: Clamping hub/Hub 2: Half-shell
BGK	Hub 1: Clamping hub/Hub 2: External taper
BGS	Hub 1: Clamping hub/Hub 2: Expanding hub
BCH	Hub 1: Cl. hub compact/Hub 2: Half-shell
BCK	Hub 1: Cl. hub compact/Hub 2: External taper
BHK	Hub 1: Half-shell/Hub 2: External taper
BHS	Hub 1: Expanding hub/Hub 2: Half-shell
BKS	Hub 1: Expanding hub/Hub 2: External taper

1) Standard version

Hub variants

Set screw

Clamping hub

Compact camping hub

Half-shell clamping hub

External taper

Expanding hub

Cam rings

98 ShoreA (red) 92 ShoreA (yellow) 80 ShoreA (blue) 64 ShoreD (green)

Особенности

BIPEX-S couplings are suitable for mounting horizontally, vertically or in any desired position. The coupling parts can be arranged as required on the shaft ends to be connected. The coupling can be axially plugged in.

The cam ring is pretensioned and is therefore assembled without backlash. The cams attached to the cam ring allow the coupling to compensate shaft misalignment, and also provide electrical isolation since they prevent contact between the two hub parts.

BIPEX-S couplings are fail-safe. When the cam ring is worn, the claws of the coupling hubs provide for fail-safe operation.

Available in 4 different Shore hardness grades, the cam rings allow to select the optimum degree of rigidity for any application.

Технические данные

Preliminary dimensioning

Dimensioning according to torque

The coupling must be dimensioned such that the rated torque of the drive including service factors does not exceed the rated torque of the coupling:

T_KN ≥ T_N × FB × FT

Torque characteristic	Service factor FB
Uniform	1.25
Nonuniform	1.5
Rough	2.0

In order to increase the torsional rigidity and therefore minimize the torsional backlash, it is possible to apply significantly higher service factors for main spindle or positioning drives.

Temperature range	Temperature factor FT
-30 °C to +30 °C	1.0
to +60 °C	1.4
to +80 °C	1.8
to +100 °C	2.0
to +120 °C	2.8

Note:

Please note the permissible temperature ranges of different cam rings.

Starts per hour	Startup factor FA
< 125	1.0
125 to 250	1.3
250 to 500	1.6
500 to 1000	1.8
> 1000	2.0

Checking the peak torques

The coupling size selected during the preliminary dimensioning process must also be suitable with respect to peak torques at the drive and load ends:

T_KN ≥ T_S × FB × FT

T_S = T_AS × J_L : (J_A + J_L)× FA or T_S = T_LS × J_A : (J_A + J_L)× FA

Checking the maximum speed

For all load situations n_Kmax > n_max

Checking the permitted shaft misalignment

The actual shaft misalignment must be less than the permitted shaft misalignment for all load situations.

Checking the shaft-hub connection

In the case of clamping connections without feather key, it must be ensured that the transmissible torque of the hub connection is greater than the peak torque at the coupling.

Formula symbols

Key to formula symbols

Name	Formula symbols	Unit	Explanation
Rated coupling torque	T_KN	Nm	Torque which can be transmitted as static torque by the coupling over the period of use.
Coupling overload torque	T_KOL	Nm	Torque which can be transmitted very rarely as maximum torque by the coupling.
Peak torque at drive end	T_AS	Nm	Peak torque during non-periodic torque surges at drive end
Peak torque at load end	T_LS	Nm	Peak torque during non-periodic torque surges at load end
Peak torque	T_S	Nm	Peak torque at the coupling
Service factor	FB		Factor that expresses the real coupling load as a ratio of the nominal coupling load
Temperature factor	FT		Factor that takes into account the reduction in strength of flexible rubber materials at higher temperatures
Startup factor	FA		Factor that takes into account additional loading as a function of starting frequency
Moment of inertia of drive end	J_A	kgm²	Sum of the moments of inertia at the drive end referred to the coupling speed
Moment of inertia of load end	J_L	kgm²	Sum of the moments of inertia at the load end referred to the coupling speed
Torsion angle	φ	°	Torsion angle of the coupling under torsional load
Torsional stiffness, dynamic	C_Tdyn	Nm/rad	Dynamic torsional stiffness of the coupling
Axial stiffness	C_a	N/mm	Axial stiffness of the coupling
Radial stiffness	C_r	N/mm	Radial stiffness of the coupling
Rated speed	n_N	rpm	Coupling speed
Maximum coupling speed	n_Kmax	rpm	Maximum permissible coupling speed
Axial misalignment	ΔK_a	mm	Axial misalignment of the coupling halves
Radial misalignment	ΔK_r	mm	Radial misalignment of the coupling halves
Angular misalignment	ΔK_w	°	Angular misalignment of the coupling halves

Power ratings

Size	Shore hardness	Rated torque	Maximum torque	Maximum speed	Maximum speed	Maximum speed	Torsional stiffness	Radial stiffness	Permitted shaft misalignment
				Type	Type	Type
				BNN	BGG, BHH, BCC, BCS	BKK
		T_KN	T_KOL	n_Kmax	n_Kmax	n_Kmax	C_Tdyn	C_r	ΔK_a	ΔK_r	ΔK_w
		Nm	Nm	rmp	rmp	rmp	Nm/rad	N/mm	mm	mm	degrees
5	80 ShoreA	0.3	0.6	47500	38000	-	10	82	0.4	0.12	1.1
	92 ShoreA	0.5	1.0				16	154	0.4	0.06	1
	98 ShoreA	0.9	1.8				25	296	0.4	0.04	0.9
7	80 ShoreA	0.7	1.4	35000	26000	-	26	114	0.6	0.15	1.1
	92 ShoreA	1.2	2.4				43	219	0.6	0.1	1
	98 ShoreA	2.0	4.0				69	421	0.6	0.06	0.9
	64 ShoreD	2.4	4.8				103	630	0.6	0.04	0.8
9	80 ShoreA	1.8	3.6	24000	18000	-	52	125	0.8	0.19	1.1
	92 ShoreA	3.0	6				95	262	0.8	0.13	1
	98 ShoreA	5.0	10				155	518	0.8	0.08	0.9
	64 ShoreD	6.0	12				224	769	0.8	0.05	0.8
14	80 ShoreA	4.0	8	16000	12000	25000	180	153	1	0.21	1.1
	92 ShoreA	7.5	15				344	335	1	0.15	1
	98 ShoreA	12.5	25				513	655	1	0.09	0.9
	64 ShoreD	16	32				702	855	1	0.06	0.8
19	80 ShoreA	5	10	12000	9500	18500	1030	582	1.2	0.15	1.1
	92 ShoreA	10	20				1720	1125	1.2	0.1	1
	98 ShoreA	17	34				2580	2010	1.2	0.06	0.9
	64 ShoreD	21	42				3720	2950	1.2	0.04	0.8
24	92 ShoreA	35	70	8700	7000	13900	4300	1490	1.4	0.14	1
	98 ShoreA	60	120				6190	2550	1.4	0.1	0.9
	64 ShoreD	75	150				8930	3695	1.4	0.07	0.8
28	92 ShoreA	95	190	7400	6000	11800	6880	1785	1.5	0.15	1
	98 ShoreA	160	320				10310	3210	1.5	0.11	0.9
	64 ShoreD	200	400				13050	4350	1.5	0.08	0.8
38	92 ShoreA	190	380	6000	4700	9600	13750	2350	1.8	0.17	1
	98 ShoreA	325	650				21490	4410	1.8	0.12	0.9
	64 ShoreD	405	810				31620	6475	1.8	0.09	0.8
42	92 ShoreA	265	530	5000	4000	8000	24300	2440	2	0.19	1
	98 ShoreA	450	900				48000	5575	2	0.14	0.9
	64 ShoreD	560	1120				71700	7280	2	0.1	0.8
48	92 ShoreA	310	620	4600	3500	7100	18055	2590	2.1	0.23	1
	98 ShoreA	525	1050				55925	5950	2.1	0.16	0.9
	64 ShoreD	655	1310				90500	8280	2.1	0.11	0.8

Torsional stiffness and damping

The values stated in the above table apply to a capacity utilization of 50 %, an excitation amplitude of 10 % T_KN with a frequency of 10 Hz and an ambient temperature of 20 °C. The dynamic torsional stiffness is load-dependent and increases in proportion to capacity utilization..

The relative damping coefficient is
ψ = 0.8 for 98, 92 and 80 ShA
ψ = 0.75 for 64 ShD.

T_KOL is the torque which can be transmitted very rarely as maximum torque by the coupling.

Permitted shaft misalignment

The permitted shaft misalignments ΔK_a, ΔK_r und ΔK_w are maximum values and must not occur simultaneously. The following formula can be used to roughly calculate whether combinations of misalignments are permissible:

(ΔK_ract : ΔK_r) + (ΔK_aact : ΔK_a) + (ΔK_wact : ΔK_w) < 1