Brushless DC-Flat Motors Series 4221 ... BXT R

External rotor technology, without housing

Key Features

Nominal voltage:

18 ... 48 V

Rated torque up to:

134 mNm

No-load speed up to:

6070 min⁻¹

Diameter:

42 mm

Length:

21.2 mm

Advantages

External rotor motors with very high torque

Continuous output up to 100 W

Outstanding ratio of torque to weight and size

Flat design for space-critical applications. Length range of 14 to 21 mm.

Matching optical and magnetic encoders, gearheads and controls available

14-pole construction

Variants:

Values at 22° and nominal voltage		Value
Nominal voltage	U_N	18 V
Terminal resistance, phase-phase	R	0.46 Ω
Efficiency, max.	η_max.	88 %
No-load speed	n₀	5670 min⁻¹
No-load current	I₀	0.181 A
Friction torque, static	C₀	2 mNm
Friction torque, dynamic	C_V	5.63 ·10⁻⁴ mNm/min⁻¹
Speed constant	k_n	320 min⁻¹/V
Back-EMF constant	k_E	3.13 mV/min⁻¹
Torque constant	k_M	29.8 mNm/A
Current constant	k_I	0.0335 A/mNm
Slope of n-M curve	Δn/ΔM	4.93 min⁻¹/mNm
Terminal inductance, phase-phase	L	396 µH
Mechanical time constant	τ_m	3.56 ms
Rotor inertia	J	69 gcm²
Angular acceleration	α_max.	169 ·10³rad/s²
Thermal resistance	R_th1/R_th2	3 / 14.5 K/W
Thermal time constant	τ_w1/τ_w2	5 / 630 s
Operating temperature range		-40 ... 100 °C
Winding temperature, max.		125 °C
Mass		127 g
Direction of rotation		electronically reversible
Speed up to	n_max.	10000 min⁻¹
Number of pole pairs		7
Hall sensors		digital
Magnet material		NdFeB

Values at 22° and nominal voltage		Value
Nominal voltage	U_N	24 V
Terminal resistance, phase-phase	R	0.74 Ω
Efficiency, max.	η_max.	87 %
No-load speed	n₀	5960 min⁻¹
No-load current	I₀	0.186 A
Friction torque, static	C₀	2 mNm
Friction torque, dynamic	C_V	5.63 ·10⁻⁴ mNm/min⁻¹
Speed constant	k_n	253 min⁻¹/V
Back-EMF constant	k_E	3.95 mV/min⁻¹
Torque constant	k_M	37.7 mNm/A
Current constant	k_I	0.0265 A/mNm
Slope of n-M curve	Δn/ΔM	4.97 min⁻¹/mNm
Terminal inductance, phase-phase	L	664 µH
Mechanical time constant	τ_m	3.59 ms
Rotor inertia	J	69 gcm²
Angular acceleration	α_max.	177 ·10³rad/s²
Thermal resistance	R_th1/R_th2	3 / 14.5 K/W
Thermal time constant	τ_w1/τ_w2	5 / 630 s
Operating temperature range		-40 ... 100 °C
Winding temperature, max.		125 °C
Mass		127 g
Direction of rotation		electronically reversible
Speed up to	n_max.	10000 min⁻¹
Number of pole pairs		7
Hall sensors		digital
Magnet material		NdFeB

Values at 22° and nominal voltage		Value
Nominal voltage	U_N	48 V
Terminal resistance, phase-phase	R	2.6 Ω
Efficiency, max.	η_max.	88 %
No-load speed	n₀	6070 min⁻¹
No-load current	I₀	0.074 A
Friction torque, static	C₀	2 mNm
Friction torque, dynamic	C_V	5.63 ·10⁻⁴ mNm/min⁻¹
Speed constant	k_n	127 min⁻¹/V
Back-EMF constant	k_E	7.87 mV/min⁻¹
Torque constant	k_M	75.2 mNm/A
Current constant	k_I	0.0133 A/mNm
Slope of n-M curve	Δn/ΔM	4.4 min⁻¹/mNm
Terminal inductance, phase-phase	L	2550 µH
Mechanical time constant	τ_m	3.18 ms
Rotor inertia	J	69 gcm²
Angular acceleration	α_max.	201 ·10³rad/s²
Thermal resistance	R_th1/R_th2	3 / 14.5 K/W
Thermal time constant	τ_w1/τ_w2	5 / 630 s
Operating temperature range		-40 ... 100 °C
Winding temperature, max.		125 °C
Mass		127 g
Direction of rotation		electronically reversible
Speed up to	n_max.	10000 min⁻¹
Number of pole pairs		7
Hall sensors		digital
Magnet material		NdFeB

Values at 22° and nominal voltage		Value
Nominal voltage	U_N	18 V
Terminal resistance, phase-phase	R	0.46 Ω
Efficiency, max.	η_max.	88 %
No-load speed	n₀	5670 min⁻¹
No-load current	I₀	0.181 A
Friction torque, static	C₀	2 mNm
Friction torque, dynamic	C_V	5.63 ·10⁻⁴ mNm/min⁻¹
Speed constant	k_n	320 min⁻¹/V
Back-EMF constant	k_E	3.13 mV/min⁻¹
Torque constant	k_M	29.8 mNm/A
Current constant	k_I	0.0335 A/mNm
Slope of n-M curve	Δn/ΔM	4.93 min⁻¹/mNm
Terminal inductance, phase-phase	L	396 µH
Mechanical time constant	τ_m	3.56 ms
Rotor inertia	J	69 gcm²
Angular acceleration	α_max.	169 ·10³rad/s²
Thermal resistance	R_th1/R_th2	3 / 14.5 K/W
Thermal time constant	τ_w1/τ_w2	5 / 630 s
Operating temperature range		-40 ... 100 °C
Winding temperature, max.		125 °C
Mass		127 g
Direction of rotation		electronically reversible
Speed up to	n_max.	10000 min⁻¹
Number of pole pairs		7
Hall sensors		digital
Magnet material		NdFeB

Values at 22° and nominal voltage		Value
Nominal voltage	U_N	24 V
Terminal resistance, phase-phase	R	0.74 Ω
Efficiency, max.	η_max.	87 %
No-load speed	n₀	5960 min⁻¹
No-load current	I₀	0.186 A
Friction torque, static	C₀	2 mNm
Friction torque, dynamic	C_V	5.63 ·10⁻⁴ mNm/min⁻¹
Speed constant	k_n	253 min⁻¹/V
Back-EMF constant	k_E	3.95 mV/min⁻¹
Torque constant	k_M	37.7 mNm/A
Current constant	k_I	0.0265 A/mNm
Slope of n-M curve	Δn/ΔM	4.97 min⁻¹/mNm
Terminal inductance, phase-phase	L	664 µH
Mechanical time constant	τ_m	3.59 ms
Rotor inertia	J	69 gcm²
Angular acceleration	α_max.	177 ·10³rad/s²
Thermal resistance	R_th1/R_th2	3 / 14.5 K/W
Thermal time constant	τ_w1/τ_w2	5 / 630 s
Operating temperature range		-40 ... 100 °C
Winding temperature, max.		125 °C
Mass		127 g
Direction of rotation		electronically reversible
Speed up to	n_max.	10000 min⁻¹
Number of pole pairs		7
Hall sensors		digital
Magnet material		NdFeB

Values at 22° and nominal voltage		Value
Nominal voltage	U_N	48 V
Terminal resistance, phase-phase	R	2.6 Ω
Efficiency, max.	η_max.	88 %
No-load speed	n₀	6070 min⁻¹
No-load current	I₀	0.074 A
Friction torque, static	C₀	2 mNm
Friction torque, dynamic	C_V	5.63 ·10⁻⁴ mNm/min⁻¹
Speed constant	k_n	127 min⁻¹/V
Back-EMF constant	k_E	7.87 mV/min⁻¹
Torque constant	k_M	75.2 mNm/A
Current constant	k_I	0.0133 A/mNm
Slope of n-M curve	Δn/ΔM	4.4 min⁻¹/mNm
Terminal inductance, phase-phase	L	2550 µH
Mechanical time constant	τ_m	3.18 ms
Rotor inertia	J	69 gcm²
Angular acceleration	α_max.	201 ·10³rad/s²
Thermal resistance	R_th1/R_th2	3 / 14.5 K/W
Thermal time constant	τ_w1/τ_w2	5 / 630 s
Operating temperature range		-40 ... 100 °C
Winding temperature, max.		125 °C
Mass		127 g
Direction of rotation		electronically reversible
Speed up to	n_max.	10000 min⁻¹
Number of pole pairs		7
Hall sensors		digital
Magnet material		NdFeB

Operating Area

The display shows the range of possible operation points of the drives at a given ambient temperature of 22°C.

The diagram indicates the recommended speed in relation to the available torque at the output shaft.

It includes the assembly on a plastic- as well as on a metal flange (assembly method: IM B 5).

The nominal voltage linear slope describes the maximal achievable operating points at nominal voltage. Any points of operation above this linear slope will require a supply voltage U_mot >U_N.

Characteristic curves of motor

Operating Area

The display shows the range of possible operation points of the drives at a given ambient temperature of 22°C.

The diagram indicates the recommended speed in relation to the available torque at the output shaft.

It includes the assembly on a plastic- as well as on a metal flange (assembly method: IM B 5).

The nominal voltage linear slope describes the maximal achievable operating points at nominal voltage. Any points of operation above this linear slope will require a supply voltage U_mot >U_N.

Characteristic curves of motor

Operating Area

The display shows the range of possible operation points of the drives at a given ambient temperature of 22°C.

The diagram indicates the recommended speed in relation to the available torque at the output shaft.

It includes the assembly on a plastic- as well as on a metal flange (assembly method: IM B 5).

The nominal voltage linear slope describes the maximal achievable operating points at nominal voltage. Any points of operation above this linear slope will require a supply voltage U_mot >U_N.

Characteristic curves of motor