.86” (22mm) Series• High performance slotless brushless motors for military, aerospace, surgical and dental,
tools, and industrial applications•Medium and long lengths available• Vacuum versions available, also available with gearboxes, encoders and temperature
sensors (sensorless only).
• Cog free design ideal for precision motion• 2 and 4 pole designs•hollow shaft versions available• Autoclavable versions for surgical/dental applications• Highest power density• High temperature ML (240°C) insulation, hardened and ground stainless shafts, TFE
insulated lead wires. Ceramic hybrid bearings available• Available with hall sensors, sensorless, and integral electronics•Speeds up 200,000 rpm• Up to 89% efficiency
8/3/23 Specifications subject to change without notice•Up to 50,000 rpm.86" (22mm) Slotless Brushless DC motor
Long length 24v windings•Rated power up to 50 watts•2 poleInterchanges with imported slotless brushless motors but with shorter length and lighter weight.
High efficiency, speed and power. Slotless design is cog free, cost effective, and provides highefficiency and cool operation. Available with optical encoders and gearheads. 150°C rated
Neo rare earth magnets standard. ML (240°C) insulation is standard for highest reliability.
Available with hall sensors for positioning, reversing, or applications involving heavy inertial
loads and sensorless for use with our sensorless controllers, or for use with encoder controlledcommutation. These motors exhibit exceptionally smoothness at low speed when driven by
encoder controlled sinusoidal drives. Custom versions available including custom windingsfor different no load rpm or input voltage. Modified shafts can also be provided. Winding temperature sensors (thermistor)
can be provided on sensorless versions only.

Motor Data

Winding						
882		Ball Bearing type					stainless		
Nominal supply voltage		
volts		24		no load speed			
rpm ±12%
21,168		
speed/torque slope		
rpm/oz-in
618		
Stall torque			oz-in		53		Continuous torque case 60°C/no h.s. oz-in		
14/5.0		
Continuous current case 60°C/no h.s. amps		
9.4/3.2		
Motor constant Km		oz-in/√w
1.68		
Winding resistance		ohm±15%.68		
Peak output			
watts		116		No load current 			amp±50%.15		
Damping factor			oz-in/krpm.007		
Static friction			oz-in		
.08		Velocity constant			
rpm/volt		
882		
Torque constant Kt		
oz-in/amp
1.53		
Stall current			amps		
35		Maximum efficiency		%		87		Winding inductance		
mH		
.15		
Mechanical time constant		
ms		
1.9		
Rotor inerta			
10-4oz-in-sec2.468		
Thermal res. winding to case
°C/W		
1		
Thermal case to ambient		
°C/W		
8		
Weight 3.4 oz Maximum winding temperature 150°C(hall and magnet temp limited), ambient -73 to 125C
values based on winding andmagnet temperature of 20°C
Winding resistance does notinclude lead resistance of.052Ω. Leads are TFE 12"
minimum 24 gauge
1.984
Ø .864phase and 28
gauge hall.
Maximum axial bearing force 20 lb

699		
stainless		
24		
16,776		
610		
42		
14/5.2		
7.4/2.7		
1.68		
1.09		
75		.10		.007		
.08		699		1.93		
22		
87		
.23		
1.9		
.468		
1		
8		

555		
stainless		
24		
13,320		570		
34		
14/5.5		
5.9/2.3		
1.68		
1.72		
52		.08		.008		
.08		555		2.43		
14		
86		
.38		
1.9		
.468		
1		8		.1179±.0001 (3MM).394

M2 x .100 ON .669
(17MM) BASE CIRCLE

.037
.439

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22L H 700 A / A3 / P4

440		
stainless		
24		
10,560		
545		
27		
14/5.5		
4.7/1.8		
1.68		
2.73		
37		.05		.008		
.08		440		3.07		
8.8		
85		
.60		
1.9		
.468		
1		8		349
stainless
24
8,376
530
21.3
14/5.4
3.7/1.4
1.68
4.34
24
.04
.008
.08
349
3.87
5.5
84
.96
1.9
.468
1
8

Leads
Blue
Phase A
White
Phase B
Brown Phase CRed+5 volts
Black
GroundYellow Sensor A
Orange Sensor B
Green
Sensor C

Gearhead P4=3.7:1, P25=25.01:1, P93=92.70
Motor dia.								Encoder A3=360 lines, A2=256 lines
Type S=sensorless H=120°halls		
Modifications A=none V=Vacuum T=temperature sensor
Winding number					Test Data
Total System Performance
22LH882A with H24V10A Controller at 24 volts

Rpm

Torque Oz-in

Watts Out

Efficiency %

Amps

20530

0.00

0.00

0.0

0.17

18866

2.50

35.06

76.5

1.91

17985

4.12

54.89

79.7

2.87

16844

6.00

74.80

77.3

4.03

15641

7.98

92.38

73.7

5.22

14057

10.03

104.35

66.8

6.51

12635

12.03

112.49

60.9

7.70

11266

13.90

115.70

54.2

8.90

9589

15.91

112.47

46.4

10.10

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remote voltage senseon the power supply. Winding temperature is held below 40C by running test quickly and/or allowing motor to cool
between tests. Test were conducted at room temperature ambient. Full length untrimmed motor leads were used. Total
system efficiency is a function of motor efficiency, drive efficiency, and wiring losses.

Test Data
Total System Performance
22LH882A with H24V10A Controller at 12 volts

Rpm

Torque Oz-in

Watts Out

Efficiency %

Amps

10250

0.00

0.00

0.0

0.13

9589

1.03

7.29

69.0

0.88

9075

2.05

13.77

77.0

1.49

8539

3.09

19.59

76.6

2.13

8068

4.03

24.08

74.6

2.69

7524

5.01

27.87

70.4

3.30

7051

5.93

30.94

66.6

3.87

6363

6.98

32.84

60.4

4.53

5919

7.95

34.82

57.0

5.09

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remote voltage senseon the power supply. Winding temperature is held below 40C by running test quickly and/or allowing motor to cool
between tests. Test were conducted at room temperature ambient. Full length untrimmed motor leads were used. Total
system efficiency is a function of motor efficiency, drive efficiency, and wiring losses.

•Up to 46,700 rpm.86" (22mm) Slotless Brushless DC motor
long length 32 and 48v windings•Rated power 50 watts•2 poleInterchanges with imported slotless brushless motors but with shorter length and lighter weight.
High efficiency, speed and power. Slotless design is cog free, cost effective, and provides highefficiency and cool operation. Available with optical encoders and gearheads. 150°C rated
Neo rare earth magnets standard. ML (240°C) insulation is standard for highest reliability.
Available with hall sensors for positioning, reversing, or applications involving heavy inertial
loads and sensorless for use with our sensorless controllers, or for use with encoder controlledcommutation. These motors exhibit exceptionally smoothness at low speed when driven by
encoder controlled sinusoidal drives. Custom versions available including custom windingsfor different no load rpm or input voltage. Modified shafts can also be provided. Winding temperature sensors (thermistor)
can be provided on sensorless versions only.

Motor Data

Winding						
700		Ball Bearing type					stainless		
Nominal supply voltage		
volts		32		no load speed			
rpm ±12%22,400		
speed/torque slope		
rpm/oz-in
620		
Stall torque			oz-in		56		Continuous torque case 20°C/no h.s. oz-in		
17/5.0		
Continuous current case 20°C/no h.s. amps		
8.8/2.6		
Motor constant Km		oz-in/√w
1.68		
Winding resistance		ohm±15%1.09		
Peak output			
watts		128		No load current 			amp±50%.11		
Damping factor			oz-in/krpm.007		
Static friction			oz-in		
.08		Velocity constant			
rpm/volt		
700		
Torque constant Kt		
oz-in/amp
1.93		
Stall current			amps		
29		Maximum efficiency		%		87		Winding inductance		
mH		
.23		
Mechanical time constant		
ms		
1.9		
Rotor inerta			
10-4oz-in-sec2.468		
Thermal res. winding to case
°C/W		
1		
Thermal case to ambient		
°C/W		
8		
Weight 3.4 oz Maximum winding temperature 150°C(hall and magnet temp limited), ambient -73 to 125C
values based on winding andmagnet temperature of 20°C
Winding resistance does notinclude lead resistance of.052Ω. Leads are TFE 12"
minimum 24 gauge
1.984
Ø .864phase and 28
gauge hall.
Maximum axial bearing force 20 lb

1459		
stainless		
32		
46,700		680		
95		
14/3.7		
16/4.0		
1.65		
.31		
540		
.38		
.007		
.08		
1459		
.92		
103		
88		
.05		
1.9		
.468		
1		
8		

701		
stainless		
48		
33,648		650		
84		
10.8/2.7		
8.7/2.2		
1.68		
1.09		
270		.17		.007		
.08		701		
1.25		
44		
88		
.23		
1.9		
.468		
1		8		.1179±.0001 (3MM).394

M2 x .100 ON .669
(17MM) BASE CIRCLE

.037
.439

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22L H 700 A / A1 / P4883
stainless48
42,396670
107
16.8/4.4
11.0/2.9
1.68
.68
445
.24
.007
.08
883
1.53
70
89
.15
1.9
.468
1
8
Leads
Blue
Phase A
White
Phase B
Brown Phase CRed+5 volts
Black
GroundYellow Sensor A
Orange Sensor B
Green
Sensor C

Gearhead P4=3.7:1, P25=25.01:1, P93=92.70
Motor dia.								Encoder A2=256 lines
Type S=sensorless H=120°halls		
Modifications A=none V=Vacuum T=temperature sensor
Winding number					.86" (22mm) Slotless Brushless DC motor.
• Medium speed series •Up to 61,500 rpm •Rated power to 16 watts •2 pole •12 or 15 volts
Slotless design is cog free, cost effective, and provides high efficiency and cool operation.
Available with optical encoders and gearheads. 150°C rated Neo rare earth magnets standard.
ML (240°C) insulation is standard for highest reliability. Available with hall sensors for
positioning, reversing, or applications involving heavy inertial loads and sensorless for use
with our sensorless controllers, or for use with encoder controlled commutation. These motors
exhibit exceptionally smoothness when driven by encoder controlled sinusoidal drives. Custom
versions available including custom windings for different no load rpm or input voltage. Modified shafts can also be provided.
Winding temperature sensors (thermistor) can be provided on sensorless versions only.

Motor Data

Winding						1866		
5107		
933		1867			Ball Bearing type					stainless		
stainless		
stainless		
stainless			
Nominal supply voltage		
volts		
12		
12		
15		
15		
no load speed			
rpm ±12%22,400		
61,500		
14,000		
28,000		
speed/torque slope		
rpm/oz-in
2,470		1,868		2,292		2,535			Stall torque			oz-in		10.0		
47.0		
6.51		
12.5		
Continuous torque case 20°C/no h.s. oz-in		
2.7/.9		
2.1/0		2.8/1.4		
2.7/.9		
Continuous current case 20°C/no h.s. amps		
4.0/1.4		
8.2/-		2.0/1.4		
3.8/1.5		
Motor constant Km		oz-in/√w.80		
1.03		
.79		.83		Winding resistance		ohm±15%.80		
.066		
3.2		.80		
Peak output			
watts		
41		
420		
16		
64		
No load current 			amp±50%.19		
.70		
.066		
.23		Damping factor			oz-in/krpm.005		
.0026		
.005		
.005		
Static friction			oz-in		
.024		
.024		
.024		
.024		
Velocity constant			
rpm/volt		1866		
5,107		933		1,867		Torque constant Kt		
oz-in/amp.715		
.264		
1.43		
.715		
Stall current			amps		
14.1		
181		
4.57		
17.6		
Maximum efficiency		
%		
78		
88		
77		
78		
Winding inductance		
mH		
.08		
.01		
.31		
.08		
Mechanical time constant		
ms		
6		
5		
6		
6		
Rotor inerta			
10-4oz-in-sec2.280		
.280		
.280		
.280		
Thermal res. winding to case
°C/W		
5		
5		
5		
5		
Thermal case to ambient		
°C/W		
12		
12		
12		
12		
Weight 1.8 oz Maximum winding temperature 150°C.1246±.0001(3MM .1179±.0001 OPTIONAL)(magnet temp limited), ambient -73 to 125C
.669
values based on winding andLeads
magnet temperature of 20°C
V
Blue
Phase AV
M2 TAP
Winding resistance does not
White
Phase B<
.100 DEEP (3)^ ^Brown Phase C
include lead resistance ofRed+5 volts.052Ω. Leads are TFE 12"
Black
Ground> .275<1.291
120.0°
minimum 24 gauge
Yellow
Sensor A
phase and 28.864.039 ><
Orange Sensor B
gauge hall.
Green
Sensor C> .439<Maximum axial bearing force 20 lb

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22 H 100 A / A3 / S11

Gearhead S11=11.0:1
Motor dia.								Encoder A3=360 lines, A2=256 lines
Type S=sensorless H=120°halls		
Modifications A=none T=temperature sensor E=3mm shaft H=hollow
Winding number			
shaft (.085±.002 hole) S=sealed bearings, V= vacuum compatible

		.86" (22mm) Slotless Brushless DC motor.
• Medium speed series •Up to 28,800 rpm •Rated power to 17 watts •2 pole •24 volts
Slotless design is cog free, cost effective, and provides high efficiency and cool operation.
Available with optical encoders and gearheads. 150°C rated Neo rare earth magnets standard.
ML (240°C) insulation is standard for highest reliability. Available with hall sensors for
positioning, reversing, or applications involving heavy inertial loads and sensorless for use
with our sensorless controllers, or for use with encoder controlled commutation. These motors
exhibit exceptionally smoothness when driven by encoder controlled sinusoidal drives. Custom
versions available including custom windings for different no load rpm or input voltage. Modified shafts can also be provided.
Winding temperature sensors (thermistor) can be provided on sensorless versions only.

Motor Data

Winding						
675		
1200
Ball Bearing type					stainless		
stainless
Nominal supply voltage		
volts		24		24no load speed			
rpm ±12%
16,200		
28,800speed/torque slope		
rpm/oz-in
1,962		2535Stall torque			oz-in		9.12		
17.6
Continuous torque case 20°C/no h.s. oz-in		
3.0/1.2		
2.7/.9Continuous current case 20°C/no h.s. amps		
1.5/.66		
2.5/.92
Motor constant Km		oz-in/√w.87		
1.07
Winding resistance		ohm±15%5.2		
1.11
Peak output			
watts		27		72No load current 			amp±50%.056		
.12
Damping factor			oz-in/krpm.005		
.004
Static friction			oz-in		
.024		
.024
Velocity constant			
rpm/volt		
675		
1200
Torque constant Kt		
oz-in/amp
1.98		
1.13
Stall current			amps		
4.62		
21.6
Maximum efficiency		
%		
80		
86
Winding inductance		
mH		
.67		
.22
Mechanical time constant		
ms		
5		
5
Rotor inerta			
10-4oz-in-sec2.280		
.280
Thermal res. winding to case
°C/W		
5		
5
Thermal case to ambient		
°C/W		
12		
12
Weight 1.8 oz Maximum winding temperature 150°C.1246±.0001(3MM .1179±.0001 OPTIONAL)(magnet temp limited), ambient -73 to 125C
.669
values based on winding andmagnet temperature of 20°C
V
V
M2 TAP
Winding resistance does not<.100 DEEP (3)^ ^include lead resistance of.052Ω. Leads are TFE 12"> .275<1.291
120.0°
minimum 24 gauge
phase and 28.864.039 ><
gauge hall.
> .439<Maximum axial bearing force 20 lb

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22 H 1200 A / A2 / S11

Leads
Blue
Phase A
White
Phase B
Brown Phase CRed+5 volts
Black
GroundYellow Sensor A
Orange Sensor B
Green
Sensor C

Gearhead S11=11.0:1
Motor dia.								Encoder A3=360 lines, A2=256 lines
Type S=sensorless H=120°halls		
Modifications A=none T=temperature sensor E=3mm shaft H=hollow
shaft (.085±.002 hole) S=sealed bearings, V= vacuum compatible
Winding number					.86" (22mm) Slotless Brushless DC motor.
•High speed series •Up to 200,000 rpm •Sensorless •Rated power 32 watts •2 pole •24volts
Use where size or weight considerations do not allow use of the larger 48mm high speed motor. Slotlessdesign is cog free, and provides high efficiency. High speed ceramic hybrid bearings for longest life.
Intermittent duty up to 200,000 rpm and continuous operation up to 126,000 rpm with light load. The V(vacuum compatable option) is constructed using all non outgassing materials suitable for vacuum use.
Water or refrigerant cooling is required for continuous vacuum operation since there is no cooling by ambient air. A winding temperature sensor is available. The motor features a hardened stainless shaft, Teflon
insulated lead wires, 240°C magnet wire, precison balance, anodized machined aluminum housing. Special
modifications are possible such as hollow shafts, custom shaft lengths, and custom windings. For 8333, 5284
and 6785 use S24V12A or S24V5A-4G drives. These motors can be used for autoclavable applications as long as an autoclave bag is used.

Motor Data

Winding							Nominal supply voltage			
volts		no load speed				rpm ±12%speed/torque slope			
rpm/oz-in
Continuous torque no heat sink 		oz-in		Continuous current no heat sink		
amps		
Maximum cont. power no heat sink		
watts		Motor constant Km			oz-in/√w
Winding resistance			
ohm±15%Torque at 5 amps				oz-in		No load current 				amp±50%Damping factor				oz-in/krpm
Static friction				oz-in		Velocity constant				
rpm/volt		Torque constant Kt			
oz-in/amp
Maximum efficiency			%		Winding inductance			mH		
Rotor inerta				10-4oz-in-sec2
Thermal res. winding to case		°C/W		
Thermal case to ambient			
°C/W		

8333		
24		200,000		
15,990		
-		
-		
.30		
.30		
.7		
.40		
.00026		
.012		
8,333		
.162		
86		.011		
.111		
5		12		6785		
24		
162,840		
13,560		
-		
-		
-		
.32		
.37		
.9		
.29		
.00028		
.012		
6,785		
.199		
87		.017		
.111		
5		12		5284				24			126,818		
10,562			
.34		
2.5		
28		
.33			
.62			
1.2			
.21			
.00032		
.012		
5284		
.255			86		.027			
.111		
5		
12		

Weight 1.6 oz. Maximum winding temperature 150°C (magnet temp limited), ambient -73 to 125C, Values based on winding and magnet
temperature of 20°C. Winding resistance does not include lead resistance of.052Ω. Leads are TFE 12" minimum 24 gauge phase and28 gauge hall. Maximum axial bearing force 20 lb.
.1246±.0001
V

V

^

^
.864

<

1.291

<

> .275120.0°.039 ><<>.439

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22 S 8333 A S11
Motor dia.
Type S=sensorless
Winding number				.669 (17mm)

Gearhead S11=11.0:1

M2 TAP.100 DEEP (3)

Leads
Blue
Phase A
White
Phase B
Brown Phase CRed+5 volts
Black
GroundYellow Sensor A
Orange Sensor B
Green
Sensor C

Modifications A=none, V=vacuum compatible, T=thermistor
H=hollow shaft (.085±.002 hole).86" (22mm) Slotless Brushless DC motor.
• High speed series •Up to 81,408 rpm •Rated power up to 33 watts •2 pole •24 volts
Slotless design is cog free, cost effective, and provides high efficiency and cool operation.
150°C rated Neo rare earth magnets standard. ML (240°C) insulation is standard for highest
reliability. Available with hall sensors for positioning, reversing, or applications involving heavy
inertial loads and sensorless for use with our sensorless controllers, or for use with encoder
controlled commutation. These motors exhibit exceptionally smoothness when driven by
encoder controlled sinusoidal drives. Custom versions available including custom windingsfor different no load rpm or input voltage. Modified shafts can also be provided. Winding temperature sensors (thermistor)
can be provided on sensorless versions only. If encoders or gearboxes are added then the maximum rpm will be restricted
to the limits of that device.

Motor Data

Winding						1680		
2668		
3392
Ball Bearing type					stainless		
ceramic		
ceramic
Nominal supply voltage		
volts		
24		
24		
24
no load speed			
rpm ±12%40,320		
64,030		
81,408speed/torque slope		
rpm/oz-in
5,613		11,403		
7,981
Stall torque			oz-in		10.9		
11.8		
6.3
Cont. torque case 60°C/no h.s. 20C oz-in		
1.2/1.1		
.7/.6		
.63/.60
Cont. current case 60°C/no h.s. 20C amps		
1.6/1.4		
1.3/1.2		
1.7/1.5
Motor constant Km		oz-in/√w
.51		
.51		
.33
Winding resistance		ohm±15%2.2		
1.00		
1.5
Peak output			
watts		
48		
111		
153
No load current 			amp±50%
.05		
.11		
.10
Damping factor			oz-in/krpm.0006		
.0005		
.00032
Static friction			oz-in		
.012		
.012		
.012
Velocity constant			
rpm/volt		
1680		
2,668		3392Torque constant Kt		
oz-in/amp.80		.506		
.398
Stall current			amps		
10.90		24.0		
16.0
Maximum efficiency		
%		
80		
87		
85
Winding inductance		
mH		
.24		
.12		
.068
Mechanical time constant		
ms		
6		
6		
6
Rotor inerta			
10-4oz-in-sec2.111		
.111		
.111
Thermal res. winding to case
°C/W		
5		5		
5Thermal case to ambient		
°C/W		
12		12		
12Weight 1.8 oz Maximum winding temperature 150°C.1246±.0001(3MM .1179±.0001 OPTIONAL)(magnet temp limited), ambient -73 to 125C
.669
values based on winding andmagnet temperature of 20°C
V
V
M2 TAP
Winding resistance does not<.100 DEEP (3)^ ^include lead resistance of.052Ω. Leads are TFE 12"
minimum 24 gauge> .275<1.291
120.0°
phase and 28.864.039 ><
gauge hall.
> .439<Maximum axial bearing force 20 lb

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22 S 2668 A
A1
S11

Leads
Blue
Phase A
White
Phase B
Brown Phase CRed+5 volts
Black
GroundYellow Sensor A
Orange Sensor B
Green
Sensor C

Gearhead S11=11.0:1
Motor dia.								Encoder A3=360 lines, A2=256 lines
Type S=sensorless H=120°halls		
Modifications A=none T=temperature sensor E=3mm shaft H=hollow
Winding number			
shaft (.085±.002 hole) S=sealed bearings, V=vacuum compatible		Test Data
Total System Performance
22S3392A with S24V5A Controller at 24 volts
Rpm

Torque Oz-in

Watts Out

Efficiency %

Amps

80410

0.00

0.00

0.0

0.11

78848

0.13

7.71

61.3

0.50

77308

0.33

18.94

79.0

1.00

75570

0.55

30.66

85.1

1.50

74569

0.75

40.95

85.2

2.00

72798

0.97

52.04

86.7

2.50

71093

1.17

62.67

87.0

3.00

69278

1.39

73.78

87.9

3.50

67738

1.59

81.47

84.8

4.00

66429

1.80

88.17

81.7

4.50

64449

2.00

94.55

78.8

5.00

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remotevoltage sense on the power supply. Winding temperature is held below 40C by running test quickly and/or
allowing motor to cool between tests. Test were conducted at room temperature ambient.

Test Data
Total System Performance
22S3392A-S11 with S24V5A Controller at 24 volts

Rpm

Torque Oz-in

Watts Out

Efficiency %

Amps

7310

0.00

0.00

0.0

0.20

7168

1.39

7.35

61.3

0.50

7028

3.48

18.04

75.2

1.00

6870

5.77

29.20

81.1

1.50

6779

7.84

39.00

81.2

2.00

6618

10.13

49.56

82.6

2.50

6463

12.22

59.69

82.9

3.00

6298

14.54

70.27

83.7

3.50

6158

16.65

77.59

80.8

4.00

6039

18.87

83.97

77.8

4.50

5859

20.96

90.05

75.0

5.00

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remotevoltage sense on the power supply. Winding temperature is held below 40C by running test quickly and/or
allowing motor to cool between tests. Test were conducted at room temperature ambient.

.86" (22mm) Slotless Brushless DC motor.
•Autoclavable series•Maximum rpm 120,000 •Peak output 122 watts •2 pole

Autoclavable high speed motor design for use in surgical or dental tools or severe environments. While the other motors in this catalog can be used for autoclavable applications
as long as an a sealed autoclave bag is used, these motor can be exposed to live steam andwithstand a thousand or more cycle. These motors can also operate in wet hydrogen. These
motors feature a Samarium Cobalt magnet, ceramic hybrid ball bearings with Torlon® retainers, polyimide insulation (ML (240°C) wire, Kapton® ground) Teflon® insulated leads,
and anodized aluminum housing. Slotless design provides cool operation at high speed
and high efficiency. Sensorless S24V5A drives can be used up to 183,000 rpm and provide the coolest most efficient operation, however they are not suitable for starting very high inertia loads. H24V5Adrives
are suitable for operation up to 60,000 rpm with brief operation up to 80,000 rpm and will start high inertia loads. Operating ambient temperature range is -73 to 150°C (limited by hall sensors) Sensorless versions can operate up to 160°C

Motor Data

Winding							2669			Ball Bearing type						ceramic			
Nominal supply voltage			
volts		15			no load speed				rpm ±12%40,000			
speed/torque slope			
rpm/oz-in
7,026			Stall torque (theoretical)			
oz-in		7.59			Continuous torque case 20°C/no h.s.
oz-in		1.4/.7			
Continuous current case 20°C/no h.s.
amps		
4.0/1.4			
Motor constant Km			oz-in/√w.50			
Winding resistance			
ohm±15%1.00			Peak output				watts		48			No load current 				amp±50%.07			
Damping factor				oz-in/krpm.0006			Static friction				oz-in		
.012			Velocity constant				
rpm/volt		
2,669			Torque constant Kt			
oz-in/amp.506			Stall current				amps		
15.0			Maximum efficiency			
%		
84			
Winding inductance			mH		
.12			
Mechanical time constant			
ms		
10			
Rotor inerta				10-4oz-in-sec2.111			Thermal res. winding to case		°C/W		
5			
Thermal case to ambient			
°C/W		
12			
Weight 1.6 oz. Maximum winding.1246±.0001
temperature 200°C ambient -73 to 125C
values based on winding andmagnet temperature of 20°C
V
V
Winding resistance does not^^include lead resistance of.052Ω. Leads are TFE 12"> .275<
1.291
minimum 24 gauge
phase and 28.864.039 ><
gauge hall.
> .439<Maximum axial bearing force 20 lb.

5333			ceramic			
15			
80,000			
10,600			
15.1			1.8/.6			
7.3/2.7			
.50			
.25			
96			.24			
.0004			.012			5333			
.253			60.0			86			.03			
10			.111			5			12			.669 (17mm)<

M2 TAP.100 DEEP (3)120.0°

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22 S 2669 C S11
Motor dia.
Type S=sensorless H=120°halls		
Winding number					Gearhead S11=11.0:1

C=Autoclavable H=hollow shaft (.085±.002 hole)

10000
ceramic
12
120,000
21,60013.6
1.3/.410.4/3.2
.39
.12
122
.35
.0003
.012
9,999
.136
100
88
.008
12
.111
5
12
Leads
Blue
Phase A
White
Phase B
Brown Phase CRed+5 volts
Black
GroundYellow Sensor A
Orange Sensor B
Green
Sensor C

.86" (22mm) Slotless Brushless DC motor.
•Low speed windings•Maximum rpm 9,220 rpm •Rated power 8 watts •2 pole

Slotless design is cog free, cost effective, and provides high efficiency and cool
operation at high speed. ML (240°C) insulation for highest reliability. 150°C rated Neorare earth magnets standard. Available with hall sensors, sensorless or with integral
16 volt maximum, 1 amp electronics. Winding temperature sensors (thermistors) areavailable on sensorless models only. Hall sensors are recommended for positioning andreversing applications and sensorless motors for pump, blowers and beam choppers
applications in conjuction with our sensorless controllers, or for use with encoder controlled commutation. Integral
electronics is suitable for 6-12 volt applications with low torque such as filter wheels and small pumps or blowers.
These motors are suitable for use with sine drives (also known as brushless AC) and exhibit exceptionallysmoothness when driven by encoder controlled sinusoidal drives. Custom windings and shafts can be provided.

Motor Data								Winding						Ball Bearing type					Nominal supply voltage		
volts		no load speed			
rpm ±12%speed/torque slope		
rpm/oz-in
Stall torque			oz-in		Continuous torque case 20°C/no h.s. oz-in		Motor constant Km		oz-in/√w
Winding Resistance		ohm±15%
Peak output			
watts		No load current 			amp±50%Damping factor			oz-in/krpm
Static friction			oz-in		Velocity constant			
rpm/volt		Torque constant Kt		
oz-in/amp
Stall current			amps		
Maximum efficiency		%		Winding inductance		mH		
Mechanical time constant		
ms		
Rotor inerta			
10-4oz-in-sec2
Thermal res. winding to case
°C/W		
Thermal case to ambient		
°C/W		

221		
stainless		
12		
2,660		1,727		1.54		
1.5/1.5		
.89		
46.6		
.7		.010		
.010		
.034		
221		
6.08		
.26		
65		
6		
5		
.280		
5		
12		

383		
stainless		
12		
4,596		1,760		2.71		
2.7/2.0		
.89		
15.7		
2.1		.020		
.008		
.034		
383		3.52		
.76		
70		
3		
5		
.280		
5		
12		

674		
stainless		
12		
8,100		1,830		4.56		
3.5/1.9		
.87		
5.2		
6.0		
.037		
.006		
.024		
674		
1.98		
2.31		
76		5		5		.280		
5		
12		

222		
stainless		
24		
5,320		1,790		3.09		
3.6/2.0		
.89		
46.6		
1.4		.013		
.008		
.034		
222		6.08		
.52		
71		
6		
5		
.280		
5		
12		

Weight 1.8 oz. Maximum winding.1246±.0001(3MM .1179±.0001 OPTIONAL)
temperature 150°C (magnet temp limited), ambient -73 to 125C
.669 (17mm)
values based on winding andmagnet temperature of 20°C
V
V
M2 TAP
Winding resistance does not<^.100 DEEP (3)^include lead resistance of.052Ω. Leads are TFE 12"> .275<1.291
120.0°
minimum 24 gauge
phase and 28.864.039 ><
gauge hall.
> .439<Maximum axial bearing force 20 lb.

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22 H 384 A / A3 / P25
Motor dia.
Type S=sensorless H=120°halls
D=integral electronics		

			Winding number		384
stainless
24
9,220
1,871
5.42
3.6/1.9
.89
15.5
9.0
.026
.006
.034
384
3.50
1.55
76
3
5
.280
5
12

Leads
Blue
Phase A
White
Phase B
Brown Phase CRed+5 volts
Black
GroundYellow Sensor A
Orange Sensor B
Green
Sensor C

Gearhead P4=3.7:1, S11=11.0:1,
P25=25.01:1, P93=92.70
Encoder A3=360 lines, A2=256 lines
Modifications A=none E=3mm shaft T=temp sensor
H=hollow shaft (.085±.002 hole) S=sealed bearings, V= vacuumTest Data
Total System Performance
22H384A with H24V5A Controller at 24 volts
Rpm

Torque Oz-in

Watts Out

Efficiency %

Amps

9520

0.00

0.00

0.00

0.06

8377

1.00

6.14

75.20

0.34

7942

1.25

7.34

72.80

0.42

7530

1.50

8.36

69.70

0.50

6999

1.79

9.29

66.73

0.58

6579

2.07

10.10

62.80

0.67

5718

2.54

10.75

54.62

0.82

5040

2.95

10.78

47.80

0.94

3940

3.45

10.07

38.10

1.10

2927

3.95

8.74

29.13

1.25

1710

4.50

5.67

16.30

1.45

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remotevoltage sense on the power supply. Winding temperature is held below 40C by running test quickly and/or
allowing motor to cool between tests. Test were conducted at room temperature ambient.

.86" (22mm) Slotless Brushless DC motor.
•4 pole•Maximum rpm 17,640 rpm •Rated power 33 watts

4 pole design doubles resolution of hall sensor velocity feedback compared to 2 poledesigns and increases power and efficiency. Slotless design is cog free, cost effective,
and provides high efficiency. ML (240°C) insulation for highest reliability. 150°C rated
Neo rare earth magnets standard. Available with hall sensors, sensorless or with integral 16 volt maximum, 1 amp electronics. Hall sensors are recomended for positioning
and reversing applications and sensorless for use with our sensorless controllers, orfor use with encoder controlled commutation. Integral electronics is suitable for 6-12
volt in applications with low torque such as filter wheels and small pumps or blowers.
These motors are suitable for use with sine drives and exhibit exceptionally smoothness when driven by encoder
controlled sinusoidal drives. Custom versions including, hollow shafts, frameless, can be provided. Application
include accuators, minature servo systems, filter wheels, medical pumps, and blowers

Motor Data

Winding						
331		
477		
735
Ball Bearing type					stainless		
stainless		
stainless
Nominal supply voltage		
volts		
24		
24		
24
no load speed			
rpm ±12%
7,944		11,448		
17,640speed/torque slope		
rpm/oz-in
800		
950		
838
Stall torque			oz-in		13.2		
18.3		
28.5
Continuous torque case 20°C/no h.s. oz-in		
5.8/2.9		
5.8/2.9		
5.7/2.9
Motor constant Km		oz-in/√w
1.60		
1.47		
1.48
Winding Resistance		ohm±15%7.38		
3.71		
1.21
Peak output			
watts		
12		
26		
68
No load current 			amp±50%
.04		
.05		
.09
Damping factor			oz-in/krpm.018		
.009		
.007
Static friction			oz-in		
.034		
.034		
.034
Velocity constant			
rpm/volt		
331		
477		
735
Torque constant Kt		
oz-in/amp
4.08		
2.83		
1.84
Stall current			amps		
3.25		
6.47		
19.9
Maximum efficiency		
%		
79		
83		
87
Winding inductance		
mH		
1.0		
.49		
.22
Mechanical time constant		
ms		
1.5		
1.5		
1.5
Rotor inerta			
10-4oz-in-sec2.240		
.240		
.240
Thermal res. winding to case
°C/W		
5		5		
5Thermal case to ambient		
°C/W		
12		12		
12Weight 1.8 oz. Maximum winding
temperature 150°C (magnet temp limited) ambient temperature -73 to 125C
.1246±.0001(3MM .1179±.0001 OPTIONAL)
values based on winding and.669 (17mm)
magnet temperature of 20°C
V
Winding resistance does not
V
M2 TAP
include lead resistance of<^.100 DEEP (3)^.052Ω. Leads are TFE 12"
minimum 24 gauge> .275<1.291
120.0°
phase and 28
gauge hall.
.864.039 ><
Maximum axial bearing force 20 lb.
> .439
<
			

Leads
Blue
Phase A
White
Phase B
Brown Phase CRed+5 volts
Black
GroundYellow Sensor A
Orange Sensor B
Green
Sensor C

Ordering Information: Please send your order to: mail@koford.com
Example: Part Number 22 H 331 A / A3 / S11 Gearhead P4=3.7:1, S11=11.0:1,
Motor dia.
Type S=sensorless H=120°halls
D=integral electronics		

			Winding number		

P25=25.01:1, P93=92.70
Encoder A3=360 lines, A2=256 lines
Modifications A=none E=3mm shaft T=temp sensor
H=hollow shaft (.085±.002 hole) S=sealed bearings, V=vacuumTest Data
Total System Performance
22H331A with H24V5A Controller at 24 voltsrpm

torque oz-in

watts out

efficiency %

amps

7425

0.00

0.0

0

0.1

6856

0.67

3.4

71

0.2

6585

1.00

4.9

72

0.3

6200

1.50

7.0

73

0.4

5840

2.00

8.6

72

0.5

5430

2.50

9.9

69

0.6

5020

3.00

11.2

58

0.8

4590

3.50

11.8

55

0.9

4070

4.00

12.2

51

1.0

3750

4.50

12.4

47

1.1

3300

5.00

11.3

43

1.2

3010

5.50

12.5

40

1.3

2538

6.10

11.5

32

1.5

2146

6.50

9.3

24

1.6

1560

7.10

8.2

21

1.7

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remote voltage sense on the power
supply. Winding temperature is held below 40C by running test quickly and/or allowing motor to cool between tests. Test were conductedat room temperature ambient.

Test Data
Total System Performance
22H477A with H24V5A Controller at 24 volts
RPM

Torque oz-in

Watts out

Efficiency %

Amps

10986

0.00

0.00

0.0

0.07

10242

0.90

6.80

76.6

0.37

9830

1.54

11.15

81.5

0.57

9471

2.03

14.18

82.0

0.72

9127

2.53

17.10

81.0

0.88

8781

3.00

19.46

79.5

1.02

8437

3.52

21.92

77.4

1.18

8106

4.01

24.00

74.6

1.34

7477

4.90

27.11

69.3

1.63

6772

5.85

29.29

62.3

1.96

6267

6.60

30.62

57.7

2.21

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remote voltage sense on the power
supply. Winding temperature is held below 40C by running test quickly and/or allowing motor to cool between tests. Test were conductedat room temperature ambient.

Test Data
Total System Performance
22S735A with S24V5A Controller at 24 volts
RPM

Torque oz-in

Watts out

Efficiency %Amps

17,640

0

0

0

0.07

16177

1.75

20.91

81.4

1.07

15993

2.00

23.68

82.9

1.19

15773

2.25

26.22

82.1

1.33

15592

2.50

28.69

81.9

1.46

15113

3.02

33.74

81.7

1.72

14207

4.09

43.02

78.9

2.27

13246

5.24

51.35

75.3

2.84

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remote voltage sense on the power
supply. Winding temperature is held below 40C by running test quickly and/or allowing motor to cool between tests. Test were conductedat room temperature ambient.

Test Data
Total System Performance
22S735A-S11 with S24V5A Controller at 24 volts
Rpm

Torque Oz-in

Watts Out

Efficiency %

Amps

1685

0.00

0.00

0.00

0.12

1669

0.43

0.52

10.90

0.20

1569

14.32

16.62

69.30

1.00

1442

30.45

32.50

67.70

2.00

1269

46.02

43.24

60.10

3.00

Dyno test results of a motor and drive combination with voltage held to 24v at input of drive using remote voltage sense on the power
supply. Winding temperature is held below 40C by running test quickly and/or allowing motor to cool between tests. Test were conductedat room temperature ambient.

.82" (21mm) Frameless Slotless
Brushless motor.

Frameless version of the .86” (22mm) housed motor. The standard configuration is witha magnetized two pole rotor and a sensorless stator. Winding numbers listed under “highspeed series” housed 22mm motors are available in the frameless configuration.
The customer should epoxy the supplied rotor magnet to their magnetic shaft (440C or
416 stainless recomended) and then dynamically balance the assembly to tolerances appropiate to their rpm and bearing system. Suitable heat cure epoxies can be found underthe “epoxy” section at Koford.com. The cure temperature should not exceed 150°C. Do
not attempt press fitting as this will damage the magnet.
The part number of a frameless motor is the same as a housed motor except F is added.
For example a 22S9999A becomes a 22FS9999A in the frameless configuration.

.961

.740
.062

.126 ±.001

.296

.315

.819 ±.002

Optical Encoders
A2=256 lines, A3=360 lines. A and B channels in
quadrature. Combined this gives 1024 or 1440 counts
per shaft revolution. Supplied with mating connector
and 12 in leads. Hook up red=5v, blue=channel A,
brown =ground, yellow=channel B. If you wish to
make your own cable use Molex 51021-0400/500798025 . Supply voltage 5±.5V. Max rpm A2=23,437,
A3=16,666. Inertia .07 x10-4oz-in-sec2, Temperature
rating -20 to 100°C.

Spur Gearheads
S11 is a 11.0:1 ratio all ball bearing autoclavable spur gearbox The maximum input speed is 81,000 rpm. The
ambient temperature range is -73°C to 150°C.

S11 13 oz-in continuous, 40 oz-in peak, 85%
eff.
Weight .8 oz
Max backlash 1.5°
Inertia 10-4 oz-in-sec2 = .06

2.308

.080

.537

.568

Ordering Information: Please send your order to: mail@koford.com

M3 TAP (3) ON .709 DIA.
.1572±.0002

Planetary Gearheads
P4,P25, P93 are planetary gearboxes with nitrided alloy steel gears, and double sheilded ball bearings on output.
Input speed for best life is 6,000 rpm or lower. Bearing lube rated for -35C to 140C. Low temp lube rated for-60 to 130C available on special order. Other ratios are available on special order.

3.70:1 L=1.054 127 oz-in peak 85 oz-incont. 90% eff.
25.01:1 L=1.431 149 oz-in peak 99 cont.
80% eff.
92.70:1 L=1.695 168 oz-in peak 112 cont.
70% eff.
Weight 3.70:1=1.4 oz, 25.01:1=2.0 oz,
92.70:1=2.6 oz
Max backlash 3.70:1=1.5°, 25.01:1=2°,
92.70:1=2.5°
Inertia 10-4 oz-in-sec2 = .05

M3 x .138 (3) ON .709 D

.568

.171

Ø

.5512
.5501

.315

.080
"L"

Ordering Information: Please send your order to: mail@koford.com

Ø

.1575
.1570

Thermistor resistance for Koford motors
Temp

Temp

Rt/R25[degreeC][degree F]

Temp Coef Resistance
[%/C]

[ohm]

-50

-58

66.9707.10

334850-45-4947.2506.86236250-40-4033.7406.62168700-35-3124.3706.40

121850-30-2217.800

6.19

89000

-25

-13

13.130

5.99

65650

-20

-4

9.776

5.80

48880

-15

5

7.347

5.63

36735

-10

14

5.570

5.46

27850

-5

23

4.257

5.30

21285

0

32

3.279

5.10

16395

5

41

2.550

4.95

12750

10

50

1.998

4.81

9990

15

59

1.576

4.68

7880

20

68

1.252

4.55

6260

25

77

1.000

4.43

5000

30

86

0.804

4.31

4019

35

95

0.650

4.20

3249

40

104

0.528

4.09

2641

45

113

0.432

3.99

2158

50

122

0.355

3.74

1773

55

131

0.295

3.63

1474

60

140

0.247

3.54

1233

65

149

0.207

3.44

1035

70

158

0.175

3.35

874

75

167

0.148

3.26

741

80

176

0.126

3.18

631

85

185

0.108

3.10

539

90

194

0.092

3.03

462

95

203

0.080

2.95

398

100

212

0.069

2.86

344

105

221

0.060

2.78

299

110

230

0.052

2.70

261

115

239

0.046

2.63

228

120

248

0.040

2.56

200

125

257

0.035

2.50

177

130

266

0.031

2.44

156

135

275

0.028

2.37

138

140

284

0.025

2.31

123

145

293

0.022

2.26

110

150

302

0.020

2.20

98

Unit conversions°F -32 ÷1.8=°C example: 212°F=100°C, °C x1.8+32=°F example: 100°C=212°F,
in x 25.40=mm,
mm x.03937= in.,oz x 28.3495=g, oz-in x 7.06=mNm,
mNm x .142=oz-in,
Nm x 142=oz-in,		
-1
2
rpm x .1047=rad s , V/R/S x .1047=volts/rpm,
746 watts=1hp,
lb-in x .04144=oz-in-sec2
Understanding Data Sheets
When comparing Koford motors to data sheets for other motors be careful to note the conditions associated withthe rated torque listed. For example many manufactures list continuous torque at stall or at rpm less then the
maximum. This specsmanship results in unrealistically high continuous torque ratings for these motors. Attempting to operate these motors continuously at the nominal operating voltage will often result in overheating even if
the motor is unloaded.
Hall Sensors
Hall sensors have the wide speed range, sensorless drives have a much narrower speed range especially at noor low load. If sensorless operation is desired and a wide speed range is required the S24V12A drive should be
used. If quick start up and rapid speed changes are required then hall sensors should be used. Typically hall sensors are used for positioning applications and sensorless motors are used for applications like blower and fans.
Hall Sensor precautions
Like other semiconductor components hall sensors are electrostatic sensitive. Hall motors are supplied inelectrostatic safe packaging and should be kept in the packaging until use. When trimming wire length, adding
connectors, and hooking up motors, workers should be grounded to prevent electrostatic damage to the sensors.
BalancingComponents attached to the motor shaft should be dynamically balanced to G6.3 or better and located as close
to the motor body as possible. This is especially critical over 20,000 rpm. G6.3 is equal to 0.64 x weight (oz.)/
rpm=unbalance in milli oz-in. If the components have appreciable length they must be balance in 2 planes.
Motor technology
The Koford 22mm brushless series of motors are slotless sintered rare earth permanent magnet motors withunique technology. Compared to brush motors they have much longer life (up to 25,000 hours +), much higher
speed capability (200,000+rpm), can operate in a vacuum, and will not introduce contamination from brush dust.
Compared to conventional slotted bonded rare earth magnet with the same no load speed and phase resistance
Koford motors are smaller, lighter, have higher efficiency, higher peak torque (equal to stall torque), and are cog
free. Compared to other slotless motors they have higher speed capabilities, better efficiency, lighter weight andmore durable construction (ML Class 220C wire insulation bonded with solventless Class 205 thermoset resin)compared to the low temp bondable wire used in other slotless motors which will soften and fail under thermal
overload.
Operating speed
Motors can be operated at any lower voltage and also at somewhat higher voltages and speeds then shown on
the data sheet. For example 24 volt motors can be run on 28 volt system. Running a 24 volt motor on a 36 voltssystem is not recommended. Hall drives
Motor selection
Motors for continuous duty applications such as pumps, blowers etc. Should in most cases be selected to operate
at about 10% of stall torque. This point is close to peak efficiency. Keep in mind that the drive used has a great
effect on motor operating temperature. The lowest motor temperature rise will occur with the drive pwm duty
cycle at 100% (maximum speed). Using a higher speed winding then necessary and reducing the speed throughthe drive will result in higher motor and drive operating temperatures then if a winding is selected that will run

as close as possible to full speed. During variable speed operation, when the motor is operating at less then fullspeed, both the motor and drive operating temperature will be influenced by the drive frequency. Drive pwm
frequencies of 37kHz or higher are recommended for best performance. H
For variable speed applications where the motor does not operate continuously, the safest approach is to specify
the motor with the continuous operating torque equal to the maximum load. If the maximum load is not known
then the continuous motor current rating should be more then the current limit of the drive. This will prevent thepossibility of overload. For example if the current rating of the drive is 5 amps, the motor Kt is 3.0 and the noload current is 1.0 amps, continuous torque rating should be more then (5-1.0) x 3.0=12 oz-in. If the duty cycle is
known then the equivalent continuous torque can be estimated. Keep in mind that the resistance losses are a function of the current squared so reducing the duty cycle to fifty percent will only allow the torque to be increased
by 41% not 100%.
When comparing Koford motors to data sheets for other motors be careful to note the conditions associated withthe rated torque listed. For example many manufactures list continuous torque at stall or at 10,000 rpm. Usually
this is because these motors will overheat if run continuously at full speed even with no load.
Selection of Hall, Sensorless, or integral electronics
The most common motor configuration is the hall sensor design. They will operate down to zero speed and haveno start up delay. Sensorless motors have only three leads which can be helpful in applications where the motor
must be hundred or thousands of feet away from the drive. It also makes for a more flexible cable for surgical ordental handpieces. In addition sensorless motors operate with higher efficiency especially at speeds above 60,000rpm. In certain frameless hermetic pump applications hall sensor designs are not possible and sensorless motors
must be used. Integral electronic motors are available in some larger sizes and simplify connection and mounting.
In general integral electronic motors will have a lower power rating for a given motor size.
Linear characteristics
Koford motors exhibit highly linear behavior. This is not the case with slotted motors and even some slotless
motors. A slotted motor with the same rpm and phase resistance may only be capable of less then half of the peaktorque of a Koford motor with the same specifications. The stall torque of Koford motors is equal to the Kt times
the current. However keep in mind that at stall the winding will heat up rapidly increasing the resistance so thefull stall torque may only be available for a fraction of a second. In most cases the current limit of the drive ismuch less then the stall current so this is not an issue.
Speed torque calculations
A motors no load speed is equal to the supply voltage times the velocity constant (rpm/v). Under load the rpm
will drop. To determine the approximate speed, use dyno data if listed, or use the speed torque slope from thedata sheet. For example if the supply voltage is 28 volts and the rpm/volt is 500 then the no load speed will be
14,000 rpm. If the speed torque slope is 800 rpm/oz-in and a 5 oz-in load is applied to the shaft then the speed
will be 14,000-(5 x 800) = 10,000 rpm. If there is extra wiring between the drive and the motor, or the supply andthe drive, then the speed will drop at a more rapid rate due to the voltage drop in the wiring. A design margin of
at least 15% should be used to allow for motor tolerances, so for example with the above motor the rpm can be
expected to be at least 8,500 rpm.
Motor cooling
The continuous output torque which can be achieved from a motor is limited by the allowable maximum temperature. This in turn is determined by the cooling provided by the user, and the ambient temperature. In the case ofsome high speed motors the continuous output torque is shown as zero if the motor does not have heat sinking.
In these cases the motor can only be used in intermittent duty applications unless appropriate heatsinking isused. The data sheet lists continuous torque with a 20°C (68°F) ambient and full rated voltage with 100% duty
cycle and block commutation. Two values are listed, the first with the motor case cooled to 20°C and the second
with no cooling in still air. Most applications will fall somewhere between these two extremes. If the ambient
temperature is above 20°C then the continuous duty torque is reduced. Sensorless motors are available withtemperature sensors and this can be useful during prototyping to evaluate cooling. The actual limitation is therotor (magnet) temperature, but since the windings surround the rotor, the temperature can be assumed to be thesame in most cases. One exception is in pump applications (frameless or housed) if the motor is immersed in refrigerant. In these applications the rotor temperature can be expected to closely follow the fluid temperature. For
applications in air the allowable output torque can be increased by mounting the motor to a thick aluminum platewith surface area several times larger then the surface area of the motor. Further improvements can be obtainedwith the use of a fan directed at the body of the motor. Even higher performance can be obtained by the use ofa refrigerant cooled sleeve around the outside diameter of the motor coupled with heatsink grease. If the motor
housing can be cooled below 20°C then improved performance above data sheet values can be obtained. If only
natural convection is used and the motor is mounted to plastic or a low thermal conductivity material such as
steel then consideration should be given to ensuring free flow of air over the motor. Placing the motor in a small
enclosed space with poor thermal connection to the outside ambient can result in considerable reduction in theamount of output power possible without overheating. When performing temperature rise calculations rememberthat the resistance of the copper windings increases with temperature. You must use the resistance at the operating
temperature not at 20C.
Frameless motors
Frameless motors are useful for certain specialized applications where housed motors cannot be used. These
include air bearing or magnetic bearing motors, and pump applications where the rotor and impeller are part of asingle assembly with the working fluid inside of the motor. All Koford motors can withstand continuous exposure to refrigerants. Frameless motors should be avoided for any application where a housed motor can be used.
The use of water without corrosion inhibitors inside the motor requires special magnets. In many cases sleevebearings are used with water instead of ball bearings so as to prevent corrosion and the possibilities of particles
from jamming the ball bearings. Contact the factory if your application requires a frameless version of one of
the motors listed in the catalog.
Motors for surgical and dental tools
Surgical and dental tool motors typically operate at high speed so high efficiency is important to prevent the toolfrom heating up excessively in the users hand. Sensorless motors are popular for this application due to cooler
operation especially over 60,000 rpm, and since only three wires are required, the cord to the tool can be smaller
and more flexible. However there is approximately a 0.25 seconds of delay in start up with a sensorless motor.
Also the speed range is approximately 35% to 100% of maximum. If these characteristics are not acceptable thena hall sensor motor should be used. If the design of the tool requires the motor to withstand being placed in a sterilizer (autoclave) then an autoclavable motor is recommended. Because high pressure steam is highly corrosive astandard motor will only withstand about 100 autoclave cycles of twenty minutes at temperature. The number ofcycles will increase when the motor is placed in an housing. The greater thermal mass the housing has, the more
the motor is sealed against steam pressure, and the shorter the autoclave cycle used the more cycles that can beobtained. For long life eg. 1000 cycles an autoclavable motor should be used. This is option C which is available on a number of motors. These motors are made with highly corrosion resistant magnet, shaft and laminationmaterials and the polymeric materials are polyimide, Teflon®, or high performance heat cured epoxy.
Vacuum Applications
All Koford motors are suitable for low vacuum applications. For high vacuum applications (option V) contact
the factory. Vacuum grade motors are made with low outgassing material and baked before shipping. A vacuum
bake by the customer immediately prior to use may be desirable to reduce pump down time. An important consideration is that in a vacuum there is no heat removal by air contacting the motor housing. Therefore the mounting

of the motor should be made of highly thermally conductive material, such as copper or aluminum, should be ofas heavy a cross section as possible, and should connect to a large surface exposed to the outside air.
Motor hook up
Koford hall sensor motors typically separate the phase and sensor wires. These wires should be kept apart andaway from other wires. The leads should be trimmed as short as possible to reduce EMI and power losses. Where
electrical noise is a consideration the phase wires may be twisted or braided with each other or enclosed in ashielded jacket. The same can be done with the hall leads to prevent their picking up EMI from noise sources.
EMI
Koford drives and motors have low levels of emi relative to other motors but in sensitive applications the following steps are suggested. First keep the phase wires as short as physically possible and twist or braid them together
and if necessary add a shield jacket terminated at one end. Add a 5,000µF cap at the input to the drive along with acommon mode inductor. Add small inductors to each of the phase wires. If possible vary the input voltage to thedrive rather then using the speed control. Place the drive and motor as close together as possible. Also consider
enclosing the drive or motor and drive in a metal enclosure.
Sine Drives
Koford motors are especially suitable for sine drives due to their exceptionally low harmonic distortion (typicallywell under 1%). Sine drives are useful for very accurate motion around zero speed. At higher speeds e.g. above
3,000 rpm there in not any noticeable difference in noise/vibration/velocity accuracy with sine drives. The useof Sine drives results in lower power output and reduced efficiency compared to standard drives (block commutation) when compared with the same motor.
Permanent Magnet Synchronous motors, DC Brushless motors, AC Permanent Magnet motors
These are all different names for the same type of motor.
System efficiency
The system efficiency is different then the motor efficiency. The system efficiency takes into account motor losses, drive losses, wiring losses, and gearbox losses. The choice of a drive will make a large difference in the total
system efficiency. The data sheet value for maximum motor efficiency is at maximum speed. At less then 100%speed efficiency will be reduced. For example if a motor is operated at 12 volts with the speed control turned allof the way up, the efficiency will be better then if the motor is operated with 24 volts into the drive and the speed
set at 50%. Although the motor speed is the same, there are additional losses in the drive and motor to drop the
24 volts down to 12 volts. The amount of these losses is determined by the drive and motor design. High frequency drives (37 kHz or above) provide slightly better overall efficiency then 18khz drives. Drives with a pwm
frequency below 18kHz are not recommended for slotless motors.
PWM basics
Variable speed drives operate using PWM where the voltage to the motor is rapidly turned on and off. This is
the same as a switching power supply where the motor is the filter. A PWM drive operates like a transformer, forexample if the motor pulls 20 amps at 12 volts and the input to the drive is 36 volts then the input current to thedrive will be 12/36 x 20 or 6.66 amps (neglecting losses). A drive rated at 20 amps will only pull 20 amps fromthe power supply or battery if the speed is turned all of the way up (no PWM).