Stearns Series 320 Catalog Page

Series 320 Armature Actuated Brakes

Maintained manual release option

(Shown with and without maintained manual release)

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• Torque rating 3 to 50 lb-in / (.34 to 5.6 NM)

• UR and CUR Recognized insulation system,

E-125303 and sizes 1.8, 2.8 brakes with internal power supply File E-71115

Class B temperature rise with Class H mag wire

• Available for holding (H) or dynamic (D) stopping applications

• Corrosion resistance

• Optional “double D” friction discs are available in

3-7 lb-in dynamic and 3-15 lb-in holding brakes. DD shafts fit the brake directly without a brake hub, no shaft keyway cost and simplify assembly

• Optional maintained manual release

• Optional mounting plates to make conversion over

to the superior Stearns product easy

• Optional AC Rectifiers - internal or external in-line

• Optional band seal (not available for 1.2 size)

• Installation and Service Instructions: P/N 8-078-889-00

Dimensional Data

Model

Size

1.2D

1.2H

1.8D

1.8H

2.0D

2.0H

2.8D

2.8H

Number

3-20-2401G 3-20-2501G

3-20-4401G 3-20-4501G

3-20-5401G 3-20-5501G

3-20-7401G 3-20-7501G

Qty. B K F F` Long Short

Mounting Screw

Ø.140

#4, (M3)

Ø.177

#6 (M3.5)

Ø.145

#6 (M3)

Ø.188

#8 (M4)

Optional Manual Release Shown

Maximum Shaft Length (Manual

Release Units)

Ø1.545

(39.243)

Ø2.125

(53.975)

Ø2.220

(56.388)

Ø2.844

(72.738)

.300 (7.62)

.430 (10.92)

.490

(12.45)

Hub Location

.685

(17.40)

.860

(21.84)

.995

(25.27)

.933

(23.70)

.954

(24.23)

.015

(.381)

.015

(.381)

.015

(.381)

.050*

(1.27)

Brake

Size

1.2

1.8

E** G

.410

(10.41

.450

(11.43)

.530

(13.46)

1.10

(27.94)

.25 + .05/-.00 .30 + .13/-.00

.890

(22.60)

1.065

(27.05)

1.260

(32.00)

1.190

(30.23)

1.415

(35.94)

.075 max. .075 max.

Long

Hub

1.065

(27.05)

1.240

(31.50)

1.405

(35.69)

1.623

(41.22)

1.364

(34.64)

Shaft

Size

5/16 3/8

H3 H5 J

2.5

(63.5)

3.775

(95.885)

3.775

(95.885)

4.5

(95.885)

.052 .063

.40

(10.16)

.55

(10.16)

.55

(10.16)

.55

(10.16)

.105 /.103 .126 /.124

1.77

(44.96)

2.43

(61.72)

2.50

(63.5)

3.25

(82.55)

.3135 /.3115 .376 /.374

D Hub Lengths

.38

(9.65)

.410

(10.41)

.69

(17.53)

.410

(10.41)

.19

(4.83)

.25

(6.35)

.31

(7.87)

*Size 2.8 can be pressure plate mounted using the long hub. The F` dimension shown for size 2.8 is for pressure plate mount using the long hub. ** No thru bore with manual release option.

1.925

(48.90)

2.55

(64.77)

2.50

(63.50)

3.32

(84.33)

Series 320 Continued

Engineering Specifications

Nominal

Size Part Number

1.2D 3-20-2401G-XX-XX 3 .34 Dynamic .4 .181 7 7.02 x 10



3-20-2501G-XX-XX

1.2H

1.8D 3-20-4401G-XX-XX 7 .79 Dynamic 1.1 .499 10 4.8 x 10



3-20-4501G-XX-XX

1.8H

1.8D 3-20-4601G-XX-XX 15 1.69 Dynamic 1.1 .499 10 4.8 x 10

2.0D 3-20-5401G-XX-XX 18 2.03 Dynamic 1.2 .544 12.5 2.23 x 10



3-20-5501G-XX-XX

2.0H

2.8D 3-20-7401G-XX-XX 35 3.95 Dynamic 2.0 .91 17 2.3 x 10



3-20-7501G-XX-XX

2.8H



For holding applications only. Set Screws located 120° from keyway.

Static

Torque

lb-in Nm Type lbs kg (watts) oz-in-sec



.56

1.69

3.39

5.65

Friction Material

Holding

Approx

Electric

Weight



.4 .181 9 7.02 x 10



1.1 .499 10 4.8 x 10



1.2 .544 12.5 2.23 x 10



2.0 .91 17 2.3 x 10

Power

Hub and

Disc Inertia

Thermal

Capacity

HP-sec/min in mm

-5

Consult Factory

-5

-4

-3

.26

.32

.17

1/2 1/2 1/2

1/2 1/2

Maximum

Bore

3/8 9 3/8 9



1/2 12 1/2 12



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Ordering Information

Character

Size

1.245 4

Size

1.8

9 5 4 5

Size

2.0 6

Size

2.845

Table 1: 320-44010 - -JD

Characters

to insert

0H 0J 05 06 07 08 09 10 11 12

Set screws located 120° from keyway. Hubs are provided without keyway.

*Keyseats made to ANSI B17.1 standard.

Bore

3/16 3/16

1/4

1/4 5/16 5/16

3/8

1/2

5 6 7 8

9 10 11 12

* *

Keyway Size*

Width (in.) x

Depth (in.)

Group “3” Armature Acting Brake.

320 = For AAB-R Models

AAB-R Unit Sizes Part Number

1.2

1.8

2.0

2.8

Nominal Static Torque

(lb-in)

3 Dynamic

5 Holding

7 Dynamic

15 Dynamic

9 Dynamic 15 Holding

18 Dynamic

30 Holding

15 Dynamic

25 Holding 7 Dynamic

35 Dynamic

50 Holding

Bores Available

Mag Body Size

1.8 2.01.2

N/AN/A

1/321/16

N/AN/A

1/321/16

N/AN/A

1/321/16

N/AN/A 3/643/32 1/161/8

1 mm2 mm



1 mm2 mm



1 mm2 mm



1 mm2 mm



1.4 mm3 mm



1.4 mm3 mm

1.8 mm4 mm

2 4 5 7

List

Adder

---

--$20.00 $10.00

---

2.8

320-4401G-0H-JD

Options – Table 3

Voltages – Table 2 Hub bore and Keyway – Table 1

For Double “D” Bores See Table 1A

Numeral

Enclosure type

Characters

to insert

Brake release indicator (NC)

Brake release indicator (NO)

Standard - GGA Friction Material

CCW manual release rotation

Carrier ring friction disc

Numeral or Letter

A-Z

Modification

Options

Standard Unit Reserved for Mounting Plates

0 None 2 Band seal

Table 1A: 320-44010 - -JX (Double “D” Bores)

Characters

to insert

Bore

Bores Available

Mag Body Size

1.2 1.8H

0F 5/16 X X 0H 3/8 X X

NOTE: Can be used up to 15 lb-in for holding.

Table 3:

Options 320-44010-0H-J

Basic Brake, Magnet Body Mounted, Long Hub

Basic Brake, Pressure Plate Mounted, Short Hub*

Short Hub, Pressure Plate Mounted with Maintained Manual Release*

Long Hub with Maintained Manual Release, Size 2.8 Only

Double “D” Friction Disc, 1.2H, 1.2D, 1.8H

*Short hub not required for size 2.8 pressure plate mount.

Option X with Maintained Manual Release Pressure Plate Mounted

Table 2: 320-44010-0H- D Standard Coil Voltage

Character

*For external in-line rectifier (for internal rectifier, add $30.00 list)

NOTE: 65 in-line rectifiers

OptionsCharacters

Voltage

to Insert

C 12 Vdc - .632 .826 1.04 1.37 E 24 Vdc - .307 .421 .53 .70 G 48 Vdc - .158 .216 .27 .36

J 90 Vdc - .076 .123 .13 .17 K 103 Vdc - .085 .115 .121 .140 L 180 Vdc - .039 .060 .069 .09 N 115 Vac $50.00 .085 .115 .140 .140 P 230 Vac $50.00 .044 .059 .075 .097

115/230

Vac

C maximum ambient temperature for all external

List

Adder*

$50.00 .085/.044 .115/.059 .140/.075 .140/.097

Current Rating in Amps

Size 1.2 Size 1.8 Size 2.0 Size 2.8

NOTE: Final part number may change due to specifications or options selected or other product design considerations. A number such as a 2, 3, 4 etc., in the 12 position is used to designate a unique brake (custom) and can only be assigned by Stearns Design Engineering Department.

Modifications are available - see AAB Modification Section.

Stearns Series 320 Catalog Page

Specifications and Main Features

Frequently Asked Questions

User Manual