BMS Brushless, Slotless Rotary Motors

Description

Design Features

  • Slotless, brushless stator design provides zero cogging torque for unsurpassed velocity control
  • Smoother velocity than with standard DC brush-type motors with the advantage of reliable brushless technology
  • Standard NEMA frame sizes
  • Ultra-high resolution capability with amplified sine-wave encoder and multiplier



Aerotech's BMS series brushless, slotless servomotors represent the ultimate in high-performance rotary motors. Available in standard NEMA frame sizes, these motors utilize a slotless stator design for superior velocity smoothness and control.

Featuring rare-earth magnets and a high pole-count rotor, the BMS series provides maximum torque and acceleration in a small package. Custom mechanical or electrical variations of the BMS can be engineered with minimal lead time.

Smoother than DC Motors

The BMS series motors can replace standard brushless or brush-type motors when superior velocity smoothness and control are required. DC brush-type motors have been popular in applications such as machine tool and scanning because of their smooth low-speed control. The BMS motors provide superior smoothness and have higher acceleration capability than a DC brush motor. Higher acceleration results in higher machine throughput and performance.

High Performance Design

The BMS series is unlike conventional brushless servomotors because it incorporates a totally slotless stator design that provides the ultimate in smooth velocity control. These motors are designed for applications requiring superior torque and stability performance. The unique design of the BMS series motors provides a closer inertia match with mechanical systems than comparable models. This means better stability and easier tuning.

Ultra-High Encoder Resolution

The BMS series motors can be equipped with a variety of encoder resolution options for any application. In addition to the standard RS-422 line driver output, an optional amplified sine-wave encoder can be used to provide ultra-high resolution. Aerotech offers encoder multipliers as an option for drives connected to the A3200 system, as well as external multiplier boxes. Resolutions as high as 1,000,000 counts per revolution are achievable.

Specifications

Motor ModelUnitsBMS35BMS60BMS100BMS280BMS465
Winding Designation  A A A A A
Performance Specifications(1,5)
Stall Torque, Continuous(2) N·m 0.27 0.33 0.56 1.60 2.86
oz·in 38.0 46.2 80.0 227.0 404.8
Peak Torque(3) N·m 1.07 1.31 2.26 6.41 11.43
oz·in 152.0 184.9 320.0 908.0 1619.2
Rated Speed rpm 4,000 4,000 3,000 3,000 2,000
Rated Power Output, Continuous W 96.0 112 133 381 457
Electrical Specifications(5)
BEMF Constant (Line-Line, Max) Vpk/krpm 12.9 19 40 57 79
Continuous Current, Stall (2) Apk 2.5 2.3 2.1 3.8 4.9
Arms 1.7 1.6 1.5 2.7 3.5
Peak Current, Stall (3) Apk 9.8 9.2 8.4 15.2 19.6
Arms 6.9 6.5 5.9 10.7 13.9
Torque Constant(4,8) N·m/Apk 0.11 0.14 0.27 0.42 0.58
oz·in/Apk 15.5 20.1 38.1 59.7 82.6
N·m/Arms 0.15 0.20 0.38 0.60 0.82
oz·in/Arms 21.9 28.4 53.9 84.5 116.8
Motor Constant(2,4) N·m/√W 0.046 0.050 0.076 0.179 0.280
oz·in/√W 6.52 7.02 10.74 25.34 39.70
Resistance, 25°C (Line-Line) Ω 5.8 8.4 12.9 5.7 4.4
Inductance (Line-Line) mH 1.7 1.30 2.40 1.10 0.87
Maximum Bus Voltage VDC 160 340 340 340 340
Thermal Resistance °C/W 2.21 1.73 1.35 0.93 0.72
Number of Poles - 8 8 8 14 14
Mechanical Specifications
Motor Weight kg 0.6 1.1 1.5 3.60 5.00
lb 1.3 2.4 3.3 7.9 11.0
Rotor Moment of Inertia kg·m2 1.96x10-5 1.96x10-5 3.71x10-5 4.66x10-4 9.28x10-4
oz·in·s2 0.0028 0.0028 0.0053 0.0660 0.1314
Max Radial Load N 45 89 89 178 178
lb 10 20 20 40 40
Max Axial Load N 45 89 89 89 89
lb 10 20 20 20 20
  1. Performance is dependent upon heat sink configuration, system cooling conditions, and ambient temperature.
  2. Values shown @ 75°C rise above a 25°C ambient temperature, with housed motor mounted to a 250 mm x 250 mm x 6 mm aluminum heat sink.
  3. Peak torque assumes correct rms current; consult Aerotech.
  4. Torque constant and motor constant specified at stall.
  5. All performance and electrical specifications ±10%.
  6. Maximum winding temperature is 100°C; thermistor trips at 100°C.
  7. Ambient operating temperature range 0°C - 25°C. Consult Aerotech for performance in elevated ambient temperatures.
  8. All Aerotech amplifiers are rated Apk; use torque constant in N·m/Apk when sizing.

Dimensions

  • NEMA 17
  • NEMA 23
  • NEMA 34

Ordering Information

Ordering Example

BMS 35 -A -D25 -E1000H -BK1

Ordering Options

Options in green available from Aerotech's Fast Delivery program.

Motor Series Motor Torque CodeMotor Winding Connector Option Encoder Resolution Options
BMS 35 -A -D25
-FLY		 -E1000H
-E2000H
-E5000H
-E1000ASH
 -NBK
-BK
-VAC6

Brushless Rotary Servomotors

Options Description
BMS35 NEMA 17 - Tcont = 0.27 N·m (38.0 oz·in) brushless motor

Winding Options

Options Description
-A Standard winding

Connectors

Options Description
-DB25 25 conductor plastic D-shell for feedback and motor power (std)
-FLY-x Flying leads for feedback and motor power with custom length cable

Feedback Options

Options Description
-E1000H 1000 lines incremental square wave encoder with marker and Hall effect tracks (RS-422 line drive output)
-E2000H 2000 lines incremental square wave encoder with marker and Hall effect tracks (RS-422 line drive output)
-E5000H 5000 lines incremental square wave encoder with marker and Hall effect tracks (RS-422 line drive output)
-E1000ASH 1000 lines incremental amplified sine wave encoder with marker and Hall tracks

Options

Options Description
-NBK No brake
-BK Brake, 29 oz-in (0.2 N-m), 24 VDC, 0.2 A for BMS35
-VAC6 Vacuum preparation to 10-6 torr

Ordering Example

BMS 100 -A -D25 -E1000H -BK1

Ordering Options

Options in green available from Aerotech's Fast Delivery program.

Motor Series Motor Torque CodeMotor Winding Connector Option Encoder Resolution Options
BMS 60
100		 -A -D25
-FLY
-MS		 -E1000H
-E2000H
-E2500H
-E5000H
-E1000ASH
 -BK1
-VAC6

Brushless Rotary Servomotors

Options Description
BMS60 NEMA 23 - Tcont = 0.33 N·m (46.2 oz·in) brushless motor
BMS100 NEMA 23 - Tcont = 0.56 N·m (80.0 oz·in) brushless motor

Winding Options

Options Description
-A Standard winding

Connectors

Options Description
-DB25 25 conductor plastic D-shell for feedback and motor power (std)
-MS MS connectors for feedback and motor power
-FLY-x Flying leads for feedback and motor power with custom length cable

Feedback Options

Options Description
-E1000H 1000 lines incremental square wave encoder with marker and Hall effect tracks (RS-422 line drive output)
-E2000H 2000 lines incremental square wave encoder with marker and Hall effect tracks (RS-422 line drive output)
-E2500H 2500 lines incremental square wave encoder with marker and Hall effect tracks (RS-422 line drive output)
-E5000H 5000 lines incremental square wave encoder with marker and Hall effect tracks (RS-422 line drive output)
-E1000ASH 1000 lines incremental amplified sine wave encoder with marker and Hall tracks

Options

Options Description
-BK1 Brake, 112 oz-in (0.8 N-m), 24 VDC, 0.3 A for BMS60, BMS100
-VAC6 Vacuum preparation to 10-6 torr

Accessories

Options Description
MC-HPD25-M Connector, HPD25 motor power mate for BMS60, BMS100 motors
MC-DB25-F Connector, DB25 motor feedback mate for BMS60, BMS100 motors
MCM-3 Connector, MS motor power mate for BMS60, BMS100
MCF-3 Connector, MS motor feedback mate for BMS60, BMS100

Ordering Example

BMS 280 -AH -MS -E2000H -BK2

Ordering Options

Options in green available from Aerotech's Fast Delivery program.

Motor Series Motor Torque CodeWinding
Option 		Connector
Option 		Encoder Resolution with Hall Tracks Options
  280
465		 -AH -MS -E1000H
-E2000H
-E2500H
-E5000H
-E1000AS
 -BK2
-NS
-VAC6

Brushless Rotary Servomotors

Options Description
BMS280 NEMA 34 - Tcont = 1.6 N·m (227.0 oz·in) brushless motor
BMS465 NEMA 34 - Tcont = 2.86 N·m (404.8 oz·in) brushless motor

Winding Options

Options Description
-AH Standard winding with Hall board; required for all encoder options

Connectors

Options Description
-MS MS connectors for feedback and motor power (standard)

Feedback Options

Options Description
-E1000H 1000 lines incremental squarewave encoder with marker (RS-422 line drive output)
-E2000H 2000 lines incremental squarewave encoder with marker (RS-422 line drive output)
-E2500H 2500 lines incremental squarewave encoder with marker (RS-422 line drive output)
-E5000H 5000 lines incremental squarewave encoder with marker (RS-422 line drive output)
-E1000AS 1000 lines incremental amplified sinewave encoder with marker; maximum speed 2400 rpm

Options

Options Description
-BK2 Brake; holding torque = 1.7 N·m (240 oz·in), 24 VDC, 0.4 A
-NS IP65 rated Nitrile front shaft seal
-VAC6 Vacuum preparation to 10-6 torr

Example: Motor with 2000-lines encoder and Nitrile shaft seal: BMS280-AH-MS-E2000H-NS

Accessories

Options Description
MCM-3 Connector; MS motor power mate
MCF-3 Connector; MS motor feedback mate