The relentless pursuit of perfection, once the slogan of a major luxury car company, could easily be the slogan of the brushless motor industry. Today’s products represent finely honed designs that are the result of multiple design cycles and lots of customer feedback mixed with engineering creativity.
As a group, new motor products are highly refined and meet a larger variety of needs more successfully than the products of the last generation. But the fundamental goals remain largely the same. Engineers are looking for higher power densities, more power from the same package or the same amount of power from a smaller package. A main focus is improvements in magnet materials, since as new magnets are developed with higher power densities they fuel additional advancements in motors. But engineering efforts are also concentrating on new materials and processes that can make motor designs more reliable, efficient and cost-effective at the same time.
SERVO MOTORS BOOST PERFORMANCE, REDUCE VOLUME
The new DST series servo motors from Baumüller provide higher torque densities while drastically reducing the volume of the motor at the same time. Compared to conventional servomotors, the company says the DST series is more compact by up to 30 percent. The motors offer a speed range up to 4,500 RPM. The DST 45-100 provides the core features of the DSD series including the smooth surface on the housing design which protects against dirt and other contaminants. As a result, the motors are suited for application in sensitive industrial environments in the textile, robotics or packaging industries. Based on their electromechanical properties, the motors are also well suited for direct drive applications.
AC SERVO MOTORS DELIVERMORE TORQUE
Baldor’s BSM C-series of brushless ac servo motors employ rare-earth neodymium iron boron magnets to deliver more torque from a smaller form factor. A total of 25 motors are available in versions offering up to 30 Nm (265 ib-in) continuous stall torque. Novel ring-shaped magnets that are pressed onto the motor shaft boost magnetic flux levels significantly, increasing torque levels by from 20 to 60 percent compared with Baldor’s ferrite-based BSM B-series motors. The magnets are so efficient that the length of motors have typically been reduced by 2.5 to 5 cm (1 to 2 inches). BSM C-series motors offer the same heavy inertias as equivalent BSM B models. Inertias range from 1.81 to 42.68 Kg-cm-sec². BSM C-series provides machine builders with a compact solution for continuous stall torques ranging from 1.2 to 30 Nm (10.6 to 265 lb-in) and peak torques from 3.6 to 90 Nm (31.8 to 796 lb-in).
SERIES 1300 BRUSHLESS DC SERVOMOTORS
New PITTMAN® brand Series 1300 slotted brushless dc servomotors deliver more power in a smaller, cost-effective package. Despite their small size (1.3”/33 mm diameter), these motors can achieve peak torque from 12.6 oz-in to 54.3 oz-in, continuous torque from 5 to 9 oz-in and speeds up to 8,000 RPM. Hall sensors provide rotor position feedback for electronic commutation. Other standard features include 3-phase stator with 6-slot silicon steel laminations, 4-pole rotor integrating high-energy neodymium ring magnets for optimized motor performance and large ABEC ball bearings with high dynamic load ratings (up to 390 lb) and shielded to protect against contaminants. Series 1300 brushless motors are available in three lengths (1.5, 2 and 2.5 inches). Optional square flanges can be specified for NEMA 14 mounting. Motors can be customized with a range of components to meet application demands, including planetary or spur gearboxes and optical encoders.
STEPPER MOTOR SOLUTION OFFERS VERSATILITY AT LOW COST
The new AS1xxx stepper motors from Beckhoff Automation provide an alternative to servo motors in the small and medium capacity ranges. The motors are designed to conveniently interface Beckhoff stepper motor I/O terminals and offer a cost-effective motor solution. Different stepper motor types in this series have nominal current ratings from 1.0 to 5.0 A and torques ranging between 0.38 and 5 Nm. The AS1xxx series can be used as actuators or auxiliary axes for numerous machine designs and automation applications. In conjunction with the company’s stepper motor I/O Bus Terminals and TwinCAT automation software, axes can be integrated into any stepper application without the need for remote amplifiers. The KL2531 bus terminal covers the lower capacity range up to a peak current of 1.5A per phase with a supply voltage up to 24V dc. The KL2541 offers higher performance comparable to that of small servo drives.
STEPPER MOTOR PROVIDESHIGH OUTPUT TORQUE
Portescap has introduced a new h3 housed hybrid stepper motor. These 1.8-degree step motors are available in NEMA 17, 23 and 34 frame sizes. The h3 series offers several upgrades when compared with standard hybrid step motors. The aluminum housing improves heat dissipation to create higher output torque during operation, and stator-enhanced magnets deliver up to 40 percent more torque in the same footprint. Neodymium iron boron magnets offer high torque density, while the bearing retainer and o-ring help reduce motor noise. Large bearings enable the motor to effectively handle high side and radial loads. Various stack lengths are available in each frame size, and windings can be customized to suit individual application needs. The h3 is designed for a range of applications, including medical equipment, textile, semiconductor and electronic assembly.
STAINLESS-STEEL SERVO MOTORS
Baldor’s SSBSM Series stainless-steel servo motors provide optimized protection for automation applications in clean environments such as bio-pharm and food packaging and processing lines, or hostile operating situations such as inside machine tools. The new family delivers higher speeds, accelerations and positioning accuracies in clean-in-place machinery and automation. They are also designed to withstand high-pressure washdown environments and incorporate a 304 stainless-steel housing protected to IP67 standards and which will easily withstand cleaning using caustic materials at pressures up to 103 bar (1500PSI). Other advanced protection features include an FDA shaft seal to comply with food and baking industry standards, a potted stator for environmental and high voltage protection and an internal thermal switch. The motors are available in five frame sizes with continuous torques from 0.45 to 32N-m (3.9 to 280 lb-in), and peak torques ranging from three to four times the continuous duty ratings.