SANMOTION PB servo stepper

SANYO DENKI Communication Servo New Benchmark: SANMOTION PB Series

In the field of industrial automation, there has long been a trade-off between performance and cost between stepper systems and servo systems. Although open-loop stepper systems have low cost and high low-speed torque, they have disadvantages such as out of step, high heat generation, and limited positioning accuracy; The communication servo system has excellent performance, but the price is high and the control is complex. The "SANMOTION Model No. PB" series launched by Sanyo Denki in Japan was born to fill this market gap. This series of products was initially applied to positioning equipment in conveyor systems, as well as short stroke, high-frequency action scenarios that utilize the low-speed and high torque characteristics of stepper motors. In recent years, with the increasing speed and reliability of stepper systems, as well as the demand for servo system replacements, the market's demand for high torque, cost-effective, and high-performance solutions has been growing. In this context, Sanyo Electric has developed the "SANMOTION Model No. PB" series of new products with AC power input. This article will comprehensively analyze product architecture, technical specifications, core innovations, and user functions.

Product architecture and system composition

The SANMOTION PB series consists of an amplifier (driver) and a stepper motor, using closed-loop control technology that combines the advantages of stepper motors and servo drives.

1. Amplifier (driver)

The external dimensions of the amplifier are 150 mm high, 42 mm wide, and 120 mm deep, with a weight of approximately 0.64 kg. It adopts a tray type structure, which is easy to install in the control cabinet. Power input support:

Single phase AC 100/115 V

Single phase or three-phase AC 200/230 V (allowable voltage fluctuation+10%/-15%)

The amplifier interface is divided into four types, combining pulse chain input with RS-485/parallel I/O (point controlled, programmable type, referred to as R-type). The specific models are PB4A002R30 * (RS-485/parallel I/O interface) and PB4A002P30 * (pulse chain input interface). The driving method is sine wave PWM control.

2. Motor series

There are 5 types of motors, covering three machine base sizes: 42mm square, 60mm square, and 86mm square. The same amplifier can drive all motors, achieving flexible power matching. The basic parameters of the motor are as follows:

Motor model, machine base size, maximum holding torque (N · m), rotor inertia (kg · cm ²), allowable axial load (N), allowable radial load (N), mass (kg)

PBM423FXK20 42 mm 0.39 0.056 9.8 49 0.35

PBM603FXK20 60 mm 1.3 0.4 14.7 167 0.85

PBM604FXK20 60 mm 1.9 0.84 14.7 167 1.42

PBM861FXK20 86 mm 3.5 1.48 60 200 1.9

PBM862FXK20 86 mm 6.6 3.0 60 200 3.1

The motor is equipped with an optical incremental encoder as standard, with a resolution of 4000 P/R (A/B/C phase, with phase origin signal), and can reach 16000 P/R after four harmonics, providing a hardware foundation for high-precision positioning.

Optional accessories include:

Maintain the brake (applicable to 42 mm and 60 mm motors)

Low backlash gear (suitable for 42 mm and 60 mm motors)

Harmonic gear (applicable to 42 mm and 60 mm motors)

Detailed specifications of amplifier

The main technical parameters of the amplifier are as follows:

Positioning resolution: up to 3200 P/R (can be set through electronic gear function)

rotation speed

42mm and 60mm motors: 0~4500 min ⁻¹

86mm motor: 0~4000 min ⁻¹

Speed command resolution: 1 min ⁻¹

Built in features:

Maintain brake control function

Regeneration control function (no external regeneration unit required)

Point control function, program function

Teaching function

Operation function:

Positioning, jog, origin reset, forced operation

Module length function

Digital operator: parameter setting, motor combination, resolution setting, jog, teaching, etc

Protection function:

Motor overheating, amplifier overheating, abnormal power supply voltage

Sensor disconnection, overspeed, RST action, CPU error, EEPROM error

PAM voltage error, overload error, overcurrent detection

The input and output signals are very rich:

Input signal:

Universal input: 8 points (selectable point/program number selection, execution, origin, limit, pause, stop, interlock, jog, deviation reset, counter reset, brake control, etc.)

Pulse input: 1 or 2 channels

Dedicated inputs: positive/negative limit, emergency stop, alarm clearing

Universal input (communication type): 2-point (deviation reset, forced, current selection, brake control, counter reset, etc.)

Output signal:

alarm output

Universal output: 7 points (positioning completed, busy, response, ZONE, point number, push end, origin end, etc.)

Positioning completed, ready, encoder signal (phases A/B/C)

Universal output (communication type): 2-point (origin end, push end, ZONE, input monitoring, pulse input, etc.)

All input/output signal functions and logic can be set through communication, with extremely high flexibility.

Core technology innovation

1. The motor's heating is significantly reduced

The traditional open-loop stepper system adopts constant current drive, and regardless of the load size, the motor always flows through the rated current, resulting in severe heating. The PB series adopts proportional integral control, which only provides necessary current based on the operating status of the load, thereby reducing heat generation. However, although PB products with early communication input had fast current response, the current ripple caused by PWM control was large, resulting in iron loss of multipole stepper motors becoming the main cause of heating. The newly developed communication input PB series adopts innovative control methods to significantly reduce current ripple without compromising responsiveness. Taking the 42mm motor as an example, the motor heating during stop is reduced by about 80% compared to traditional products. Comparison of current waveforms shows that the new product has a smoother current waveform and significantly reduced ripple amplitude.