Case Study on Using Brushless Motor BLH Series for Reduced Noise and Improved Reliability in Dialyzer/Liquid Feed Module

Issue: To Increase Dialysis Patient Comfort and Equipment Safety Through Noise Reduction and Stable Drive

Conventional Problems

• In hospitals, the dialyzer/liquid feed module is often placed close to the patient's ear, and the noise of the motor's operation is detrimental to the patient's comfort
• If the tubing is not placed properly, it may interfere with the dialyzer/liquid feed module case, there was a risk of the tube becoming pinched
• Due to limited equipment space, the goal is to have enough torque margin without increasing the current motor size
• The current motor is driven at the very limit of permissible torque, which generates a lot of heat, and there are concerns about the thermal effects on infusion due to prolonged operation

Solution: Brushless Motor BLH Series for Quiet Operation, Reliability, and a Comfortable Medical Environment

In the operating environment of a dialyzer/liquid feed module, it is essential to consider the quietness of the motor and temperature rise. The brushless motor BLH Series offers the quietness and reliability required in the medical field, thanks to its silent design and highly efficient drive. In addition, the driver outputs an overload alarm in the event of abnormalities such as tube becoming pinched, contributing to improved safety.

Sine Wave Driver Reduces Drive Noise

The BLH Series uses a sine wave drive system, which smoothly multiplies the motor current to reduce torque ripple and lower noise compared to conventional products. Even in the quiet environment of a hospital, the drive noise is not bothersome, contributing to improved patient comfort.

Concept Image of Low Noise Driving by the BLH Series

Stable Low-Speed Operation Ensures Reliable Liquid Feeding Control

Brushless motors monitor the feedback signals from the motor at all times to compare with the setting speed and adjust the voltage applied. For this reason, even if the load changes, rotation at a stable speed is performed from low speed to high speed. The BLH Series (digital setting type and RS-485 communication type) supports low-speed operation at 80 rpm, enabling reliable liquid feeding control by setting the speed in 1 rpm increments.

Reduced Motor Heat Generation Reduces Thermal Effects on Infusions

Brushless motors have flat and lightweight bodies and provide high power due to permanent magnets being used in the rotor. The BLH Series motor is the same size as the current motor but has larger output torque and can reduce heat generation. Temperature rise is suppressed even during long hours of continuous operation, minimizing thermal effects on infusions.

Low heat generation allows easy temperature control inside the equipment and simplifies heat dissipation design and maintenance.

Improved Equipment Reliability Through Alarm Output in Case of Overload

The brushless motor BLH Series is equipped with a function that outputs an alarm in the event of an overload. This enables real-time detection of load changes such as tube becoming pinched and blockages. In the event of an overload or other abnormality, the motor can be stopped, and the driver can output an alarm to notify that the equipment has stopped. This feature prevents equipment damage and tubing breakage, allowing for reliable operation.

Image of Alarm Output by the BLH Series

Proposed Product: Brushless Motor BLH Series (30 W) + Parallel Shaft Gearhead + Digital Setting Type Driver 

Motor Output Shaft Type

• Parallel Shaft Gearhead GFS Gearhead
• Hollow Shaft Flat Gearhead FR Gearhead
• Round Shaft Type

Driver Type

• Analog Setting Type
• Digital Setting Type
• RS-485 Communication Type