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Koki Holdings Co.,Ltd.

Our Brushless Motor Technology for AC(corded) / DC(cordless) Tools

the next generation motor developed from jobsite needs and Our original technology

Movie & Poster

  • No wearing parts (carbon brushes, commutator, field coil)
  • Our original compact controller

1. High Durability. Long Lifetime (AC/DC)


The brushless motor has large FETs (Field Effect Transistors) and highly durable electronic circuits for superior durability. The electronic circuit board is also silicone-coated to protect from dust.

2. Maintenance-free (AC/DC)

Even under heavy use, the brushless motor significantly extends the product life cycle without causing troubles such as armature burnout, layer short or commutator wear. Plus, it does not require the regular replacement of carbon brushes.


3. Compact, Lightweight. (AC/DC)

More compact. More lightweight.

Due to the more compact design compared to brushed motors, incorporating the brushless motor permits a reduction in size and weight of tools for easier handling.

*A comparison between the brushless motor of the WR16SE and the brushed motor of the WR16SA.

4. Compatible with Engine Generators (AC)

Equipped with Our original, compact and high efficiency inverter circuit, the brushless motor works with an engine generator that doesn't have an onboard inverter.

Compatible with engine generators

5. Stable Performance during Voltage Drops (AC)

The brushless motor runs cooler, and its performance isn't affected as much by voltage drop from long extension cables on site.

Stable performance even during voltage drop

6. Up to 1.3 times more runtime per charge (DC)

1.3 times more runtime per charge

* The data presented above is for reference purposes. It varies according to conditions including the temperature, bit sharpness, materials, working method.

Aluminium Housing Body (AHB) Construction

Aluminium Housing Body (AHB)

Robust & Highly Durable
The internal double-insulation construction with an aluminium die-cast body and a plastic stator holder

Due to the internal double-insulation construction with a plastic stator holder and an aluminium die-cast body which firmly holds the armature shaft, the durability of the motor and the tool body has remarkably improved.

The internal double-insulation construction with an aluminium die-cast body and a plastic stator holder

User Vibration Protection (UVP) System

User Vibration Protection (UVP)

Reduced vibration and improved operating efficiency

1.Our original, spring-type dynamic vibration absorber for DH40MEY Rotary Hammer

Our original, spring-type dynamic vibration absorber

Vibration-absorbing handle

2.Vibration-absorbing handle for H90SG Demlition Hammer
Reduces vibration from the main unit by means of four handle dampers bent by the rotating holder(A).

Low vibration handle (LVH)

Low vibration handle (LVH)

Vibration-absorbing mechanism with the Transatory unit (rubber dampers) and the hinge unit (for rotary / demolition hammers) provides high vibration absorbing effect.

Reactive Force Control (RFC)

When the tool bit is suddenly overburdened during operation, a tool's built-in control stops the motor to lessen the twisting of the operator's arms.