Hedge Trimmer

Overview

A hedge trimmer shapes hedges and shrubs with two long toothed blade bars that slide back and forth in opposition, shearing branches between their teeth. This model is cordless: a lithium-ion pack and a brushless motor drive the blades through a reduction gear and an eccentric crank.

The Power Unit is a brushless DC motor with its own Motor Controller. The controller is a three-phase speed controller whose MOSFET Inverter Bank commutates the motor windings under MCU control and handles trigger and brake logic. DC power comes from the Battery Pack, a removable slide-on 5S2P Li-ion pack with a BMS for protection and balancing.

How it works

Motor rotation enters the Drive Mechanism, where a Reduction Gearbox steps the speed down and a twin-lobe Eccentric Crank drives two scotch-yoke pins 180° apart. This reciprocates the two blade bars in opposition: as one moves left, the other moves right, so the cutting teeth pass each other to shear.

The Cutting Assembly carries an upper and a lower hardened-steel blade bar with a ground tooth profile, held in alignment by a slotted guide plate and shimmed for free sliding. A moulded tip cover guards the bar end and reduces kickback.

Construction

The Handle Assembly pairs a wrap-around front bail with a rotating rear pistol grip that detents through several angles for cutting tops and vertical faces. A variable-speed trigger and a front-handle safety switch form a two-hand interlock that must both be held before the blades run. The motor, drive, and controller sit inside the Housing, two glass-filled nylon clamshell halves with a louvred vent grille; power and signals run through the Wiring Harness harness.