Electric Hammer Device with Linear Motor for Excavators

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Hydraulic hammer devices cause pressure shocks and have high power consumption, leading to inefficiencies and challenges in hydraulic systems of working machines like excavators.

Innovation Solution

An electrically driven hammer device with a linear electric machine comprising a mover with permanent magnets and a ferromagnetic core-structure stator, supported by structures with low electrical conductivity to reduce eddy currents and enhance efficiency, eliminating pressure shocks and offering lower energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a hydraulic hammer device is used to break up material, then breaking capability is achieved, but pressure shocks are generated that are destructive to the hydraulic system

Engineering Contradiction:
Improvebreaking capabilityVSAvoidpressure shocks
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the hydraulic drive system with an electric motor-driven system. The electric motor directly drives the hammer mechanism through a reduction gear, eliminating the hydraulic pump, hoses, and valves that generate pressure shocks. This substitution of mechanical/electric system for hydraulic system resolves the contradiction by maintaining breaking capability while eliminating the source of harmful pressure shocks.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Strength

If a hydraulic hammer device is used to break up material, then breaking capability is achieved, but power consumption is relatively high due to multiple energy-loss producing elements

Engineering Contradiction:
Improvebreaking capabilityVSAvoidpower consumption
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent eliminates the hydraulic transmission chain (engine → hydraulic pump → hoses → valves → hammer) and replaces it with a direct electric motor → reduction gear → hammer drive system. This substitution removes multiple energy-loss producing elements including hydraulic friction, flow resistance, and valve losses, thereby reducing overall power consumption while maintaining breaking capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the hydraulic system components from the drive chain, eliminating the intermediate energy-loss producing elements. By taking out the hydraulic pump, piping, and valve system, the patent creates a more efficient direct-drive electric system that reduces energy losses at each transmission stage.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If a hydraulic system with multiple energy-loss producing elements is used, then hammer operation is achieved, but efficiency of the whole system is reduced

Engineering Contradiction:
Improvehammer operationVSAvoidsystem efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent replaces the complex hydraulic operation system with a simpler electric motor control system. The electric motor provides direct torque control through electronic control, eliminating the need for hydraulic valves and flow control mechanisms. This substitution maintains ease of operation through electronic control while significantly improving overall system efficiency by removing hydraulic transmission losses.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The electrically driven hammer device minimizes pressure shocks and improves energy efficiency, reducing energy costs and system stress, with operational energy sourced from the electrical grid at a lower unit price compared to hydraulic systems.

Implementation Method 1

a stator connected to the frame and provided with windings for producing a magnetic force directed to the mover in response to electric current supplied to the windings

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

The support element comprises a sliding surface being against the mover and material whose electrical conductivity is at most half of the electrical conductivity of the solid metal. The support element is tubular and arranged to surround an end-portion of the mover.

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Data Source

PatentEP3692217B1A hammer device
Publication Date: 2022.08.10 LEKATECH OY
  • EP3692217B1 patent drawingFigure 1a
  • EP3692217B1 patent drawingFigure 1b
  • EP3692217B1 patent drawingFigure 1c

AI summary

A hammer device (100) comprises a frame (101), an actuator member (103) linearly movable with respect to the frame, and a linear electric machine for linearly moving the actuator member. The frame comprises attachment members (102) for attaching to a working machine so that the frame is nondestructively detachable from the working machine. The linear electric machine comprises a mover (104) for linearly moving the actuator member and a stator (105) connected to the frame and comprising windings (106) for generating a magnetic force directed to the mover in response to electric current supplied to the windings.