Locking Device for Hammer Fixation in Impact Crushers
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Solution Overview
Problem
Existing locking devices for mounting and dismounting hammer parts on horizontal shaft impact crushers require two fitters, posing health and safety risks and inefficiencies, and are prone to damage from abrasive materials.
Innovation Solution
A locking device with a locking-wedge and nut holder that allows single-person operation, featuring a protective member to prevent damage from rocks and a resilient mechanism to secure the screw element, reducing the need for a second fitter and enhancing safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional locking device with a locking nut and screw element is used, then the hammer element can be securely fixed to the rotor disc, but two fitters are required for installation which reduces productivity and increases health and safety risks
Solution Approach 1:
The locking nut holder combines multiple functions into a single integrated component: it holds the locking nut, prevents its rotation during screw tightening, and provides structural support. This merging eliminates the need for a second fitter to manually hold the nut, allowing one fitter to complete the installation while maintaining secure fixation.
Solution Approach 2:
The locking nut holder acts as an intermediary device that mediates between the screw element and the locking nut. It provides a controlled interface that automatically prevents nut rotation during tightening, replacing the manual intervention previously required and enabling single-person operation.
2Reliability
If a traditional locking device is used, then the hammer element can be fixed to the rotor disc, but significant health and safety risks exist as fitters must place hands underneath the locking device and hammer
Solution Approach 1:
The locking nut holder is designed to be self-sufficient during the tightening operation. It automatically prevents the locking nut from rotating as the screw element is tightened, eliminating the need for a second fitter to manually hold the nut. This self-service mechanism removes the requirement for fitters to position their hands in dangerous locations, significantly reducing health and safety risks.
3Ease of operation
If the central hole is left open to allow access to the screw element, then the screw can be tightened and removed, but crushed rock can enter the hole and prevent tool access making dismounting difficult
Solution Approach 1:
The locking nut holder is designed with a structure that preliminarily protects the central hole from rock ingress during operation. The holder's geometry and positioning create a barrier that prevents crushed rock from entering the hole while still allowing tool access for screw tightening and removal, resolving the contradiction between protection and accessibility.
4Reliability
If a plastic cap is inserted into the central hole to block rock ingress, then rock protection is provided, but the cap often becomes dislodged during crusher use allowing rock into the hole
Solution Approach 1:
The locking nut holder serves as a permanent, robust protective structure that replaces the disposable plastic cap solution. Instead of relying on a cheap, temporary cap that can become dislodged, the holder provides continuous, reliable protection against rock ingress while maintaining tool accessibility, eliminating the need for repeated replacement and maintenance.
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 solution enables safer, quicker, and more efficient mounting and dismounting of hammer elements by eliminating the need for a second fitter and protecting the locking nut from damage, thus reducing health risks and operational inefficiencies.
Implementation Method 1
a resilient means, such as at least one spring or compression washer, located between locking-wedge and the nut holder
Implementation Method 2
The locking screw drives the wedge-shaped body against the hammer element thereby fixing the hammer element to a rotor disc
Data Source
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AI summary
A locking device (60) for a crusher rotor (4) of a horizontal shaft impact crusher (1), said rotor (4) including at least one hammer element (46) and at least one rotor disc (66) having a plurality of rotor arms (70). The locking device (60) comprises: a locking-wedge (80), including a first through bore (88); a screw element (90) for driving the locking-wedge (80) into a locking position between a rotor arm (70) and the hammer element (46), and for holding the locking-wedge (80) in the locking position, thereby fixing the hammer element (46) to the rotor disc (66); a locking nut (108) for receiving the locking screw element; and a locking nut holder (98,120); wherein the screw element (90) is at least partly located in the first through bore (88) and extends through the locking nut (108), and the locking nut holder (98,120) holds the locking nut (108) in a manner that prevents the locking nut (108) from rotating as the screw element (90) is driven through the locking nut (108).