Boom Link Sensor Linkage for Protected Swing Position Measurement
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Solution Overview
Problem
Existing machines, such as excavators, face issues with unreliable position sensors on boom links due to exposure, limited measurement capabilities in horizontal planes, and space constraints, leading to frequent damage and reduced accuracy.
Innovation Solution
A configuration using a first link with a vertical bend and a second link with a horizontal bend to transfer horizontal rotation of the boom to a position sensor, which is mounted internally within the machine, protected by casings, and connected via a mounting bracket to a swing casting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If position sensors are located on exposed portions of the boom, then movement measurement is enabled, but the sensors are frequently damaged by dirt, debris, or contact with objects
Solution Approach 1:
The position sensor is nested within the hollow interior of the boom, specifically mounted on the swing casting inside the boom's hollow structure. This nesting protects the sensor from external damage while still allowing it to measure boom movement through the mechanical linkage system.
2Device complexity
If straight-bar links are used to connect position sensor to machine element, then connection is simplified, but space constraints limit sensor placement and link configuration
Solution Approach 1:
The first link is configured with a bend (curved portion) instead of being a straight bar. This bend allows the link to accommodate three-dimensional space constraints and enables the position sensor to be placed in the hollow interior of the boom while maintaining proper mechanical connection and rotation transfer.
3Measurement precision
If sensors are used to measure boom movement in vertical plane, then extension/retraction measurement is enabled, but horizontal plane measurement capability is limited
Solution Approach 1:
The bent first link acts as an intermediary mechanism that transfers horizontal rotation of the boom to vertical rotation of the position sensor's rotary element. The bend in the link converts the horizontal movement vector into a rotational motion that the sensor can accurately measure in the vertical plane.
Data Source
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AI summary
A machine (10) may include a body (12), a boom link (30), a swing casting (31), and a boom (20). The boom (20) and the swing casting (31) may be configured to rotate horizontally about an axis (34) through the boom link (30). The machine (10) may further include a mounting bracket (46) fixedly connected to the swing casting (31), a position sensor (38) fixedly connected to the boom link (30), a first link (42) fixedly connected at a first end (56) to the position sensor (38) and configured to rotate about an axis through a rotary element (48), and a second link (44) fixedly connected at a first end (50) to the mounting bracket (46) and at a second end (52) to a second end (54) of the first link (42). The first link (42) and the second link (44) may be configured to rotate horizontally with horizontal rotation of the boom (20) and the swing casting (31) and to transfer the horizontal rotation of the boom (20) and the swing casting (31) to the rotary element (48).