Bifurcated Pivot Joint Link Member for Hydraulic Crane Reliability
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Solution Overview
Problem
Existing link members between hydraulic crane arms and rotators suffer from inadequate lubrication and loading of bearings, leading to frequent defects and reduced reliability in crane operations due to the use of ball bearings, which are not rotated at high enough velocities to maintain lubricating conditions, especially during the limited pivoting angles and heavy loads encountered in crane operations.
Innovation Solution
The link member design incorporates a bifurcated upper pivot joint with hollow cylindrical bushes and bearing bushes, along with a limitation means to guide hydraulic conduits and ensure proper alignment, and includes a lubricating device to maintain lubrication between the bearing bushes and bolt, allowing for efficient lubrication and reduced wear even at small pivoting angles and heavy loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If ball bearings are used in the pivot joint to reduce width, then the width of the pivot joint is reduced, but the bearings are not rotated at high enough velocities to maintain lubricating conditions
Solution Approach 1:
The patent changes the bearing type from ball bearings to roller bearings, altering the contact mechanics and rotation characteristics. This parameter change enables the bearing to rotate at higher velocities during crane operation, maintaining lubricating conditions while accepting a wider pivot joint design
Solution Approach 2:
Instead of using ball bearings that rotate at low velocities, the patent inverts the approach by using roller bearings that rotate at high velocities. This inversion of the bearing type resolves the contradiction by prioritizing lubrication maintenance over minimal width
2Ease of operation
If the pivot joint is made narrow to prevent crane hooking, then the maneuverability is improved, but there is insufficient space for hydraulic conduits to move unhindered
Solution Approach 1:
The patent resolves the space conflict by directing hydraulic conduits through a different spatial path - between the two protrusions of the bifurcated pivot joint rather than through the central bearing area. This dimensional reorganization allows narrow pivot joint design for maneuverability while providing adequate space for hydraulic conduits
3Force
If roller members are used in bearings to handle heavy loads, then the load capacity is improved, but the lubricant is removed from the roller member area in very short time
Solution Approach 1:
The patent introduces a lubricating device that proactively supplies lubricant to the bearing area. This preliminary action ensures continuous lubrication of the roller members during heavy load operation, preventing lubricant depletion and extending the duration of effective lubrication
Solution Approach 2:
The lubricating device is integrated into the bearing assembly, creating a self-servicing system that automatically maintains lubrication without external intervention. The bearing assembly itself provides for its own lubrication needs during operation
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
This design enhances the reliability and longevity of crane operations by ensuring adequate lubrication and reduced wear on the bearings, minimizing the need for frequent replacements and improving the overall maneuverability and efficiency of the crane.
Implementation Method 1
at least one lubricating device which is adapted for transferring each lubricant towards both contact surfaces between said bearing bushes and the bolt
Data Source
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AI summary
The purpose of the invention is to create a link member (1) between a portable hydraulic crane arm (2) and a hydraulic rotator (3), which should enable reliable operation of the hydraulic crane. The pivot joint (11) of said link member (1) is fork-shaped on the side of said crane arm (2) and comprises two protrusions (111, 112) located apart from each other, which are each per se furnished with a throughout bore (111', 112'') adapted to receive a bolt (13) serving for establishing a connection with a crane arm (2). A hollow cylindrical bush (113) is inserted through said bores (111', 112') in said protrusions (111, 112) of the pivot joint (11) on the side of crane arm (2), and a bearing bush (114', 114'') is inserted therein on each side thereof, so that said bolt (13) is extending throughout said bearing bushes (114', 114'') for the purposes of establishing a pivoting interconnection between the link member (1) and the crane arm (2).˙