Tapered Threaded Liner Bolt for Rotation-Based Mill Liner Removal
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Solution Overview
Problem
Existing liner bolts in grinding mills require impact tools for removal, posing safety hazards and increasing downtime, and existing quick release bolts are prone to failure due to narrowed portions.
Innovation Solution
A liner bolt design featuring an elongate stud with an inwardly tapered head and threaded connection allowing rotation-based removal, eliminating the need for impact tools and reducing the risk of failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If impact tools are used to drive bolts inwardly during liner replacement, then the bolts can be installed, but safety hazards and operator injury risks increase
Solution Approach 1:
The liner bolt is divided into two separate parts: an inner bolt part that remains inside the liner and an outer bolt part that is removed during liner replacement. This segmentation eliminates the need for impact tools during removal, as the outer part can be simply pulled out after the liner is detached, thereby resolving the safety hazard associated with using impact tools.
Solution Approach 2:
The outer bolt part is extracted from the assembly during liner replacement. Instead of driving the entire bolt inwardly with impact tools, only the inner bolt part remains embedded in the liner while the outer part is removed and discarded. This extraction eliminates the safety risk of operating impact tools during the replacement process.
2Ease of manufacture
If impact tools are used to drive bolts inwardly, then the bolts can be installed, but the time taken for liner replacement increases
Solution Approach 1:
By segmenting the bolt into inner and outer parts, the removal process is simplified. The outer part can be quickly pulled out after the liner is detached, eliminating the time-consuming process of using impact tools to drive bolts inwardly. This significantly reduces the overall liner replacement time.
Solution Approach 2:
Instead of driving the bolt inwardly during installation (conventional method), the invention inverts the approach by having the outer bolt part protrude outward for easy removal. During liner replacement, the process is reversed: the outer part is simply pulled out rather than driven in, saving considerable time and effort.
3Ease of operation
If a quick release liner bolt with a narrowed portion is used, then removal can be achieved by rotation, but the likelihood of breakages during mill operation increases
Solution Approach 1:
The bolt is segmented into two separate pieces: the inner bolt part that remains in the liner and the outer bolt part that is removed. This eliminates the narrowed portion that caused weakness in quick release bolts, as each part can be designed with uniform, adequate cross-section for its specific function, thereby maintaining high reliability during mill operation while still enabling easy removal.
Solution Approach 2:
The outer bolt part is extracted and removed during liner replacement. By removing this part entirely rather than relying on a narrowed section for release, the design eliminates the structural weakness that led to breakages. The inner bolt part remains as a simple, strong anchor without any narrowed portions, ensuring reliability 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
Enables safe and efficient removal of liners by rotation, minimizing downtime and preventing structural weaknesses.
Implementation Method 1
the first end of the head includes an inwardly tapered opening having an internal thread and the first end of the stud includes an inwardly tapered end portion having an external thread such that the first end of the stud is engageable in the opening in the head
Implementation Method 2
the first end of the head includes an inwardly tapered opening having an internal thread and the first end of the stud includes an inwardly tapered end portion having an external thread
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
A liner bolt (10) comprising an elongate stud (12) and a head (14) engageable with a first end (16) of the stud (12). The head (14) including an inwardly tapered first end portion (24) adjacent a first end (21) thereof. A threaded portion (18) is provided adjacent a second end (17) of the stud for receiving a nut (20). The first end (21) of the head (14) includes an inwardly tapered opening (28) having an internal thread (30) and the first end (16) of the stud (12) includes an inwardly tapered end portion (32) having an external thread (34) such that the first end (16) of the stud (12) is engageable in the opening (28) in the head (14).