Rotationally Locked Drive Assembly for VSI Crusher
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Solution Overview
Problem
Conventional taper lock-and-keyway designs in VSI crushers are prone to fretting, notching, and shaft failure due to vibrational forces and manufacturing tolerances, leading to premature wear and maintenance challenges.
Innovation Solution
A rotationally locked drive assembly featuring a flywheel with a tapered center opening and a locking key with radiating extensions, eliminating the longitudinal keyway and using a locking key secured in a flywheel receptor to ensure rotational alignment and simplify maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional taper lock-and-keyway design is used, then torque transfer is achieved, but fretting, notching, and shaft failure occur due to vibrational forces and manufacturing tolerances
Solution Approach 1:
The patent removes the longitudinal keyway from the shaft entirely, extracting the source of fretting and notching. Instead, a locking key with radiating extensions is secured in a receptor on the flywheel, eliminating the harmful keyway while maintaining torque transfer functionality.
Solution Approach 2:
The locking key is divided into multiple extensions that radiate from a central body, with each extension fitting into a separate slot in the flywheel receptor. This segmentation distributes the locking function across multiple contact points, improving reliability and reducing stress concentration.
2Ease of operation
If a taper lock-and-keyway system is used, then the impeller can be attached to the shaft, but disassembly and reinstallation are complex and time-consuming
Solution Approach 1:
The flywheel is designed with a tapered center opening that allows dynamic adjustment during assembly. The taper provides self-alignment and automatic seating of the flywheel on the shaft, simplifying the installation process and reducing maintenance time compared to rigid fixed-position systems.
Solution Approach 2:
The locking key is pre-secured to the flywheel in the key receptor before final assembly with the shaft. This preliminary positioning ensures proper rotational alignment is established early in the assembly process, preventing misalignment issues during installation and reducing adjustment time.
3Manufacturing precision
If a conventional keyway is used for rotational alignment, then the shaft and impeller are connected, but manufacturing tolerances lead to misalignment and increased wear
Solution Approach 1:
The locking key features an asymmetric design with a square center opening that fits over a square pilot key on the shaft, providing precise rotational alignment. The radiating extensions then engage with slots in the flywheel, creating a multi-point alignment system that compensates for manufacturing tolerances better than a conventional symmetric keyway.
Solution Approach 2:
The square pilot key and square center opening act as an intermediary alignment mechanism between the shaft and flywheel. This intermediary feature establishes precise rotational alignment before the final locking engagement, ensuring accurate positioning while accommodating manufacturing variations.
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 provides a robust, low-maintenance torque transfer system that reduces shaft failure risks, simplifies impeller removal and reinstallation, and minimizes component distress, thereby enhancing operational reliability and reducing maintenance costs.
Implementation Method 1
When properly tightened, the bolts 26, 28 cause a sliding interference fit between the outer surface 16 of the taper lock 18 and the inner surface 20 of the impeller boss 22. A taper lock fitting thus establishes maximum surface contact between the adjoining parts and achieves a high-pressure, compressed, non-slipping joint through which driving torque is transferred from the shaft 12 to the impeller 44.
Data Source
AI summary
A rotationally locked drive assembly for a VSI crusher comprises a drive shaft 52 rotatably securable in a bearing cartridge assembly 60, the drive shaft having a tapered upper end portion 62 for forming a taper joint in cooperation with the tapered central opening 72 of a flywheel 54, a top opening key receptor 81 formed on the top surface 76 of the flywheel for receiving a locking key 56, whereby tightening of fasteners 58 secures locking key 56 in key receptor 81, presses flywheel 54 onto drive shaft 52, thereby fortifying the taper joint between the flywheel 54 and drive shaft 52, and locking drive shaft 52, flywheel 54 and locking key 56 in rotational alignment.