Variable Speed Baler Drive for Smooth High-Inertia Starting
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Solution Overview
Problem
Conventional hay balers face difficulties in starting due to the large mass of moving components, leading to excessive time to reach operating speed, potential tractor stalling, and risk of component failure or damage during initiation.
Innovation Solution
A square baler equipped with a variable speed drive transmission that includes an adjustable sheave and driven sheave system, allowing for selective speed reduction to ease starting and minimize stress on the tractor and baler components, featuring a continuously variable transmission with hydraulic fluid control to adjust speed ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional balers use a large mass flywheel and transmission components to transfer large torque, then the baler can operate smoothly and continuously, but the baler becomes difficult for the tractor to start and may cause tractor stalling
Solution Approach 1:
The patent applies a variable speed drive system that dynamically adjusts the speed ratio between the tractor PTO shaft and the baler transmission input shaft. During starting, the speed ratio is reduced to lower the torque demand on the tractor, making it easier to start without stalling. Once started, the speed ratio can be increased to maintain smooth operation, thus resolving the contradiction between ease of starting and operational stability.
2Power
If conventional balers use large mass moving components including flywheel and plunger, then the transmission can transfer large torque, but the tractor may take excessive time to bring the baler up to operating speed
Solution Approach 1:
The variable speed drive system allows the transmission input shaft to rotate at a higher initial speed during the starting phase, reducing the time required to bring the heavy moving components up to operating speed. The speed ratio is then adjusted to maintain the necessary torque transfer capability once operational speed is reached, thus resolving the contradiction between power transfer capability and acceleration time.
3Power
If conventional balers use large mass moving components, then the transmission can handle high torque loads, but the mass may cause failure or excessive wear to transmission components and tractor components during initiation
Solution Approach 1:
The variable speed drive system dynamically reduces the speed ratio during the starting phase, which proportionally reduces the torque demand on the transmission components and tractor components. This prevents excessive wear and potential failure during the most stressful period of operation. Once started, the speed ratio is increased to maintain the necessary torque handling capacity for normal operation, thus resolving the contradiction between power handling and component reliability.
Solution Approach 2:
The variable speed drive system provides a cushioning effect during starting by limiting the peak torque demand on the transmission and tractor components. This beforehand cushioning prevents shock loads that could cause immediate failure or accelerate wear, protecting the components before the full torque load is applied during normal 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 smooth and reliable initiation of baler operation, reducing the risk of tractor stalling and component damage, while allowing efficient bale formation by adjusting speed ratios during operation.
Implementation Method 1
featuring a continuously variable transmission with hydraulic fluid control to adjust speed ratios
Data Source
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AI summary
A square baler (30) includes a chassis (32), a plunger (36), and a variable speed transmission (42). The plunger assembly (36) includes a reciprocating plunger head (76) slidably mounted relative to the chassis (32) and operable to reciprocate within a chamber (54) to apply a compressive force against the material. The transmission (42) includes drive (86) and driven components (90) and an endless drive element (98) that drivingly interconnects the components. The driven component is drivingly connected to the plunger head. The drive component is operable to be driven by a prime mover at a drive input speed. At least one of the components has an adjustable operating diameter so that the driven component has a variable output speed.