Rotary Rake Positioning via Double-Spring Damping

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Solution Overview

Problem

Existing hay-making machines with rotary windrowers face issues due to mechanical stops wearing out, leading to excessive movement of rotary rakes during transport, which increases loads on the machine and reduces stability.

Innovation Solution

A double-spring arrangement is used to hold the rotary rake in a predetermined position, with springs acting against each other to absorb and dampen movements, reducing the risk of abrupt stops and stabilizing the rake during both operation and transport.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical stops are used to limit the movement of the rotary rake, then the rake position is constrained, but the stops are subject to wear and become unreliable over time

Engineering Contradiction:
Improvereliability of position limitingVSAvoidservice life of mechanical stops
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the mechanical stop system with a hydraulic positioning system. A hydraulic cylinder is used to actively control and maintain the rake in a predetermined position, eliminating the need for mechanical stops that are subject to wear. The hydraulic system provides continuous, wear-free position control through fluid pressure.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The hydraulic system incorporates a position sensor that continuously monitors the rake position and provides feedback to the control unit. The system automatically adjusts the hydraulic cylinder to maintain the predetermined position, making the system self-regulating and eliminating the need for external mechanical stops.

Inventive Principle:
Principle #25Self-service

2Stability of the object's composition

If mechanical stops are used to limit rotary rake movement, then position control is achieved, but excessive movement occurs during transport when stops wear out

Engineering Contradiction:
Improvestability of rotary rake positionVSAvoidreliability of position control
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent employs a position sensor that continuously monitors the actual position of the rotary rake and feeds this information back to the control unit. The control unit compares the actual position with the predetermined position and automatically adjusts the hydraulic cylinder to eliminate any deviation, ensuring stable position control throughout the machine's service life.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The hydraulic positioning system with active control replaces the passive mechanical stop system, providing reliable and stable position control without the wear-related degradation that plagues mechanical stops.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If mechanical stops are used to constrain the rotary rake, then movement is limited, but loads on the machine increase due to abrupt stops

Engineering Contradiction:
Improvesmoothness of position transitionsVSAvoidloads on the machine
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The hydraulic cylinder provides controlled, gradual positioning of the rotary rake through fluid pressure regulation. This replaces the abrupt mechanical contact of stops with a smooth, controllable movement system that minimizes冲击 loads on the machine structure during position transitions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The hydraulic system can control the speed and acceleration parameters of the rotary rake movement, allowing for smooth transitions that minimize dynamic loads. The control unit can adjust the hydraulic flow rate to achieve gentle, load-reducing position changes rather than abrupt mechanical stops.

Inventive Principle:
Principle #35Parameter changes

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 effectively reduces loads on the machine by maintaining the rotary rake in a stable position, minimizing movement and absorbing dynamic forces during transport, and allows for smoother transitions between working and headland positions.

Implementation Method 1

A first spring (26) and a second spring (27) are guided on the respective rod (25)... The first spring (26) is arranged on a first side of the second retaining bracket (24) facing the first retaining bracket (23), and wherein the second spring (27) is arranged on a second side of the second retaining bracket (24) facing away from the first retaining bracket (23).

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The first spring (26) and the second spring (27) are each compression springs. This is particularly preferred in order to minimize relative movement between the respective rotary head and the respective guide carriage in the transport position, and to dampen and minimize loads acting on the haymaking machine in the working and headland positions.

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3620043B1Haymaking machine, in particular rotary windrower
Publication Date: 2021.05.05 CLAAS SAULGAU GMBH
  • EP3620043B1 patent drawingFigure 1~2
  • EP3620043B1 patent drawingFigure 3~4
  • EP3620043B1 patent drawingFigure 5

AI summary

Haymaking machine, comprising a base frame with a longitudinal beam and boom arms (13), with at least one rotary rake (16) driven around a rotary axis, which has tine arms (17) with rake tines (18), wherein the respective rotary rake (16) is mounted on the respective boom arm (13) such that the respective rotary rake (16) can be displaced translationally relative to the respective boom arm (13) and rotationally relative to the guide carriage (20) via a guide carriage (20). A first retaining bracket (23) engages the guide carriage (20) of the respective rotary rake (16). A second retaining bracket (24) engages the respective rotary rake (16).A rod (25) extends through these retaining brackets (23, 24), wherein a first spring (26) and a second spring (27) are guided on the respective rod (25), wherein the first spring (26) is arranged on a first side of the second retaining bracket (24) facing the first retaining bracket (23), and wherein the second spring (27) is arranged on a second side of the second retaining bracket (24) facing away from the first retaining bracket (23).