Hydraulic Steering Unit Measuring Motor Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hydraulic steering units face challenges in providing comfortable steering and maintaining functionality, especially during emergencies when pressure is insufficient, due to a large dead band and limited auxiliary pumping capabilities.
Innovation Solution
Incorporating a measuring motor arrangement with a pair of measuring motors in the working flow paths, along with a valve system for parallel connection or short-circuiting, and additional orifices for improved pressure distribution and stability, allowing for reduced steering effort and auxiliary pumping assistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single measuring motor is used in the working flow path, then the device complexity is reduced, but the steering comfort and auxiliary pumping capability are insufficient
Solution Approach 1:
The measuring motor arrangement is segmented into two separate measuring motors (first measuring motor and second measuring motor) that can operate independently or in parallel. This segmentation allows the system to provide enhanced steering comfort through combined operation while maintaining the ability to function with a single motor in emergency situations, thus resolving the contradiction between device complexity and steering comfort.
Solution Approach 2:
The measuring motors are designed with multi-functionality, serving dual purposes: they assist in steering operation under normal conditions and function as auxiliary pumps during emergencies when pressure is insufficient. This universal design allows a single motor to provide both steering assistance and emergency pumping capability, reducing the need for additional components while maintaining comprehensive functionality.
2Force
If the measuring motor arrangement operates as auxiliary pump with single motor, then the force required is reduced, but the steering assistance capability is compromised
Solution Approach 1:
The valve system dynamically switches between different operational modes: under normal conditions, both measuring motors operate in parallel to provide maximum steering assistance; in emergency situations, the system transitions to single-motor auxiliary pump mode with reduced force requirements. This dynamic adaptability allows the system to optimize performance based on real-time pressure and steering demands, resolving the contradiction between force requirements and steering assistance capability.
3Measurement precision
If the orifices are kept closed to minimize dead band, then the steering precision is improved, but the auxiliary pumping capability is reduced
Solution Approach 1:
The orifices are designed to open periodically or conditionally based on system needs: they remain closed during normal steering operation to minimize dead band and maximize precision, but open when auxiliary pumping is required to maintain reliability. This periodic or conditional opening strategy allows the system to achieve both high steering precision and reliable auxiliary pumping capability at different operational phases.
Data Source
AI summary
A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (8) connected to a main flow path (6) and a tank port (T) connected to a tank flow path (7), a working port arrangement having a left working port (L) connected to a left working flow path (9) and a right working port (R) connected to a right working flow path (10), a bridge arrangement (14) of variable orifices having a first left orifice (A2L) connected to the main flow path (6) and to the left working flow path (9), a first right orifice (A2R) connected to the main flow path (6) and to the right working flow path (10), a second left orifice (A3L) connected to the left working flow path (9) and to the tank flow path (7), and a second right orifice (A3R) connected to the right working flow path (10) and to the tank flow path (7). Such a hydraulic steering unit should allow comfortable steering. To this end a measuring motor arrangement is arranged in one of the left working flow path (9) and the right working flow path (10), the measuring motor arrangement (15) having a first measuring motor (16) and a second measuring motor (17).