Gerotor Hydraulic Device with Adjustable Eccentricity
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Solution Overview
Problem
Existing hydraulic devices, such as gerotors, face limitations in efficiency, size, cost, and vibration due to their design, with Low Speed High Torque (LSHT) gerotors experiencing slow rotation and oscillating parts causing noise, and High Speed Low Torque (HSLT) gerotors suffering from high leakage and efficiency losses.
Innovation Solution
A compact hydraulic device with a gerotor design featuring an eccentrically disposed inner rotor and a stationary outer ring, utilizing radial fluid feeder channels and control sleeves to regulate fluid flow, allowing for variable displacement and torque, and incorporating a drive shaft cylinder with eccentric displacement to minimize leakage and enhance efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If LSHT gerotor design is used, then high torque is achieved, but rotation speed is limited and oscillating parts cause noise and vibrations
Solution Approach 1:
The patent implements variable displacement capability allowing the gerotor to dynamically adjust its operating parameters. The inner rotor can vary its eccentricity relative to the outer ring, enabling transition between high-torque low-speed and low-torque high-speed operating modes, thus resolving the fixed trade-off in traditional LSHT designs
Solution Approach 2:
The invention changes the geometric parameters of the gerotor system by allowing variable eccentricity between the inner rotor and outer ring. This parameter variation enables the system to optimize between torque and speed based on operational requirements, overcoming the fixed performance characteristics of conventional designs
2Speed
If HSLT gerotor design is used, then high rotation speed is achieved, but leakage increases and efficiency decreases
Solution Approach 1:
The variable displacement mechanism allows the system to optimize the gap between lobes dynamically. At high speeds, the eccentricity can be reduced to minimize leakage paths, while maintaining adequate clearance to prevent mechanical contact, thus preserving efficiency at high rotation speeds
Solution Approach 2:
The patent introduces fluid control mechanisms that act as intermediaries to manage pressure distribution within the chambers. This intermediary fluid control helps maintain sealing effectiveness and reduces leakage losses even at high rotation speeds where direct mechanical sealing becomes difficult
3Ease of operation
If separate valve constructions are used in LSHT gerotor, then fluid direction is achieved, but device complexity and cost increase
Solution Approach 1:
The patent merges the fluid direction control function directly into the gerotor structure itself. The lobes of the inner rotor and outer ring perform dual functions: mechanical fluid displacement and flow direction control, eliminating the need for separate valve constructions and reducing overall system complexity
Solution Approach 2:
The gerotor components are designed with multi-functionality, where the same structural elements that create volume changes for fluid displacement also serve to direct fluid flow through their geometric configuration, reducing the need for additional dedicated components
4Force
If eccentric inner rotor with orbital movement is used, then high torque is generated, but device size and weight increase
Solution Approach 1:
The patent employs a nested configuration where the inner rotor with external lobes is positioned within the outer ring with internal lobes. This nested arrangement allows the torque-generating eccentric mechanism to be compactly integrated, reducing the overall footprint and weight compared to distributed torque mechanisms
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 compact, efficient, and cost-effective hydraulic device with reduced noise and vibrations, capable of high rotational speed and efficient fluid management, overcoming the limitations of existing gerotor designs.
Implementation Method 1
the inner rotor is adapted to slide against a drive shaft cylinder
Implementation Method 2
a plurality of expanding and contracting volume pressure chambers between the inner rotor and the outer ring
Data Source
AI summary
A hydraulic device (1) comprising a housing (2) and a gerotor (3) contained within the housing (2), the gerotor (3) having an inner rotor (4) eccentrically disposed within an outer ring (5), the outer ring having a central axis (19), the outer ring (5) being fixed to the housing, the inner rotor (4) having external lobes (4a) extending radially outwardly engaging the outer ring (5) having internal lobes (5a) extending radially inwardly, the inner rotor (4) being arranged for orbital and rotational movement relative the outer ring (5), wherein the orbital and rotational movement will define a plurality of expanding and contracting volume pressure chambers (7) between the inner rotor (4) and the outer ring (5). The hydraulic device (1) comprises a fluid feeder tube (8) with a central axis (19), the fluid feeder tube (8) is provided with at least one fluid inlet line (8a, 8c) and at least one fluid outlet line (8b, 8d), the inner rotor (4) is adapted to slide against a drive shaft cylinder (10b), the drive shaft cylinder (10b) having a circumference which is eccentrically disposed relative the central axis (19), the inner rotor (4) comprises at least one radial fluid feeder channel (9) disposed radially from the center of and through the inner rotor (4) and out to at least one of the plurality of expanding and contracting volume pressure chambers (7), wherein said fluid inlet line (8a, 8c) and said fluid outlet line (8b, 8d) respectively are radially connectable to said radial fluid feeder channel (9) for fluid communication into and out from said expanding and contracting volume pressure chambers (7).