Internal Gear Pump Asymmetric Tooth Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal gear pumps for hydraulic vehicle brake systems face a conflict between minimizing leakage and friction, with existing designs experiencing inefficiencies due to axial and radial leakage gaps, which affect mechanical and hydraulic efficiency and service life.
Innovation Solution
The design features a pinion and ring gear with tooth geometry where the axial width of the tooth root is greater than the tooth crest, allowing for fluid friction mode operation, reduced mechanical friction, and increased reliability by configuring the tooth flanks and crest faces as convex or freeform surfaces, and machining these surfaces to minimize solid contact pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional tooth geometry with equal axial width at tooth root and tooth crest is used, then manufacturing is simpler, but mechanical friction increases and fluid friction mode cannot be achieved
Solution Approach 1:
The patent applies asymmetry by configuring the tooth geometry such that the axial width of the tooth root is greater than the axial width of the tooth crest. This asymmetric design creates a specific contact pattern between meshing teeth that enables fluid friction mode operation, reducing mechanical friction and energy loss in the gear pump.
Solution Approach 2:
The patent changes the geometric parameters of the tooth profile, specifically the axial widths at different locations. By defining that the axial width at the tooth root exceeds the axial width at the tooth crest, the invention modifies the contact characteristics to achieve fluid friction operation, thereby reducing mechanical losses.
2Loss of energy
If axial width of tooth root equals axial width of tooth crest, then manufacturing is easier, but leakage increases and hydraulic efficiency decreases
Solution Approach 1:
The asymmetric tooth geometry with wider tooth root than tooth crest creates an optimized contact and sealing pattern that reduces leakage paths while maintaining manufacturability. This asymmetric configuration improves hydraulic efficiency by minimizing energy loss through leakage.
3Reliability
If conventional tooth geometry is used, then service life is reduced due to solid body friction, but manufacturing remains standard
Solution Approach 1:
The asymmetric tooth design with greater root width than crest width enables fluid friction mode operation, which significantly reduces wear and extends service life compared to conventional symmetric teeth that operate in solid body friction mode.
Solution Approach 2:
The patent replaces solid body friction with fluid friction by designing the tooth geometry to operate in a lubricated regime. This substitution of friction mechanism dramatically improves reliability and service life of the gear pump components.
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
This configuration reduces mechanical friction, lowers drive power requirements, minimizes leakage, and enhances reliability, particularly in applications with high starting/stopping cycles, by transitioning from solid body to fluid friction at low pump speeds.
Implementation Method 1
the internal gear pump can be operated in a fluid friction mode in operation
Implementation Method 2
solid body friction and/or mixed friction that occurs as a matter of principle can already be replaced with fluid friction at low pump speeds
Data Source
AI summary
An internal gear pump for a hydraulic vehicle brake system includes a pump shaft, a pinion, a ring gear, a first axial plate, and a second axial plate. The pinion is disposed on the pump shaft, is configured to rotate conjointly therewith, and is arranged eccentrically within the ring gear so as to mesh therewith. The first and second axial plates are adjacent to the pinion and the ring gear. A toothing on at least one of the ring gear and the pinion is configured such that an axial width of a root of a respective tooth is greater than an axial width of a crest of the respective tooth. A corresponding method relates to producing such an internal gear pump.