Internal Gear Pump Leakage Reduction via Pressure Equalization
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Solution Overview
Problem
Internal gear pumps experience leakage losses and energy inefficiencies due to manufacturing inaccuracies and thermal deformations, which are exacerbated by increased wear and mechanical friction when applying compressive prestress to the gear teeth, as per the Eckerle principle.
Innovation Solution
The design incorporates an internal gear pump with an integrated electric motor and a unique configuration where the inflow channel partially opens into the outflow working space at the head end, and the outflow channel is formed only within the pressure angle range, ensuring that the flanks of the internal and external gear teeth lie on top of each other, eliminating leakage losses by maintaining pressure differences within the pressure angle range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a clearance is provided between the inner and outer gears at the headspace to compensate for manufacturing inaccuracies and thermal deformations, then manufacturing precision and thermal stability are improved, but leakage losses increase due to pressurized fluid flowing from the outlet working chamber to the inlet working chamber
Solution Approach 1:
The invention extracts the harmful pressure difference from the head region by providing a communication path between the outlet working chamber and inlet working chamber through the head region. This allows the pressure buildup that would otherwise cause leakage to be eliminated, while the clearance for manufacturing tolerances is maintained.
Solution Approach 2:
The invention converts the potentially harmful clearance at the headspace into a beneficial feature by allowing it to serve as a pressure equalization path. The clearance that would normally cause leakage is instead used to communicate pressure between chambers, preventing the formation of harmful pressure differences.
2Loss of energy
If the teeth of the internal and external gears are placed under pressure preload in the head region according to the Eckerle principle, then leakage losses at the head are prevented or reduced, but wear on the teeth increases and mechanical friction losses significantly increase
Solution Approach 1:
Instead of applying pressure preload to prevent leakage (the conventional approach), the invention inverts the approach by creating a pressure equalization path that eliminates the pressure difference causing leakage. This removes the need for pressure preload entirely.
Solution Approach 2:
The invention converts the potential harm of pressure differences into a benefit by using the head region as a pressure equalization path. This eliminates leakage without requiring the harmful pressure preload that would otherwise be necessary.
3Loss of energy
If pressure differences are maintained at the head end to prevent leakage, then leakage losses are reduced, but energy efficiency decreases due to compressed fluid flowing back from outlet to inlet working chamber
Solution Approach 1:
The invention extracts the harmful pressure difference from the system by providing a communication path between the outlet and inlet working chambers through the head region. This allows compressed fluid to equalize pressure without flowing back through the gear teeth, eliminating the energy waste.
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 significantly reduces leakage losses and enhances the efficiency and energy efficiency of the internal gear pump by preventing fluid leakage from the outflow to the inflow working space, ensuring that pressure build-up occurs only within the designated pressure angle area, thus minimizing energy wastage.
Implementation Method 1
An electric motor with a stator and a rotor is integrated into the internal gear pump, and the outer gear is formed by the rotor
Implementation Method 2
the flanks of the teeth of the internal gear bear against the flanks of the teeth of the external gear, and a torque can be transmitted from the external gear to the internal gear
Implementation Method 3
The inlet working chamber thus represents the suction side, and the outlet working chamber the pressure side of the internal gear pump
Data Source
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AI summary
The invention relates to an internal gear pump (6), in particular for a motor vehicle, for conveying a fluid, comprising an internal gear (22) having an internal toothed ring (23), an external gear (24) having an external toothed ring (25), wherein the teeth (21) of the internal and external gears (22, 24) mutually engage, a work space (47) formed between the internal gear (22) and the external gear (24), which is divided into an inflow work space (30) and an outflow work space (31), an inflow channel (28) opening into the inflow work space (30) for introducing the fluid to be conveyed into the inflow work space (30), and an outflow channel (29) opening into the outflow work space (31) for discharging the fluid to be conveyed from the outflow work space (31), wherein the inflow work space (30) and the outflow work space (31) are separated from one another at a head location (48) and at a cog point (49) between the internal and the external gears (22, 24), wherein the inflow channel (28) in addition opens in part in an angular area (50) of the outflow work space (31).