Compact Oil Pump with Side-by-Side Rotors for Gearbox Lubrication
Solution Overview
Problem
Existing oil pumps for vehicles are bulky and require significant structural volume to generate independent volume flows for main and auxiliary circuits, limiting their compactness and flexibility in vehicle gearboxes.
Innovation Solution
A compact electric oil pump design featuring two independent pump chambers with rotatable pump rotors, where the first pump rotor is an external gearwheel and the second is a gerotor, both driven by a common external toothing, allowing for efficient lubrication and cooling of gearbox components with reduced structural size and component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If two pump rotors are arranged coaxially one above the other in the pump housing with a partition separating the pump chambers, then two independent volume flows are generated, but the structural volume becomes relatively large
Solution Approach 1:
The patent transitions from a vertical coaxial arrangement (one dimension) to a horizontal side-by-side arrangement (another dimension). The first and second pump rotors are positioned adjacent to each other in the same plane, sharing a common drive shaft axis, which reduces the axial height requirement and allows for a more compact overall structure while maintaining independent pump chambers.
Solution Approach 2:
The patent merges the drive mechanisms by using a single common drive shaft to power both pump rotors simultaneously. This eliminates the need for separate drive systems, reduces component count, and consolidates the structural footprint while still delivering independent volume flows through the separately positioned pump chambers.
2Device complexity
If a common drive shaft powers both pump rotors, then device complexity is reduced, but the pump chambers must be arranged in a configuration that may increase structural footprint
Solution Approach 1:
The patent arranges pump chambers in the radial plane rather than stacking them axially. The first pump chamber and second pump chamber are positioned side-by-side around the common drive shaft, utilizing the radial space efficiently. This dimensional reconfiguration reduces the axial footprint while maintaining the benefits of a unified drive mechanism.
3Quantity of substance
If pump chambers are arranged coaxially one above the other, then independent volume flows are achieved, but flexibility in gearbox integration is limited
Solution Approach 1:
The patent positions pump chambers in the radial direction rather than stacking them vertically. This allows the oil pump assembly to have a lower profile and can be more easily integrated into various gearbox configurations and mounting positions, enhancing adaptability while preserving independent volume flow capability through the separately positioned chambers.
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 design achieves a compact, efficient, and flexible oil pump that reduces structural size and production costs while ensuring uniform lubrication and cooling of gearbox parts, enabling additional degrees of freedom in vehicle gearbox design.
Implementation Method 1
The externally toothed first pump rotor (36) and the second pump rotor (38) are coupled to one another in terms of drive by way of an external circumferential toothing (52, 46, 50), in particular with the external toothing (52) of the outer toothed ring (42) of the gerotor (38)
Implementation Method 2
Pump types that are commonly used for such purposes are for example positive-displacement pumps (external-gearwheel pumps), sickle-cell pumps or vane-type pumps
Implementation Method 3
An electric oil pump typically serves for delivering oil as lubricant for in particular moving parts or components... by means of a single drive motor, two mutually independent volume flows, in particular for a main circuit and an auxiliary or additional circuit, are generated
Data Source
AI summary
An oil pump having a pump housing with a suction-side inlet and with a pressure-side first outlet, which is coupled to a first pump chamber, and with a pressure-side second outlet, which is coupled to a second pump chamber having a first pump rotor which is situated in the first pump chamber so as to be rotatable about a first axis, and having a second pump rotor which is situated in the second pump chamber so as to be rotatable about a second axis, wherein the pump rotors are arranged in a plane, oriented substantially perpendicular to the axes of the pump housing and are coupled by way of an external circumferential toothing.