Self-aligning Gear Pump Housing with Split Bearings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gear pumps face challenges in maintaining tight tolerances between gears and the pumping chamber, leading to wear issues and inefficiency, which is typically addressed by using a replaceable liner that may require frequent replacement.
Innovation Solution
The design of the gear pump incorporates a housing divided into three portions with strategically placed drive and idler shaft bearings that extend into the pumping chamber, aligning the housing elements and maintaining precise tolerances between the gears and the chamber, eliminating the need for a replaceable liner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gears are positioned close to the pumping chamber wall, then pumping efficiency is improved, but wear between gears and chamber wall increases
Solution Approach 1:
The housing is divided into three separate elements (first housing element, central housing element, second housing element) that can be assembled together. The drive shaft bearing is split between the first and second housing elements, allowing precise positioning of the bearing relative to the pumping chamber wall without requiring the entire housing to be a single precision-machined piece. This segmentation enables the gears to be positioned optimally close to the wall for efficiency while the bearing structure prevents excessive wear.
2Reliability
If a replaceable liner is used to maintain tight tolerances, then gear-chamber wear is reduced, but device complexity and maintenance requirements increase
Solution Approach 1:
The replaceable liner concept is replaced by integrating the tolerance-maintaining function directly into the bearing structure. The drive shaft bearing is positioned such that it extends into the pumping chamber and maintains the precise clearance between the drive gear and chamber wall. This eliminates the need for a separate replaceable liner component, reducing structural complexity while maintaining wear resistance through the self-aligning bearing structure.
3Productivity
If tight tolerances are maintained between gears and chamber wall, then pumping efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The drive shaft bearing serves as an intermediary element that indirectly controls the clearance between the drive gear and pumping chamber wall. Instead of requiring direct precision machining between the gear and chamber, the bearing position and dimensions act as the precision reference. The bearing is machined to precise dimensions and positioned in recesses in the housing elements, which then determines the gear-chamber clearance. This intermediary approach reduces the overall manufacturing precision requirements compared to direct gear-chamber interfacing.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed herein is a gear pump (100) for pumping a fluid (404). The gear pump comprises: a sealed internal chamber (102); a pumping chamber (104) within the sealed internal chamber; a first pump port (122) fluidically connected to the pumping chamber; a second pump port (114) fluidically connected to the pumping chamber; a drive gear (120) within the pumping chamber; an idler gear (122) within the pumping chamber, wherein the drive gear and the idler gear are configured for pumping the fluid between the first pump port and the second pump port; a drive shaft (124) coupled to the drive gear, wherein the drive shaft is configured for rotationally driving the drive gear, wherein the drive shaft is within the sealed internal chamber; an idler shaft (126) coupled to the idler gear, wherein the idler shaft is within the sealed internal chamber, wherein the idler gear is coupled to the idler shaft; a pump housing (106, 108, 110) formed from a first housing element (106), a central housing element (108), and a second housing element (110), wherein the central housing element is positioned between the first housing element and the second housing element, wherein the first housing element, the second housing element and the central housing element form at least a portion of the sealed internal chamber, wherein the pumping chamber is formed entirely within the central housing; a first drive shaft bearing (128), wherein the first drive shaft bearing is mounted partially within the first housing element; a second drive shaft bearing (130), wherein the second drive shaft bearing is mounted partially within the second housing element, wherein the first drive shaft bearing and the second drive shaft bearing both partially extends into and align the drive gear with the pumping chamber; a first idler shaft bearing (132), wherein the first idler shaft bearing is mounted partially within the first housing; a second idler shaft bearing (134), wherein the second idler shaft bearing is mounted partially within the second housing element, wherein the first idler shaft bearing and the second idler shaft bearing both partially extends into the pumping chamber and align the idler gear with the pumping chamber.