CA1211987A

CA1211987A - Hydraulic devices

Info

Publication number: CA1211987A
Application number: CA000437644A
Authority: CA
Inventors: Harry Haigh; Rudy C. Sonmor
Original assignee: R C S ENTERPRISES Ltd
Current assignee: R C S ENTERPRISES Ltd
Priority date: 1983-09-27
Filing date: 1983-09-27
Publication date: 1986-09-30

Abstract

IMPROVEMENTS IN HYDRAULIC DEVICES
ABSTRACT OF THE DISCLOSURE

A hydraulic device, pump or motor, useful with the hydraulic fluid used in a mine. The device comprises a housing with an impeller within the housing. A drive shaft extends through the housing and carries the impeller. There are bearings for the shaft on either side of the impeller.
The improvement is an isolator member positioned between each bearing and the impeller chamber to prevent contact between the bearing and the pumped hydraulic fluid. The invention reduces the damage to hydraulic pumps and motors without increasing fire risk within the mine and helps conserve oil. This latter advantage applies to use of the invention anywhere, including use outside a mine.

Description

This invention relates to a hydraulic motor or pump useful in a mine for pumping or being driven by a hydraulic fluid.

Minîng and drilling equipment is most efficiently operated by hydraulic pumps and motors.

Generally hydraulic pumps and motoxs use a hydrau-lic fluid that is an oil, therefore, the lubrication of the bearings is not a problem. But with underground mining equipment, because of the fire hazard, regulations require the use of a water based oil product in all hydraulic systems. Therefore, in mining equipment, bearing lubri-cation is a problem. Water based fluid has resulted in greatly reduced pump and motsr life ~approximately 20~
life), efficiency, speed and.pressure in systems. A hydrau-lic fluid comprising 60 parts water and 40 part~ of oil has been used in mining but there are regulations to be brought in that will require the fluid to comprise 95 parts of water and 5 parts of oil. Using the 6n 40 combination the bearing failure rate among hydraulic pumps and motors which rely on the hydxaulic fluid to lubricate the.bearings is high.
Using the 95:5 ration the bearing failure is extremely high.

Accordingly, the present .invention seeks to provide a hydraulic device, a pump or motor, for use with hydraulic fluid and particularly useful in mines in which, in tests carried out, the failure rate has been extremely low. ~hat is, there has been extended pump and motor life using the present invention. Extended life has also been .' ~ .

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provided for devices, pumps and motors, in systems using a standrad hydraulic oil.
Accordingly, the present invention provides a gear pump useful with a hydraulic fluid having a water base, the gear pump comprising a housing: a drive gear on a driveable hub and an idler gear engaging with the drive gPar and carried by an idler hub, the drive hub and the idler hub each being mounted in bearings at both ends of the housing; an isolator between each bearing and the hydraulic fluid, said isolator comprising a recess to receive an end of each bearing; a sealing member posi-tioned within each recess to seal agains~ the outer surface of the shaft at the sealing members inner edge and to seal against the outer edge of the recess at the sealing member's outer edge.
Aspects of the invention are illustrated J merely by way of example, in the accompanying drawings in which:
Figure 1 is an exploded view of a pump according to the present invention; and ~0 Figure 2 is a view, partially exploded and par-tially in section, showing an isolatox member useful in the pump of Figure 1.
The drawings illustrate a gear pump comprising a driven gear 2 on a driveable shaft 4 and an idler gear 6 engaging with the drive gear 2 and carried by an idler shaft 8. ~iquid is pumped by the rotation of the gear mem-bers 2 and 6 impelling the liquid centrifugally in known manner. The drive shaft with kay or spline to drive gear 2 and hub 4 is not shown as it can be many styles including integral with gear 2 and hub 4.
The pump comprises a main body 10 having end mem-bers 12. Sealing rings 14 are provided between the main . --2~

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body 10 and the end members 12. The end members 12 are provided with recesses 16 to receive bearings 18 to receive hubs 4 and 8. A shaft seal 20 is also shown for a drive shaft, which is earlier mentioned and not shown.
Details such as studs to hold the component parts of the pump together are also not shown. These components are entirely conventional.
According to the invention there is a ~earing isolator on each vf the four hubs 4 and 8. As more clearly illustrated in Figure 2 the isolator comprises a plate 22 having two openings 24 through. There are two recesses 34, and two recesses ~6 to receive the bearings 18. Each recess 34 contains an O ring 28. A second O ring 30 engages the outer edge OL the recess 26 and an annular plate 32 abuts both O rings to locate them within the recess.
It should be emphasized that the particular isolator illustrated in the form of two O rings and a plate locating the O rings within the recesses 26 and 34 may be replaced by other styles of isolators such as a one piece seal plate, isolating thrust plate etc., that is leak proof and will prevent hydraulic fluid moving from the body 10 past the isolators and on to the bearings 18. If such a leakage occurs the liquid will wash away the lubricant of the bearings and will cause their early failure. It should be noted that the bearings in the pump according to the present invention may be greased with bearing grease in conventional manner. In this way life of several thousand hours can be expected. If the isolator is not present, that is if the bearing relies upon hydraulic fluid for lubrica-tion then an unacceptably low number of hourse of l~fe isthe probable result.
A pump has been illustrated but the skilled man wîll appreciate that the invention is equally applicable to hydraulic motors~ Similarly although a gear pump is shown, a vane-type device could also be il.lustrated.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A gear pump useful with a hydraulic fluid having a water base, the gear pump comprising:
a housing;
a drive gear on a driveable hub and an idler gear engaging with the drive gear and carried by an idler hub, the drive hub and the idler hub each being mounted in bearings at both ends of the housing;
an isolator between each bearing and the hydraulic fluid, said isolator comprising a recess to receive an end of each bearing:
a sealing member positioned within each recess to seal against the outer surface of the shaft at the sealing members inner edge and to seal against the outer edge of the recess at the sealing member's outer edge.

2. A device as claimed in claim 1 in which the sealing member comprises a first O ring to engage the shaft:
a second O ring to engage the outer edge of the recess;
a plate abutting both O rings to locate them within the recess.

3. A device as claimed in claim 2 in which the first ring is of PTFE and in which the second O ring is of neoprene.