1. * GB780094 (A)
Description: GB780094 (A) ? 1957-07-31
Improvements relating to thrust bearings
Description of GB780094 (A)
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
PATENT SPECIFICATION
Inventor: JOHN ALBERT HERD Date of filing Complete Specification: Feb.
3, 1956.
Application Date: Feb. 17, 1955.
No. 4805/55.
oO Complete Specification Published: July 31, 1957.
Index at acceptance: -Class 12 (3), C5AI, International
Classification;-FO6P., COMPLETE SPECIFICATION
Improvements relating to Thrust Bearings We, THE BRITISH
THOMSON-HOUSTON COMPANxs LIMITED, a British Company having its
registered office at Crown House, Aldwych, London, W.C.2, do hereby
declare the invention, for Which we pray that a patent may be granted
to us, and the method by which it is to be performed, to be
particularly described in and by the following statement: -
This invention is concerned with the lubrication of thrust bearings,
in particular of such bearings as are suitable for large vertical

2. shaft hydro-electric generators or pump motors.
Awell knlmowkind of thrustbearingcommonly used for such machines
comprises a runner secured to the shaft and provided with a highly
polished surface which rests on a segmented stationary ring which is
made up of a number of pads, for example eight or ten according to
size; the pads are spaced apart and are each provided with a babitted
surface for co-operation with the polished surface of the rotating
runner. The pads are each tiltingly supported on a base ring which in
turn is supported by the base of the bearing housing, and may be of
the well-known "line-pivoted" or Michell type, "'point-pivoted" or
Kingsbury type, or they may be resiliently supported on a number of
precompressed springs. A typical example of such a bearing showing the
latter type of supporting pads is described in British Patent
Specification No. 720,816.
The bearing assembly of the aforesaid kind is totally enclosed in an
oil reservoir which is made up of a bottom plate which is the base of
the bearing housing, an outer wall concentric with the shaft, a sleeve
adjacent to and closely surrounding the shaft forming the inner wall,
and a cover plate to complete the enclosure.
The reservoir thus comprises an inner chamber situated between the
inner side of the bearing and the sleeve, and an outer chamber between
the outer side of the bearing and the outer wall. The inner chamber is
open to atmosphere and thus constitutes a low pressure area in the
lubrication system, while the outer chamber is sealed from atmosphere
and pro[Price 3s. 6d.1 vides an area of high pressure in the
reservoir.
Cooling coils may be provided in known manner in the outer chamber.
Ducts extend radially through the runner and provide oil passages
between the inner and outer chambers. The oil circulation system is
described in the aforesaid patent specification. Briefly, the rotating
runner provides a centrifugal pumping action, drawing oil from the
inner chamber and delivering it under pressure through the radial
passages to the outer chamber where it circulates around the cooling
coils, when provided, passing between andT around the bearing pads,
whence it is directed between the babitted surface and the runner back
to the inner chamber ready for circulation.
According to a feature of this invention the circulation of
lubricating oil in a thrust bearing of the kind hereinbefore described
is materially assisted by a radial flow impeller pump which comprises
a number of blades Which are carried by, and therefore rotate with,
the rotating member and are positioned above the thrust face of lthe
pads adjacent the inner ends of the radial ducts through the runner.
The blades are conveniently mounted on a cylinder which depends from
an upper part of the runner and extends between the segmented

3. stationary pad ring and the inner wall elf the reservoir to the bottom
thereof. The impeller blades may be pivotally mounted if desired s6 as
to be adaptable for either direction of shaft rotation.
According to a further feature of the invention, the outer ends of the
radial passages, where they open into the outer chamber of the
reservoir, are provided with means for regulating the rate of flow,
and hence the pressure of the issuing oil. These means may
conveniently be provided by removable nozzles fitted into the ends of
the ducts as by screwing. One set of nozzles may thus be readily
exchanged for another set of different size to vary the size of the
orifice.
The invention is illustrated in the schematic drawing filed with the
provisional specifica780,094 2 780,094 tion, in which Fig. 1 is a part
sectional elevation taken on the axis of a bearing of the kind herein
referred to, and Fig. 2 is a part sectional plan of the rotating
member taken on the line A-A of Fig. 1.
In the drawings the rotating ring or runner 1 is shown fixed to the
shaft 2 through a thrust collar 3 and is provided with a number of
radial oil ducts 4. The thrust bearing surface exists at the area of
contact between the runrner 1 and a stationary ring made up of a
number of Michell pads 5 supported in well known manner on the base 6
of the bearing housing.
The oil reservoir is defined by the base 6, an upstanding inner wall 7
closely surrounding the shaft 2, and an outer wall 8 and comprises an
inner chamber 9 between wall 7 and the bearing, and an outer chamber
10, between the bearing and wall 8, in which are situated cooling
coils represented by the reference 11.
A number of blades 12 constituting a radial impeller are mounted on a
cylinder 13 depending from the thrust collar 3. These blades are
located above the plane of the bearing surfacer of the pads 5 and
adjacent ithe inner ends of ducts 4. The cylinder 13 extends
downwardly practically to the bottom of the inner oil chamber 9. At
their outer ends the ducts 4 are screw-threaded or otherwise adapted
to receive removable nozzles 14 whereby the size of outlet orifice may
be varied to suit different operating conditions.
In Fig. 2 the blades are shown as curving outwardly in the direction
of rotation; they may however have any other suitable shape and may be
mounted so as to pivot about a vertical axis and thereby be adaptable
for either direction of shaft rotation.
The circulation of oil through the bearing is shown by the arrows in
Fig. 1. As the runner 1 rotates oil will be drawn by centrifugal
pumping action from the,chamber 9 through the ducts 4 with the
assistance of the blades 12 and out through nozzles 14, into chamber
10, through cooling coils 11, through the spaces between the pads 5 to

4. the babitted bearing surfaces 15 thereof and back into chamber 9.
Many details shown in the drawings have not been described as they are
not necessary for an understanding of this invention.
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* 5.8.23.4; 93p