FIELD OF THE INVENTION
The present invention relates to a spindle for spinning or twisting machines comprising a radial foot bearing .More particularly this invention relates to a spindle for spinning or twisting machines comprising an improved radial foot bearing which facilitates reduction in the power required to operate the spindle.
BACKGROUND ART
Spindle used in a ring spinning and twisting machine, comprises a spindle blade assembled in the conical part of upper part of the spindle which is rotatably supported in the bottom part and driven by the drive system of the ring spinning and twisting machine in a known way. The spindle blade is rotatably supported by a neck bearing and a foot bearing. The neck bearing is positioned in a tube-like neck bearing housing which is pressed at the top portion of the bolster. The bottom portion of the bolster is closed and so designed that it can be fitted on the spindle rail in a known way and vertically aligned.
The foot bearing comprises a radial bush bearing provided to take the radial force and an axial foot bearing to take up the axial force which are generated due to the rotation of the upper part of the spindle . The bottom portion of the spindle blade is disposed on the axial foot bearing . The radial bush bearing is fitted to a centering sleeve and the centering sleeve carrying the radial bush bearing is fitted to the neck bearing housing at its bottom side. The centering sleeve is provided with annular helical grooves. Between the annular outer contour of the centering sleeve and the hollow cylindrical inner contour of the bolster the oil spool is placed vertically . The oil spool is retained in its required position by means of a spacer. The annular helical grooves provided on the centering sleeve provides an orbit ally variable spring action to the centering sleeve which is transmitted to the oil spool for vibration damping.

Between the cylindrical outer contour of the centering sleeve and the hollow cylindrical inner contour of the bolster there is a narrow damping gap which is filled with oil. The arrangement is so designed that the oil is also the lubricating oil in the area of the axial foot bearing and radial bush bearing . In the spindles employed in the prior art, the spindle blade is supported by the entire inside surface of the given length radial bush bearing . This is liable to increase the friction and consequently liable to consume more power required to drive the spindle.
OBJECT OF THE INVENTION:
It is an object of the invention to reduce the area of contact between the spindle blade and the radial bush bearing retaining the same length of the radial bush bearing known in the art.
It is an another object of the invention to reduce the power required to drive the spindle.
It is yet another object of the invention to provide an effective circulation and spill out of oil for better cooling of the system.
The invention provides a spindle bearing for textile machine with improved
foot bearing comprises a neck bearing fitted to the upper end of the bearing
head sleeve fitted to the bolster of the spindle assembly, a combination foot
bearing having a radial bush bearing and an axial foot button fitted to a
centering sleeve fitted to the bearing head sleeve, wherein the neck bearing
and the combination foot bearing being disposed to rotatably support the
spindle blade attached to the top part of the spindle assembly
characterized in that the radial bush bearing of the said combination foot bearing is provided with grooves .

BRIEF DESCRIPTION OF THE DRAWINGS
Fig 1 of the drawing schematically illustrate bottom part of the spindle according to the invention.
Fig 2 of the drawing schematically illustrate the enlarged view of the foot bearing according to the invention.
DESCRIPTION OF THE INVENTION
The spindle bearing assembly (1) shown in figure 1, which is suitable for a ring spinning machine or a ring twisting machine, is disposed to rotatably support the spindle blade(2) attached to the top part of the spindle assembly which is driven to rotate in a known way. The spindle blade(2) is rotatably supported in a neck bearing (4) and a combination foot bearing (3). The neck bearing (4) is fitted to the upper end of the bearing head sleeve (5) , which is fixed to the bolster (B) of the spindle assembly and fitted to the spindle rail and vertically aligned. A combination foot bearing(3) comprises a radial bush bearing (7), which serves to take up the radial forces. The combination foot bearing(3) is supported in a radially movable and floatingly arranged centering sleeve (9) , The upper end of the centering tube (9) is fitted to the bearing head sleeve (5) underneath the neck bearing (4). The take up of the axial forces of the combination foot bearing (3) is served by an axial foot button (8) which takes up the axial forces caused by the rotation of the spindle blade (2). The axial foot button (8) itself is supported by means of a plurality of intermediary components on the bottom of the bolster (B). The hollow space available between the bottom of the bearing head sleeve (5)and the closed bottom end of the bolster (B) is used as oil bath as well as to locate the oil spool (6) surrounding the centering sleeve (9) . The centering sleeve (9), having grooved slots (10) which provide an orbital variable spring action to the centering sleeve (9) that is transmitted to the oil spool (6) for vibration dampening. The damping gap is filled with oil. The arrangement is

so designed that the oil is also the lubricating oil in the area of the axial foot button (8) and the radial bush bearing (7),
Two sets of oil holes (11) are provided in the centering sleeve (9) to facilitate the circulation of the oil between the annular gap of the oil spool (6) and the oil bath. The oil spool (6) is retained at a pre determined position by means of a spacer (12).
Though lubricating arrangement is provided to minimize the frictional forces produced due to frictional contact between the inner annular portion of the radial bush bearing (7) and outer surface of the spindle blade (2) this invention employs grooves (13) which may be radial grooves or helical grooves and are provided at the inner annular portion of the radial bush bearing (7) . This is aimed at by around 25 % to 35 % , preferably 30% reduction in the area of contact between radial bush bearing (7) and the spindle blade(2) comparing the radial bush bearing (7) without the grooves (13) . The helix of grooves (13) are either in left hand direction or right hand direction. A radial bush bearing (7) with helical grooves is shown in figure 2 of the drawings.
The helical grooves are designed in such a way that the oil agitated by the spindle blade(2) due to the rotation of the spindle top part to resulting in an effective circulation and spill out consequently resulting in better cooling of the system.
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

Advantage of the invention.
• Reduced area of contact between the bush bearing and spindle blade resulting in reduction in power required for the driving of the spindle.
• Annular grooves provided in the bush bearing provides better oil circulation and enhance the life of the spindle insert.
• Effective lubrication supply to neck bearing due to the capillary effect of annular grooves.
• Improved cooling effect.

WE CLAIM
1. A spindle bearing for textile machine with improved foot bearing
comprising a neck bearing (4) fitted to the upper end of the bearing head
sleeve (5) fitted to the bolster (B) of the spindle assembly, a
combination foot bearing (3) having a radial bush bearing (7) and an
axial foot button (8) fitted to a centering sleeve (9) fitted to the bearing
head sleeve (5), wherein the neck bearing (4) and the combination foot
bearing(3) being disposed to rotatably support the spindle blade(2)
attached to the top part of the spindle assembly characterized in that the
inner annular surface of the radial bush bearing (7) is provided with
grooves (13).
2. A spindle bearing for textile machine with improved foot bearing according
to claim 1, characterized in that the grooves (13) are helical grooves or
radial grooves.
3. A spindle bearing for textile machine with improved foot bearing according
to claim 1 and 2 characterized in that the helix of the grooves(13) are
arranged either in left hand direction or right hand direction.
4. A spindle bearing for textile machine with improved foot bearing
substantially herein described and illustrated with reference to the
accompanying figures.