FIELD OF THE INVENTION

The present invention relates to spindles of textile ring spinning and twisting machines. More particularly the present invention relates to neck bearing in the spindle bolster of the ring spinning and twisting machines.

BACKGROUND OF THE INVENTION

Spindle assemblies in the ring spinning and twisting machines are used to form the yarn by twisting the textile fibres delivered from the drafting rollers and to wind the yarn in the bobbins provided on the upper part of the spindles. In use, a large number of similar spindle assemblies are attached to spinning or twisting machine frame members (spindle rails) and are rotatably driven by a drive belt. The drive belts are drivingly engaged to at least four driving wharves carried on respective spindle shafts of the spindle assembly modules.

Spindle used in a ring spinning and twisting machine comprises a conical upper part, a driving wharve and a spindle shaft. The spindle shaft assembled in the spindle is supported by a bolster in the bottom part. Said spindle shaft is rotatably supported by a neck bearing and a foot bearing provided in the spindle bolster. The neck bearing is positioned in a tube-like neck bearing housing which is pressed at the top portion of the spindle bolster. The foot bearing comprises a radial bush bearing provided to take up 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. Between the cylindrical inner contour of the bearing housing and the cylindrical outer contour of the spindle shaft, a damping spiral is arranged entirely in the oil bath and is supported upwards by means of the bearing housing.

In order to keep the speed of the driving belt as low as possible, and still achieve rotational speeds of 25,000 revolutions per minute (RPM) or more, it is endeavored to keep the outside diameter of the driving wharve as small as possible. The outside diameter of the driving wharve depends essentially on the diameter of the spindle shaft, diameter of the head bearing sleeve and on the diameter of the neck bearing.

In the known art, the diameter of the shaft at the neck bearing is reduced upto 6.8 mm and the bearing sleeve wall thickness is reduced upto 1 mm. Reducing the spindle shaft diameter lesser than 6.8 mm would lead to increasing instabilities of spindle upper part. Reducing the wall thickness lesser than 1 mm would affect the strength of the bearing sleeve. In connection with the neck bearing which is constructed as a needle roller bearing which is standard one used in practice, it is not possible to reduce the outside diameter of the driving wharve lesser than 18.5 mm.

There has been a persistent need to develop a spindle bolster that would reduce the driving wharve diameter and thereby increasing the productivity of ring spinning and twisting machines and reducing the energy cost. The present invention provides an improved spindle bolster that will overcome all disadvantages present in the existing spindle assemblies.

OBJECTS OF THE INVENTION

It is a basic object of the present invention to provide an improved spindle bolster which avoids aforementioned disadvantages of spindle bolster assembly in the existing ring spinning and twisting machines.

Another object of the present invention is to provide a spindle assembly with reduced driving wharve diameter that will increase the productivity and reduce the energy consumption compared to the existing ring spinning and twisting machines.

These and other objects, features and advantages of the present invention will become more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION

According to the present invention, the spindle assembly for textile machines comprises a spindle bolster, a spindle shaft and a driving wharve. The spindle shaft is supported in a neck bearing in the form of a needle bearing at the top, and in a foot step bearing at the bottom. The said neck bearing and the foot step bearing are located in a bearing housing. The wharve is provided with an outer diameter of less than or equal to 17 mm and the diameter of needle rollers used in the neck bearing is less than or equal to 2.4 mm.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1 of the drawings illustrates the spindle assembly of the existing ring spinning and twisting machines.

Figure 2 describes the neck bearing arrangement of the spindle assembly according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows the spindle assembly of the ring spinning and twisting machines. The vertically arranged spindle comprises a spindle bolster (1), spindle shaft (2) and a driving wharve (3). Said spindle shaft (2) being supported in a neck bearing (4) in the form of a needle bearing, and in a foot step bearing (5). The neck bearing (4) and the foot step bearing (5) are located in a bearing housing (6), which has a closed bottom (7).

The bearing housing (6) essentially comprises a head bearing sleeve (8) in its top portion which takes up the neck bearing (4). Said head bearing sleeve (8) is inserted from above into the bearing housing (6). In the inner side of the bearing housing (6), an oil bath is located in the area of the foot step bearing (5). The step bearing (5) comprises a foot step bearing bush (9) which takes up the radial forces, and a foot step button (10) comprising a stop ring (11) which takes up the axial forces. The step bearing bush (9) supports the spindle shaft (2) which renders the spindle shaft (2) flexibility to rotate in free manner.

Between the cylindrical inner contour of the bearing housing (6) and the cylindrical outer contour of the spindle shaft (2), an annular gap is located, which takes up in a known way a damping spiral (12). The damping spiral (12) is arranged entirely in the oil bath and is supported upwards by means of the bearing housing (6).

The bearing housing (6) which is equipped with a flange (13) and an external thread (14) is affixed in a spindle rail (15) using a spindle nut (16). The spindle with the spindle shaft (2) is mounted over the spindle bolster (1) in a freely rotatable manner. The driving wharve (3) is further arranged at the spindle and reaches around the neck bearing (4), whereby at least four driving wharves are driven by one drive belt and a main drive shaft arrangement (not shown) extending in machine longitudinal direction.

Figure 2 discloses the embodiment of the present invention. The present invention deals with a technique of reducing the driving wharve diameter by reducing the diameter of needle rollers in neck bearing (4). In the spindle bearing housing (6), the head bearing sleeve (8) is held by means of a press fit and forms a bearing receiving device (21) for the neck bearing (4). The bearing receiving device (21) contains an outer bearing ring (22) and a bord ring (23). In upward direction, the needle bearing is shielded by means of a sealing ring (24). The bord ring (23) which holds the bearing ring (22) sits on a radial projection (25) of the head bearing sleeve (8). Plurality of needle rollers (27) is mounted on the bearing cage (26). The neck bearing (4) holds the spindle shaft (2) through the needle rollers (27) in a freely rotatable manner.

According to the present invention, the outside diameter of the driving wharve (3) is reduced to a value lesser than or equal to 17 mm by reducing the diameter of needle rollers (27) used in the neck bearing (4) to a value less than or equal to 2.4 mm. Accordingly, the diameter of the spindle shaft (2) at neck bearing (4) is maintained at 6 mm and at the foot step bearing (5) is maintained at 4 mm.

By means of the construction according to the invention, it is possible to reduce the outside diameter of the driving wharve by 1.5 mm than the known art so that, as a result, the speed of the driving belt can be reduced which is required for the high rotational speeds. Also, there is a reduction in weight of the spindle due to the diameter reduction of spindle wharves. On the basis of the diameter and weight reduction resulting from the construction according to the invention, it is possible to reduce the driving power for each spindle. The driving power required during running of the spindles is reduced and in relation to the spinning output, the energy costs also considerably reduced.

We claim:

1. AN IMPROVED SPINDLE ASSEMBLY FOR TEXTILE MACHINES comprising a spindle bolster (1), a spindle shaft (2) and a driving wharve (3);

said spindle shaft (2) being supported in a neck bearing (4) in the form of a needle bearing at the top, and in a foot step bearing (5) at the bottom;

characterized in that the diameter of needle rollers (27) in the neck bearing (4) is less than or equal to 2.4 mm.

2. An improved spindle assembly for textile machines as claimed in claim 1, wherein the diameter of the spindle shaft (2) at neck bearing (4) is 6 mm and at the foot step bearing (5) is 4 mm.

3. An improved spindle assembly for textile machines as claimed in claim 1, wherein the outer diameter of the wharve (3) is less than or equal to 17 mm.

4. An improved spindle assembly for textile machines as claimed in claim 1, wherein said textile machine is a ring spinning and/or twisting machine.