Claims:WE CLAIM :

1. Coolant attachment (1, 20, 25, 26, 28) for a bearing (4, 5, 21, 27) with a housing (2),

whereby the housing (2) is provided with a cylindrical opening (3) to take up the bearing (4, 5, 21, 27),

whereby the opening (3) is provided with an inside wall of the housing (7) with a cylindrical outside surface (6),

whereby the inside wall of the housing (7) is surrounded by a jacket wall (8),

whereby the inside wall of the housing (7) and the jacket wall (8) are connected with each other by side walls (10) which results a hollow space (9) that surrounds the inside wall of the housing (7),

characterized by the fact that

the inside wall of the housing (7) is supported against the jacket wall (8) by struts (11, 11a, 11b) which extend from the inside wall of the housing (7) to the jacket wall (8).

2. Coolant attachment (1, 20, 25, 26, 28) according to claim 1, whereby at least the inside wall of the housing (7), the struts (11, 11a, 11b) and the jacket wall (8) have been manufactured in one piece by means of an additive process.

3. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the struts (11, 11a, 11b) extend from the inside wall of the housing (7) to the jacket wall (8) in a non-radial, inclined direction (S, S’) with reference to the cylindrical outside surface (6).

4. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the struts (11, 11a, 11b) are inclined at an angle in one axial plane resp. with reference to the cylindrical outside surfaces (6).

5. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby with reference to the cylindrical outside surface (6) a first part of the struts (11b) in a first circumferential direction extends into a first inclined direction (S) and a second part of the struts (11b) in a second circumferential direction extends into a second inclined direction (S’) opposite to the first direction.

6. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby with reference to the cylindrical outside surface (6) a first part of the struts (11b) in a first radial plane extends into a first inclined direction (S) and a second part of the struts (11b) in an adjacent second radial plane extends into a second inclined direction (S’) opposite to the first direction.

7. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby with reference to a tangent (T), the struts (11b) extend through a circle resulting from an axial section through the cylindrical outside surface (6) into an angle (a) of less than 90o and a maximum of 45o from the inside wall of the housing (7) to the jacket wall (8).

8. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the first and the second part of the struts resp. (11b) extend at the same angle (a) each from the inside wall of the housing (7) to the jacket wall (8).

9. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the inside wall of the housing (7) has the shape of a pipe section.

10. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the jacket wall (8) is designed at least in parts as per the type of another pipe section.

11. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the jacket wall (8) is designed as an outside wall of a housing or is surrounded by an outside wall of a housing (12)

12. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the housing (2) is at least provided with one plane surface (12a).

13. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the jacket wall (8) and/or in at least one of the side walls (10) a first opening (13) to feed a coolant and/or a second opening (14) to drain the coolant is provided.

14. Coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, whereby the first (13) and the second (14) openings to feed and drain the coolant extend from the plane surface (12a) to the hollow space (9).

15. Arrangement consisting of a coolant attachment (1, 20, 25, 26, 28) according to one of the above claims, with a bearing (4, 5, 21, 27) integrated into such.

16. Lathe with a main spindle (29), whereby the main spindle (29) is kept rotatable by means of several rolling contact bearings (21, 27), whereby the rolling contact bearings (21, 27) are integrated into a coolant attachment (1, 20, 25, 26, 28) according to one of the above claims.

17. Lathe according to claim 16, whereby the rolling contact bearings (21, 27) are taken up in a form-fit way into the opening (3).

18. Lathe according to claim 16 or 17, whereby several front rolling contact bearings (21) are integrated into a front coolant attachment and at least one rear rolling contact bearings (27) is integrated into a rear coolant attachment.
, Description:FIELD OF INVENTION :

The invention relates to Spindle bearing cooling system with coolant attachment for bearings, with the said arrangement with a bearing and a lathe.

BACKGROUND AND PRIOR ART :

Many coolant attachments associated with lathe is known. Some of the known prior art is detailed below :

Such coolant attachment is known from EP 1 647 740 A1. It consists of a sleeve-like housing that encloses the nut of a ballscrew spindle drive. A helical coolant channel is provided within the housing. In the coolant channel, a liquid coolant is helically moved from one end of the ball screw spindle drive to the other. In doing so, the coolant is growing warm. As a consequence, one end of the nut of the ballscrew spindle drive is cooled in a better way than the other end. Apart from this, a surface between two adjacent helical spirals is cooled worse than another surface that is located within the immediate contact range of the coolant channel.

DE 10 2017 202 699 A1 reveals a ballscrew spindle drive with a nut and counternut cooling. The geometry of the nut and counternut cooling is specifically adapted to a spindle of the ball screw spindle drive. It is not universal.

OBJECTS OF THE INVENTION :

The main object of the invention is to remedy the sufferings of prior art. It is the task of the invention to remedy the disadvantages in accordance with the state of the current technology. In particular, a coolant attachment of a simple design is to be specified for a bearing in order to enable improved cooling. In accordance with another objective of the invention, the coolant attachments to be at best of universal use. Apart from that, an arrangement with a bearing and a lathe with a bearing with an improved cooling are to be specified.

SUMMARY OF THE INVENTION :

The invention describes a coolant attachment for a bearing in accordance with the generic term of patent claim 1. Furthermore, it refers to an arrangement of a bearing and a lathe with such coolant attachment.

This task of overcoming the suffering in prior art is resolved by the characteristics of patent claims 1, 15 and 16. The appropriate arrangements are revealed from the characteristics of the dependent patent claims.

The invention concerns a coolant attachment (1, 20, 25, 26, 28) for a bearing (4, 5, 21, 27) with a housing (2), whereby the housing (2) is provided with an opening (3) to take up the bearing (4, 5, 21, 27), whereby the opening (3) is provided with an inside wall of the housing (7) with a cylindrical outside surface (6), whereby the inside wall of the housing (7) is surrounded by a jacket wall (8), whereby the inside wall of the housing (7) and the jacket wall (8) are connected to each other by side walls (10) so that a hollow space (9) is formed that surrounds the inside wall of the housing (7). To enhance the cooling of the cylindrical outside surface (6), it is suggested in line with the invention to prop the inside wall of the housing (7) against the jacket wall (8) by means of struts (11, 11a, 11b) which extend from the inside wall of the housing (7) to the jacket wall (8).

DESCRIPTION OF INVENTION :

In accordance with the requirement of the invention, it is suggested that the inside wall of the housing is supported by struts against the jacket wall that such extend from the inside wall of the housing to the jacket wall.

The term “struts” is to be understood in general terms in the scope of the present invention. It is about sustaining elements that are located at a distance from each other and that connect the inside wall of the housing with the jacket wall or that support the inside wall against the jacket wall of the housing. The struts extend from the inside wall of the housing to the jacket wall. The direction in which they extend can be radial or also inclined with regard to the cylindrical outside surface. In a cutsection view in vertical direction to the direction of extension, the struts can have different shapes. The struts can be round, preferentially circular or elliptical, angular or elongated. They can also have a cross-section surface that is designed, for example, in accordance with the type of a streamlined aerofoil profile.

In general, the term “bearings” refers to rolling contact bearings, friction bearings or control devices, in particular linear control devices, for example a ballscrew spindle drive or the like which contain rolling elements.

According to the invention and on the grounds of the suggested support of the inside wall of the housing by means of struts at a distance from each other a hollow space is created, and in deviation from the state of the art current technology, the consequence is a completely different flow configuration in the hollow space for a coolant flowing in such space: the coolant is no longer forced to flow over the long distance, for example, in case of a helically-shaped coolant channel. In line with the invention, it can flow considerably faster from one coolant inlet to a coolant outlet. Another outside wall of a bearing adjacent to the cylindrical outside surface can thus be improved and cooled more consistently.

In line with an advantageous design, at least the inside wall of the housing, the struts and the jacket wall are manufactured in one piece by means of an additive process. The coolant attachment can, for example, be manufactured by means of a 3D-printer in which metal powder is welded layer by layer by means of a laser or electronic beam along predefined travel paths.

In line with an advantageous design, the struts extend from the inside wall of the housing to the jacket wall in a non-radial, inclined direction with reference to the cylindrical outer surfaces. The suggested inclined position of the struts ensures an improved shearing strength of the inside wall of the housing with reference to the jacket wall when under stress, for example, in its circumferential direction or in axial direction. For example, such stress can occur if a bearing integrated in the inside wall of the housing becomes defective. The suggested inclined position of the struts thus contributes to an improved operation under emergency conditions of a bearing integrated into the coolant attachment in line with the invention.

The struts can be transversally inclined with reference to the cylindrical outside surface in one axial plane each, respectively. In particular, it can be the case that with reference to a cylindrical outside surface a first part of the struts extends in a first circumferential direction into a first inclined direction and a second part of the struts extends into a second circumferential direction in a second inclined direction opposite to the first direction. In this case, adjacent struts in circumferential direction, for example, adjacent struts of a circumferential direction form can be of a “V”-like shape or a “V” in upside down position. On the whole, the structure of the struts resembling a square framed work is the consequence.

In line with another design, it may also be the case that a first part of the struts with reference to the cylindrical outside surface in a first radial plane extends into a first inclined direction and a second part of the struts in an adjacent second radial plane extends into a second inclined direction opposite to the first direction.

It is also possible, that the struts within an axial plane or a radial plane extend into the first and second inclined direction.

With reference to a tangent, the struts can extend into a circle resulting from an axial section through the cylindrical outside surface at an angle a of less than 90o and a maximum of 45o from the inside wall of the housing to the jacket wall. In this case, the angle a refers in turn to the “extension direction” of the struts. It became apparent that the suggested angles a contribute particularly efficiently to increasing the shearing strength of the inside wall of the housing opposite to the jacket wall.

In line with another design, it is suggested that the first and the second part of the struts each extend at the same angle a from the inside wall of the housing to the jacket wall. This simplifies manufacturing.

The inside wall of the housing can have the shape of a pipe section. At least in sections, the jacket wall can be designed in accordance with another pipe section. In this case, the pipe section and the additional pipe section are preferentially arranged in a coaxial way. As a consequence, there is a hollow space in the shape of a circular orifice in which the struts are incorporated. As per the suggested design, the coolant attachment is at least in sections designed in the shape of a sleeve. – The jacket wall can also be designed as an outside wall of the housing.

In line with another design, it can also be the case that the jacket wall is surrounded by an outside wall of the housing. The outside wall of the housing can be designed in a way that its construction is adapted to the mounting of the bearing in a device. In particular for this purpose, the housing can be provided with at least one plane surface.

In the jacket wall and/or at least one of the side walls, a first opening for feeding a coolant and/or a second opening for discharging a coolant can be provided. In case of the coolant, a liquid is preferred, for example, oil, water, emulsions from oil and water or other suitable coolants.

In line with an advantageous design, the first and second openings for feeding and discharging the coolant extend from the entry point to the hollow space, i.e. in this case, the connections to feed the coolant and to discharge the coolant are provided at the face of the component.

In line with another requirement of the invention, an arrangement is suggested that consists of a coolant attachment as per the invention with at least one integrated bearing.

In line with another requirement of the invention, a lathe with a main spindle is suggested, whereby the main spindle is rotatable by means of several rolling contact bearings and whereby the rolling contact bearings are integrated in at least one coolant attachment in line with the invention. The suggested lathe enables the manufacturing of particularly precise parts. Due to the suggested improved cooling of the rolling contact bearings, an undesired clearance of the main spindle can be minimized. Thus, precision in manufacturing can be enhanced.

In line with another design, the rolling contact bearings are taken up into the recess in a form-fit way. This allows, in particular, to dissipate the heat away from the rolling contact bearing. It is considered particularly advantageous that several front rolling contact bearings are integrated in a front coolant attachment and at least one rear rolling contact bearing into a rear coolant attachment. The suggested design facilitates an equal cooling of all rolling contact bearings that support the main spindle.

Subsequently, the following design examples of the invention are explained in detail by means of the drawing. The following is shown:

Fig. 1 a perspective view of the coolant attachment with a ball screw spindle drive,

Fig. 2 a perspective view in line with fig. 1, whereby the coolant attachment is cut sectioned in parts

Fig. 3 a perspective view of the coolant attachment,

Fig. 4 a sectional view according to Fig.3,

Fig. 5 a perspective view opened in part of the coolant attachment according to Fig. 1 to 4,

Fig. 6 a schematic sectional view through another coolant attachment,

Fig. 7a to e sectional views through struts,

Fig. 8 a sectional view through a cross slide of a lathe

Fig. 9 a perspective view of a second coolant attachment with a first bearing

Fig. 10 a perspective view according to Fig. 9, whereby the coolant attachment is cut sectioned in parts,

Fig. 11 a perspective view of a third coolant attachment in parts

Fig. 12 a perspective view of a fourth coolant attachment with third bearings integrated in such,

Fig. 13 a perspective view according to Fig. 12, whereby the third coolant attachment is sectioned in parts,

Fig. 14 a perspective view of a fifth coolant attachment cut sectioned in parts

Fig. 15 a schematic sectional view through the main spindle of a lathe.

Reference numerals list

1 first coolant attachment
2 housing
3 cylindrical opening
4 ball screw spindle drive
5 spindle
6 cylindrical outside surface
7 inside wall of housing
8 jacket wall
9 hollow space
10 side wall
11 strut
11a radial strut
11b inclined strut
12 outside wall of housing
12a plane surface
13 first opening
14 second opening
15 brace
16 x-slide
17 carriage
18 servomotor
19 coolant channels
20 second coolant attachment
21 first bearing
22 flange
23 shoulder
24 outside bearing shell
25 third coolant attachment
26 fourth coolant attachment
27 second bearing
28 fifth coolant attachment
29 main spindle

A axis
R radial direction
S, S’ inclined direction
T tangent
X x-direction
a angle

Fig. 1 to 5 show a first coolant attachment described in general by means of reference numeral 1. The first coolant attachment 1 is provided with a housing 2 in which there is an opening 3 that is designed as a cylindrical opening in this case. In the cylindrical opening 3, a bearing is integrated preferentially in a form-fit way, in this case, in the form of a nut 30 of a ballscrew spindle drive 4. Reference numeral 5 describes a spindle of the ball screw spindle drive 4.

The cylindrical opening 3 is provided with a cylindrical outside surface 6. The cylindrical outside surface 6 limits an inside wall 7 of the housing. The housing’s inside wall 7 is surrounded by a jacket wall 8 so that there is a hollow space 9 in between the housing’s inside wall 7 and the jacket wall 8. The hollow space 9 is limited by side walls 10. In this case, the side walls 10 run approx. perpendicularly to an axis A (see Fig. 6) with reference to the cylindrical outside surface 6.

As is in particular clearly revealed by Fig. 6, the housing’s inside wall 7 is supported by struts 11 against the jacket wall 8. The housing’s inside wall 7 is designed in the form of a pipe section in this execution example. In this case, the jacket wall 8 is at least in parts designed in the form of another pipe section. The pipe sections are coaxially arranged with reference to axis A. As a consequence, the hollow space 9 is, for example, shaped in the form of a circular orifice.

As is revealed by Fig. 6, radial struts 11a can extend from the housing’s inside surface 7 in radial direction R to the jacket wall 8. As per another version, is also possible that inclined struts 11b with reference to a tangent T can extend at an inclined angle through a circle resulting from an axial section through the cylindrical outside surface 6. The corresponding inclined direction is described by means of reference numeral S in Fig. 6. An angle a with reference to tangent T advantageously amounts to less than 90o and more than 45o.

The struts 11 or 11a, 11b can be of different geometrical design in a section perpendicular to the direction into which they extend. As can be seen from Fig. 7a to 7e, the struts 11 can be designed with a circular cross section as is the case for pillars. However, it is also possible that the struts 11 are designed with a square cross-section (see Fig. 7b, c and e) or in an oblong shape (see Fig. 7c and d).

The inclined struts 11b can – as shown in Fig. 6 – extend into a radial plane comprising the radius – into a first inclined direction S and into a second inclined direction S’. The inclined struts 11b can also be positioned in an inclined way in an axial plane comprised in axis A into a first inclined direction S and/or into a second inclined direction S’. With reference to the arrangement and inclination, all variations are possible.

As is revealed in particular by Fig. 1 and 3, the housing 2 is provided with a plane surface 12a at an outside wall of the housing 12, which is designed in the form of a box in this case. In the plane surface 12a, first openings 13 and second openings 14 are provided to feed and discharge a coolant. The openings 13 and 14 connect the plane surface 12a with the hollow space 9.

As is in particular revealed by Fig. 5, the hollow space 9 can be subdivided by a brace 15 in a way that the coolant is forced to flow in a predefined direction in hollow space 9 from the first opening 13 to the second opening 14.

Fig. 8 shows a sectional view through a lathe. An x-slide or a cross slide are described by means of reference numeral 16 which can be traversed in linear direction back and forth on a carriage 17 into an x-direction, described by reference numeral X. The carriage 17 can be traversed into a z-direction which runs in parallel to the axis of a main spindle 29 (as shown in Fig. 15).The x-direction runs perpendicularly to the z-direction in the horizontal plane. A servomotor is described by means of reference numeral 18 the drive of which is connected to the spindle 5. A nut 30 of the ball screw spindle drive 4 engages into the spindle 5. The housing 2 of the first coolant attachment 1 with its plane surface 12a is mounted to the correspondingly designed plane counter surface underneath x-slide 16. Thus, the openings 13 and 14 open up into the correspondingly arranged coolant channels 19 provided within x-slide 16. Thus, it is possible that the x-slide 16 and the first coolant attachment 1 can be cooled by means of coolant channels 19.

Fig. 9 shows a schematic sectional view through a second coolant attachment 20 with a first bearing 21 integrated into such. With regard to the second coolant attachment, the jacket wall 8 is, in essential, the housing’s outside wall. A flange 22 extends from the jacket wall 8 or the housing’s outside wall resp. . A radial revolving shoulder 23 extends from the cylindrical outside surface 6 of the housing’s inside surface 7 radially to the inside, against which the first bearing 21 with its outside bearing shell 24 is retained (see Fig. 9). As for the second coolant attachment, the first openings 13 and the second openings 14 are located in a side wall 10 adjacent to the flange 22.

As is revealed by Fig. 10, the inclined struts 11b are inclined into the same direction in every radial plane, i.e. the inclined struts 11b are arranged in parallel in every radial plane. In every adjacent radial plane, the inclination of the inclined struts 11b run into the opposite direction. Thus, a particularly high strength of the housing’s inside wall 7 with reference to the jacket wall 8 is the consequence against any strain into axial direction.

Fig. 11 shows a perspective view cut sectioned in parts of a third coolant attachment. Here, the first openings 13 and the second openings 14 are provided at a side wall 10 adjacent to no flange.

Fig. 12 and 13 view a fourth coolant attachment 26. As is revealed by Fig. 12, the fourth coolant attachment 26 serves to take up several second bearings 27. In contrast to the second coolant attachment 20, no shoulder 23 is provided at the cylindrical outside surface 6 of the fourth coolant attachment 26. The first openings 13 and the second openings 14 open up to the side wall 10 which are located at a distance to flange 22. Moreover, the fourth coolant attachment 26 is designed in a similar way as the second coolant attachment.

Fig. 14 shows a perspective view of a fifth coolant attachment 28 cut sectioned in parts. In this case, the first openings 13 and the second openings 14 are located at the side wall 10 which is provided with flange 22.

Fig. 15 shows a schematic sectional view through the bearing of a main spindle 29 of a lathe. The main spindle 29 is kept rotatable by means of a first bearing 21 which is integrated in a form-fit way into the second coolant attachment 20. The first bearing 21 is as a rear bearing for the spindle bearing arrangement. Moreover, the main spindle 29 is kept rotatable by means of second bearings 27. The second bearings 27 are integrated in a form-fit way into the fourth coolant attachment 26.

By means of the suggested bearing of the main spindle 29, a predefined temperature can be excellently maintained in the first bearings 21 and the second bearings 27. Thus, the main spindle 29 can be operated without any clearance in a very wide speed and load range which enables the manufacturing of parts with very high precision.

Apart from the bearing of a main spindle 29 on a lathe, in particular, the bearing of another main spindle or any spindle of any Equipment or any Machine tool like a milling machine can be cooled by means of the coolant attachment in line with the invention.

The various features of novelty which characterises the invention are pointed out with particularly in claims annexed to and forming a part of this specification. The operating advantages and specific objects obtained by its use are putforth in descriptive matter and illustrations annexed herein.

The examples and embodiments are provided only for the purpose of understanding and none of them shall limit the scope of the invention. All variants and modifications as will be envisaged by skilled person are within the spirit and scope of the invention.