DE8610226U1 - Spindle bearing - Google Patents

Description

The invention relates to a spindle bearing according to the preamble of claim 1.

In the context of modern manufacturing technology, automatic tool monitoring is of considerable importance, since there is a close connection between tool wear and manufacturing accuracy. Experience has shown that optical or pneumatic systems, for example, are not suitable for continuous tool monitoring. In practice, therefore, more and more electronic monitoring systems are being used, with sensors made from piezo crystals or strain gauges, for example, which allow a statement to be made about the state of wear of tools using wear-dependent forces. The problems that arise here lie not least in the appropriate arrangement and placement of the sensors, with the difficulties increasing as the space available for accommodating the sensors decreases. A typical example of a case in which the arrangement of force measuring sensors presents spatial difficulties is spindle bearings in multi-spindle drilling heads.

The invention is based on the object of equipping a spindle bearing of the type under consideration with sensors for measuring the feed force and thereby showing a way that is satisfactory in terms of both functionality and space and manufacturing technology. This object is achieved in a generic device by the characterizing features of claim 1.

The spindle bearing according to the invention offers the advantage that the intermediate bush is cleverly designed in such a way that it can be used as a sensor, while at the same time

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•a protected accommodation of the sensors is guaranteed.

It proves to be particularly advantageous if the intermediate bushing is designed in accordance with the subclaims, whereby the features of these claims promote economical production of the measuring device and allow a division of the axial force flow that facilitates the acquisition of the measured value.

The invention is explained in more detail below with reference to the accompanying drawings. They show:

Fig. 1 a spindle bearing with a multi-part intermediate bush for a multi-spindle head,

Fig. 2 shows a modified intermediate bush for a spindle bearing of the type shown in Fig. 1,

Fig. 3 shows another modified intermediate bush for a bearing of the type shown in Fig. 1,

Fig. 4 shows a fourth embodiment of an intermediate bush for a bearing of the type shown in Fig. 1 and

Fig. 5 shows a fifth embodiment of an intermediate bushing for a bearing of the type shown in Fig. 1.

In Fig. 1, 1 is the spindle of a multi-spindle drilling head with a spindle housing 2. An axial bearing 4, which is designed as a deep groove ball bearing, is used to absorb the axial forces acting on the spindles in the direction of arrow 3. 5 is a counter bearing designed as an NKX bearing, which is also used to absorb radial forces. The NKX bearing offers the advantage of a very compact design of the spindle bearing.

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enables. An intermediate bushing consisting of two parts 6 and 7 connected to one another by screw bolts (not shown) and an annular web 8, which is generally designated 9, serves to transfer the axial forces exerted on the axial bearing 4 to the spindle housing 2. The part 6 of the intermediate bushing has an inwardly directed support part 10 designed as an elastic deformation member, which is supported via the annular web against a rigid abutment 11 formed by the part 7. The parts 6 and 7 as well as the annular web &thetas; form a hermetically sealed annular space 12 for accommodating strain gauges 13 and 14. The parts 6 and 7 of the intermediate bushing 9 can be connected to one another in such a way that both the ring web 8 and the support part 10 are subjected to a preload. The intermediate bushing 9 is supported by an annular shoulder 15 against an end wall 16 of the spindle housing 2.

Due to the arrangement, the strain gauges 13 and 14 are not only protected against external influences from lubricating oil and coolant, but they can also be easily applied to the ring web 8 or the support part 10.

Fig. 2 to 5 show possible modifications of the intermediate bushing installed in the spindle housing 2. The same reference numerals as in Fig. 1 were used for corresponding parts.

The solution according to Fig. 5 has proven to be particularly advantageous, in which the ring web 8 is supported against the abutment 11 via a ring flange 17. Here the support part 10 and the ring flange 17 form lateral guides for the strain gauges 14 to be applied.

Claims (7)

DIPL,-INQ. DIETER JANDER DR,-!NQ, MANFRED BÖNINQ PATENT ATTORNEYS European Patent Attorneys KURFORSTENDAMM 66 1 BERLIN IS Telephone: 030 / 3 83 50 71 / 72 Telegrams: Consideration Berlin 1254/19 754 EN 11 April 1986 Registration of the Lord Dr.-Ing. Gerhard Lechler Steinäckerstrasse 28 1000 Berlin 45 Expectations : 1. Spindle bearing, in particular for a multi-spindle drilling head, with an axial bearing serving to absorb feed forces, in particular designed as a ball or roller bearing, a counter bearing designed in particular as an NKX bearing and an intermediate bush serving to transmit the forces introduced by the spindle into the axial bearing to a spindle housing, which is provided with a support part for the axial bearing, characterized in that the support part (10) is designed as an elastic deformation member, that the intermediate bush (9) has, in addition to the support part (10), a rigid abutment (11) and an annular web (8) serving to transmit an axial force component from the support part (10) to the abutment (11), and that it has a hermetically sealed annular space (12) for several spaced-apart bearings applied to the support part (10) and/or the annular web (Θ). Strain stress strips (13,14) for the axial force measurement. Postal Check Account Bn/I.n West Account 1 MJ <H 100 Belüner Ban an» AQ . Konlo Ol 10931 900 .&ldquor;I r · DIPL.-INQ. DIETER JANDER DR.-INQ. MANFRED BDNINQ PATENT ATTORNEYS 2. Spindle bearing according to claim 1, characterized in that all strain gauges (13, 14) are applied to the outer surface of the ring web (8). 3. Device according to claim 1 or 2, characterized in that the intermediate bush (9) is supported in the axial direction via an annular shoulder (15) against an end wall (6) of the spindle housing (2). 4. Device according to claim 1 and one of claims 2 or 3, characterized in that the intermediate bush (9) has two parts (6, 7) screwed together and the annular web (8) is pressed against the support part (10) by the abutment (11) applying a prestress. 5. Device according to one of claims 1 to 4, characterized in that the annular web (8) is detachably mounted between the support part (10) and the abutment (11) of the intermediate bush (9). 6. Device according to one of claims 1 to 4, characterized in that the support part (10) and the annular web (8) form a one-piece measuring body. 7. Device according to claim 6, characterized in that the annular web (8) is supported against the abutment (11) via an annular flange (17) forming one part therewith. It ti I ··«<·· ··«* tt 4 i II