The invention relates to a changing device for rotary indexing tables, having a stand component, which is used as a base component and through which a shaft passes, which defines the axis of rotation of tables rotatable by an electric motor and which has an interface for coupling concerned tables, which can be fixed in predeterminable rotational positions relative to a respective assigned table unit by means of a clamping device.
To ensure an exact machining of workpieces, arranged on rotary indexing tables, it is not only required to position the rotary indexing table precisely in the concerned rotary positions, but, in order to achieve a high machining quality, it is essential to firmly fix the rotary indexing table in the selected rotary positions. As shown by way of example in document DE 103 51 694 C5, it is state of the art in this respect to provide a clamping device by means of which, by supplying a hydraulic pressure medium, a clamping force can be generated, which establishes a frictional engagement between the table and the stationary, assigned table unit. In the industrial use of rotary indexing tables, different requirements result for the construction of the table unit depending on the various machining tasks, the different types of workpieces to be machined on the rotary indexing table and the type of tools used for this purpose. This often also applies to the constructive formation of the clamping device, which, depending on the intended use, for instance has to meet different demands with regard to the amount of holding torque. To meet changing demands, table units and stand components of various construction are often used alternately for tables of the same size class. Such changing operations, which are adapted to the area of application, represent a considerable cost factor while operating of rotary indexing tables.
Based on this problem, the invention addresses the object of providing a changing device permitting an efficient and more cost-effective operation of rotary indexing tables.
According to the invention, this object is achieved by a changing device having the features of claim 1 in its entirety.
Accordingly, the invention provides, as a solution of this problem, a changing device of the genus mentioned above, in which at least two table units, differing from each other at least with respect to their clamping devices, together with their assigned table as exchange components can be fixed in an interchangeable manner on the base component for their operation. Because table units of different types are conceived as exchange components, that can be coupled to the stand component via the interface of the shaft of the stand component, required changing operations are limited to the exchange of the respective table unit together with its table. By means of one and the same stand component as the base component, rotary indexing tables of different construction, for instance with regard to their clamping device, can be operated in this way and, accordingly, a cost-effective operation of rotary indexing tables can be achieved.
In advantageous exemplary embodiments, at one free end of the shaft, and at least partially enclosed by the stand component, an incremental encoder or an absolute encoder, hereinafter referred to as a rotary encoder, is arranged and at the other free end the interface for the respective table of a table unit is arranged. The rotary encoder for the rotary position of the table can be formed for high-precision rotary positioning by a rotary encoder as is marketed by the company Dr. Johannes Heidenhaim GmbH, D 83301 Traunreut. Because in the device according to the invention the same stand component continues to be used across changing operations, for high-precision rotary positioning such a relatively expensive component can be used for changing operations without any substantial increase in the cost.
Advantageously, the coil winding of an electric motor for driving the respective table is accommodated in the table unit.
In advantageous exemplary embodiments, the cylindrical outer circumference of the stand component forms a guide surface, along which the differently formed table units can be placed as exchange units. Changing operations can therefore be performed using little assembly effort.
With regard to the different construction of the table units, the arrangement can advantageously be made such that the respective clamping device can be at least partially hydraulically operated, wherein the one type of clamping device between the table and the assigned table unit establishes the frictional engagement between the rotating table and the table unit arranged stationarily on the stand component by hydraulic spreading, and wherein the other type of clamping device is provided with a lamellar frictional engagement device.
In advantageous exemplary embodiments, the stand component is divided into two parts, having a rotary guide for the shaft and a foot part, which is flange-like and widens radially outwards in relation to the rotary guide, wherein on said foot part the table unit together with the respective type of clamping device is placed in a stationary manner.
Advantageously, a coaxial hollow cylinder can adjoin to the foot part of the stand component and encompasses the rotary encoder.
Particularly favorable manufacturing and operating costs can be achieved if the stand component always has the same predeterminable size for all sizes of tables and table units and irrespective of the type of clamping device used in the individual case.
The respective rotatable table can be flush with the outer circumference of the assigned table unit or, in contrast, be offset radially inwards.
In particularly advantageous exemplary embodiments, on part of the stand component at least one rotary seal extends between the rotary guide of the stand component and the shaft, wherein said rotary seal is interrupted by lubrication grooves. With particular advantage, a seal made of Zurcon (material name by Trelleborg; based on polyurethane) can be used here, wherein lubricating fluid, supplied from a supply point, is distributed along the axial length of the rotary guide via the lubricating grooves. Furthermore, a variant having gap seals and bearings can be used instead of contact seals to be able to achieve higher rotary speeds.
Below, the invention is explained in detail with reference to exemplary embodiments shown in the drawing. In the Figures:
In the figures, a table, which has a circular, planar table surface 4, as is common for rotary indexing tables, is designated by the numeral 2. In the exemplary embodiment of
In this respect,
A rotary encoder 24, arranged at the bottom of the foot part 16, interacts with an extension 26 of the shaft 18 to determine its rotational position and thus the rotational position of the table 2. In the rotary guide, formed by the hollow body 14 and in which the shaft 18 is guidably supported with and without roller bearings 28, there is a rotary distributor for lubricating fluid and other media, which are beneficial to the seal. The rotary distributor has along the outside of the shaft 18 between the rolling bearings 28 a rotary seal 30, in this case a Zurcon seal, which is interrupted by supply grooves. Furthermore, a variant having gap seals and bearing instead of contact seals can be used. Starting from a feed point (not shown), to which the lubricant or other medium is routed via a supply line 32, the lubricant or other medium is distributed along the seal 30 via the lubrication grooves and/or supply grooves. The circular cylindrical outer circumference of the hollow body 14 of the stand component 12 forms a guide surface 34, along which the table unit 8 together with the assigned table 2 as an exchange component can be put on the base component formed by the stand component 12. As shown in
Bolts 48, 50 and 52 are used to connect the table 2 to a shell part 54, which as an outer rotor encompasses a coil winding 56, which is fixed to the housing bottom part 42 using bolts 58. Also feasible with an internal rotor. This arrangement forms the electric drive motor of the table 2. The main difference between the exchange component shown in
In the example of
The lamellar pack 72 is formed by a stacked sequence of disks in the manner of clutch plates, wherein the pack 72 comprises a succession of stationary lamellas, connected to the stationary compression ring 68 by bolts 74, and movable lamellas, connected to the movable intermediate ring 70 by bolts not shown. Every device body 62 has a hydraulically actuated piston 76, the end face of which can be used to load and press the lamellar pack 72 against the compression ring 78 and the intermediate ring 70, establishing a frictional engagement between the lamellas, by means of which the compression ring 68 and the intermediate ring 70 are fixed non-rotatable to each other.
In
In all other respects, however, the stand component 12 fully matches that of the example of
The clamping units 84, which are hydraulically actuated like the clamping units 60 of
Number | Date | Country | Kind |
---|---|---|---|
10 2018 006 306.3 | Aug 2018 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2019/070606 | 7/31/2019 | WO | 00 |