DE4207280C2 - Round dividing table with electromechanical drive - Google Patents

Description

The invention relates to a circular dividing table according to the preamble of Claim.

In the field of the machine tool industry and special machine construction numerous circular dividing tables have become known, which with a wide variety of drive types, clamping and fixing devices and table top bearings are equipped.

The DD 250 077 C2 became a clamping device for hydraulic Rotary indexing tables known, preferably for use in machine tool construction, which with a minimum flow rate of the pressure medium high clamping force enables. This is solved by the fact that at a rotary indexing table with hydrostatic thrust bearing with wrap-around an intermediate ring axially movable in the wrap on a guide ring rests and by a collar bolt, which is in a groove of the intermediate ring engages, is secured against rotation.

However, this solution has the disadvantage that it is not in the Location, manufacturing-related hydrostatic gap deviations, which have an adverse effect on the amount of clamping force. This solution is also not able to control the temperature and viscosity fluctuations in the different viscosity of the hydraulic oil to compensate and compensate during the operating process.

The object of the invention is a circular dividing table with electromechanical, To create a reversible drive that over a wear-free, uniform clamping device with high Clamping force and a wear-free, axial table top bearing with high load capacity.

This object is achieved on the features of the patent claim.

From EP 0294871 A1 a generic round dividing table is known, the but has a rolling bearing for axial storage. The invention The expert is therefore not advised of a solution.  

On the on the table top lying on the table top is a guide ring arranged by the attached to the table case Intermediate ring, clamping ring and wrap axially and radially enclosed is. The table housing faces the underside of the guide ring facing groove-shaped arranged concentrically to the axis of rotation Bags on which supply lines for the pressure medium assigned. Likewise, the clamping ring faces the top of the Guide ring facing a concentric to the axis of rotation Ringnut on, which is also a supply line for the Pressure medium is assigned. Facing the underside of the wrap are located in the clamping ring concentric to the axis of rotation arranged groove-shaped pockets in which the seal serving O-rings are arranged. The pockets are sized that the O-rings have a defined pressure and thus Experience preload. This creates a very high degree of storage stability in axial direction reached. The pockets are also leads assigned for the pressure medium. The clamping ring has further two, concentric to the axis of rotation, offset opposite, cross-sectional ring grooves. Since the clamping ring is firmly clamped axially and radially, results the advantage of two friction points during the state "Clamping", namely once on the contact surface of the clamping ring to the guide ring and the other to the contact surface of the Guide ring to the table housing with the resulting high permissible tangential moment.

It is also located on the table top outside of the wrap on the underside is a toothed ring with which the drive for the table top rotation is coupled via a pinion. Of the Center distance between pinion and gear ring is adjustable via Fitting strips, whereby the backlash can be minimized. Of the It is also driven by the respective drive motor via duplex worm and worm wheel, which also means that Backlash can be reduced in a known manner can. The game adjustment is made using fitting rings.

The radial table top storage takes place from the central one Axis of the table housing via a double-row adjustable play  Cylindrical roller bearings with a tapered inner ring.

Furthermore, the central axis of the table housing is designed that rotary displacement measuring systems for the purpose of angular positioning the table top can be arranged.

In the interest of a simple hydraulic control for the hydrostatic, axial table top mounting and for clamping the table top it is advantageous if a pump is present, which is the pressure medium from the table interior sucks and via a directional control valve either the table top storage or feeds the clamping ring.

It is also advantageous if each of the individual Pocket cases and the concentric Ring groove in the clamping ring using a flow regulator with the pressure medium is supplied, whereby the axial table top storage becomes almost independent of load.

The flow controller is thus related to the gap size to interpret the hydrostatic thrust bearing that the required pump pressure for the hydraulic circuit is the same the required clamping pressure. A pressure relief valve is responsible for the level of the pump pressure.

Embodiment

The invention is based on a preferred embodiment explained in more detail.

In the accompanying drawings

Fig. 1 shows a longitudinal section through the indexing table center;

FIG. 2 shows a section AA according to FIG. 1;

Fig. 3 shows the principle of the hydraulic control for the hydrostatic table top storage and clamping.

The round dividing table consists of a fixed table housing 1 designed as a lower part and a rotatable upper part which forms the table top 2 . The guide ring 3 is attached to the table top 2 . An intermediate ring 4 , a clamping ring 5 and a wrap 6 are fixedly arranged on the table housing 1 . In the table housing 1 there are also several groove-shaped pockets 7, arranged concentrically to the axis of rotation. In the clamping ring 5 are located to the upper side of the guide ring 3 faces a concentrically arranged to the rotational axis of the annular groove 8 and the underside of the wrap-around 6 facing concentric to the axis of rotation disposed groove-shaped pockets. 9 In the pockets 9 serving O-rings 10 are arranged.

Pockets 7 and 9 and annular groove 8 are assigned supply lines 11 , 12 and 13 for the pressure medium. In the clamping ring 5 there are also grooves 14 and 15 , which reduce its section modulus in the interest of elasticity.

Furthermore, a toothed ring 16 , to which the drive 17 is coupled via a pinion 18, is located on the table top 2 outside the wrap 6 on the underside thereof. A worm wheel 20 and a worm shaft 21 are operatively connected to the pinion 18 via a shaft 19 .

Due to the pressure of the medium in the pockets 7 and the annular groove 8 , the table top 2 is evenly raised to a predetermined dimension. Each of the individual pockets 7 and the annular groove 8 are assigned to a separate pressure medium supply via a quantity regulator 25 , so that a very high bearing stiffness is achieved, which is increased by the pretensioning of the O-rings 10 in the pockets 9 .

By relieving pressure on the pockets 7 and the annular groove 8 and pressure of the medium in the pockets 9 , the guide ring 3 and with it the table top 2 are pressed onto the table housing 1 . It is thus possible to turn the table top 2 into any desired angular position with the aid of the drive 17 or to let it rotate for a longer time or to clamp it in any desired angular position. As shown in FIG. 3, this happens as follows:

During the "turning" state of the table top 2 , the directional control valve 26 is moved into position "b" by the electrical control. As a result, the pump 27 pumps the pressure medium into the flow regulator 25 , from which it is fed to the pockets 7 via individual feed lines 11 and to the annular groove 8 via the feed line 13 .

During the "clamping" state of the table top 2 , the directional control valve 26 is moved into the position "a" by the electrical control, as a result of which the pressure medium conveyed by the pump 27 is fed to the pockets 9 via the feed line 12 , which is designed as a ring line. The level of the pump pressure is set with the pressure limiting valve 28 . An incremental angle measuring system 22 , which is arranged on the table axis 23 , enables high positioning accuracy. The radial mounting of the table top 2 takes place via a double-row cylindrical roller bearing 24 with a conical inner ring. This makes it possible to adjust the bearing clearance in a known manner up to a defined preload.

Reference list

1 table case
2 table top
3 guide ring
4 intermediate ring
5 clamping ring
6 wrap
7 pockets
8 ring groove
9 pockets
10 O-ring
11 supply line
12 supply line
13 supply line
14 groove
15 groove
16 tooth ring
17 drive
18 sprockets
19 wave
20 worm wheel
21 worm shaft
22 angle measuring system
23 table axis
24 cylindrical roller bearings
25 flow regulator
26 way valve
27 pump
28 pressure relief valve

Claims (1)

Round dividing table with a table housing designed as a lower part, a table top rotatably mounted on it to which a guide ring is fastened, which is enclosed by a wrap that is fixed to the housing, a clamping ring being arranged between the wrap and the guide ring and a hydrostatic element on the top and bottom of the guide ring with the housing and the clamping ring Form axial bearings and between the clamping ring and the grip hydraulic clamping pockets are formed, whereby by means of a control device for rotating the axial bearing and for clamping the clamping pockets can be pressurized with pressure medium, characterized in that the clamping ring ( 5 ) is fixed to the housing and in the axial direction is elastically resilient, the table top ( 2 ) can be driven by a servo-electric motor with a reversible drive unit and the pressure medium can be supplied either to the thrust bearing or to the clamping pockets ( 9 ).