CZ200919A3 - Oil distribution system to hydrostatic bearing of vertical boring and turning machine - Google Patents

Abstract

The distribution of hydraulic oil to a hydrostatic bearing of a vertical lathe, fitted with a pump (2) and a filter (3), has means to divide the oil flow into branches (6) for individual cells (7) of the hydrostatic bearing (8) formed by at least one delicacy (4, 5) ) current.

Description

Oil distribution to hydrostatic bearing of vertical lathe

Technical field

The invention relates to the distribution of hydraulic oil to a hydrostatic bearing of a vertical lathe comprising a pump, filters and means for splitting the oil stream into branches for individual cells of the hydrostatic bearing.

BACKGROUND OF THE INVENTION

Vertical lathes - carousels have a clamping plate rotatably mounted on a stationary bed, which is radially guided by a vertical double row cylindrical roller bearing and driven by an electric motor through a pinion box. In large carousels, the clamping plate is mounted axially on the bed by means of a hydrostatic bearing. It is a precisely machined planar horizontal surface in the form of an annulus on the perimeter of the bed, in which they are formed at equal pitches of recesses - cells, each with its own hydraulic oil supply. The cells are sealed from above by a precisely machined planar surface in the form of an annulus formed on the underside of the clamping plate. When aligning the carousel, the flatness of the table top must not exceed 0.02 mm / m in four positions of 90 ´. The same tolerance applies to the distances of the two bearing surfaces. To this end, it must be ensured that all the cells are supplied with exactly the same amount of hydraulic oil at the same time. If the clamping plate is loaded eccentrically on the workpiece, there is a greater leakage of oil in the cells under the less stressed place and thus a pressure reduction, and vice versa, on the other hand, the oil pressure in the cells increases under the more stressed place. This compensates workpiece imbalance and minimizes the flatness tolerance of the clamping plate.

The hydraulic pump is supplied to the hydrostatic bearing cells by a gear pump through a filter. After the filter, the oil stream branches. In the known carousels, each branch is provided with a throttle valve which is set to pass a constant amount of oil into the branch. The amount of oil passed through the throttle valves cannot be influenced by the pump performance. If it is necessary to change the flow rate if necessary, all choke valves must be adjusted, which is somewhat difficult.

· «** ** ** ** ** ** 4 ** 4 4 4

4 ** 4 * 4 «| ··· «·« 4 »** · **« φ

- 2 Flow dividers are known which divide the flow of hydraulic oil into 2 to 12 branches. They are essentially parallel-connected, interlocking gear pumps provided with inlets and outlets. This ensures a sufficiently equal minute flow through each branch.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the above-described disadvantages of known distributions and, moreover, to substantially simplify their construction.

SUMMARY OF THE INVENTION

This object is achieved by distributing hydraulic oil to a hydrostatic bearing of a vertical lathe comprising a pump, filters and means for separating the oil stream into branches for individual cells of the hydrostatic bearing, the principle being that the means for dividing the oil stream are at least one flow divider.

The advantage of using dividers is that they divide the incoming oil stream relatively precisely into individual branches. They thus enable the regulation of the pressure conditions in the hydrostatic bearing by controlling the speed of the pump, which can be, for example, three-stage.

If the number of n cells in the bearing is higher than the number of branches in the type of divider available, it is advantageous to divide the oil stream into 2 or 4 branches using a primary divider and to connect 2 or 4 after the primary divider. 4second dividers, each of which is adapted for n / 2 and 2/3, respectively. n / 4 branches.

In such a case, it is structurally advantageous if the two secondary dividers are connected to the common distribution block by their outputs.

Advantageously, the secondary dividers can be screwed directly into the boreholes of the internally threaded block.

For fine control of the oil quantity, a relief valve can be integrated in the block for each branch to transfer the oil to the drain line.

Correct operation of the hydraulic circuit is indicated by a pair of pressure switches on each secondary divider that control the pressure in one of the divider outlets.

Advantageously, downstream of the filter there is an outlet for the pinion housing lubrication branch and the central table bearing lubrication branch, each of which is fitted with a pressure switch.

- 3 Overview of the drawings

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a hydraulic diagram of an exemplary hydraulic oil distribution circuit to a hydrostatic carousel bearing; FIGS. 2 to 4 show a preferred embodiment of a primary divider and two secondary divider configurations; 3 in a side view and FIG. 4 in section BB according to FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

As can be seen from FIG. 1, the hydraulic oil sucked through the filter from the tank 1 is pushed by the gear pump 2 through the filter unit 3 into the primary flow divider 4, which divides it into two branches. The oil flow in each of these branches is further divided in secondary dividers 5 into twice 8 branches. Thus, 16 terminal branches 6 are available, which corresponds to the number of cells 7 of the hydrostatic bearing 8 on the bed 9 of the carousel. Each branch 6 has its own fine control of the amount of oil through the overflow valve 10, which transfers the oil to the drain line It is indicated by a pair of pressure control switches 12 on each secondary divider 5 that checks the pressure in one of the divider outlets 5. Downstream of filter 3 the outlet for the lubrication branch 13 of the pinion housing 14 and the lubrication branch 15 of the central bearing 16 of the carousel table are connected, each of these branches 13, 15 being fitted with its own pressure switch 17.

The design of the primary and secondary divider 4, 5 is shown in Figures 2 to 4: The primary divider 4 is screwed directly to the filter unit 3 and connected only by two tubes 19 to the supply chambers 20 of the secondary divider 5. These form together with the secondary divider 5 and a single construction node. Components of this node also include relief valves 10, lubrication manifolds and pressure control switches 12. The secondary dividers 5 are offset on the manifold block 21 and are bolted to it with special hexagon socket screws. The described solution enables the supply of hydraulic oil to 6, 8, 10, 12, 14, 16 or 18 cells by selecting the appropriate combination of dividers 4, 5, or, if the aggregate is doubled, to 20, 24, 28 or 32 cells.

Claims (7)

PATENT CLAIMS A hydraulic oil to a hydrostatic bearing of a vertical lathe comprising a pump (2), a filter (3) and means for distributing the oil flow into branches (6) for individual cells (7) of the hydrostatic bearing (8), characterized in that the means to divide the oil flow, they are formed by at least one flow divider (4, 5). Hydraulic oil distribution system according to claim 1, characterized in that two or four secondary dividers (5) are connected downstream of the primary divider (4), each dividing the current in half or half respectively. quarters of finite branches (6). Hydraulic oil distribution system according to claim 2, characterized in that the two secondary dividers (5) are connected to the common manifold block (21) by their outlets. Hydraulic oil distribution system according to claim 3, characterized in that the secondary dividers (5) are screwed directly into the bores of the internally threaded block (21). Hydraulic oil distribution system according to claim 3 or 4, characterized in that a flow relief valve (10) is integrated in the block (21) for each branch to transfer the oil to the drain line (11). Hydraulic oil distribution system according to claims 2 to 5, characterized in that each secondary divider (5) is provided with a pair of pressure switches (12) to control the pressure in one of the divider outlets (5). Hydraulic oil distribution system according to one of Claims 1 to 6, characterized in that an outlet for the pinion housing lubrication branch (13) and the center table bearing lubrication branch (16) is connected downstream of the filter unit (4), each of these branches (13, 15) is fitted with a pressure switch (17).