JP2014151429A - Seizure prevention device for sliding surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seizure prevention device for a sliding surface which prevents seizure of the sliding surface of a large-sized vertical lathe.SOLUTION: The seizure prevention device for the sliding surface includes: recovery grooves 13-1, 13-2 which are provided on both redial-direction sides of a guide face 8; first holes 27 which are provided in the bottoms of the recovery grooves 13-1, 13-2 and are communicated with an oil collection pipe 12; second holes 28 which are provided in the vertical-direction lower sides of the first holes, are separated from the first holes 27 by walls 29 and are communicated with a lubrication oil supply pipe 26; pistons 14 which penetrate the wall 29 and are movable in the vertical direction; first valves 17 which are provided on the upper parts of the pistons 14 and can open and close openings of the recovery grooves 13-1, 13-2 and the first holes 27; second valves 30 which are provided on the lower parts of the pistons 14 and receive an upwards pressure in the vertical pressure generated by a supply pressure of a lubrication oil; springs 15 applying onto the pistons 14a, downwards elastic force in the vertical direction which is lower than the supply pressure of the lubrication oil,; and an edge 16 which is higher than the guide face 8.

Description

  The present invention relates to a seizure prevention device for a sliding surface of a large vertical lathe.

  FIG. 4 is a vertical sectional view of a conventional small vertical lathe. As shown in the figure, a general small vertical lathe places a workpiece 2 on a rotary table 1 and rotates the rotary table 1 by a motor 3 and a gear train 4. The workpiece 2 is processed by a tool post 5. To do.

  The bearing 7 is provided at the rotation center of the turntable 1. The thrust bearing 6 is arranged in the rotation direction of the rotary table 1 and receives the load of the workpiece 2 and the rotary table 1. Further, grease is applied to the thrust bearing 6 as a lubricant. The application prevents the contact portion between the rotary table 1 and the thrust bearing 6 from being seized when the rotary table 1 is rotated.

  If the motor 3 stops due to a power failure or the like, it takes time until the rotation stops naturally due to the moment of inertia of the workpiece 2 and the rotary table 1, but even during that time, the contact portion between the rotary table 1 and the thrust bearing 6 remains. There will be no seizure.

  In the design of a normal small vertical lathe, if the diameter of the rotary table 1 is up to about 5 m, the diameter of the thrust bearing 6 is up to about 3 m. If the thrust bearing 6 has a diameter of about 3 m, it can be manufactured with general production equipment and is available on the market.

Japanese Utility Model Publication No. 60-027279

  However, when the diameter of the rotary table 1 exceeds φ6 m as in a large vertical lathe, it is very difficult to manufacture and obtain a thrust bearing. Therefore, as shown in the vertical sectional view of the conventional large vertical lathe in FIG. 5, a hydrostatic bearing (part C in FIG. 5) is provided instead of the thrust bearing. FIG. 6 is an enlarged view of a portion C in FIG. The arrows in FIGS. 5 and 6 indicate the flow of the lubricating oil.

  In the normal pressure bearing, when the lubricating oil in the lubricating tank 10 is supplied from the lubricating oil supply pipe 26 to the pocket 9 during normal operation, the sliding surface that is the lowermost surface of the rotary table 1 is generated by the supply pressure. 21 floats up from the guide surface 8 of the bed 23, and the floating amount h can be secured. Thereby, the contact part of the rotary table 1 and the bed 23 is lost, and seizure is prevented. At this time, the lubricating oil that has flowed from the guide surface 8 is guided to the oil collecting pipe 12 from the collection grooves 24-1 and 24-2 and returned to the lubricating tank 10.

  However, there is a possibility that the lubricating oil is not supplied to the pocket 9 due to a power failure or the like. Then, the sliding surface 21 and the guide surface 8 come into close contact with each other. In the large vertical lathe, since the total load of the workpiece 2 and the rotary table 1 exceeds 150 t, the workpiece 2 and the rotary table 1 continue to rotate for a considerable time due to the moment of inertia and centrifugal force during the rotation. Therefore, seizure also occurs between the sliding surface 21 and the guide surface 8.

  When power is cut off due to a power failure, a mechanical brake can be installed. However, a device that stops a large weight and inertial force exceeding 150 tons is very large, and the lifespan becomes a problem. Often no mechanical brakes are installed.

  Therefore, as a general measure, a method of preventing seizure by adopting a material such as resin for either one of the sliding surface 21 and the guide surface 8 is adopted. However, even with this method, seizure occurs when the contact surface pressure is high and the rotational speed is high when the stop time is long because the supply of lubricating oil is stopped and the load and inertia moment exceed 150 t. there is a possibility.

  In Patent Document 1, as a static pressure bearing seizure prevention method at the time of a power failure, the air motor is activated at the time of a power failure, and the pressure oil supply auxiliary pump is driven by the activation of the air motor. A method is disclosed.

  An object of the present invention is to provide a sliding surface seizure prevention device that prevents seizure of the sliding surface of a large vertical lathe without providing an auxiliary pump.

An apparatus for preventing seizure of a sliding surface according to a first aspect of the present invention that solves the above problems
A rotary table having an annular sliding surface;
A bed having an annular guide surface that faces the sliding surface, supports the sliding surface in the vertical direction, and is provided with a pocket, and a central shaft that rotatably supports the rotary table;
A lubricating tank for storing lubricating oil;
A lubricating oil lubricating oil supply pipe having a pump motor for communicating the lubricating tank and the pocket and discharging lubricating oil from the lubricating tank side to the pocket side;
An anti-seizure device for the sliding surface disposed on a large vertical lathe provided with an oil collecting pipe for collecting lubricating oil in the lubricating tank,
An annular collection groove disposed on both radial sides of the guide surface;
A first hole disposed at one or more locations on the bottom of the recovery groove and communicating with the oil collecting pipe;
A second hole disposed on the lower side in the vertical direction of each of the first holes, separated from the first hole by a wall, and communicated with the lubricating oil supply pipe;
A piston penetrating the wall and movable in the vertical direction;
A first valve disposed on the piston and capable of opening and closing an opening between the recovery groove and the first hole;
A second valve disposed under the piston and receiving a vertical upward pressure due to a supply pressure of lubricating oil during normal operation;
A spring that is smaller than the supply pressure of the lubricating oil during normal operation and gives an elastic force downward in the vertical direction to the piston;
The recovery groove is an annular convex portion that forms the guide surface together with an edge that is higher than the guide surface in the vertical direction.

An anti-seizure device for a sliding surface according to a second invention for solving the above-mentioned problems is
In the sliding surface seizure prevention device according to the first invention,
The lubricating oil supply pipe is
An accumulator having a capacity equal to or greater than a total volume of the pocket and the collection groove when the height is the edge is further provided.

  According to the seizure preventive device for a sliding surface according to the first aspect of the present invention, an annular collection groove disposed on both sides in the radial direction of the guide surface, and one or more portions are disposed at the bottom of the collection groove, A first hole that communicates with each other, a vertical hole below each of the first holes, and a second hole that is partitioned by the first hole and the wall and communicates with the lubricating oil supply pipe. A movable piston, a first valve disposed at the upper part of the piston and capable of opening and closing an opening of the recovery groove and the first hole, and disposed at a lower part of the piston for supplying lubricating oil during normal operation A second valve that receives vertical upward pressure due to pressure, a spring that is smaller than the supply pressure of the lubricating oil during normal operation and gives vertical downward elastic force to the piston, and a recovery groove are formed with the guide surface An annular convex part that has a higher edge than the guide surface in the vertical direction. It is possible to prevent with the sliding surface of the baked.

  According to the device for preventing seizure of a sliding surface according to the second aspect of the invention, the lubricating oil supply pipe has a capacity equal to or greater than the total volume of the pocket and the collection groove when the height is an edge. Since the accumulator is further provided, seizure of the sliding surface of the large vertical lathe can be more reliably prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view of a large vertical lathe equipped with a sliding surface seizure prevention device according to Embodiment 1 of the present invention. It is an enlarged view of A part in FIG. It is a BB arrow line view in FIG. It is a vertical sectional view of a conventional small vertical lathe. It is a vertical sectional view of a conventional large vertical lathe. FIG. 6 is an enlarged view of a portion C in FIG. 5.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, sliding surface seizure preventing devices according to the present invention will be described with reference to the accompanying drawings.

  A sliding surface seizure preventing device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a vertical sectional view of a large vertical lathe equipped with this apparatus. The arrows in the figure indicate the flow of the lubricating oil, and P indicates the supply pressure of the lubricating oil (the same applies to the other figures). The figure shows the rotary table 1, the bed 23, the bearing 7, the drive motor 3, the gear train 4, the large diameter gear 6, the lubricating tank 10, the lubricating oil supply pipe 26 and the oil collecting pipe 12.

  The turntable 1 can place the work 2 on the upper part, has a sliding surface 21, and can rotate around a central axis 25. The sliding surface 21 is an annular surface located at the lowermost part of the turntable 1.

  The bed 23 has a central shaft 25 and a guide surface 8 and supports the rotary table 1. The central shaft 25 supports the rotary table 1 via the bearing 7 so as to be rotatable. The guide surface 8 is an annular surface that faces the sliding surface 21 and supports the sliding surface 21 in the vertical direction, and the pocket 9 is disposed therein. The pocket 9 is a recess disposed on the guide surface 8.

  The drive motor 3 and the gear train 4 apply power to the large-diameter gear 22. The large-diameter gear 22 is fixed to the turntable 1 and transmits power to the turntable 1.

  The lubricating tank 10 is a lubricating oil storage tank. The lubricating oil supply pipe 26 communicates the lubricating tank 10 and the pocket 9. The oil collecting pipe 12 collects the lubricating oil in the lubricating tank 10.

  With the above configuration, in the large vertical lathe equipped with this apparatus, first, the work 2 is placed on the rotary table 1, and the drive motor 3, the gear train 4, the large-diameter gear 6, Thus, the rotary table 1 is rotated.

  Next, the weight of the workpiece 2 and the rotary table 1 is received by the guide surface 8 of the bed 23. The guide surface 8 is provided with a pocket 9, a lubricating tank 10 is provided to float the weight, and lubricating oil is supplied to the pocket 9 by a pump motor (not shown in FIG. 1). As a result, the sliding surface 21 of the turntable 1 is prevented from being seized without contacting the guide surface 8 of the bed 23.

  Lubricating oil flowing out from both sides of the pocket 9 passes through the oil collecting pipe 12 and is collected in the lubricating tank 10. As long as the pump motor 11 is rotating, the lubricating oil is supplied to the pocket 9 and then collected and circulated to the lubricating tank 10.

  FIG. 2 is an enlarged view of a portion A in FIG. As shown in the drawing, the apparatus includes recovery grooves 13-1 and 13-2, a first hole 27, a second hole 28, a piston 14, a first valve 17, a second valve 30, a spring 15 and an edge 16. . In addition, the arrow in the said figure has shown the flow of lubricating oil. Further, in the drawing, the recovery groove 13-1 and the recovery groove 13-2, or the pistons 14 described in the left and right two places are shown in different states on the left and right for the sake of explanation. It is a structure and performs the same operation.

  The collection grooves 13-1 and 13-2 are annular grooves disposed on both sides in the radial direction of the guide surface 8.

  One or more first holes 27 are disposed at the bottom of the collection grooves 13-1 and 13-2 and communicate with the oil collecting pipe 12.

  The second hole 28 is disposed below the first hole 27 in the vertical direction, is partitioned by the first hole 27 and the wall 29, and communicates with the lubricating oil supply pipe 26.

  The piston 14 penetrates the wall 29 and is movable in the vertical direction.

  The first valve 17 is disposed in the upper part of the piston 14 and can open and close the opening between the recovery grooves 13-1 and 13-2 and the first hole 27.

  The second valve 30 is disposed below the piston 14 and receives an upward pressure in the vertical direction due to the supply pressure of the lubricating oil during normal operation.

  The spring 15 is smaller than the supply pressure of the lubricating oil during normal operation, and applies a vertically downward elastic force to the piston 14.

  The edge 16 is an annular convex portion that forms the collecting grooves 13-1 and 13-2 together with the guide surface 8, and is higher than the guide surface 8 by t in the vertical direction.

  With the above configuration, in this apparatus, first, lubricating oil is supplied from the lubricating oil supply pipe 26 to the pocket 9 and the second hole 28.

  The lubricating oil supplied to the pocket 9 floats from the guide surface 8 by a floating amount h, and flows out from both sides to the collecting grooves 13-1 and 13-2. On the other hand, the lubricating oil supplied to the second hole 28 presses the second valve 30.

  When the second valve 30 is pressed, the piston 14 and the first valve 17 move upward in the vertical direction, as shown on the recovery groove 13-1 side in FIG. 2, and the recovery grooves 13-1, 13-2 and An opening with the first hole 27 is opened. As a result, the lubricating oil that has flowed into the collection grooves 13-1 and 13-2 enters the first hole 27.

  Since the first hole 27 and the oil collecting pipe 12 communicate with each other, the lubricating oil that has entered the first hole 27 is guided to the oil collecting pipe 12 and is collected from the oil collecting pipe 12 to the lubricating tank 10.

  Next, the operation when the power is turned off due to a power failure or the like will be described. When the power is turned off, the pump motor (not shown in FIG. 2) stops, and the supply of lubricating oil stops.

  Then, as shown on the collection groove 13-2 side in FIG. 2, the piston 14 is pushed down by the spring 15, and the first valve 17 is the opening between the collection grooves 13-1 and 13-2 and the first hole 27. The lubricating oil is collected in the collecting grooves 13-1 and 13-2.

  At this time, since the edge 16 is higher than the guide surface 8 by t, the lubricating oil accumulated in the collecting grooves 13-1 and 13-2 remains on the guide surface 8.

  In this state, even if the floating amount h = 0 due to the load of the work 2 and the turntable 1, the accumulated lubricating oil is drawn onto the guide surface 8 by the rotation of the turntable 1, so that seizure is prevented. It becomes possible to do.

  FIG. 3 is a BB arrow view in FIG. The arrangement relationship of each member will be described with reference to the drawing.

  First, the annular guide surface 8 is provided with pockets 9 in the circumferential direction. Further, recovery grooves 13-1 and 13-2 are provided on both radial sides of the guide surface 8.

  The collection grooves 13-1 and 13-2 are provided with a first hole 27 (the first valve 17 is shown in FIG. 3) in the circumferential direction. Further, edges 16 are provided on the radially outer side of the collection groove 13-1 and on the radially inner side of the collection groove 13-2, respectively.

  The lubricating oil supply pipe 26 communicates between the lubricating tank 10 and each pocket 9, but as shown in FIG. 3, the lubricating oil supply pipe 26 of the present apparatus supplies the lubricating oil from the lubricating tank 10 to the pocket 9. In the flow path, a filter 32, a check valve (check valve) 33, a pump motor 11, a pressure reducing valve 18, an accumulator 31, and a flow rate adjusting valve 19 are provided from upstream.

  The pump motor 11 discharges lubricating oil from the lubricating tank 10 side to the pocket 9 side.

  The pressure reducing valve 18 adjusts the supply pressure of the lubricating oil. The pressure reducing valve 18 can adjust the pressure of the lubricating oil supplied to the pocket 9 according to the weight of the workpiece 2.

  The accumulator 31 has a capacity equal to or greater than the total volume of the pocket 9 and the collection grooves 13-1 and 13-2 when the height is the edge 16. Thereby, the accumulator 31 not only prevents pulsation of the lubricating oil discharged from the pump motor 11 during normal operation, but also into the pocket 9 and the collection grooves 13-1 and 13-2 when the power is turned off. The lubricating oil can be replenished. In addition, since the supply pressure by the accumulator 31 is very small, the second valve 30 is not pressed.

  The flow rate adjusting valve 19 adjusts the supply pressure and flow rate of the lubricating oil. Thereby, the floating amount h can be adjusted.

  With the above configuration, when there is a difference between the time when the floating amount h = 0 when the power failure occurs and the time when the recovery grooves 13-1 and 13-2 are closed, the recovery grooves 13-1 and 13- It is also possible to prevent a situation where the lubricating oil does not sufficiently accumulate in 2. In addition, since the lubricating oil pushed out by the accumulator 31 is always accumulated in the pocket 9, the oil is not lost inside the guide surface 8.

  The sliding surface seizure preventing device according to the first embodiment of the present invention has been described above. In other words, the present device faces the rotary table 1 having the annular sliding surface 21 and the sliding surface 21. The bed 23 having an annular guide surface 8 that supports the sliding surface 21 in the vertical direction and in which the pockets 9 are disposed, and a central shaft 25 that rotatably supports the rotary table 1, and stores lubricating oil. The lubricating tank 10, the lubricating tank 10 and the pocket 9 communicate with each other, the lubricating oil supply pipe 26 having the pump motor 11 that discharges the lubricating oil from the lubricating tank 10 side to the pocket 9 side, and the lubricating oil is collected in the lubricating tank 10. An anti-seizure device for a sliding surface disposed on a large vertical lathe provided with an oil collecting pipe 12, and annular recovery grooves 13-1 and 13-2 disposed on both radial sides of the guide surface 8. And one or more places at the bottom of the collection grooves 13-1 and 13-2 The first hole 27 that is disposed and communicates with the oil collecting pipe 12, and is disposed on the lower side in the vertical direction of each of the first holes 27, is partitioned by the first hole 27 and the wall 29, and communicates with the lubricating oil supply pipe 26. The second hole 28, the piston 14 penetrating the wall 29 and movable in the vertical direction, and disposed at the upper part of the piston 14, the openings of the recovery grooves 13-1 and 13-2 and the first hole 27 are formed. A first valve 17 that can be opened and closed, a second valve 30 that is disposed below the piston 14 and that receives the upward pressure in the vertical direction due to the supply pressure of the lubricating oil during normal operation, and the supply of lubricating oil during normal operation It is an annular convex part that forms a spring 15 and a collection groove 13-1, 13-2, together with the guide surface 8, which are smaller than the pressure and give an elastic force downward in the vertical direction to the piston 14. With a higher edge 16 than the surface 8.

  With this configuration, the present apparatus can store the lubricating oil on the guide surface 8 until the turntable 1 naturally stops after a power failure. Further, since the edges 16 of the collection grooves 13-1 and 13-2 are higher than the guide surface 8, the lubricating oil can be reliably accumulated. Further, since the first valve 17 closes the openings of the recovery grooves 13-1 and 13-2 and the first hole 27 at the moment of power failure, the flow of the lubricating oil immediately stops, and the recovery grooves 13-1 and 13 -2 can store lubricating oil. Further, the lubricating oil pushed out from the accumulator 31 is also stored in the pocket 9, so that it is possible to prevent seizure of the sliding surface of the large vertical lathe.

  Further, the lubricating oil supply pipe 26 of this apparatus has an accumulator 31 whose capacity is equal to or greater than the total volume of the pocket 9 and the collection grooves 13-1 and 13-2 when the height is the edge 16. In addition.

  With this configuration, the apparatus can store the lubricating oil more reliably. Therefore, seizure of the sliding surface of the large vertical lathe can be more reliably prevented.

  The present invention is suitable as a seizure prevention device for the sliding surface of a large vertical lathe.

DESCRIPTION OF SYMBOLS 1 Rotary table 2 Workpiece 3 Drive motor 4 Gear train 5 Tool post 6 Thrust bearing 7 Bearing 8 Guide surface 9 Pocket 10 Lubrication tank 11 Pump motor 12 Oil collection pipes 13-1, 13-2, 24-1, 24-2 Collection groove 14 Piston 15 Spring 16 Edge 17 First valve 18 Pressure reducing valve 19 Flow rate adjusting valve 21 Sliding surface 22 Large diameter gear 23 Bed 25 Central shaft 26 Lubricating oil supply pipe 27 First hole 28 Second hole 29 Wall 30 Second valve 31 Accumulator 32 Filter 33 Check valve

Claims (2)

A rotary table having an annular sliding surface;
A bed having an annular guide surface that faces the sliding surface, supports the sliding surface in the vertical direction, and is provided with a pocket, and a central shaft that rotatably supports the rotary table;
A lubricating tank for storing lubricating oil;
A lubricating oil lubricating oil supply pipe having a pump motor for communicating the lubricating tank and the pocket and discharging lubricating oil from the lubricating tank side to the pocket side;
An anti-seizure device for the sliding surface disposed on a large vertical lathe provided with an oil collecting pipe for collecting lubricating oil in the lubricating tank,
An annular collection groove disposed on both radial sides of the guide surface;
A first hole disposed at one or more locations on the bottom of the recovery groove and communicating with the oil collecting pipe;
A second hole disposed on the lower side in the vertical direction of each of the first holes, separated from the first hole by a wall, and communicated with the lubricating oil supply pipe;
A piston penetrating the wall and movable in the vertical direction;
A first valve disposed on the piston and capable of opening and closing an opening between the recovery groove and the first hole;
A second valve disposed under the piston and receiving a vertical upward pressure due to a supply pressure of lubricating oil during normal operation;
A spring that is smaller than the supply pressure of the lubricating oil during normal operation and gives an elastic force downward in the vertical direction to the piston;
An anti-seizure device for a sliding surface, characterized in that the recovery groove is an annular convex portion that forms the guiding surface together with the guiding surface, and has an edge that is higher than the guiding surface in the vertical direction. The lubricating oil supply pipe is
The sliding surface seizure prevention device according to claim 1, further comprising an accumulator whose capacity is equal to or greater than a total volume of the pocket and the collection groove when the height is the edge. .

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