JP2005076858A - Rotary distribution valve and lubricating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary distribution valve in which, even if a minute amount of lubricating oil is, for example, distributed equally, the rotary accuracy of a rotor and durability are improved, and the number of components and a cost are reduced. <P>SOLUTION: The rotary distribution valve 20 includes a stator 22 fixed to a housing 21, the rotor 23 supported rotatably to the housing 21, and a driving motor for driving rotatably the rotor 23 through a shaft 24. The rotary distribution valve 20 communicates an oil supply port 25 and respective discharge ports 26 of the stator 22 through an oil groove 27 of the rotor 23, and thereby distributes a predetermined quantity of minute amount lubricating oil equally. An angular contact ball bearing 29 which supports the shaft 24 of the rotor 23 has a contact angle of 15-60°, and can receive both a radial load and a thrust load. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to oil lubrication that does not use air instead of oil-air lubrication. Specifically, for example, a minute amount of lubricating oil is evenly distributed from one pipe to a plurality of pipes, and is evenly distributed by the rotary distributor. The present invention relates to a lubrication apparatus for intermittently supplying the lubricated oil from a plurality of nozzles to required lubrication locations.

  In machine tools, lubrication devices used for high-speed spindles include oil air and oil mist that discharge and convey lubricating oil into the compressed air circuit in order to minimize the lubricating oil stirring resistance inside the bearing during high-speed rotation. The equipment that employs the oil-air micro lubrication system is the mainstream.

  However, in the above-described oil / air micro-lubrication system using compressed air as a medium, the air curtain around the bearing that occurs during high-speed rotation of the bearing hinders the arrival of the lubricating oil into the bearing. To be complicated. Further, when the compressed air passes near the air curtain and the revolving bearing rolling element, noise, so-called wind noise, is generated.

  Therefore, as shown in FIG. 6 or FIG. 7, the lubricating oil is supplied from the solenoid valves 101 and 111 to the nozzles 102 and 113 adjacent to the bearing 112, and directly from the nozzles 102 and 113 to the bearing 112 without using compressed air. A lubricating device 100 (for example, see Patent Document 1) or a lubricating structure 110 (for example, see Patent Document 2) that injects lubricating oil and reliably reaches a small amount of lubricating oil into the bearing 112 without generating wind noise. Are known.

  Although the above-described lubrication apparatus and lubrication structure are epoch-making technologies in that a small amount of lubricating oil can reliably reach the inside of the bearing without using compressed air, a solenoid valve is used as a switching valve. Therefore, it was disadvantageous in terms of cost.

Therefore, as shown in FIG. 8 or FIG. 9, a lubrication device 120 (for example, a cost reduction is realized by using a switching valve 122 capable of distributing lubricating oil to a plurality of nozzles 121 in place of the solenoid valve. Patent Document 3) is known. In addition, the multi-branch piping apparatus 130 provided in the main shaft apparatus is also known as having a function equivalent to that of the switching valve 122 (see, for example, Patent Document 4).
Japanese Unexamined Patent Publication No. 2000-110711 (pages 4-5, FIG. 1) JP 2000-74076 A (2nd page, FIG. 2) JP 2002-130593 A (pages 4-6, FIG. 2) JP 2001-315041 A (3rd to 4th pages, FIG. 2)

  In the switching valve of the lubricating device disclosed in Patent Document 3, the rotor rotates while being in contact with the sliding surface of the stator by a spring load with respect to the stator having the sliding surface in the axial direction. The oil supply port and the discharge port provided on the sliding surface of the stator communicate with each other through an oil groove provided in the rotor at a predetermined rotor rotation position, and supply lubricating oil to the nozzle.

  In order to supply the lubricating oil into the bearing that rotates at high speed, a discharge speed of 10 to 20% of the inner ring peripheral speed is required. Therefore, it is possible to increase the supply pressure of the lubricating oil. Lubricating oil leaks from the sliding surface of the rotor. In order to reduce the leakage of the lubricating oil, it is possible to increase the pressing force of the rotor against the stator by compressing the spring with an adjusting nut.

  Further, in the switching valve 40 shown in FIG. 5, the rotor 41 is provided so that the axis center of the shaft 42 serving as the rotation center coincides with the center of the stator 43, and a carbon sleeve 44 as a slide bearing is provided. The shaft 42 is rotatably supported by the housing 45 through a radial bearing 46 and a bearing case 47. That is, the rotor 41 is positioned in the radial direction and prevented from vibration by the carbon sleeve 44. For this reason, the sleeve 44 is required to be subjected to strict processing accuracy management on the micron order.

  When the processing accuracy condition of the sleeve 44 is not satisfied and the gap between the inner diameter surface of the sleeve 44 and the outer diameter surface of the rotor 41 is increased, the rotor 41 is displaced in the radial direction, and the lubricating oil The discharge amount becomes unstable or the communication between the oil groove 48 of the rotor 41 and the discharge port 49 of the stator 43 becomes difficult, and the oil is supplied from the oil supply port 50 of the stator 43 to the discharge port 49 via the oil groove 48. There was a risk that the lubricant could not be discharged.

  Further, when the gap between the inner diameter surface of the sleeve 44 and the outer diameter surface of the rotor 41 is small or tightened, wear due to sliding friction between the sleeve 44 and the rotor 41 occurs, resulting in durability. There was a problem of lowering. In addition, since the dynamic torque becomes large, a drive motor (not shown) that rotates the rotor 41 is required to have a large torque, leading to a problem that the drive motor is increased in size.

  Further, in addition to the radial bearing 46 that supports the shaft 42 of the rotor 41 to the housing 45 via the bearing case 47, a force is exerted in the thrust direction between the spring 51 that presses the rotor 41 against the stator 43 and the bearing case 47. A thrust bearing 52 is provided for receiving. An adjustment nut 53 is provided through the bearing case 47 and the thrust bearing 52 so that the urging force of the spring 51 can be adjusted. Therefore, the increase in the number of parts and the number of assembling steps is unavoidable, and there is a problem that the cost increases and the size increases.

  The present invention is capable of distributing even a small amount of lubricating oil evenly at low cost, and improving the rotational accuracy and durability of the rotating body, reducing the number of parts and cost, and a rotary distributor It is an object of the present invention to provide a lubricating device capable of intermittently supplying lubricating oil evenly distributed by a distributing valve from a plurality of nozzles to a required lubricating location without using compressed air or the like.

  1) The rotary distribution valve of the present invention has a fuel supply port, a fixed member having a plurality of discharge ports arranged in a predetermined positional relationship with the fuel supply port, and a rotation center that coincides with the center of the fixed member. As described above, a rotating body that is rotatably supported by a housing via two rolling bearings and that is slidably contacted with a fixed member by being loaded with a predetermined axial load, and a fixing in the rotating body An oil groove provided in a radial direction from the rotation center of the rotating body on the sliding surface with the member, and communicating the oil supply port of the fixing member and each discharge port at a predetermined rotation position of the rotating body with respect to the fixing member. Among the two rolling bearings that rotatably support the rotating body on the housing, at least the rolling bearing on the side opposite to the sliding surface with the fixed member has a contact angle.

The contact angle of the rolling bearing is preferably in the range of 15 ° to 60 °. When the contact angle is less than 15 °, the load capacity of the axial load is insufficient. On the other hand, when the contact angle exceeds 50 °, the load capacity of the radial load becomes insufficient.
The contact angle of the rolling bearing is more preferably in the range of 25 ° to 50 °. By setting the contact angle to 25 ° or more, the starting friction moment can be further reduced, and by setting the contact angle to 50 ° or less, higher rotational accuracy in the radial direction is ensured.

  According to the rotary distributing valve having the above-described configuration, the lubricating oil can be simultaneously supplied from one oil supply port of the fixing member to the plurality of discharge ports via the oil groove of the rotating body. Evenly distributed from piping to multiple piping.

  Of the two rolling bearings that rotatably support the rotating body on the housing, at least the rolling bearing on the side opposite to the sliding surface with the fixing member has a contact angle. On the side opposite to the surface, a pressing force and a radial load on the fixing member side are simultaneously applied. Therefore, the rotating body is pressed against the fixed member without using, for example, a combination of a thrust bearing and a radial bearing as the support bearing of the rotating body. As a result, the axial dimension can be shortened to make the entire rotary distributing valve compact, and the number of parts and assembly man-hours can be reduced, leading to cost reduction.

  2) In the rotary distribution valve of the present invention, it is preferable that the rolling bearing having the contact angle is an angular ball bearing.

  According to such a configuration, the pressing force and the radial load on the fixed member side are simultaneously applied to the rotating body opposite to the sliding surface of the fixed member via the angular ball bearing having a contact angle. . Therefore, the rotating body is pressed against the fixed member without using, for example, a combination of a thrust bearing and a radial bearing as the support bearing of the rotating body. As a result, the axial dimension can be shortened to make the entire rotary distributing valve compact, and the number of parts and assembly man-hours can be reduced, leading to cost reduction.

  3) The rotary distribution valve according to the present invention includes an inner ring or a rotating body of a rolling bearing on a sliding surface side with a fixed member, and a fixed member of two rolling bearings that rotatably support the rotating body on a housing. A thrust load load spring, which is interposed between the inner ring of the rolling bearing on the opposite side of the sliding surface and urges the rotating body toward the fixed member, and is screwed to the housing so that the position can be adjusted. It is preferable to provide an adjustment nut for adjusting the biasing force of the spring.

  According to such a configuration, the pressing force and radial load on the fixed member side are provided on the opposite side of the rotating member from the sliding surface of the fixed member via the rolling bearing having a contact angle from the thrust load load spring. Are simultaneously loaded. The urging force of the thrust load spring is adjusted by adjusting the position of the adjustment nut relative to the housing.

  Therefore, the rotating body is pressed against the fixed member without using, for example, a combination of a thrust bearing and a radial bearing as the support bearing of the rotating body. The pressing force is adjusted by adjusting the urging force of the thrust load loading spring by the adjusting nut. As a result, the axial dimension can be shortened to make the entire rotary distributing valve compact, and the number of parts and assembly man-hours can be reduced, leading to cost reduction.

  4) The lubricating device of the present invention includes a hydraulic pump that supplies lubricating oil to the oil supply port of the rotary distributing valve described in 1), 2), or 3) via a pump side pipe, and 1), 2) Or the lubricating oil sent from each discharge port of the rotary distribution valve of 3) is supplied via the nozzle side piping for each discharge port, and a plurality of nozzles that respectively supply the lubricating oil to a required lubricating location It is characterized by having.

  According to the lubricating device having the above-described configuration, the lubricating oil that is evenly distributed by the rotary distributing valve is intermittently supplied from a plurality of nozzles to each required lubricating location accurately. Therefore, the lubrication point is properly and reliably lubricated without causing an increase in torque or the like due to excessive lubricating oil.

  According to the rotary distributing valve of the present invention, even a small amount of lubricating oil can be distributed evenly at low cost, and the rotational accuracy and durability of the rotating body can be improved, and the number of parts and cost can be reduced. . Further, according to the lubricating device of the present invention, the lubricating oil evenly distributed by the rotary distributing valve can be intermittently supplied from a plurality of nozzles to a required lubricating location without using compressed air or the like.

  Hereinafter, one embodiment of the rotary distribution valve and lubrication device of the present invention is described. 1 is a schematic configuration diagram showing a lubrication apparatus to which a rotary distribution valve according to an embodiment of the present invention is applied, FIG. 2 is a schematic sectional view showing a rotary distribution valve of the lubrication apparatus of FIG. 1, and FIG. It is a schematic side view which shows the positional relationship of each discharge port of the stator of a rotary distribution valve, and the oil groove of a rotor.

  As shown in FIG. 1, a lubricating device 10 is applied to a machine tool spindle, and a minute amount of lubricating oil is evenly distributed and supplied to a plurality of nozzles 11 arranged for each of a plurality of bearings 1 of the machine tool spindle. Lubricating device.

  That is, the lubrication apparatus 10 performs rotary distribution of lubricating oil supplied at a predetermined pressure (for example, 2.5 MPa) from the hydraulic pump 12 to the oil supply port 25 of the rotary distribution valve (switching valve) 20 via the pump side pipe 13. The nozzles 20 are equally distributed from the plurality of discharge ports 26 of the valve 20 to the nozzle-side pipes 14 for the respective nozzles 11, supplied from the nozzle-side pipes 14 to the nozzles 11, and each nozzle 11 enters the corresponding bearing 1. A small amount of lubricating oil is injected.

  In the lubricating device 10, the number of discharge ports 26 of the rotary distribution valve 20 is the same as the number of the nozzles 11. However, when the number is insufficient, a plurality of rotary distribution valves 20 are arranged in parallel with respect to one hydraulic pump 12. You may respond by connecting to. Moreover, as a material of piping used as the pump side piping 13 and each nozzle side piping 14, it is desirable that they are a thing with little deformation | transformation by a pressure, for example, a steel pipe and a pressure | voltage resistant resin pipe.

  As shown in FIGS. 2 and 3, the rotary distribution valve 20 includes a stator 22 fixed to the housing 21, a rotor 23 supported to be rotatable with respect to the housing 21, and the rotor 23 rotated via a shaft 24. A driving motor (not shown) for driving. The rotary distributing valve 20 includes one oil supply port 25 and six discharge ports 26 provided in the stator 22 at one oil position provided in the rotor 23 at a predetermined rotational position of the rotor 23 with respect to the stator 22. By communicating with each other through the grooves 27, a predetermined amount of a minute amount of lubricating oil is evenly distributed.

  The stator 22 has one oil supply port 25 at the center of rotation, and six discharge ports 26 that are spaced apart from the oil supply port 25 in the radial direction at equal intervals in the circumferential direction. That is, six discharge ports 26 are provided in the stator 22 every 60 ° along the circumferential direction, and are formed to have a predetermined diameter.

  The rotor 23 is provided so that the axial center of the shaft 24 coincides with the center of the stator 22, and is rotatably supported by the housing 21 via a radial bearing 28, and the shaft 24 is interposed via an angular ball bearing 29. The housing 21 is rotatably supported. The rotor 23 is pressed against the stator 22 with a predetermined pressure by being subjected to a predetermined axial load by the thrust load spring 31 and is slidably contacted with the stator 22.

  The shaft 24 of the rotor 23 is rotatably supported by the housing 21 via an angular ball bearing 29. The rotor 23 is integrally formed at one end (the left end in FIG. 2) and the other end (see FIG. (2 middle right end portion) is connected to a drive motor.

  The thrust load loading spring 31 is provided between the inner ring 28a of the radial bearing 28 and the inner ring 29a of the angular ball bearing 29 via a spacer 32, and urges the rotor 23 toward the stator 22 side. The biasing force of the thrust load loading spring 31 is adjusted via the angular ball bearing 29 by adjusting the position of the adjusting nut 30 for preload adjustment screwed into the housing 21 along the axial direction of the shaft 24 (left and right direction in FIG. 2). Adjusted.

  The thrust load load spring 31 may be directly interposed between the inner ring 28a of the radial bearing 28 and the inner ring 29a of the angular ball bearing 29 without using the spacer 32, or the inner ring 28a of the radial bearing 28. Instead, it may be provided between the end face 23 a of the rotor 23 and the inner ring 29 a of the angular ball bearing 29.

  The adjustment nut 30 is managed with high accuracy in the gap with the housing 21, and can be prevented from falling due to backlash accompanying the screwing into the housing 21. As a result, the adjustment nut 30 applies a uniform load to the angular ball bearing 29.

  One oil groove 27 is provided in the radial direction from the rotation center of the rotor 23 on the sliding surface of the rotor 23 with the stator 22. That is, the oil grooves 27 are provided in one direction along the radial direction for the six discharge ports 26 of the stator 22. The oil groove 27 has a predetermined width direction dimension (dimension along the circumferential direction) corresponding to the diameter of the discharge port 26.

  Since the radial bearing 28 that supports the rotor 23 can be managed with a precise clearance fit between the rotor 23 and the housing 21, the radial bearing 28 is displaced only in the micron order in the radial direction. Therefore, high rotation accuracy of the rotor 23 is maintained, and the discharge amount of the lubricating oil is stabilized. In addition, since a rolling bearing is used as the radial bearing 28, friction and durability can be improved, and dynamic torque during rotation of the rotor 23 can be reduced, and the drive motor for the rotor 23 can be downsized. It becomes.

  FIG. 4 is a graph showing the relationship between the contact angle of the angular ball bearing and the starting friction moment when a load of 300 N is applied by the thrust load spring to the angular ball bearing of the rotary distributing valve of FIG.

  As can be understood from FIG. 4, when the contact angle of the angular ball bearing 29 increases when the angular ball bearing 29 is loaded with the same spring load, the starting friction moment decreases. Therefore, if the angular ball bearing 29 having a larger contact angle is used in the rotary distributing valve 20 of FIG. 2, the starting frictional moment can be reduced even if a larger pressing force is applied to the rotor 23.

  That is, the contact angle of the angular ball bearing 29 is preferably in the range of 15 ° to 60 °. If the contact angle is less than 15 °, the load capacity of the axial load is insufficient, while the contact angle 50 If it exceeds °, the load capacity of the radial load will be insufficient. Further, the contact angle of the angular ball bearing 29 is more preferably in the range of 25 ° to 50 °. By setting the contact angle to 25 ° or more, the starting friction moment can be further reduced, while the contact angle is By setting it to 50 ° or less, higher rotational accuracy in the radial direction can be ensured.

The operation of this embodiment will be described.
In the rotary distribution valve 20, the phase of the rotor 23 and the stator 22 is controlled so that the oil groove 27 of the rotor 23 is positioned at the approximate center between the discharge ports 26 of the stator 22 when the lubricating oil is shut off. From this state, when supplying lubricating oil, the rotor 23 is rotated 360 ° by the drive motor and stopped. As the rotor 23 rotates, the oil supply port 25 and each discharge port 26 communicate with each other via the oil groove 27, and one lubricating oil amount is discharged from each discharge port 26.

  In addition, since the rolling bearing that supports the shaft 24 of the rotor 23 is an angular ball bearing 29 having a contact angle, the pressing force to the stator 22 side and the radial are provided on the opposite side of the rotor 23 to the sliding surface of the stator 22. The load is applied at the same time. Therefore, for example, the rotor 23 is pressed against the stator 22 without using a combination of a thrust bearing and a radial bearing as a support bearing of the rotor 23. Thereby, the axial dimension can be shortened to make the rotary distribution valve 20 compact, and the number of parts and the number of assembling steps can be reduced, thereby reducing the cost.

  As described above, according to the embodiment, in the rotary distribution valve 20, the lubricating oil can be supplied from one oil supply port 25 of the stator 22 to the six discharge ports 26 via the oil groove 27 of the rotor 23. A small amount of lubricating oil can be evenly distributed from one pipe to a plurality of pipes.

  Of the two rolling bearings 28 and 29 for rotatably supporting the rotor 23 on the housing 21, the rolling bearing 29 on the side opposite to the sliding surface with the stator 22 is an angular ball bearing having a contact angle of 30 °. Therefore, the pressing force to the stator 22 side and the radial load can be simultaneously applied to the opposite side of the rotor 23 to the sliding surface of the stator 22.

  Accordingly, the rotor 23 can be pressed against the stator 22 without using, for example, a combination of a thrust bearing and a radial bearing as a support bearing for the rotor 23. The pressing force can be adjusted by adjusting the biasing force of the thrust load loading spring 31 by the adjusting nut 30. As a result, the axial dimension can be shortened to make the entire rotary distribution valve 20 compact, and the number of parts and assembly man-hours can be reduced, thereby reducing the cost.

  Further, as in the conventional example shown in FIG. 5, the carbon sleeve 44 (see FIG. 5), which requires strict processing accuracy control on the order of microns, is positioned and vibrated in the radial direction of the rotor 41 (see FIG. 5). This is not necessary for prevention, and problems such as an increase in the gap between the inner diameter surface of the sleeve 44 and the outer diameter surface of the rotor 41 can be eliminated. Therefore, the displacement of the rotor 23 in the radial direction can be suppressed as much as possible. Thereby, the positional relationship between the oil groove 27 of the rotor 23 and the discharge port 26 of the stator 22 can be maintained appropriately, and the discharge amount of the lubricating oil from the discharge port 26 can be stabilized.

  Further, problems such as wear due to sliding friction between the sleeve 44 and the rotor 41 as in the conventional example shown in FIG. 5 can be eliminated, and durability can be improved. In addition, the dynamic torque of the rotor 23 can be remarkably reduced. As a result, a small motor having a small torque can be used as a drive motor for rotating the rotor 23, and the entire lubrication apparatus 10 can be downsized. be able to.

  In the above embodiment, an angular ball bearing having a small torque and a high rotational accuracy is used as the rolling bearing 29 that supports the shaft 24 of the rotor 23 on the housing 21. However, the present invention is not limited to this, and equivalent performance can be obtained. Various other bearings such as a tapered roller bearing can be applied. In addition, an appropriate shape change can be added to the screwed portion between the housing 21 and the adjusting nut 30.

It is a schematic block diagram which shows the lubricating device to which the rotary distribution valve which is one Embodiment of this invention was applied. It is a schematic sectional drawing which shows the rotary distribution valve of the lubricating device of FIG. It is a schematic side view which shows the positional relationship of each discharge port of the stator of the rotary distribution valve of FIG. 2, and the oil groove of a rotor. It is a graph which shows the relationship between the contact angle of the angular ball bearing of the rotary distribution valve of FIG. 2, and a starting friction moment. It is a schematic sectional drawing which shows the conventional switching valve. 1 is a cross-sectional view showing a lubricating device disclosed in Patent Document 1. FIG. 10 is a cross-sectional view showing a lubricating structure disclosed in Patent Document 2. FIG. It is a block diagram which shows the lubricating device currently disclosed by patent document 3. It is a figure which shows the structure of the main axis | shaft apparatus currently disclosed by patent document 4. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bearing of machine tool spindle 10 Lubricating device 11 Nozzle 12 Hydraulic pump 13 Pump side piping 20 Rotary distribution valve 25 Oil supply port 14 Nozzle side piping 21 Housing 22 Fixed member (stator)
23 Rotating body (rotor)
24 Shaft 25 Oil supply port 26 Discharge port 27 Oil groove 28 Radial bearing 29 Rolling bearing (angular ball bearing) on the opposite side of the sliding surface with the fixed member
30 Adjustment nut 31 Thrust load spring 32 Spacer

Claims (4)

A fixing member having a plurality of discharge ports arranged with a predetermined positional relationship with the oil supply port, together with the oil supply port;
It is rotatably supported by the housing via two rolling bearings so that the center of rotation coincides with the center of the fixed member, and is slidably contacted with the fixed member by being loaded with a predetermined axial load. A rotating body,
Provided on the sliding surface of the rotating body with the fixed member along the radial direction from the center of rotation of the rotating body, and the oil supply port of the fixing member and each discharge port communicate with each other at a predetermined rotational position of the rotating body with respect to the fixed member. With an oil groove,
Of the two rolling bearings that rotatably support the rotating body on the housing, at least the rolling bearing on the side opposite to the sliding surface with the fixed member has a contact angle. The rotary distribution valve according to claim 1, wherein the rolling bearing having the contact angle is an angular ball bearing. Of the two rolling bearings that rotatably support the rotating body on the housing, the inner ring or the rotating body of the rolling bearing on the sliding surface side with the fixed member and the rolling bearing on the opposite side of the sliding surface of the fixing member A thrust load loading spring interposed between the inner ring and urging the rotating body toward the fixed member;
The rotary distribution valve according to claim 1, further comprising an adjustment nut that is screwed to the housing so as to be position-adjustable and adjusts a biasing force of a thrust load load spring. A hydraulic pump for supplying lubricating oil to the oil supply port of the rotary distribution valve according to claim 1, 2 or 3 via a pump-side pipe;
A plurality of lubricant oils supplied from each discharge port of the rotary distribution valve according to claim 1, 2 or 3 is supplied via a nozzle side pipe for each discharge port, and each of the lubricant oils is supplied to a required lubrication location. And a nozzle.

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