JP4913577B2 - Air-carrying oil lubricator - Google Patents

Description

  The present invention relates to an air-conveying oil lubrication device, and in particular, an air-conveying oil-lubricating device that conveys a small amount of oil to a lubrication point by air, such as oil mist lubrication and air-oil lubrication used in a spindle unit or gear box of a machine tool It relates to the device.

Known as one of the lubrication methods for bearings and gear meshing parts of rotary shafts that rotate at high speeds are oil mist lubrication that conveys a small amount of oil to a lubrication point by air and air conveyance type oil lubrication represented by air oil lubrication. . In this lubrication system, in addition to lubrication with oil, a cooling effect can be expected by air used for oil conveyance (for example, Patent Document 1).
JP 11-44396 A

  A small amount of oil used for oil mist lubrication and air-oil lubrication is conveyed by relatively low pressure air. The oil transport air in oil mist lubrication and air-oil lubrication varies depending on the part used and the type of oil, but usually requires a considerably large flow rate, and since it is low pressure, it is required to be released to atmospheric pressure. The condition of the air permeability on the exhaust side has a great influence on the lubrication performance.

  Since the rolling elements and the cage of the rolling bearing move faster as the rotation speed increases, dynamic pressure is generated in the rolling part (lubricating part) of the rolling element. For this reason, it becomes difficult for the air on the supply side to enter the lubrication part of the rolling bearing.

  In such a case, as a usual measure, it is conceivable to vacuum the inside of the main shaft unit or the gear box from the outside to lower the back pressure of the lubricating portion.

  However, many vacuuming devices from outside have a small amount of air that can be sucked into the air supplied to the case, and in order to obtain the desired degree of vacuum, the supply air is consumed in large quantities. It can't be said that.

  Further, the air staying in the main shaft unit or the gear box increases the internal pressure of the main shaft unit or the gear box, and the oil lubrication may be insufficient under high speed rotation. On the other hand, when vacuuming from the outside, vacuum generation suitable for vacuuming with sufficient exhaust pressure to pass through a filter that collects oil mist even if the exhaust capacity is satisfactory. There is no vessel at present.

  The problem to be solved by the present invention is that the back pressure of the lubrication part is effectively reduced without consuming a large amount of energy without evacuation from the outside, and lubrication of air-conveying oil lubrication is possible even at high speed rotation. To increase performance.

The present invention air transport oil lubrication system according to, in an air transport oil lubrication system for conveying the air oil to rotary motion of the housing to rotatably support the rotary shaft which is rotated by the built-in motor, the rotational motion An annular first rotary scroll member fixedly attached to the outer peripheral portion of one end of the rotor shaft of the built-in motor on the part side, and fixedly attached to the housing and concentrically facing the first rotary scroll member A first scroll exhaust pump that is rotationally driven by the rotor shaft, and is configured to be fixedly mounted on the outer periphery of the other end of the rotor shaft. A two-rotation scroll member fixed to the housing and concentrically opposed to the second rotation-side scroll member; By the side scroll member, the configured second scroll vacuum pump which is rotated by the rotor shaft, the suction force by the pumping action of the said first scroll exhaust pump second scroll vacuum pump, sent to the rotary motion part the air that has been found the first scroll vacuum pump, the annular gap built-in motor, said second sequentially passes through the scroll vacuum pump is shall be discharged out of the housing.

The air conveying oil lubrication device according to the present invention, an exhaust passage for guiding the air to the suction port of the first scroll vacuum pump than the previous SL rotational motion portion is formed in the housing, in the middle of the exhaust passage , vacuum generator of the ejector with compressed air is shall be provided.

According to the air-conveying oil lubrication device of the present invention, the built-in first scroll exhaust pump and second scroll exhaust pump are directly driven by the rotation shaft (rotor shaft) , and the suction force by the pump action is sent to the rotary motion unit. Since it acts on the exhaust side of the air, the back pressure of the lubrication part can be effectively reduced without consuming a large amount of energy without evacuation from the outside, and the higher the speed, the higher the speed . By increasing the rotation speed of the first scroll exhaust pump and the second scroll exhaust pump, a large suction force is generated, and the lubrication performance of the air conveying oil lubrication is improved even at high speed rotation. Further, the first scroll exhaust pump and the second scroll exhaust pump can generate a pressure sufficient to pass through a filter that collects oil mist.

Further, according to the air conveyance type oil lubrication device of the present invention, in order to enhance the suction capability of the first scroll exhaust pump and the second scroll exhaust pump, lubrication is performed by a built-in vacuum generator disposed in the middle of the exhaust passage. Since the back pressure of the part is further reduced, the back pressure of the lubrication part can be effectively reduced, and the lubrication performance of the air-conveying oil lubrication is improved.

  An embodiment of an air conveyance type oil lubrication device according to the present invention will be described with reference to the drawings.

  FIG. 1 shows one embodiment of a built-in motor type spindle unit of a machine tool to which an air conveying oil lubrication device (oil mist lubrication device) according to the present invention is applied.

  The built-in motor type spindle unit has a housing 11, a front ring 12 attached to the front end (left side in the figure) of the housing 11, and a rear cover 13 attached to the rear end (right side in the figure) of the housing 11. .

The housing 11 rotatably supports a main shaft (rotating shaft) 18 by two front roller bearings 14 and 15 and two rear roller bearings 16 and 17. The bearings 14, 15, 16, and 17 are attached by inner collars 19, 20, and 21, outer collars 22, 23, and 24, tightening nuts 25, and the like.

  The front end side (front side) of the main shaft 18 protrudes outside the housing 11. A tapered hole 26 for tool mounting is formed on the tip end side of the main shaft 18.

The housing 11 has a built-in Birutoi Nmo over data 30 on the rear side. Birutoi Nmo over data 30, the rotor shaft 31 integrally coaxially with the main shaft 18, a rear collar 32, a rotor 34 which is more fixedly attached to the fastening nut 33 or the like, the stator cooling sleeve 35 which is fixedly mounted to the housing 11, A stator 37 fixedly mounted via a stator attachment member 36 inside the stator cooling sleeve 35. The rear end of the rotor shaft 31 is rotatably supported by the rear cover 13 by rolling bearings 38.

The built-in motor construction, Birutoi Nmo over data 30 is driven to rotate the main shaft 18 directly by the rotor shaft 31.

Next, it describes the oil mist lubrication Nitsu of the built-in motor type spindle unit.

Each of the outer collar 22 between the front roller bearing 14 and the front roller bearing 15 and the outer collar 24 between the rear roller bearing 16 and the rear roller bearing 17 has a plurality of oil mist injection holes 41 and 42, respectively. It is formed at an equal angular position in the circumferential around.

  The oil mist injection holes 41 and 42 communicate with circumferential grooves 43 and 44 formed in the housing 11 and an oil mist supply passage 45, and are supplied with oil mist from an oil mist supply source (not shown). The oil mist supplied to the oil mist injection holes 41 and 42 is ejected from the injection holes 41 and 42 into the space between the bearings, and lubricates and cools the front rolling bearings 14 and 15 and the rear rolling bearings 16 and 17.

An outer collar 23 between the front roller bearing 15 and the rear roller bearing 16, a front outer collar 27 disposed on the front side of the front roller bearing 14, and a rear outer collar 28 disposed on the rear side of the rear roller bearing 17. Are formed with exhaust suction holes 51, 52, and 53, respectively. Exhaust suction holes 51, 52 and 53, respectively, are formed at equal angular position plurality in the circumferential around. The exhaust suction holes 51, 52, 53 communicate with an exhaust passage 57 formed in the housing 11 by peripheral grooves 54, 55, 56 formed in the outer collar 23, the front outer collar 27, and the rear outer collar 28. Yes.

A rotary exhaust pump (first scroll exhaust pump) 60 is incorporated on the rear side of the main shaft 18. The exhaust pump 60 is shown in the housing 11 and a ring-shaped rotary scroll member ( first rotary scroll member, rotor) 63 attached to the outer periphery of the main shaft 18 by a spacer ring 61 and a fastening nut 62. And an annular fixed-side scroll member ( first fixed-side scroll member, stator) 64 that is fixedly mounted concentrically with the rotary-side scroll member 63 by a mounting bolt or the like that is not provided, and forms a scroll exhaust pump. .

  The rotation-side scroll member 63 and the fixed-side scroll member 64 are opposed to each other with a small gap in the axial direction, and the scroll grooves 65 and 66 having the same shape are formed on the respective opposing surface portions with their centers slightly shifted from each other. Both are airtightly held by a chip seal (not shown) attached to the fixed scroll member 64.

The fixed scroll member 64 is formed with a suction port 67 communicating with the outer peripheral side of the scroll groove 66. The suction port 67 communicates with the exhaust passage 57 via a circumferential groove 68 formed in the fixed scroll member 64. A discharge port 69 communicating with the center side of the scroll groove 66 is formed in the rotation side scroll member 63 so as to penetrate in the axial direction.

Further, in this embodiment, another rotating type exhaust pump (second scroll exhaust pump) 70 is incorporated in the rear side of the Birutoi Nmo over data 30. The exhaust pump 70 includes an annular rotary scroll member ( second rotary scroll member, rotor) 71 integrally formed in a bowl shape on the outer periphery of the rear collar 32 that is pivotally attached to the rotor shaft 31, a stator attachment An annular fixed-side scroll member ( second fixed-side scroll member, stator) 72 fixedly mounted concentrically with the rotation-side scroll member 71 by a mounting bolt or the like (not shown) at the rear end of the member 36; It has a scroll exhaust pump.

  The rotation-side scroll member 71 and the fixed-side scroll member 72 are opposed to each other with a small gap in the axial direction, and the scroll grooves 73 and 74 having the same shape are formed on the respective opposing surface portions with their centers slightly shifted from each other. Both are held airtight by a tip seal (not shown) attached to the fixed scroll member 72.

The rotation-side scroll member 71 is on the front side of the fixed-side scroll member 72, and the rotation-side scroll member 71 is formed with a suction port 75 communicating with the center side of the scroll groove 73 in the axial direction. The fixed scroll member 72 is formed with a discharge port 76 communicating with the outer peripheral side of the scroll groove 74.

  An exhaust port 81 is formed in the rear cover 13. An external pipe 83 including a mist filter 82 is connected to the exhaust port 81, and the external pipe 83 communicates with the oil recovery tank 84.

According to the above configuration, by the main shaft 18 is rotated by Birutoi Nmo over data 30, the rotation-side scroll member 63 and rotation of the exhaust pump 60 which is fixedly attached to the main shaft 18, the pumping action of vacuum pump 60 The suction force due to the above acts on each of the exhaust suction holes 51, 52, 53 via the suction port 67, the circumferential groove 68, the exhaust passage 57, and the circumferential grooves 54, 55, 56.

  As a result, the suction force by the pumping action of the exhaust pump 60 acts on the exhaust side of the oil mist (air) sent to the front roller bearings 14 and 15 and the rear roller bearings 16 and 17, and the exhaust side becomes a low pressure, and the lubrication part The back pressure of the (front roller bearings 14 and 15 and the rear roller bearings 16 and 17) is effectively reduced without consuming a large amount of energy without evacuation from the outside.

  Accordingly, the oil mist smoothly enters the front roller bearings 14 and 15 and the rear roller bearings 16 and 17, and the lubrication performance of the front roller bearings 14 and 15 and the rear roller bearings 16 and 17 by the oil mist is improved. .

The oil mist is less likely to enter the front roller bearings 14 and 15 and the rear roller bearings 16 and 17 as the rotation speed increases, but the exhaust pump 60 rotates at a higher speed as the rotation speed increases. suction force is strong, because this a that strong suction force of the exhaust pump 60 which acts on the exhaust side in response to, at high speed, the bearing 14, 15 oil mist rolling front, inside the rear rolling bearing 16, 17 It smoothly enters and the lubrication performance of the front roller bearings 14 and 15 and the rear roller bearings 16 and 17 by oil mist is improved.

The oil mist on the exhaust side after the lubrication and cooling of the front roller bearings 14 and 15 and the rear roller bearings 16 and 17 are completed from the exhaust suction holes 51, 52, and 53, the circumferential grooves 54, 55, and 56, the exhaust passage 57, and the circle. reaches the suction port 67 of the exhaust pump 60 through the circumferential groove 68, rotation-side scroll member 63 from the suction port 67, is sucked into the scroll groove 66, 65 of the stationary scroll member 64, Birutoi Nmo over data from the discharge port 69 It is discharged to the 30 side.

  As the main shaft 18 rotates, the rotation-side scroll member 71 of the exhaust pump 70 fixedly attached to the rotor shaft 31 also rotates, and the suction force generated by the pump action of the exhaust pump 70 acts on the suction port 75.

Thus, the oil mist ejected on the side of Birutoi Nmo over data 30 from the discharge port 69, the suction port 75 of the rotor 34 and the stator 37 exclusively exhaust pump 70 an annular narrow gap 39 to smoothly pass through the Then, the air is sucked into the scroll grooves 73 and 74 of the rotation-side scroll member 71 and the fixed-side scroll member 72 from the suction port 75 and discharged from the discharge port 76 to the rear cover 13 side.

  The oil mist discharged to the rear cover 13 in this way flows from the exhaust port 81 to the external pipe 83 and is separated into gas and liquid by the mist filter 82, and the oil in the oil mist is recovered in the oil recovery tank 84.

Thus, it no internal pressure of Birutoi Nmo over data 30 is raised by the oil mist, the front rolling bearing 14, the oil mist lubrication of the rear rolling bearing 16, 17 is favorably performed.

  FIG. 2 shows another embodiment of a built-in motor type spindle unit of a machine tool to which an air conveyance type oil lubrication device (oil mist lubrication device) according to the present invention is applied. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.

  In this embodiment, a vacuum generator 90 is attached in the middle of the exhaust passage 57 from the exhaust suction holes 51, 52, 53 to the suction port 67 of the exhaust pump 60.

  As shown in FIG. 3, the vacuum generator 90 is of an ejector type using compressed air, and includes a jet nozzle 91 for compressed air, a suction port 92, and an exhaust diffuser 93. Compressed air is supplied from a compressed air passage 94 formed in the housing 11. The suction port 92 communicates with the exhaust passage 57 via the circumferential groove 95, and the exhaust diffuser 93 communicates with the suction port 67 of the exhaust pump 60 via the circumferential groove 68.

  The vacuum generator 90 generates negative pressure at the suction port 92 in an ejector manner, that is, in a spraying manner, by ejecting compressed air from the ejection nozzle 91 toward the exhaust diffuser 93.

  The negative pressure of the vacuum generator 90, that is, the suction force, also acts on each of the exhaust suction holes 51, 52, and 53 via the exhaust passage 57 and the circumferential grooves 54, 55, and 56.

  As a result, the vacuum generator 90 exerts a suction force on the exhaust side of the oil mist (air) sent to the front roller bearings 14 and 15 and the rear roller bearings 16 and 17 in addition to the suction force by the pump action of the exhaust pump 60. However, the exhaust side has a sufficiently low pressure, and the back pressure of the lubrication parts (front roller bearings 14 and 15 and rear roller bearings 16 and 17) does not involve large energy consumption without evacuation from the outside. Effectively reduces.

  Thereby, also in this embodiment, the oil mist smoothly enters the inside of the front roller bearings 14 and 15 and the rear roller bearings 16 and 17, and the front roller bearings 14 and 15 and the rear roller bearings 16 and 17 are lubricated by the oil mist. Performance is improved.

  The exhaust pump 60 can be omitted if the exhaust side is sufficiently low in pressure only by the suction force of the vacuum generator 90.

 Note that the air-conveying oil lubrication device (oil mist lubrication device) according to the present invention is not limited to application to the built-in motor type spindle unit, and can be similarly applied to a gear box and the like.

It is sectional drawing which shows one Embodiment of the built-in motor type spindle unit of the machine tool to which the air conveyance type oil lubrication device (oil mist lubrication device) by this invention is applied. It is sectional drawing which shows other embodiment of the built-in motor type spindle unit of the machine tool to which the air conveyance type oil lubrication device (oil mist lubrication device) by this invention was applied. It is an expanded sectional view of an ejector type vacuum generator used for an air conveyance type oil lubrication device by other embodiments.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Housing 12 Front ring 13 Rear cover 14, 15 Front rolling bearing 16, 17 Rear rolling bearing 18 Main shaft (rotating shaft)
19,20,21 inner collar 22, 23, 24, outer collar 25 fastening nut 26 tapered hole 27 front outer collar 28 rear outer collar 30 Birutoi Nmo over motor 31 rotor shaft 32 Rear collar 33 nut 34 rotor 35 stator cooling sleeve tightening 36 Stator mounting member 37 Stator 38 Rolling bearing 39 Air gap 41, 42 Oil mist injection hole 43, 44 Circumferential groove 45 Oil mist supply passage 51, 52, 53 Exhaust suction hole 54, 55, 56 Peripheral groove 57 Exhaust passage 60 Exhaust pump ( (First scroll exhaust pump)
61 Spacer ring 62 Fastening nut 63 Rotating scroll member ( first rotating scroll member, rotor)
64 Fixed scroll member ( first fixed scroll member, stator)
65, 66 Scroll groove 67 Suction port 68 Circumferential groove 69 Discharge port 70 Exhaust pump (second scroll exhaust pump)
71 Rotating scroll member ( second rotating scroll member, rotor)
72 Fixed scroll member ( second fixed scroll member, stator)
73, 74 Scroll groove 75 Suction port 76 Discharge port 81 Exhaust port 82 Mist filter 83 External piping 84 Oil recovery tank 90 Vacuum generator 91 Injection nozzle 92 Suction port 93 Exhaust diffuser 94 Compressed air passage 95 Circumferential groove

Claims (2)

In an air conveyance type oil lubrication device that conveys oil by air to a rotary motion part in a housing that rotatably supports a rotating shaft that is rotationally driven by a built-in motor ,
A first rotary scroll member having an annular shape fixedly attached to an outer peripheral portion of one end of a rotor shaft of the built-in motor on the rotary motion portion side; and a first rotary scroll member fixedly attached to the housing ; A first scroll exhaust pump that is rotationally driven by the rotor shaft is configured by a concentric and opposed annular fixed first scroll member .
An annular second rotation-side scroll member fixedly attached to the outer peripheral portion of the other end of the rotor shaft, and an annular-shaped second scroll member fixedly attached to the housing and concentrically facing the second rotation-side scroll member. A second scroll exhaust pump that is rotationally driven by the rotor shaft by the two fixed-side scroll members;
The air sent to the rotary motion part by the suction force generated by the pump action of the first scroll exhaust pump and the second scroll exhaust pump causes the first scroll exhaust pump, the annular clearance of the built-in motor, Sequentially passing through the second scroll exhaust pump and discharged out of the housing;
Air transport oil lubrication system you wherein a. In the air conveyance type oil lubrication device according to claim 1,
An exhaust passage is formed in the housing for guiding the air from the rotary motion part to an intake port of the first scroll exhaust pump;
An ejector-type vacuum generator using compressed air is provided in the middle of the exhaust passage.
Air transport oil lubrication equipment, characterized in that.

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