JP4438419B2 - Spindle device - Google Patents

Description

  The present invention relates to a spindle device that supports a shaft that rotates at high speed.

  As a typical lubrication method for bearings that support shafts that rotate at high speeds, such as machine tool shafts, grease lubrication is performed by filling a suitable amount of paste-like grease into the bearing, and low-viscosity lubricating oil is used together with compressed air. There is oil-air lubrication in which lubrication is performed by jetting continuously to a rotating bearing.

  In general, grease lubrication does not require replenishment for a long time because it is not necessary to replenish the grease for a long period of time. However, the grease deteriorates with use time, and the lubrication function deteriorates. In particular, when rotating continuously at a high speed, the grease life may be reached early, resulting in poor lubrication and seizure.

  On the other hand, with oil-air lubrication, new lubricant can be continuously supplied to the bearing from the lubricant supply unit, so there is no concern about bearing seizure due to the life of the lubricant, and the optimum amount of oil for each bearing is used. It is possible to control the quantity quantitatively, and further, the cooling effect by the compressed air ejected together with the lubricating oil can be obtained, so that the temperature rise of the bearing can be suppressed and it is suitable for the lubrication of the bearing which rotates continuously at a high speed.

  In general, a shaft of a machine tool is desirably a bearing capable of rotating as fast as possible in order to improve machining accuracy and machining efficiency, and oil-air lubrication is often used for lubricating a bearing used for the shaft of a machine tool.

  However, in oil-air lubrication, compressed air is ejected at a high speed into the inner space of the bearing in order to convey the lubricating oil to the lubrication site. However, a plurality of rolling elements that are held at intervals between the outer ring and the inner ring of the bearing. Rotates and rotates on the raceways of the outer ring and the inner ring as the bearing rotates, and the flow of compressed air is interrupted intermittently by the rolling elements. As a result, a so-called wind noise is generated.

  In view of this, a spindle device is known in which wind noise is reduced by preventing the jet stream of compressed air and lubricating oil from being directly applied to rolling elements (see, for example, Patent Document 1).

JP 2002-130303 (3rd page, FIG. 1)

  As shown in FIG. 4, the main shaft device disclosed in Patent Document 1 is rotatable between an outer ring 1 attached to a housing, an inner ring 2 fitted to the shaft, and the outer ring 1 and the inner ring 2. It is composed of a plurality of balls 3 arranged and held at intervals in the circumferential direction by a cage 4 and an outer ring spacer 5 arranged adjacent to the outer ring 1 in the axial direction and held in a housing. Yes. The inner ring 2 is formed so as to protrude in the axial direction from the end face of the outer ring 1 and to be reduced in diameter toward the protruding end. At the tip of the outer ring spacer 5 is formed a jet hole for jetting lubricating oil together with the compressed air toward the outer peripheral surface 7 of the shoulder portion, so that the wind noise is prevented from being directly applied to the ball 3. I try to reduce it. In the spindle device, in order to reliably apply the jet flow to the outer peripheral surface 7 and to form a flow path of the jet flow, the tip of the outer ring spacer 5 in which the jet hole 6 and the jet hole 6 are formed is the outer peripheral surface 7. Are arranged so as to face each other with a slight gap.

  In the above spindle device, when an angular ball bearing is used, the angular ball bearing allows an axial load in one direction. Therefore, with the shaft and the outer ring spacer 5 assembled in advance, the shaft is mounted on the housing. It is possible to insert. However, when a cylindrical roller bearing is used, as shown in FIG. 5, the cylindrical roller bearing has a structure in which the inner ring 12 and the outer ring 11 can be easily separated and cannot apply an axial load. When inserting into the housing 17, the outer ring 11 and the outer ring spacer 15 are fitted in the housing 17 in advance, and then the main shaft 16 on which the inner ring 12 assembled with the cylindrical roller 13 and the cage 14 is fitted. Insert. However, in the above-described main shaft device, the outer ring spacer 15 is disposed so that the tip of the outer ring spacer 15 faces the shoulder of the inner ring 12 with a slight gap, so that it is assembled to the inner ring 12 or the inner ring 12 fitted on the main shaft 16. The rolling element 13 and the cage 14 collided with the outer ring spacer 15, and the main shaft 16 could not be inserted into the housing 17.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to use both an angular ball bearing and a cylindrical roller bearing, thereby reducing noise such as wind noise and a minute amount of lubricating oil. It is an object of the present invention to provide a spindle device that can reliably feed the shaft to the raceway surface.

  In order to achieve the above-described object, the spindle device according to the present invention is characterized by the following (1) to (4).

(1) a bearing having an inner ring, an outer ring, and a plurality of cylindrical rollers arranged so as to roll between the inner ring and the outer ring;
A housing for holding an outer ring of the bearing and an outer ring spacer disposed adjacent to the outer ring in the axial direction;
A lubricating oil supply member for supplying lubricating oil to the bearing;
A spindle device comprising:
A mounting hole for holding the lubricating oil supply member is formed so as to penetrate the housing and the outer ring spacer,
One peripheral end portion of the inner ring is formed so as to protrude in the axial direction from the end surface of the outer ring, and the peripheral end portion is formed so as to be reduced in diameter toward the protrusion end,
The lubricating oil supply member has an ejection hole for ejecting lubricating oil together with air at one end thereof,
An expanded air reservoir is formed at the opening of the ejection hole,
The lubricating oil supply member holds the ejection hole and the air reservoir close to the outer peripheral surface of the peripheral end portion, is held by the mounting hole, and supplies the lubricating oil to the outer peripheral surface.

  (2) The spindle device according to (1), wherein the lubricating oil supply member has at least one air vent hole communicating with the air reservoir.

  (3) The spindle device according to (1) or (2), which is used for a high-speed rotation motor.

  (4) The spindle device according to (1) or (2), wherein the spindle device is used for a shaft of a machine tool.

  According to the spindle apparatus of the present invention, the lubricating oil supply member is an individual member, and the mounting hole is formed so as to penetrate the housing and the outer ring spacer after the shaft, the bearing, and the outer ring spacer are assembled to the housing. Therefore, even when a cylindrical roller bearing is used as the bearing, the lubricating oil injection hole can be opposed to the outer peripheral surface of the inner ring with a slight gap. Noise due to sound can be reduced and a small amount of lubricating oil can be reliably fed into the raceway surface. In addition, it becomes easy to form a supply path for air and lubricating oil that communicates with the ejection holes. Further, the lubricating oil supply member is removed, and the lubricant that adheres to and remains on the outer peripheral surfaces of the circumferential ends of the supply paths, the ejection holes, and the inner ring. It is also easy to remove foreign matters such as oil and dust.

  Further, since the air reservoir formed by expanding the ejection hole is formed at the tip of the ejection hole of the lubricating oil supply member, the air pressure applied to the inside of the bearing can be relieved and wind noise can be further reduced. Can be reduced.

  Furthermore, since the air vent hole communicating with the air reservoir is formed in the lubricating oil supply member, the air pressure applied to the inside of the bearing can be relaxed, and wind noise can be further reduced.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.

(First embodiment)
1 is a longitudinal sectional view of a first embodiment of a spindle device according to the present invention, FIG 2 is Ri Components Figure der of Nozurukoma a lubricating oil supply member according to the first embodiment shown in FIG. 1, (a) is FIG. 1 is a vertical sectional view of the nozzle piece viewed from the direction of arrow A in FIG. 1A , and FIG. 3 is a vertical sectional view of a second embodiment of the spindle device according to the present invention. In FIG. 2, the mounting flange is omitted for easy understanding of the drawing.

As shown in FIGS. 1 and 2, the main shaft device 20 according to the first embodiment of the present invention is arranged to roll freely between the outer ring 22, the inner ring 23, and the outer ring 22 and the inner ring 23, and the cage 25. A cylindrical roller bearing 21 having a plurality of rolling elements cylindrical rollers 24 held at intervals from each other in the circumferential direction, and an outer ring spacer disposed adjacent to the outer ring 22 and the outer ring 22 in the axial direction. A housing 42 holding 40 and a nozzle piece 31 which is a lubricating oil supply member for supplying lubricating oil to the cylindrical roller bearing 21 are provided.

  The nozzle piece 31 has a cylindrical body portion 32, and a disc-shaped mounting flange 33 having a diameter larger than that of the body portion 32 is provided at a peripheral portion on one side of the body portion 32. A U-shaped groove 34 is formed along the circumference concentric with the barrel 32 at the periphery of the joint portion of the mounting flange 33 with the barrel 32, and a sealing member such as an O-ring is embedded. On the central axis of the body portion 32, an introduction hole 36 having an open end on the axial end surface on the mounting flange 33 side is formed, and a lubricating oil supply connected to a compressed air and a lubricating oil supply source (not shown). A tube 45 is inserted. An injection hole 37 having a diameter smaller than that of the tip end portion is formed continuously at the tip end portion of the introduction hole 36 other than the opening end portion, and the jet hole 37 has a body portion 32 on the other side of the mounting flange 33 side. It is formed so that it may open in the peripheral part of the end surface of. An air reservoir 38 is provided at the opening of the ejection hole 37 so as to expand the ejection hole 37, and the air reservoir 38 is an annular concentric ring-shaped concentric section with the body portion 32 and has a peripheral edge portion. It is formed in one circle. The air vent hole 39 is formed inside the body portion 32 so as to communicate with the air reservoir portion 38 and open to the end surface of the body portion 32 on the mounting flange 33 side, and the opening portion of the air vent hole 39 in the air reservoir portion 38. Is provided at a position symmetrical to the opening of the ejection hole 37 with respect to the center point of the air reservoir 38.

  The housing 42 is formed with an insertion hole through which the shaft 41 is inserted. Inside the insertion hole, the outer ring 22 and an outer ring spacer 40 adjacent to the outer ring 22 in the axial direction are fitted and fixed. . Further, an inner ring 23 in which a plurality of cylindrical rollers 24 and a cage 25 are assembled in advance and an inner ring spacer 44 adjacent to the inner ring 23 in the axial direction are fitted and fixed to the outer peripheral surface of the shaft 41. The shaft 41 is inserted into the insertion hole of the housing 42 until the cylindrical roller 24 engages with the raceway surface of the outer ring 22. At this time, the inner peripheral surface of the outer ring spacer 40 and the outer peripheral surface of the inner ring spacer 44 face each other. Thus, the outer ring 22 and the outer ring spacer 40 are disposed on the housing 42, and the inner ring 23 and the inner ring spacer 44 are disposed on the shaft 41, respectively.

  The peripheral end of the inner ring 23 on the outer ring spacer 40 side protrudes axially outward from the end surface of the outer ring 21, that is, in the direction of the outer ring spacer 40, and the peripheral end is reduced in diameter toward the protruding end. Is formed. That is, the outer peripheral surface 26 of the peripheral end portion is inclined so as to rise from the protruding end toward the cylindrical roller 24 side. The protruding end has the same diameter as the adjacent inner ring spacer 44, and the outer peripheral surface 26 of the peripheral end and the outer peripheral surface of the inner ring spacer 44 are continuous without a step.

  The housing 42 and the outer ring spacer 40 are provided with mounting holes 43 penetrating both members in the radial direction of the shaft 41, and the mounting holes 43 are formed at the opening ends facing the outside of the housing 42 at the nozzle piece 31. It has a shelf that engages with the mounting flange 33 and is formed to have a diameter that is equal to or slightly larger than the body 32. The nozzle piece 31 is inserted into the mounting hole 43, and the end of the nozzle piece 31 provided with the ejection hole 37 and the air reservoir 38 protrudes from the outer ring spacer 40 into the insertion hole of the housing 42, so that the inner ring 23. It faces the outer peripheral surface 26 and the outer peripheral surface of the inner ring spacer 44 with a slight gap. At this time, the nozzle piece 31 is arranged so that the ejection hole 37 is positioned on the outer peripheral surface 26 side, the mounting flange 33 engaged with the shelf portion of the mounting hole 43 is fastened by a bolt, and the nozzle piece 31 is moved to the housing 42. It is fixed to. As a result, a lubricating oil flow path is formed between the end face of the nozzle piece 31 on the ejection hole 37 side and the outer peripheral face 26 and the outer peripheral face of the inner ring spacer 44.

  Next, a method for assembling the spindle device 20 will be described.

  First, the outer ring 22 and the outer ring spacer 40 are inserted into the insertion hole of the housing 42. At this time, the mounting hole 43 formed in the housing 42 and the mounting hole 43 formed in the outer ring spacer 40 are positioned and fixed so that they are continuously aligned. Further, the inner ring 23 and the inner ring spacer 44 in which the plurality of cylindrical rollers 24 and the cage 25 are assembled in advance are fitted on the shaft 41 and fixed.

  Next, the shaft 41 is inserted into the insertion hole of the housing 42, and the cylindrical roller 24 is engaged with the raceway surface of the outer ring 22. Then, the nozzle piece 31 is inserted into the attachment hole 43 through the opening of the attachment hole 43 facing the outside of the housing 42 with the end of the nozzle piece 31 provided with the ejection hole 37 and the air reservoir 38 as the head. At this time, the nozzle piece 31 is arranged so that the ejection hole 37 is positioned above the outer peripheral surface 26 of the inner ring 23.

  Next, the lubricating oil supply pipe 45 connected to the compressed air and lubricating oil supply source is inserted into the introduction hole 36 of the nozzle piece 31, and the exhaust pipe 46 is inserted into the air vent hole 39 to complete the assembly of the spindle device 20. To do.

  Next, the operation of the spindle device 20 will be described.

  When the shaft 41 rotates with respect to the housing 42, a mixed flow of compressed air and lubricating oil from the compressed air and lubricating oil supply source passes through the introduction hole 36 of the nozzle piece 31 at an appropriate pressure and flow rate. Supplied.

  Lubricating oil ejected from the ejection hole 37 passes through the air reservoir 38 and adheres to the outer peripheral surface 26 of the inner ring 23. At this time, since the outer peripheral surface 26 and the ejection hole 37 are close to each other and the lubricating oil and compressed air do not directly flow into the cylindrical roller bearing, wind noise is reduced.

  The outer peripheral surface 26 is inclined so as to rise from the protruding end toward the cylindrical roller 24, and centrifugal force is generated in the lubricating oil attached with the rotation of the shaft 41 (that is, with the rotation of the inner ring 23). The lubricating oil reaches the raceway surface of the inner ring 23 through the outer peripheral surface 26 and adheres to the rolling surface of the cylindrical roller 24. Thereby, lubrication is performed.

  Further, the air reservoir portion 38 communicating with the ejection hole 37 and the air vent hole 39 communicating with the air reservoir portion 38 alleviate pressure fluctuations of the compressed air and the compressed air supplied from the lubricating oil supply source. In addition, since the compressed air can be prevented from being ejected at a pressure higher than normal, wind noise is reduced.

  The air reservoir 38 is formed as an annular groove, and the opening in the air reservoir 38 of the air vent hole 39 is provided at a position symmetrical to the ejection hole 37 with respect to the center point of the air reservoir 38. Therefore, the compressed air ejected from the ejection hole 37 is exhausted from the air vent hole 39 through the air reservoir 38 without displacing the lubricating oil supplied to the flow path.

(Second Embodiment)
Next, with reference to FIG. 3, a spindle device 50 according to a second embodiment of the present invention will be described. In addition, in 2nd Embodiment, about the same member as the spindle apparatus 20 which is the above-mentioned 1st Embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol in a figure.

  As shown in FIG. 3, the spindle device 50 according to the second embodiment of the present invention uses an angular ball bearing 51 instead of the cylindrical roller bearing 21 in the first embodiment described above. The peripheral end portion of the inner ring 53 on the outer ring spacer 40 side protrudes axially outward from the end surface of the outer ring 52, that is, toward the outer ring spacer 40, and the peripheral end portion is reduced in diameter toward the protruding end. Is formed. That is, the outer peripheral surface 56 of the peripheral end portion is inclined so as to rise from the protruding end toward the ball 54 side. The protruding end has the same diameter as the adjacent inner ring spacer 44, and the outer peripheral surface 56 of the peripheral end and the outer peripheral surface of the inner ring spacer 44 are continuous without a step.

  As for the method of assembling the spindle device 50, a state where an angular ball bearing 51 in which a plurality of balls 54, a cage 55 and an outer ring 52 are assembled to an inner ring 53, an inner ring spacer 44, and an outer ring spacer 40 are mounted on a shaft 41. Then, the shaft 41 is inserted into the insertion hole of the housing 42, and the mounting hole 43 formed in the housing 42 and the mounting hole 43 formed in the outer ring spacer 40 are positioned and fixed so as to be continuously aligned. To do. Then, the nozzle piece 31 is inserted into the mounting hole 43 from the opening of the mounting hole 43 facing the outside of the housing 42. At this time, the nozzle piece 31 is arranged so that the ejection hole 37 is positioned above the outer peripheral surface 56 of the inner ring 53. Next, the lubricating oil supply pipe 45 connected to the compressed air and lubricating oil supply source is inserted into the introduction hole 36 of the nozzle piece 31, and the exhaust pipe 46 is inserted into the air vent hole 39 to complete the assembly of the spindle device 50. To do. The operation of the spindle device 50 is the same as that of the spindle device 20 according to the first embodiment described above, and a description thereof will be omitted.

  The spindle device of the present invention is not limited to the above-described embodiments, and appropriate modifications and improvements can be made.

  For example, a plurality of nozzle pieces 31 may be used. At this time, it is preferable that the ejection hole 37 of each nozzle piece 31 is located above the bearing center. Thereby, the whole supply amount of lubricating oil can be maintained, the pressure of the lubricating oil and compressed air supplied to each ejection hole 37 can be reduced, and wind noise can be further reduced.

  Further, a spiral groove may be formed on the outer peripheral surface 26 of the inner ring 23. At this time, the spiral groove is preferably formed so as to rotate in a direction opposite to the rotation direction of the shaft 41 from the protruding end of the outer peripheral surface 26 toward the cylindrical roller 24. As a result, a pumping action is generated in the lubricating oil adhering to the outer peripheral surface 26 as the shaft 41 rotates, and the lubricating oil is reliably conveyed in the direction of the cylindrical roller 24.

1 is a longitudinal sectional view of a first embodiment of a spindle device according to the present invention. Ri Nozurukoma Components Figure der of a lubricating oil supply member of the first embodiment shown in FIG. 1, (a) is the same longitudinal sectional view as FIG. 1, viewed from the direction of an arrow A in (b) a is Nozurukoma (a) It is a figure. It is a longitudinal cross-sectional view of 2nd Embodiment of the spindle apparatus which concerns on this invention. It is a longitudinal cross-sectional view of the conventional main shaft device using a ball bearing. It is a longitudinal cross-sectional view before the assembly of the conventional main axis | shaft apparatus using a cylindrical roller bearing.

Explanation of symbols

20 Spindle device 21 Cylindrical roller bearing (bearing)
22 Outer ring 23 Inner ring 24 Roller (rolling element)
31 Nozzle piece (lubricant supply member)
37 Ejection hole 38 Air reservoir 39 Air vent hole 40 Outer ring spacer 42 Housing 43 Mounting hole

Claims (4)

A bearing having an inner ring, an outer ring, and a plurality of cylindrical rollers rotatably disposed between the inner ring and the outer ring;
A housing for holding an outer ring of the bearing and an outer ring spacer disposed adjacent to the outer ring in the axial direction;
A lubricating oil supply member for supplying lubricating oil to the bearing;
A spindle device comprising:
A mounting hole for holding the lubricating oil supply member is formed so as to penetrate the housing and the outer ring spacer,
One peripheral end portion of the inner ring is formed so as to protrude in the axial direction from the end surface of the outer ring, and the peripheral end portion is formed so as to be reduced in diameter toward the protrusion end,
The lubricating oil supply member has an ejection hole for ejecting lubricating oil together with air at one end thereof,
An expanded air reservoir is formed at the opening of the ejection hole,
The main spindle apparatus characterized in that the lubricating oil supply member holds the ejection hole and the air reservoir portion close to the outer peripheral surface of the peripheral end portion, is held by the mounting hole, and supplies the lubricating oil to the outer peripheral surface. .   The spindle device according to claim 1, wherein the lubricating oil supply member has at least one air vent hole communicating with the air reservoir.   3. The spindle device according to claim 1, wherein the spindle device is used for a high-speed rotation motor.   3. The spindle device according to claim 1, wherein the spindle device is used for a shaft of a machine tool.

Images