JP2008075724A - Spindle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spindle device having relatively simple construction for detecting the malfunction of a seal portion. <P>SOLUTION: The spindle device 10 comprises a rotating shaft 12, a rotary joint 20 arranged at the end of the rotating shaft 12 and having the seal portion 23 for communicating a rotating shaft flow path with a fixed side flow path, a housing 21 rotatably supporting the rotating shaft 12 via a bearing 13 and forming a storage chamber 32 encircling the seal portion 23 to store liquid leaking from the seal portion 23, and a detecting liquid discharge hole 34 and a detecting sensor 24 provided facing the storage chamber 32 for detecting the malfunction of the seal portion 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spindle device that is used in a machine tool or the like and includes a rotary joint that supplies a liquid such as a coolant to a rotating side, and more particularly to a bearing or a motor built in the spindle by detecting an abnormality during liquid supply. The present invention relates to a spindle device for protection.

  In a conventional spindle device, when supplying liquid such as cutting coolant to a rotary tool or the like attached to the spindle tip of a machine tool, a rotary joint is attached to the spindle rear end or the rotor spindle rear end of a direct-coupled spindle motor. Are directly connected to each other, and the coolant liquid is pumped from the rotary joint through flow paths provided in the respective shaft centers.

  Since this type of rotary joint is required to rotate at high speed, a seal ring is installed between the fixed part and the rotating shaft, and the seal ring on the fixed part side is moved to the rotating shaft side by the hydraulic pressure of the coolant supplied when driving the machine tool. It seals by making it slide to the seal ring direction of this, and adhering both.

  In such a seal structure, a small amount of coolant may flow out by loading or unloading the coolant pressure even under normal use conditions. For this reason, the spindle device is provided with a drain hole for discharging the coolant.

  The operator knows that there is an abnormality in the seal part according to the state of discharge from the drain hole, and stops the pump by shutting off the power supply of the equipment, etc. If the motor has a built-in bearing part or motor in the spindle device, the motor may enter the motor, causing damage to the bearing part or coil burnout due to leakage of the spindle motor. there were.

For this reason, the 1st storage chamber which receives leaked liquid when the amount of leaks from a seal part is in a normal range, and the 2nd storage room which receives leaked liquid when the amount of leaks from a seal part exceeds the normal range, And air purge is performed around the rotary shaft so that the leaked liquid in the seal portion does not flow out from the gap between the partition wall and the rotary shaft separating the storage chambers, and when the leaked liquid flows into the second storage chamber A structure is known in which leakage liquid is introduced into a detection sensor by force (see, for example, Patent Document 1).
JP 2004-28164 A

  By the way, in the rotary joint described in Patent Document 1, it is necessary to introduce the leaked liquid exceeding the normal range to the detection sensor by the air purge force, and there is a problem that the structure is complicated and a large amount of air is consumed.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a spindle device that can detect an abnormality of a seal portion with a relatively simple configuration.

The above object of the present invention can be achieved by the following constitution.
(1) a rotating shaft;
A rotary joint that is disposed at an end of the rotating shaft and has a seal portion that communicates the rotating shaft channel and the fixed-side channel;
A housing that rotatably supports the rotating shaft via a bearing and that forms a storage chamber that surrounds the seal portion so as to store liquid leaked from the seal portion;
A detecting means provided facing the storage chamber and detecting an abnormality of the seal portion;
A spindle apparatus comprising:
(2) The housing is formed with a drain hole for discharging the liquid accumulated in the storage chamber to the outside.
The spindle device according to (1), wherein the detection unit is provided at a position higher than the drain hole.
(3) The detection means includes a detection liquid discharge hole formed at a position higher than the drain hole of the housing, and a detection sensor for detecting the liquid flowing out from the detection liquid discharge hole. The spindle device according to (2).

  According to the spindle device of the present invention, the rotary shaft, the rotary joint that is disposed at the end of the rotary shaft and has a seal portion that communicates the rotary shaft channel and the fixed channel, and the rotary shaft via the bearing. A housing that forms a storage chamber that surrounds the seal portion so as to receive the liquid leaking from the seal portion and supports the rotation, and a detection means that faces the storage chamber and detects an abnormality of the seal portion. Thus, the abnormality of the seal portion can be detected with a relatively simple configuration. In addition, with the above configuration, it is possible to detect the occurrence of an abnormality at an early stage, and it is possible to quickly stop the operation such as shutting off the coolant or shutting off the power supply. Can be protected from.

  Hereinafter, a spindle device according to each embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a partial cross-sectional view of a horizontal spindle device. In the spindle device 10 of the present embodiment, a spindle 12 constituting a rotating shaft is rotatably supported in a housing body 11 constituting a housing 21 via a plurality of bearings 13. The rotary tube shaft 14 is screwed. A through hole 12 a is formed in the axial direction of the spindle 12, and constitutes a rotary shaft channel together with the through hole 14 a of the rotary tube shaft 14.

  A rotary joint 20 having a rotating tube shaft 14, a floating sheet 22, a seal portion 23, a floating sheet mounting portion 27, and a guide pin 29 is disposed behind the spindle 12.

  The housing 21 is attached to the housing main body 11, the rear portion of the housing main body 11, and has a first housing 25 having an opening 25a for supporting the rear end portion of the spindle 12, and a rear portion of the first housing 25, and a floating seat. And a second housing 26 having an opening 26a in which 22 is disposed.

  A floating seat mounting portion 27 is mounted on the second housing 26 so as to seal the opening 26 a of the second housing 26 from the inside. The coolant supply path of the second housing 26 is connected to the floating seat mounting portion 27. A seal hole (not shown) that communicates with 28 is provided. The floating sheet 22 is slidably attached to the seal hole in a state in which the rotation is restricted by the guide pin 29. A through hole 22a is formed in the axial direction of the floating sheet 22 and constitutes a fixed flow path.

  The seal portion 23 includes a seal ring 30 fixed to the rear end portion of the rotary tube shaft 14 and a seal ring 31 fixed to the front end portion of the floating sheet 22. Communicate.

  In addition, the housing 21 forms a storage chamber 32 that surrounds the seal portion 23 so as to store the liquid leaked from the seal portion 23 by attaching the second housing 26 to the first housing 25. In addition, the second housing 26 opens to the outside from the lower portion of the storage chamber 32, and drains the liquid accumulated in the storage chamber 32 to the outside. The second housing 26 is below the seal portion 23 and higher than the drain hole 33. A detection liquid discharge hole 34 is provided which faces the storage chamber 32 at a position and constitutes detection means that opens to the outside from the side surface of the storage chamber 32. The drain hole 33 is determined in size, quantity, and position so that the water level does not rise with a normal leakage amount.

  The detection sensor 24 constituting the detection means communicates with the detection liquid discharge hole 34 through a pipe (not shown), and detects an abnormality of the seal portion 23 by detecting the liquid flowing out from the detection liquid discharge hole 34. .

  In the spindle device 10 configured as described above, the rotary joint 20 causes the floating sheet 22 to slide downstream by the hydraulic pressure of the coolant supplied from the outside before starting the spindle motor, and the seal ring 31 is moved to the rotary tube shaft. The 14 seal rings 30 are brought into close contact with each other. In this state, the fixed-side flow path and the rotary shaft flow path are communicated with each other through the seal portion 23, and as indicated by an arrow A, the coolant is supplied to the tip end portion of the spindle 12 (not shown) with pressure. . When the coolant is supplied and stopped, the seal rings are attached to and detached from each other. Therefore, leakage of the coolant occurs, but the coolant is discharged from the drain hole each time.

  In this state, the spindle motor is started and the machine tool is in an operating state. If an abnormality occurs in the seal portion 23, for example, one of the seal rings 30 and 31 is broken during operation, the coolant is removed. A large amount leaks. In such a case, the leaked coolant cannot be discharged from the drain hole 33 and the water level in the storage chamber 32 rises. When the water level reaches the position of the detection liquid discharge hole 34, the fluid flows out from the detection liquid discharge hole 34, and this fluid is detected by the detection sensor 24, thereby detecting an abnormality in the seal portion 23. The

  Therefore, according to the spindle device 10 of the present embodiment, the rotary shaft 20 and the rotary joint 20 that is disposed at the end of the rotary shaft 12 and has the seal portion 23 that communicates the rotary shaft channel and the fixed channel. The rotary shaft 12 is rotatably supported via the bearing 13, and the housing 21 forms a storage chamber 32 that surrounds the seal portion 23 so as to store the liquid leaked from the seal portion 23. Provided with a detection liquid discharge hole 34 and a detection sensor 24 as detection means for detecting an abnormality of the seal portion 23, so that there is no need for air purging as in the prior art, and the seal portion has a relatively simple configuration. Abnormality can be detected. Also, with the above configuration, it becomes possible to detect the occurrence of an abnormality at the initial stage, and it is possible to quickly stop the operation such as shutting off the coolant or shutting off the power supply. Can be protected from liquid.

(Second Embodiment)
Next, a spindle apparatus according to a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the part equivalent to 1st Embodiment, and description is abbreviate | omitted or simplified.

  The second embodiment is an example in which the present invention is applied to a vertical spindle device. That is, as shown in FIG. 2, the spindle 12 and the rotating tube shaft 14 constituting the rotating shaft are arranged in the vertical direction, and by sliding the floating sheet 22 and communicating the seal portion 23, the arrow B As shown, coolant is supplied to the lower spindle 12 from a supply path 28 formed above the second housing 26.

  The drain hole 33 opens to the outside from the lower side surface of the storage chamber 32, and the detection liquid discharge hole 34 extends from the side surface of the storage chamber 32 at a position below the seal portion 23 and higher than the drain hole 33. Open to the outside.

Thereby, the leakage of the coolant at the normal time is discharged from the drain hole 33, but when the seal portion 23 is abnormal, it cannot be discharged from the drain hole 33, the water level in the storage chamber 32 rises, and the detection liquid discharge hole 34 And the fluid is detected from the detection liquid discharge hole 34 by the detection sensor 24, whereby the abnormality of the seal portion 23 is detected.
Therefore, by configuring as described above, the same functions and effects as those of the first embodiment can be achieved even in the case of a vertically installed spindle device.

The spindle device of the present invention is not limited to the above-described embodiment such as a spindle and a rotary joint, and can be appropriately modified and improved.
Further, the detection means is not limited to that of the above embodiment, and the detection sensor 24 may be provided in the housing 21 or may be arranged so that the detection sensor 24 faces the storage chamber 32.

It is a fragmentary sectional view of the horizontal spindle apparatus which is 1st Embodiment of this invention. It is a fragmentary sectional view of the vertical spindle apparatus which is 2nd Embodiment of this invention.

Explanation of symbols

10 Spindle device 12 Spindle (Rotating shaft)
20 Rotary joint 21 Housing 22 Floating sheet 23 Seal portion 24 Detection sensor (detection means)
30, 31 Seal ring 32 Storage chamber 33 Drain hole 34 Detection liquid discharge hole (detection means)

Claims (3)

A rotation axis;
A rotary joint that is disposed at an end of the rotating shaft and has a seal portion that communicates the rotating shaft channel and the fixed-side channel;
A housing that rotatably supports the rotating shaft via a bearing and that forms a storage chamber that surrounds the seal portion so as to store liquid leaked from the seal portion;
A detecting means provided facing the storage chamber and detecting an abnormality of the seal portion;
A spindle apparatus comprising: The housing is formed with a drain hole for discharging the liquid accumulated in the storage chamber to the outside,
The spindle device according to claim 1, wherein the detection unit is provided at a position higher than the drain hole.   The detection means includes a detection liquid discharge hole formed at a position higher than the drain hole of the housing, and a detection sensor for detecting a liquid flowing out of the detection liquid discharge hole. Item 3. The spindle device according to Item 2.

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