JP4867277B2 - Spindle device and machine tool equipped with the device - Google Patents

Description

  The present invention relates to a spindle device in which foreign matter (water, oil, etc.) is prevented from entering the housing of a spindle motor, and a machine tool including the device.

  Conventionally, some spindle motors used in machine tools and the like are used in a situation where cleaning water, cutting oil, or the like is scattered. Therefore, in such a spindle motor, in order to prevent foreign matter such as cleaning water and cutting oil from entering the housing, a sealing material is provided at the joint of each component of the housing, or the housing and the output shaft It is known to have a sealed structure with an oil sheet provided between them.

In addition, in order to prevent foreign matter (water, oil, etc.) from entering the housing of the spindle motor more reliably, compressed air is sent into the housing through the tube to improve confidentiality, and oil seals, etc. There has been known a liquid-proof motor that reinforces the sealing action by the sealing means (see, for example, Patent Document 1).
Japanese Utility Model Publication No. 8-727

  By the way, the compressed air fed into the housing of the spindle motor is mixed with various impurities such as dust, moisture, and in some cases, oil generated from the compressor. Therefore, according to the above prior art, the compressed air may directly contact the bearings and encoders in the housing, and impurities contained in the compressed air may adhere to the bearings and encoders. The adhered impurities have a problem of causing performance deterioration and failure of the spindle motor such as bearing rotation failure and encoder accuracy deterioration.

  Furthermore, in a main shaft motor in which a high-speed motor that rotates at high speed is mounted, an oil seal that seals a gap between the rotating shaft and the housing cannot be used. Therefore, due to the structure of the main shaft motor, leakage of compressed air occurs from the gap between the rotation shaft of the main shaft motor and the housing. Then, due to this leak of compressed air, the grease applied to the bearing flows out from the motor shaft end side to the outside, and there is a problem that causes performance deterioration and failure of the spindle motor.

  The present invention has been made to solve the above-described problems, and a spindle device capable of realizing a more effective air purge by controlling the flow of compressed air sent into the housing of the spindle motor, and the related It aims at providing the machine tool provided with the apparatus.

In order to achieve the above object, the main spindle device according to the first aspect of the present invention is such that the inside of the housing containing the power mechanism for rotating the rotary shaft therein is substantially sealed, and compressed air is supplied to the inside of the housing. is, the compressed air is discharged to the outside of the housing via an air leakage path is a gap formed in the housing, the spindle device intrusion of foreign matter can be prevented to said inner housing, said rotary shaft An output shaft on which an encoder is attached inside the housing is formed on one end side of the power mechanism, and an output shaft that protrudes outside the housing and outputs power on the other end side of the power mechanism There is formed, said housing, said with the outside of the housing and extending toward the outer circumferential surface of the input shaft, the said input shaft one Communicates with the outer peripheral surface of the input shaft between the ends of the side and said encoder comprises an air supply unit is a flow path for supplying the compressed air within said housing, said air leakage path, extends toward the other end side along the outer peripheral surface of the input shaft from the air supply unit, a gap via the encoder even without low, before Symbol housing, the input shaft from the air supply unit Extending toward the one end side along the outer peripheral surface of the input shaft, further extending toward the outside of the housing from the outer peripheral surface of the input shaft, and for discharging the compressed air to the outside of the housing through a path different from the air leakage path The air discharge part which is the flow path of this is provided.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, the spindle device sucks out the compressed air supplied to the inside of the housing to the outside of the housing via the air discharge portion. It is characterized by comprising suction means for generating a negative pressure for the purpose.

  According to a third aspect of the present invention, there is provided a machine tool including the spindle device according to the first or second aspect.

In the spindle device according to the first aspect of the present invention, the compressed air supplied to the inside of the housing that houses the power mechanism of the rotating shaft is discharged to the outside of the housing through the air leakage path to prevent foreign matter from entering. The housing is provided with an air discharge part for discharging compressed air through a path different from the air leakage path. Therefore, more effective air purge can be realized by controlling the flow of compressed air sent into the housing of the spindle motor.

Moreover, the air discharge part was made into the flow path for sucking compressed air outside the housing. Therefore, it is possible to greatly reduce the amount of compressed air flowing to a portion where compressed air is not desired to flow.

In addition, an encoder is disposed at a predetermined portion of the rotating shaft, the air leakage path is a gap passing through at least the encoder along the rotating shaft, and the air discharge unit discharges compressed air from a direction different from the encoder. . Therefore, it is possible to prevent impurities contained in the compressed air from adhering to the encoder, and to eliminate the performance deterioration factor of the encoder.

In addition to the effect of the invention according to claim 1, the spindle device of the invention according to claim 2 includes suction means for generating a negative pressure for sucking compressed air out of the housing via the air discharge part. It was. Therefore, the compressed air flowing through the air leakage path can be sucked from the air discharge portion and forcedly discharged outside the housing.

  A machine tool according to a third aspect includes the spindle device according to the first or second aspect. Therefore, it is possible to realize a machine tool in which foreign matter (water, oil, etc.) is appropriately prevented from entering the housing of the spindle motor.

  Hereinafter, a first embodiment of the present invention will be described. The spindle device 1 used in the machine tool according to the first embodiment includes a protective structure that prevents foreign matter (water, oil, etc.) from entering the housing 6 of the spindle motor 5. In particular, the front housing 13 of the spindle motor 5 has a characteristic device.

  First, the configuration of the spindle device 1 will be described. FIG. 1 is a front view of the spindle device 1. FIG. 2 is a cross-sectional view in the direction of the arrows in the direction of the AA line of the spindle device 1. 1 is a line that coincides with the axial direction of the main shaft 9 that is parallel to the Z-axis direction (vertical direction in FIG. 1) of the main spindle device 1.

  As shown in FIGS. 1 and 2, the main spindle device 1 according to the present embodiment has a vertically long rectangular parallelepiped casing 7 having a longitudinal direction in the Z-axis direction. A spindle 9 to which a tool holder 8 described later is attached and detached is rotatably supported by a plurality of bearings at the lower end portion of the spindle device 1. In the present embodiment, the casing 7 is a so-called saddle type that stands vertically, and is configured such that the spindle 9 is rotationally driven by a spindle motor 5 described later. A tool insertion hole 9 a that is a circular opening portion through which the tool holder 8 can be inserted and removed is formed on the lower end surface of the main shaft 9.

  On the other hand, a tool 8 a (for example, a drill) for machining a workpiece (workpiece) is attached to the tool holder 8. The tool holder 8 is conveyed by a tool changing mechanism (not shown), and is inserted upward into the main shaft 9 from the tool insertion hole 9a, or is pulled out downward.

  When a new tool holder 8 is attached to the main shaft 9, the main shaft 9 is rotationally driven by the main shaft motor 5, and machining of a workpiece (work) by the tool 8 a mounted on the tool holder 8 becomes possible. . Then, according to the machining content designated by the user from the operation panel (not shown), the workpiece (workpiece) placed on the table (not shown) is moved in the XY axis direction, and the spindle on which the tool is attached The desired workpiece (for example, “boring”, “milling”, “drilling”, “cutting”, etc.) is applied to the workpiece (workpiece) while moving 9 in the Z-axis direction.

  Next, the configuration of the spindle motor 5 in the first embodiment will be described. FIG. 3 is a side cross-sectional view of the spindle motor 5 in the first embodiment. Note that the left-right direction in FIG. 3 is parallel to the Z-axis direction of the spindle device 1, and specifically, the left direction in FIG. 3 corresponds to the downward direction of the spindle device 1 (downward direction in FIG. 1). The direction corresponds to the upward direction of the spindle device 1 (the upward direction in FIG. 1). Also, the left direction in FIG. 3 is the front direction (front direction) of the spindle motor 5, and the right direction in FIG. 3 is the rear direction (back direction) of the spindle motor 5.

  As shown in FIG. 3, the spindle motor 5 according to the present embodiment is a power mechanism that drives the rotary shaft 2 to rotate at high speed. Then, as a housing 6 that forms the housing of the spindle motor 5, a stator core 11 that is a motor stator, a rear housing 12 that is disposed at the axial rear end of the stator core 11, and a front that is disposed at the axial front end of the stator core 11. And a housing 13. The rear housing 12, the stator core 11, and the front housing 13 are fastened to each other by bolts (not shown).

  The stator core 11 surrounds a rotor 10 that is a motor rotor through a minute gap, and the rotor 10 is fixed to the rotating shaft 2. The rear end side of the rotary shaft 2 is rotatably supported by a bearing 30 provided in the rear housing 12, and an input shaft 2 a to which power is input to the rotary shaft 2 is provided at the rear end portion of the rotary shaft 2. Is formed. On the other hand, the front end side of the rotating shaft 2 is rotatably supported by a bearing 32 provided in the front housing 13, and power is output to the main shaft 9 (see FIGS. 1 and 2) at the front end portion of the rotating shaft 2. An output shaft 2b is formed. Note that the input shaft 2 a of the rotary shaft 2 is housed inside the rear housing 12, but the output shaft 2 b of the rotary shaft 2 protrudes from the front housing 13 to the outside.

  An encoder 40 that is a magnetic sensor provided in the rear housing 12 is attached to the input shaft 2 a of the rotary shaft 2. The encoder 40 is a rotary encoder in which the input shaft 2a is inserted into a ring-shaped main body, and can detect a rotation angle position and a rotation speed according to the rotation of the input shaft 2a. A rear cover 50 is attached to the rear surface of the rear housing 12, and an opening formed on the rear surface of the rear housing 12 is sealed by the rear cover 50.

  A blower fan 60 for cooling the main shaft motor 5 (particularly, the stator core 11) is installed on the rear side of the rear cover 50 in the axial direction. The blower fan 60 as air cooling means is surrounded by a fan housing 62 and is fixedly supported by the stator core 11 and the rear housing 12 via the fan housing 62. A terminal box 20 is attached to the upper portions of the rear housing 12 and the fan housing 62.

  In the spindle motor 5, after the rear housing 12, the stator core 11, and the front housing 13 are fastened to each other, they are subjected to a resin impregnation process to mechanically seal the joint portion of the assembly. In addition, gaskets (not shown) are interposed at the joint between the rear housing 12 and the rear cover 50 and the joint between the rear housing 12 and the terminal box 20, respectively.

  As described above, the spindle motor 5 according to the present embodiment has a protective structure using a sealing means such as an impregnating material and a gasket. On the other hand, the spindle motor 5 is a high-speed rotary motor, and thus the rotary shaft 2. An oil seal that seals the gap between the housing 6 and the housing 6 is not used. Therefore, in order to prevent foreign matters (water, oil, etc.) from entering the housing 6 due to deterioration of the sealing action of these sealing means over time or during high-speed rotation, the housing 6 is as follows. Compressed air is sent in to improve the sealing action of the spindle motor 5.

  That is, a power cable 24 for supplying power to the spindle motor 5 is drawn into the terminal box 20 from the hole 21 of the terminal box 20. The wiring cable 24 is inserted into the rear housing 12 through a hole (not shown) formed in the rear housing 12 in the terminal box 20. A tube 22 for sending compressed air into the spindle motor 5 is drawn into the terminal box 20 from the hole 21 of the terminal box 20. The tube 22 is connected to an air supply hole 26 formed in the rear housing 12 in the terminal box 20, and compressed air can be fed into the rear housing 12 through the air supply hole 26. In addition, the connection part etc. of the tube 22 and the air supply hole 26 are sealed with the filler, and the compressed air leak in the air supply hole 26 is prevented.

  The compressed air sent into the housing 6 through the air supply holes 26 of the rear housing 12 is generated from a joint portion between the rear housing 12 and the rear cover 50, a gap generated at a joint portion between the rear housing 12 and the stator core 11, or the like. , It flows out little by little to the outside of the housing 6. Further, the air flows into the front housing 13 through the gap between the stator core 11 and the rotor 10, and is generated at a joint portion between the front housing 13 and the stator core 11 or a joint portion on the front end side of the front housing 13 and the rotating shaft 2. From the gap or the like, it flows out little by little to the outside of the housing 6. This reliably prevents foreign matter (water, oil, etc.) from entering the housing 6 of the spindle motor 5.

  In this embodiment, the front housing 13 of the spindle motor 5 has the following structure in order to control the flow of compressed air sent into the housing 6 of the spindle motor 5. FIG. 4 is an enlarged side sectional view of the spindle motor 5 with the front housing 13 as the center in the first embodiment. In FIG. 4, the flow of compressed air is indicated by arrows.

  As shown in FIG. 4, in the front housing 13 of the spindle motor 5, the compressed air sent into the housing 6 passes through the gap (air flow path 81) between the stator core 11 and the rotor 10, and the rotor 10. And a small gap 88 formed between the front housing 13 and the front housing 13. The slight gap 88 is a part formed so as not to hinder the rotation of the rotor 10. Then, the compressed air branches at the gap 88 and is exhausted via any one of the air inflow chamber 82, the air leakage part 89, and the air discharge path 84.

  Here, the air inflow chamber 82 is a space formed inside the front housing 13. The compressed air that has flowed into the air inflow chamber 82 flows out of the air formed on the front surface of the front housing 13 via a gap (air leakage path 83) that is generated at the joint between the front housing 13 and the front end side of the rotary shaft 2. It flows out from the hole 85 to the outside. The air discharge path 84 is a compressed air flow path formed so as to bypass a bearing 32 described later in order to discharge the compressed air through a path different from the air leakage path 83. As with the air leakage path 83, the air discharge path 84 has one end communicating with the gap 88 and the other end communicating with the air outflow hole 85. The air leakage part 89 is a gap generated at the joint between the front housing 13 and the stator core 11, and allows compressed air to leak out from the side surface of the spindle motor 5.

  However, in this gap 88, the introduction port communicating with the air inflow chamber 82 is narrow, while the introduction port communicating with the air discharge path 84 is wide. Further, the air discharge passage 84 is a passage having a larger diameter than the air leakage passage 83 communicating with the air inflow chamber 82 and capable of flowing a large amount of air. In addition, since the air leak part 89 is a very narrow space | gap, the compressed air which flows toward the air leak part 89 from the clearance gap 88 is very trace amount.

  Therefore, the compressed air that has passed through the air flow path 81 flows more easily toward the air discharge path 84 than the air inflow chamber 82 and the air leakage portion 89, and the compressed air that has flowed into the air discharge path 84 bypasses the bearing 32. Then, the air is discharged from the air outflow hole 85. That is, most of the compressed air that has passed through the air flow path 81 flows into the air discharge path 84 and is difficult to flow into the air inflow chamber 82 (air leakage path 83). The reason is as follows.

  As described above, the compressed air flowing into the air inflow chamber 82 is discharged from the air outflow hole 85 via the air leakage path 83. However, the air leakage path 83 is a gap formed adjacent to the bearing 32 in which the front end side of the rotary shaft 2 is rotatably supported in the front housing 13, and the bearing 32 is disposed in the middle of the path. Yes. Therefore, when compressed air flows through the air leakage path 83, impurities contained in the compressed air adhere to the bearing 32, causing a rotation failure of the bearing 32. Further, the grease applied to the bearing 32 may leak out from the air leakage path 83 due to the compressed air. In the present embodiment, in order to prevent such inconvenience, a structure in which compressed air hardly flows through the air inflow chamber 82 (air leakage path 83) as described above is adopted.

  As a result, a flow is formed in the front housing 13 in which the compressed air that has passed through the air flow path 81 is discharged from the air outflow hole 85 via the air discharge path 84. It is possible to prevent foreign matter (water, oil, etc.) from entering the housing 6 through the gap 13 (corresponding to the air leakage path 83). Then, the flow amount of the compressed air flowing through the air leakage path 83 is greatly reduced, and the contact between the compressed air and the bearing 32 is avoided, so that impurities contained in the compressed air adhere to the bearing 32 or the bearing The grease applied to 32 is prevented from leaking out.

  As described above, according to the spindle device 1 according to the first embodiment, the compressed air supplied to the inside of the housing that houses the power mechanism of the rotating shaft 2 is discharged to the outside of the housing 6 through the air leakage path 83. The main shaft motor 5 has a protective structure that prevents foreign matter from entering, and has the following characteristics. That is, by forming the air discharge path 84 for discharging the compressed air through a path different from the air leakage path 83 so as to bypass the bearing 32, the flow amount of the compressed air passing through the bearing 32 is greatly increased. Reduced.

  Therefore, by controlling the flow of the compressed air sent into the housing 6 of the spindle motor 5, it is possible to prevent intrusion of foreign matter (water, oil, etc.) into the housing 6 and to prevent the compressed air from flowing. Therefore, more effective air purging can be realized by preventing the compressed air from flowing through. Furthermore, it is possible to prevent impurities contained in the compressed air from adhering to the bearing 32 and to prevent the grease applied to the bearing 32 from flowing out, thereby eliminating the performance deterioration factor of the bearing 32.

  Next, a second embodiment of the present invention will be described. The spindle device 1 according to the second embodiment includes a protective structure that prevents foreign matter (water, oil, etc.) from entering the housing 6 of the spindle motor 5, and in particular, the spindle motor 5. The rear housing 12 has a characteristic device. Since the spindle device 1 basically has the same configuration as that of the first embodiment, the following description will focus on differences from the first embodiment, and the same reference numerals are used for the same configuration. And

  First, the configuration of the spindle motor 5 in the second embodiment will be described. FIG. 5 is a side sectional view of the spindle motor 5 according to the second embodiment. Note that the left-right direction in FIG. 5 is parallel to the Z-axis direction of the spindle device 1, and specifically, the left direction is the downward direction of the spindle device 1 (downward direction in FIG. 1), and the right direction in FIG. This corresponds to the upward direction of the device 1 (the upward direction in FIG. 1). Further, the left direction in FIG. 5 is a front direction (front direction) of the spindle motor 5, and the right direction in FIG. 5 is a rear direction (back direction) of the spindle motor 5.

  As shown in FIG. 5, the spindle motor 5 according to the present embodiment has basically the same configuration as that of the first embodiment, but the structures of the rear housing 12 and the front housing 13 are different. That is, the air discharge path 84 (see FIG. 4) is not formed in the front housing 13. In the rear housing 12, the air supply hole 26 connected to the tube 22 communicates with a gap formed behind the encoder 40 so that compressed air can be fed into the rear housing 12.

  Further, in the present embodiment, the blower fan 60 is installed on the side of the stator core 11 and the rear housing 12. The blower fan 60 is surrounded by a fan housing 62 and is fixedly supported by the stator core 11 and the rear housing 12 via the fan housing 62. With such a configuration, the input shaft 2a of the rotary shaft 2 protrudes outward from the rear housing 12 toward the back side thereof, and an opening 96 (FIG. 6) through which the input shaft 2a can pass is provided in the rear cover 50. Reference) is formed.

  In this embodiment, the rear housing 12 of the spindle motor 5 is provided with the following structure in order to control the flow of compressed air sent into the housing 6 of the spindle motor 5. FIG. 6 is an enlarged side cross-sectional view of the spindle motor 5 with the rear housing 12 as the center in the second embodiment. In FIG. 6, the flow of compressed air is indicated by arrows.

  As shown in FIG. 6, in the rear housing 12 of the spindle motor 5, the compressed air sent into the housing 6 through the air supply hole 26 is an air flow formed from the air supply hole 26 toward the center of the rear housing 12. It flows into the space | gap (1st air inflow chamber 92) formed behind the encoder 40 (right direction in FIG. 6) via the path | route 91. FIG. The compressed air that has flowed into the first air inflow chamber 92 is a gap (air leakage portion 98) generated at the joint between the rear housing 12 and the rear cover 50, or a gap generated at the joint between the rear housing 12 and the stator core 11 ( The air is discharged from the air leakage portion 99), the opening 96 that forms a gap between the input shaft 2a of the rotating shaft 2 and the rear cover 50, or the like. Further, a part of the compressed air flows into the front housing 13 through the gap between the stator core 11 and the rotor 10 (air flow path 81 in FIG. 4).

  More specifically, the compressed air that has flowed into the first air inflow chamber 92 is directed toward the front end side of the rotary shaft 2 via an air leakage path 93 that communicates forward (to the left in FIG. 6). It goes to the rear end side of the rotating shaft 2 via the second air inflow chamber 94 communicating in the rear direction (right direction in FIG. 6). Note that the compressed air passing through the air leakage path 93 can flow out from the air leakage portion 99 or outflow from a predetermined portion of the front housing 13 (the air leakage portion 89 and the air outflow hole 85 in FIG. 4). Is possible.

  Here, the air leakage path 93 is a gap formed adjacent to the bearing 30 in which the rear end side of the rotary shaft 2 is rotatably supported in the rear housing 12. 30 and an encoder 40 are arranged. Therefore, when compressed air flows through the air leakage path 93, impurities contained in the compressed air adhere to the encoder 40 and the bearing 30 and cause deterioration in accuracy of the encoder 40 and rotation failure of the bearing 30. Further, in the front housing 13, the grease applied to the bearing 32 causes the compressed air to leak out from the front end side clearance (the air leakage path 83 in FIG. 4) of the rotating shaft 2 to the outside of the motor.

  Therefore, in the present embodiment, in order to discharge the compressed air through a path different from the air leakage path 93, an air discharge path 95 that is a flow path for sucking the compressed air from a direction different from the bearing 30 and the encoder 40. Is formed inside the rear housing 12. One end of the air discharge path 95 communicates with the second air inflow chamber 94, and the other end is led out from the side surface direction (downward in FIG. 6) of the rear housing 12.

  One end of the air discharge path 95 is connected to an ejector 70 that generates a negative pressure for sucking out compressed air supplied into the housing 6. By the operation of the ejector 70, the compressed air that has flowed into the second air inflow chamber 94 is forcibly discharged to the outside of the housing 6 via the air discharge path 95. The ejector 70 corresponds to the “suction unit” of the present invention.

  As a result, a flow is formed in the rear housing 12 in which the compressed air that has flowed into the first air inflow chamber 92 is discharged from the air discharge path 95 via the second air inflow chamber 94. Thus, foreign matter (water, oil, etc.) is prevented from entering the housing 6 through the opening 96 formed on the back side of the housing 12. Then, the flow amount of the compressed air flowing through the air leakage path 93 is greatly reduced, and the contact between the compressed air and the bearing 30 and the encoder 40 is avoided. Therefore, impurities contained in the compressed air cause the bearing 30 and the encoder 40 to contain impurities. It is prevented from adhering to. At the same time, the amount of compressed air flowing into the front housing 13 is greatly reduced, so that leakage of grease applied to the bearing 32 is prevented.

  As described above, according to the spindle device 1 according to the second embodiment, the compressed air supplied to the inside of the housing that houses the power mechanism of the rotating shaft 2 is discharged to the outside of the housing 6 through the air leakage path 93. The main shaft motor 5 has a protective structure that prevents foreign matter from entering, and has the following characteristics. That is, an air discharge path 95 for discharging the compressed air through a path different from the air leakage path 93 is formed, and the ejector 70 sucks the compressed air from a direction different from that of the encoder 40, thereby passing through the encoder 40. The amount of compressed air flow was greatly reduced.

  Therefore, by controlling the flow of the compressed air sent into the housing 6 of the spindle motor 5, it is possible to prevent intrusion of foreign matter (water, oil, etc.) into the housing 6 and to prevent the compressed air from flowing. Therefore, more effective air purging can be realized by preventing the compressed air from flowing through. Furthermore, it is possible to prevent the impurities contained in the compressed air from adhering to the encoder 40 and eliminate the performance deterioration factor of the encoder 40.

  The present invention is not limited to the embodiment described in detail above, and it goes without saying that various modifications are possible. For example, in the above-described embodiment, the main shaft motor 5 is a high-speed rotation motor that rotates the rotation shaft 2 at a high speed. However, the present invention can also be applied to a low-speed rotation motor that rotates the rotation shaft at a low speed.

  In the first embodiment, an air discharge path 84 is provided in the front housing 13 so that the compressed air bypasses the bearing 32. This air discharge path allows the compressed air to bypass any part. It can be formed at any position in the housing 6. For example, an appropriate air discharge path may be provided in the rear housing 12 so that the compressed air bypasses the encoder 40.

  Similarly, in the second embodiment, an air discharge path 95 is provided in the rear housing 12 so that the compressed air is sucked from a direction different from that of the encoder 40. It can be formed at an arbitrary position in the housing 6 so as to be sucked from a direction different from the part. For example, an appropriate air discharge path may be provided in the front housing 13 so that the compressed air is sucked from a direction different from the bearing 32.

  Further, although the ejector 70 is used as the “suction means”, other suction means can be used as long as the compressed air can be sucked from the housing 6. For example, a negative pressure for sucking out compressed air to the outside of the housing 6 may be generated by using a suction pump or forming a throttle (orifice) in the air discharge path 95.

  The spindle device of the present invention and the machine tool including the device can be used as a spindle device and a machine tool in which foreign matter (water, oil, etc.) is prevented from entering the housing of the spindle motor.

1 is a front view of a spindle device 1. FIG. FIG. 3 is a cross-sectional view in the direction of the arrow in the direction of the AA line of the spindle device 1. It is side surface sectional drawing of the spindle motor 5 in 1st Embodiment. FIG. 3 is an enlarged side cross-sectional view of the spindle motor 5 with the front housing 13 as the center in the first embodiment. It is side surface sectional drawing of the spindle motor 5 in 2nd Embodiment. It is a side cross-sectional enlarged view of the spindle motor 5 centering on the rear housing 12 in 2nd Embodiment.

DESCRIPTION OF SYMBOLS 1 Spindle device 2 Rotating shaft 2a Input shaft 2b Output shaft 4 Spindle head 5 Spindle motor 6 Housing 7 Housing 8 Tool holder 8a Tool 9 Spindle 9a Tool insertion hole 10 Rotor 11 Stator core 12 Rear housing 13 Front housing 20 Terminal box 21 Hole 22 Tube 24 Wiring cable 26 Air supply hole 30 Bearing 32 Bearing 40 Encoder 50 Rear cover 60 Blower fan 62 Fan housing 70 Ejector 81 Air flow path 82 Air inflow chamber 83 Air leak path 84 Air discharge path 85 Air outflow hole 88 Clearance 89 Air leak section 91 Air flow path 92 First air inflow chamber 93 Air leakage path 94 Second air inflow chamber 95 Air discharge path 96 Opening portion 98 Air leakage portion 99 Air leakage portion

Claims (3)

The inside of the housing that houses the power mechanism that rotationally drives the rotating shaft is substantially sealed, and compressed air is supplied to the inside of the housing, and the compressed air passes through an air leakage path that is a gap formed in the housing. In the spindle device that is discharged to the outside of the housing via and prevents foreign matter from entering the housing,
The rotary shaft has an input shaft with an encoder attached inside the housing on one end side of the power mechanism, and projects to the outside of the housing on the other end side of the power mechanism to output power. Output shaft is formed ,
The housing extends from the outside of the housing toward the outer peripheral surface of the input shaft, and communicates with the outer peripheral surface of the input shaft between the end of the one end side of the input shaft and the encoder. Provided with an air supply part which is a flow path for supplying the compressed air inside,
The air leakage path, extends toward the other end side along the outer peripheral surface of the input shaft from the air supply unit, a gap via the encoder even without low,
Before Symbol housing, extending from said air supply unit toward the one end side along an outer peripheral surface of the input shaft, extends further toward the outer circumferential surface of the input shaft to the housing exterior, different from the air leakage path A spindle apparatus comprising an air discharge portion which is a flow path for discharging the compressed air to the outside of the housing through a path. 2. The spindle device according to claim 1, further comprising suction means for generating a negative pressure for sucking out the compressed air supplied to the inside of the housing to the outside of the housing through the air discharge portion. .   A machine tool comprising the spindle device according to claim 1.

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