JP2017189836A - Spindle device of machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle device of a machine tool, in which multiple fluid flow paths are formed between a spindle and a housing, easily at low cost.SOLUTION: A spindle device 1 of a machine tool comprises: a housing 1A; a spindle 20 stored in the housing 1A; multiple spacers 30; and multiple seals 26. Each spacer 30 has: an inner peripheral surface groove 32 circumferentially provided at a cylindrical body; and through-holes 31 extending from the inner peripheral surface groove 32 radially through the spacer 30. There is a cylindrical space sandwiched between: a uniform inner diameter area in an inner peripheral surface of the housing 1A, the uniform inner diameter area keeping a uniform inner diameter; and a uniform outer diameter area in an outer peripheral surface of the spindle 20, the uniform outer diameter area being located so as to face the uniform inner diameter area, and keeping a uniform outer diameter. In the cylindrical space, there are disposed multiple spacer-seal assemblies G1-G4 each comprising: the spacer 30; and a pair of seals 26 facing each other in an axial direction of the spindle 20 across the spacer 30.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a spindle device that can be applied to a machine tool that performs machining by rotating a tool such as a sculpting electric discharge machine at a high speed.

  Conventionally, in a spindle device mounted on various machine tools, a liquid such as cooling oil used for cooling a bearing or a gas such as air used for a chuck mechanism of a tool may be supplied to the spindle. In order to allow fluid to pass through the spindle, a spindle device is known in which a fluid passage is provided on the outer periphery of the spindle or inside the spindle, and liquid or gas is supplied from the outside to the passage through a housing that houses the spindle.

  In Patent Document 1, a pair of bearings that pivotally support a spindle and a cylindrical seal block positioned between the pair of bearings are disposed in a gap between the spindle and the spindle housing, and the circumferential surface is disposed on the inner peripheral side of the seal block. A spindle device is disclosed in which a groove-like oil supply passage is provided in the direction and a minute gap is provided between the seal block and the outer peripheral surface of the spindle. According to such a spindle device, a part of the oil supplied through the housing passes through the oil supply path and the minute gap and is supplied to the bearing, and the other part of the oil passes through the oil supply path. It is supplied to a supply passage provided in the spindle.

Japanese Patent No. 3396290

  Here, there are cases where a plurality of passages for allowing fluid to pass between the passage of the housing and the passage inside the spindle are provided for various reasons, and it is desired that the plurality of passages be configured as easily and at low cost as possible. It is rare.

  However, the spindle device of Patent Document 1 is a passage structure for supplying oil to a pair of bearings, and is not intended to provide a plurality of independent fluid passages side by side in the axial direction. If a plurality of oil passages are installed in the axial direction, there is a concern that the structure becomes complicated and the manufacturing cost increases.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a spindle device of a machine tool capable of providing a plurality of passages between a spindle and a housing easily and at low cost.

  A spindle device of a machine tool according to the present invention includes a housing having a plurality of communication passages through which fluid passes, a spindle having a plurality of fluid passages through which the fluid passes, and a housing accommodated in the housing, A plurality of spacers positioned between the peripheral surface and the outer peripheral surface of the spindle; and a plurality of spacers positioned between the inner peripheral surface of the housing and the outer peripheral surface of the spindle to seal the axial movement of the fluid. Each of the spacers is provided with a cylindrical main body, and the cylindrical main body has an inner peripheral surface groove for allowing the fluid to pass in the circumferential direction; A through hole penetrating the spacer in the radial direction of the spacer from the circumferential groove, and the communication passage and the fluid passage corresponding to each other are communicated with each other through the through hole and the inner circumferential groove. And the housing It is sandwiched between the same inner diameter region that maintains a constant inner diameter of the inner peripheral surface and the same outer diameter region that is located opposite to the same inner diameter region and maintains a constant outer diameter of the outer peripheral surface of the spindle. A plurality of spacer seal assemblies including the spacer and a pair of the seals facing each other in the axial direction of the spindle across the spacer are arranged in a cylindrical gap.

  The above-mentioned “through hole penetrating the spacer from the inner peripheral surface groove in the radial direction of the spacer” means that the through hole penetrates the spacer so that the inner peripheral surface groove communicates with the outer peripheral surface of the spacer. If the outer peripheral surface of the spacer is provided with a concave portion such as an outer peripheral surface groove, this includes the case where the inner peripheral surface groove communicates with the outer peripheral surface of the spacer through the concave portion such as the outer peripheral surface groove.

  In the spindle device of the machine tool according to the present invention, the spacer includes a plurality of the through holes and an outer peripheral surface groove that communicates the plurality of through holes, and the through hole extends from the inner peripheral surface groove to the outer peripheral surface groove. It is preferable to pass through.

  According to the present invention, a housing having a plurality of communication passages for allowing fluid to pass through, a spindle having a plurality of fluid passages for allowing fluid to pass therethrough, and being accommodated in the housing, an inner peripheral surface of the housing, and an outer peripheral surface of the spindle, A plurality of spacers located between the inner peripheral surface of the housing and the outer peripheral surface of the spindle, and a plurality of annular seals for sealing the axial movement of the fluid. Each spacer includes a cylindrical main body, and the cylindrical main body has an inner peripheral surface groove for allowing fluid to pass in the circumferential direction, and a through hole that penetrates the spacer from the inner peripheral surface groove in the radial direction of the spacer. The communication passage and the fluid passage corresponding to each other are communicated with each other via the through hole and the inner peripheral surface groove, and the same inner diameter region that maintains a constant inner diameter of the inner peripheral surface of the housing, and the spindle Within the same outer peripheral surface In a cylindrical gap sandwiched between the same outer diameter region that is located opposite to the region and maintains a constant outer diameter, a spacer and a pair of seals that are positioned opposite to each other in the axial direction of the spindle with the spacer interposed therebetween A plurality of spacer seal assemblies are arranged.

  As a result, each spacer seal assembly can form a plurality of connection passages for communicating each fluid passage provided in the spindle and each communication passage provided in the housing corresponding to each of the fluid passages. A plurality of independent connection passages can be provided easily and easily in the gap.

1 is an external view of a die-sinking electric discharge machine equipped with a spindle device according to an embodiment of the present invention. It is a perspective view of the spindle device in which the spindle device according to the first embodiment is used. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is IV-IV sectional drawing of FIG. It is a perspective view of the spacer of FIG. It is sectional drawing of the spacer of FIG. It is sectional drawing of the spacer in the spindle apparatus which concerns on 2nd Embodiment. It is sectional drawing of the spacer in the main axis | shaft apparatus which concerns on 3rd Embodiment. It is sectional drawing of the spacer in the main axis | shaft apparatus which concerns on 4th Embodiment. It is a principal part enlarged view of the main axis | shaft apparatus which concerns on 5th Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an external appearance of a sculpting electric discharge machining apparatus (electric discharge machining apparatus 10) on which a spindle device 1 according to an embodiment of the present invention is mounted. 2 is a longitudinal sectional view schematically showing the spindle device 1 according to an embodiment of the present invention, FIG. 3 is a sectional view taken along line III-III in FIG. 2, and FIG. 4 is a sectional view taken along line IV-IV in FIG. 5 is a perspective view of the spacer 30 shown in FIG. 3, and FIG. 6 is a cross-sectional view of the spacer 30 shown in FIG.

  An electric discharge machining apparatus 10 includes a spindle device 1, a machining head 2 that holds the spindle device 1 and is movable in the Z-axis direction, a column 3 that is a mechanical structure, a service tank 4 that stores machining fluid, and an electric discharge machining. A processing power supply device 5 for supplying electric power for processing and a processing tank 6 for holding a processing liquid are provided. Although not shown in the figure because it is a known configuration, the electric discharge machining apparatus 10 has an XY table housing portion 3A in front of the column 3, and is installed on a floor (not shown) in the XY table housing portion 3A. And a saddle (not shown) movable on the bed in the Y-axis direction, and a table (not shown) movable on the saddle in the X-axis direction. The electric discharge machining apparatus 10 according to the embodiment shown in FIG. 1 has a structure in which a reciprocating table is mounted on a reciprocating saddle. The overall structure of the machine is the X-axis moving body as in the embodiment. For example, a configuration in which the table is fixed and the machining head 2 that holds the spindle device 1 is movable in the X-axis direction, the Y-axis direction, and the Z-axis direction is not limited to the structure in which the Y-axis moving body is stacked. In addition, as long as the configuration of the spindle device 1 is not changed, any structure in which the X-axis moving body, the Y-axis moving body, and the Z-axis moving body are arranged at arbitrary positions without departing from the gist of the present invention can be adopted. it can.

  The machining tank 6 is supported on a table, a workpiece (not shown) is placed in the machining tank 6, and the workpiece and the tool electrode are positioned in the machining liquid and attached to the spindle device 1. The workpiece is subjected to electric discharge machining by the tool electrode thus formed. In addition, the electric discharge machining apparatus 10 cools the machining liquid stored in the service tank 4 to a predetermined temperature by an oil cooler (not shown) and then supplies the machining liquid to the machining tank 6, and uses the cooled machining liquid as a refrigerant in the spindle apparatus 1. Supply. The supplied refrigerant passes through a fluid passage 24 described later, thereby cooling the spindle device 1.

  The electric discharge machining apparatus 10 is connected to an operation apparatus 9 that performs an operation on a control unit (not shown) that controls the electric discharge machining apparatus 10. The operating device 9 is a computer including a display unit such as a liquid crystal display, an input unit such as a keyboard and a mouse, a storage device such as a magnetic disk drive, a CPU, a memory, and the like.

  As shown in FIGS. 3 to 4, the main shaft device 1 includes a housing 1 </ b> A, an upper bearing 13 and an unillustrated lower bearing provided on the inner periphery of the housing 1 </ b> A in the axial direction, and the bearings 13 at high speed. It has a spindle 20 that is rotatably supported, a servo motor (not shown) that drives the spindle 20, and a rotary encoder 11 that is used for drive control of the servo motor. The spindle 20 is accommodated in the housing 1A and holds a tool electrode (not shown) at the lower end in the drawing. The spindle 20 is composed of a plurality of components fixed coaxially, and is a rotating body that rotates around an axis Z1. The housing 1A accommodates at least a part of the spindle 20, and is composed of a plurality of parts here.

  The spindle 20 has a refrigerant fluid passage 24 through which the refrigerant passes. The fluid passage 24 has an outward path 24A extending along the axis Z1 of the spindle 20, and two return paths 24B communicating with the outward path 24A at the tool electrode side end of the outward path 24A and extending along the axis Z1 of the spindle 20. Here, the two fluid passage inlets 21 that communicate with the forward passage 24A, the two fluid passage outlets 22 that communicate with the two return passages 24B and 24B, respectively, are opposed to each other across the axis Z1. Further, in the spindle 20, a first air fluid passage (not shown) for opening and closing a chuck mechanism of a tool electrode (not shown) and a second air fluid passage (not shown) for checking the seating of the chuck are provided. It has been.

  Inside the housing 1A, a communication passage 18A having an opening at a position facing the fluid passage inlet 21, a communication passage 19A having an opening at a position facing the fluid passage outlet 22, and an unillustrated first air use A communication passage 16A having an opening at a position opposite to the inlet / outlet of the fluid passage, and a communication passage 17A having an opening at a position opposite to the inlet / outlet of the fluid passage (not shown) are provided. In addition, connectors 16, 17, 18, and 19 are respectively attached to the communication passages 16 </ b> A, 17 </ b> A, 18 </ b> A, and 19 </ b> A at the ends opposite to the openings.

  Between the inner peripheral surface of the housing 1 </ b> A and the outer peripheral surface of the spindle 20, a plurality of spacers 30 having a cylindrical main body are located. Each spacer 30 has an inner peripheral surface groove 32 through which the cylindrical main body allows fluid to pass in the circumferential direction, and a through hole 31 that penetrates the spacer 30 from the inner peripheral surface groove 32 in the radial direction of the spacer 30.

  By providing the inner circumferential surface groove 32 in the circumferential direction in the spacer 30, a circumferential passage in which fluid can move in the circumferential direction can be formed between the inner circumferential surface groove 32 and the spindle 20. Here, in the axial direction, the spacer 30 is positioned at the height of the fluid passage inlet 21, the height of the fluid passage outlet 22, and the height of the inlet / outlet of the fluid passage for the first air and the second air (not shown). doing. For this reason, no matter where the spindle 20 is rotated, the inlet / outlet of each fluid passage provided in the spindle 20 and the inner peripheral surface groove 32 positioned at a height corresponding to each inlet / outlet and the spindle 20 are formed. The fluid can be transferred to and from the circumferential passage.

  Further, by providing the spacer 30 with a through hole 31 that penetrates the spacer 30 in the radial direction, a radial passage from the inner peripheral surface groove 32 to the outer peripheral side of the spacer 30 can be configured. Accordingly, the spacer 30 is connected to each of the communication passages via a connection passage including a circumferential passage formed between the inner circumferential groove 32 and the spindle 20 and a radial passage formed by the through hole 31. The opening and the entrance / exit of each fluid passage provided in the spindle 20 can be communicated with each other.

  As shown in FIG. 5, the spacer 30 in the present embodiment includes an outer peripheral groove 33 that communicates a plurality of through holes 31 in the circumferential direction, and the through hole 31 extends from the inner peripheral groove 32 to the outer peripheral groove 33. It penetrates. For this reason, a circumferential passage in which the refrigerant can move in the circumferential direction can be formed between the inner circumferential surface of the housing 1A and the outer circumferential groove 33, and the fluid can be moved more preferably in the circumferential direction. . Further, by providing the plurality of through holes 31, it is possible to suitably flow the fluid between the radially inner circumferential passage and the radially outer circumferential passage.

  In the state where a plurality of spacers 30 are arranged between the inner peripheral surface of the housing 1A and the outer peripheral surface of the spindle 20, a gap is formed between the inner peripheral surface of the spacer 30 and the outer peripheral surface of the spindle 20. The spacer 30 is configured not to slide with the spindle 20. Further, the outer diameter of the spacer 30 is configured to be, for example, about 0.01 to 1 mm smaller than the inner diameter of the housing 1A, and the outer surface of the spacer 30 and the inner diameter of the housing 1A are such that the spacer 30 can be inserted into the housing 1A. A gap is formed between the peripheral surfaces. The outer diameter and inner diameter of the spacer 30 are configured such that the inner peripheral surface of the spacer 30 does not slide on the spindle 20 in a state where the spacer 30 is disposed between the inner peripheral surface of the housing 1A and the outer peripheral surface of the spindle 20. ing. Further, when the spacer 30 abuts and supports the seal 26, the spacer 30 is configured to support the seal 26 so that the fluid sealing performance of the seal 26 can be maintained.

  In addition, a pair of seals 26 are positioned opposite to each spacer 30 with the spacer 30 interposed therebetween in the axial direction of the spindle 20. The seal 26 is an annular seal that is located between the inner peripheral surface of the housing 1 </ b> A and the outer peripheral surface of the spindle 20 and seals the axial movement of the fluid. Each seal 26 has a plurality of seals 26 disposed between the inner peripheral surface of the housing 1A and the outer peripheral surface of the spindle 20, and the inner diameter of the seal 26 and the outer diameter of the spindle 20 are substantially equal. The outer diameter of the seal 26 and the inner diameter of the housing 1A are configured to be substantially equal.

  Further, as shown in FIGS. 3 and 4, the same inner diameter region that maintains a constant inner diameter of the inner peripheral surface of the housing 1 </ b> A and the same inner diameter region of the outer peripheral surface of the spindle 20 are positioned to face each other and are constant. A spacer seal assembly comprising a spacer 30 and a pair of seals 26 positioned opposite to each other in the axial direction of the spindle 20 across the spacer 30 in a cylindrical gap S sandwiched between the same outer diameter regions that maintain the outer diameter of A plurality of solids G1 to G4 are arranged. For this reason, each spacer seal assembly G1 to G4 forms a plurality of connection passages for communicating each fluid passage provided in the spindle 20 with each communication passage provided in the housing 1A corresponding to each fluid passage. It is possible to provide a plurality of independent connection passages simply and easily.

  Further, in the example of FIGS. 3 and 4, a bidirectional sealing 1 for sealing the passage of fluid bidirectionally along the axis Z <b> 1 of the spindle 20 between the spacers 30 adjacent in the axial direction of the spindle 20. Two seals 26 are arranged. In this case, one seal 26 positioned between the spacers 30 adjacent to each other in the axial direction of the spindle 20 also serves as the seal 26 of the two spacers 30 adjacent to each other in the axial direction of the spindle 20. The number of points can be reduced, and cost saving and downsizing can be achieved. It is not essential that one seal 26 also serves as the seal 26 of the two spacers 30 adjacent in the axial direction of the spindle 20, and each spacer seal assembly G <b> 1 to G <b> 4 is separately provided for each spacer 30. A pair of seals 26 facing each other may be provided. Further, in the cylindrical gap S, another component other than the spacer seal assembly may be inserted between the spacer seal assemblies adjacent in the axial direction of the spindle 20.

  In each spacer seal assembly G1 to G4, the pair of seals 26 are positioned opposite to each other in the axial direction of the spindle 20 with the spacer 30 interposed therebetween, not only when the seal 26 and the spacer 30 are directly adjacent to each other, This includes the case where the seal 26 and the spacer 30 are positioned so as to sandwich another component such as a seal support as long as the order of the seal 26 and the spacer 30 can be maintained. In addition, when the pair of seals 26 that are opposed to each other with the spacer interposed therebetween in the axial direction are positioned so that the seal 26 and the spacer 30 are directly adjacent to each other, the area where the plurality of connection passages are provided can be reduced in size. .

  The operation of the spindle device 1 will be described.

  The refrigerant in the service tank 4 is supplied from the connector 18 by a pump (not shown), and passes through the connection passage formed by the inlet side communication passage 18A and the spacer 30 to the inside of the spindle 20 from the fluid passage inlet 21 above the spindle 20. Flow into. The refrigerant passes through the fluid passage 24 in the order of the forward path 24 </ b> A and the return path 24 </ b> B, and flows out of the spindle 20 from the fluid passage outlet 22 at the top of the spindle 20. And it is discharged | emitted from the main shaft apparatus 1 from the connector 19 via the connection path | route formed by the spacer 30, and the exit side connection channel | path 19A.

  Further, the air for confirming the seating of the chuck (not shown) is supplied from the pump (not shown) to the connector 16, the first air communication passage 16A, the connection passage formed by the spacer 30, and the spindle 20 (not shown). Move through the first air passage. Also, the chuck opening / closing air (not shown) is supplied from the pump (not shown) to the connector 17, the second air communication passage 17A, the connection passage formed by the spacer 30, and the second not shown in the spindle 20. Move through the air passage.

  According to the present embodiment, each spacer seal assembly G1 to G4 disposed in the cylindrical gap S causes each fluid passage provided in the spindle 20 and each communication passage provided in the housing 1A corresponding to each fluid passage. Can be formed, and a plurality of independent connection passages can be provided simply and easily. Further, by inserting a plurality of spacer seal assemblies side by side into the cylindrical gap S, a plurality of independent connection passages can be provided in a space-saving manner. Further, by adjusting the number of the spacers 30 and the pair of seals 26, the number of fluid passages can be increased or decreased, and the degree of design freedom can be increased.

  In addition, a connection passage that connects the communication passage and the fluid passage can be formed by the through hole 31 of the spacer 30, the circumferential passage formed between the inner peripheral surface groove 32 and the outer peripheral surface of the spindle 20. Accordingly, it is not necessary to provide a groove for a fluid passage on the outer peripheral surface of the spindle 20 or the inner peripheral surface of the housing 1A. Therefore, the structure of the spindle 20 or the housing 1A is simplified, and the groove is formed and polished ( An increase in processing steps such as a surface treatment step such as a lapping treatment can be suppressed, and the manufacturing cost of the spindle can be reduced. For this reason, a connection passage between the fluid passage of the spindle 20 and the communication passage of the housing 1A can be provided easily and at low cost.

  In particular, as in the present embodiment, when providing a fluid passage for allowing the refrigerant to pass inside the spindle 20 and / or providing a fluid passage for air inside the spindle 20 to prevent thermal displacement of the spindle 20. It is very beneficial to apply the present invention, and it is possible to provide a connection passage for connecting a plurality of fluid passages and a connection passage very easily and at a low cost.

  The through-hole 31 may be arbitrarily configured in size, shape, number, and arrangement as long as it can pass through the spacer 30 from the inner peripheral side to the outer peripheral side. A plurality of through holes 31 are preferably provided in the circumferential direction, and may be provided in the axial direction, and are preferably provided rotationally symmetrically about the axis of the spindle 20.

  The inner peripheral surface groove 32 of the spacer 30 may be arbitrarily configured in width, depth, and cross-sectional shape as long as fluid can be passed in the circumferential direction. Moreover, the outer peripheral surface groove | channel 33 may comprise arbitrarily width | variety, depth, and cross-sectional shape, as long as a fluid can be passed through to the circumferential direction, and may be abbreviate | omitted.

  7 to 9 are sectional views of the spacer 30 in the spindle device 1 according to the second to fourth embodiments. Note that the spindle device 1 of the second to fourth embodiments differs from the first embodiment only in the shape of the spacer 30 and is the same as that of the first embodiment except for the shape of the spacer 30, so that the description will be made. Omitted. As shown in FIG. 7, in the spacer 30, the corner of the inner peripheral surface groove 32 can be an R surface 32 </ b> R, and the outer peripheral surface groove 33 may be omitted. Note that the first and second embodiments shown in FIGS. 6 and 7 are common in that the corners of the inner circumferential groove 32 of the spacer 30 are R-planes. Further, as shown in FIGS. 8 and 9, the corner of the inner circumferential groove 32 may have a right-angle cross section 32S or a C surface 32C. Also in each of the second to fourth embodiments, the outer peripheral surface groove 33 may be provided or omitted as indicated by a broken line.

  FIG. 10 shows a cross-sectional view of the spindle device 1 of the fifth embodiment. In the fifth embodiment, instead of the seal 26 of the first embodiment, the passage of the fluid in one axial direction of the spindle 20 is sealed, and the fluid is allowed to pass in the other direction, while the sealing seal 26 is different from the first embodiment in that point 26 is used, and other points are the same as those in the first embodiment.

  When the one-sealing seal 26 is used as in the fifth embodiment, as shown in FIG. 10, one spacer 30 and the spindle 20 in the axial direction are provided for each spacer seal assembly G2, G3. The pair of seals 26 may be positioned facing each other with the spacer 30 interposed therebetween, and the orientation of each seal 26 may be arranged so as to seal the fluid from one spacer 30 side. Then, as shown in FIG. 10, the plurality of spacer seal assemblies G2 and G3 are formed in the cylindrical gap S, and the axial direction of the spindle 20 is formed so as to form a connection passage that allows the corresponding communication passage and fluid passage to communicate with each other. It is sufficient to place a plurality of positions in

  When the seal 26 is made of a deformable material, a desired member may be inserted as appropriate, for example, by inserting the seal support portion 25 in order to suppress fluid leakage due to deformation of the seal 26 adjacent to the seal 26. In FIG. 10, the seal support portion 25 also serves as a support member for the seals 26 on both sides in the axial direction. Further, in the seal 26 having a U-shaped cross section as shown in FIG. 10, the seal is located at a position where the fluid can reach from the circumferential passage formed between the inner peripheral surface groove 32 of the spacer 30 and the spindle 20. The spacer 30 is preferably configured in a shape that can support the seal tip portion 26A. For example, in the example of FIG. 10, the seal tip 26 </ b> A of the seal 26 is preferably supported by setting the inner diameter of the spacer 30 so that the inner peripheral surface 34 of the spacer 30 is located in the range W in which the seal tip 26 </ b> A can be supported. Thus, the fluid sealing performance of the seal 26 can be maintained.

  Here, the cooling oil and the air are targeted, but the present invention can also be applied to a spindle device having passages for various fluids such as cooling water and other gases.

  The spindle device of the present invention has been described in detail above. However, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Main shaft apparatus 1A Housing 2 Processing head 3 Column 4 Service tank 5 Processing power supply apparatus 6 Processing tank 9 Operation apparatus 10 Electric discharge processing apparatus 11 Rotary encoder 13 Upper bearing 16-19 Connector 16A-19A Connection path 20 Spindle 21 Fluid path inlet 22 Fluid Passage outlet 24 Fluid passage 24A Outgoing path 24B Return path 26 Seal 30 Spacer 31 Through hole 32 Inner peripheral surface groove 33 Outer peripheral surface groove 34 Inner peripheral surface of spacer G1 to G4 Spacer seal assembly

Claims (2)

A housing having a plurality of communication passages through which fluid passes;
A spindle having a plurality of fluid passages through which the fluid passes and housed in the housing;
A plurality of spacers positioned between the inner peripheral surface of the housing and the outer peripheral surface of the spindle;
A spindle device comprising a plurality of annular seals located between the inner peripheral surface of the housing and the outer peripheral surface of the spindle and sealing the axial movement of the fluid;
Each of the spacers includes a cylindrical main body, and the cylindrical main body allows the fluid to pass through in the circumferential direction, and the spacer extends from the inner peripheral surface groove in the radial direction of the spacer. A through-hole penetrating through, and the communication passage and the fluid passage corresponding to each other through the through-hole and the inner circumferential groove are communicated with each other.
The same inner diameter region that maintains a constant inner diameter of the inner peripheral surface of the housing, and the same outer diameter region that faces the same inner diameter region of the outer peripheral surface of the spindle and maintains a constant outer diameter. A machine tool characterized in that a plurality of spacer seal assemblies comprising the spacer and a pair of the seals facing each other in the axial direction of the spindle with the spacer interposed therebetween are disposed in a cylindrical gap sandwiched between Spindle device.   The spacer includes a plurality of the through holes and an outer peripheral surface groove communicating with the plurality of through holes, and the through hole penetrates from the inner peripheral surface groove to the outer peripheral surface groove. The spindle device of the machine tool according to 1.