spindle device

Abstract

A spindle assembly (100) includes: a rotating shaft (10); a cylindrical bearing housing (20) extending along the central axis (A) of the rotating shaft; a bearing (50) mounted on the inner circumferential surface (20a) of the bearing housing and supporting the rotating shaft for rotation; and a first elastic member (30a). A first flow path (21) and a second flow path (22) extending along the central axis of the bearing housing are formed inside the bearing housing. A first groove (24) extending circumferentially along the bearing housing and connected to the first and second flow paths is formed on the outer circumferential surface (20b) of the bearing housing. The first elastic member seals the opening of the first groove.

Description

Technical Field

[0001] This invention relates to a spindle device. Background Technology

[0002] Patent Document 1 (Japanese Patent Application Publication No. 2014-52081) discloses a bearing device. The bearing device described in Patent Document 1 includes a rotating shaft, a housing, a bearing, and a cooling jacket. The housing has a cylindrical shape extending along the central axis of the rotating shaft. The bearing is mounted on the inner circumferential surface of the housing. The bearing supports the rotating shaft to enable rotation. A cooling oil groove is formed on the outer circumferential surface of the housing. The cooling jacket is mounted on the outer circumferential surface of the housing to cover the cooling oil groove.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-52081 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] In the bearing assembly described in Patent Document 1, the periphery of the rotating shaft heats up due to its rotation. This heat may cause changes in the dimensions of the components surrounding the rotating shaft. In the bearing assembly described in Patent Document 1, the housing is cooled by cooling oil flowing through a flow path defined by a cooling oil tank and a cooling jacket, thus suppressing the aforementioned dimensional changes. However, in the bearing assembly described in Patent Document 1, the flow path is formed by installing a cooling jacket on the outer peripheral surface of the housing, thus increasing the outer diameter.

[0008] The present invention was made in view of the problems of the prior art described above. More specifically, the present invention provides a spindle device capable of suppressing the increase in outer diameter size for forming a flow path for coolant circulation.

[0009] Technical solutions adopted to solve technical problems

[0010] The spindle assembly of the present invention includes: a rotating shaft; a cylindrical bearing housing extending along the central axis of the rotating shaft; a bearing mounted on the inner circumferential surface of the bearing housing and supporting the rotating shaft to enable rotation; and a first elastic member. A first flow path and a second flow path extending along the central axis of the bearing housing are formed inside the bearing housing. A first groove extending circumferentially along the bearing housing and connecting to the first and second flow paths are formed on the outer circumferential surface of the bearing housing. The first elastic member seals the opening of the first groove.

[0011] The aforementioned spindle assembly may also include a first cover mounted on the outer peripheral surface of the bearing housing in a manner that covers the first elastic member.

[0012] In the aforementioned spindle assembly, a separator may also be provided between the portion of the first groove connected to the first flow path and the portion of the first groove connected to the second flow path.

[0013] In the aforementioned spindle assembly, the first flow path and the second flow path may also be located at different positions relative to each other in the circumferential direction of the bearing housing.

[0014] The aforementioned spindle assembly may also include a second elastic member. A second groove may also be formed on the outer circumferential surface of the bearing housing, extending circumferentially along the bearing housing, connecting to the first and second flow paths, and separating from the first groove in the direction of the bearing housing's central axis. The second elastic member may also seal the opening of the second groove.

[0015] The aforementioned spindle assembly may also include a cylindrical motor housing extending along the central axis of the bearing housing, a motor, and a second cover. The motor may also have a stator mounted on the inner circumferential surface of the motor housing and a rotor mounted on a rotating shaft radially opposite the stator. At least one third groove may be formed on the outer circumferential surface of the motor housing, extending circumferentially along the motor housing and fluidly connected to a second flow path. The second cover may also be mounted on the outer circumferential surface of the motor housing to cover at least one third groove.

[0016] In the aforementioned spindle assembly, at least one or more third grooves may also be multiple circumferential grooves arranged at intervals from each other in the direction of the central axis of the rotating shaft. Two of the multiple adjacent circumferential grooves in the direction of the central axis of the rotating shaft may also be connected to each other.

[0017] In the aforementioned spindle assembly, the bearing may also be a hydrostatic bearing that supports the load from the rotating shaft in the direction of the central axis of the rotating shaft and in the direction orthogonal to the central axis of the rotating shaft.

[0018] Invention Effects

[0019] According to the spindle device of the present invention, it is possible to suppress the situation where the outer diameter of the housing increases in order to form a flow path for coolant to flow through. Attached Figure Description

[0020] Figure 1 This is the first sectional view of the spindle assembly 100.

[0021] Figure 2 yes Figure 1 Sectional view at point II-II.

[0022] Figure 3 yes Figure 1 Sectional view at point III-III.

[0023] Figure 4 yes Figure 1 Enlarged view of point IV in the image.

[0024] Figure 5 This is the second sectional view of the spindle assembly 100.

[0025] Figure 6 This is the first perspective view of the motor housing 60.

[0026] Figure 7 From Figure 6 The second perspective view of the motor housing 60 as observed from direction VII.

[0027] Figure 8 This is a first sectional view of the spindle assembly 100 of the first modified example.

[0028] Figure 9 This is a second sectional view of the spindle assembly 100 in the second modified example.

[0029] Figure 10 This is a perspective view of the spindle assembly 100 in the fourth variation.

[0030] Figure 11 This is a perspective view of the spindle assembly 100 in the fifth variation. Detailed Implementation

[0031] Embodiments of the present invention will be described with reference to the accompanying drawings. In the following drawings, the same or equivalent parts are labeled with the same reference numerals and will not be described repeatedly.

[0032] (Structure of the spindle device in the embodiment)

[0033] The structure of the spindle assembly (hereinafter referred to as "spindle assembly 100") of the embodiment will be described.

[0034] Figure 1 This is the first sectional view of the spindle assembly 100. Figure 2 yes Figure 1 Sectional view at point II-II. Figure 3 yes Figure 1 Sectional view at point III-III. Figure 2 and Figure 3 The illustrations other than the bearing housing 20 are omitted in the text. Figure 4 yes Figure 1 Enlarged view of point IV in the image. Figure 5 This is a second sectional view of the spindle assembly 100. (See image below.) Figures 1-5As shown, the spindle assembly 100 includes a rotating shaft 10, a bearing housing 20, elastic members 30a and 30b, a cover 40, a bearing sleeve 50, a motor housing 60, a cover 70, a motor 80, and a cover 90.

[0035] The central axis of the rotating shaft 10 is designated as central axis A. The rotating shaft 10 has a first end 10a and a second end 10b in the direction of central axis A. The second end 10b is the end opposite to the first end 10a. The rotating shaft 10 has an enlarged diameter portion 11 and an enlarged diameter portion 12. The enlarged diameter portion 11 is located at the first end 10a, and the enlarged diameter portion 12 is located between the first end 10a and the second end 10b. The portion of the rotating shaft 10 located between the enlarged diameter portions 11 and 12 is designated as the first portion 13, and the portion of the rotating shaft 10 located further towards the second end 10b than the enlarged diameter portion 12 is designated as the second portion 14.

[0036] The outer diameters of the rotating shaft 10 at the expanded diameter section 11 and the expanded diameter section 12 are larger than the outer diameter of the rotating shaft 10 at the first part 13. The outer diameters of the rotating shaft 10 at the expanded diameter section 11 and the expanded diameter section 12 are larger than the outer diameter of the rotating shaft 10 at the second part 14. The expanded diameter sections 11 and 12 extend from the first part 13 and the second part 14 in a direction orthogonal to the central axis A. The expanded diameter sections 11, 12, the first part 13, and the second part 14 are circular in a cross-sectional view orthogonal to the central axis A.

[0037] The bearing housing 20 is cylindrical, extending along the central axis A. In a cross-sectional view orthogonal to the central axis A, the bearing housing 20 appears annular. The bearing housing 20 has an inner circumferential surface 20a and an outer circumferential surface 20b. Flow paths 21 and 22, and a supply port 23 are formed inside the bearing housing 20. Flow paths 21 and 22 extend along the central axis A. The supply port 23 is connected to the flow path 21 at one end and to the outside of the bearing housing 20 at the other end.

[0038] In the circumferential direction of the bearing housing 20, flow path 21 and flow path 22 are located at different positions relative to each other. For example, in a cross-sectional view orthogonal to the central axis A, flow path 22 is located at a position symmetrical with respect to the central axis A.

[0039] A groove 24 is formed on the outer peripheral surface 20b. The groove 24 extends circumferentially along the bearing housing 20. The groove 24 connects to flow paths 21 and 22. The groove 24 is, for example, a circumferential groove. However, the groove 24 is not limited to a circumferential groove. That is, the groove 24 may not circumferentially surround the outer peripheral surface 20b of the bearing housing 20. The groove 24 has a first portion 24a and a second portion 24b. The first portion 24a is the portion of the groove 24 located on the side of the outer peripheral surface 20b. The second portion 24b is the portion of the groove 24 located radially inward of the bearing housing 20 than the first portion 24a. The width of the first portion 24a in the direction of the central axis A is greater than the width of the second portion 24b in the direction of the central axis A. The width of the second portion 24b in the direction of the central axis A is less than the outer diameter of the elastic member 30a. The groove 24 connects to flow paths 21 and 22 in the second portion 24b.

[0040] A groove 25 is formed on the outer peripheral surface 20b. The groove 25 extends circumferentially along the bearing housing 20. The groove 25 connects to flow paths 21 and 22. The groove 25 is, for example, a circumferential groove. However, the groove 25 is not limited to a circumferential groove. That is, the groove 25 may not circumferentially surround the outer peripheral surface 20b of the bearing housing 20. The groove 25 has a first portion 25a and a second portion 25b. The first portion 25a is the portion of the groove 25 located on the side of the outer peripheral surface 20b. The second portion 25b is the portion of the groove 25 located radially inward of the bearing housing 20 than the first portion 25a. The width of the first portion 25a in the direction of the central axis A is greater than the width of the second portion 25b in the direction of the central axis A. The width of the second portion 25b in the direction of the central axis A is less than the outer diameter of the elastic member 30b. The groove 25 connects to flow paths 21 and 22 at the second portion 25b. The grooves 24 and 25 are separated from each other in the direction of the central axis A. In the direction of the central axis A, slot 24 is closer to the first end 10a than slot 25.

[0041] A groove 26 is formed on the outer peripheral surface 20b. The groove 26 extends circumferentially along the bearing housing 20. Grooves 24 and 25 are formed on the bottom surface of the groove 26. That is, one end of the groove 26 in the direction of the central axis A is closer to the first end 10a than the groove 24, and the other end of the groove 26 in the direction of the central axis A is closer to the second end 10b than the groove 25.

[0042] Elastic member 30a seals the opening of groove 24. Elastic member 30a is disposed within groove 24. More specifically, elastic member 30a is disposed within first portion 24a. Elastic member 30b seals the opening of groove 25. Elastic member 30b is disposed within groove 25. More specifically, elastic member 30b is disposed within first portion 25a. Elastic members 30a and 30b are, for example, annular members. Elastic members 30a and 30b are, for example, O-rings.

[0043] Coolant supplied from supply port 23 is supplied to flow path 21. A portion of the coolant flowing through flow path 21 and reaching tank 25 flows through tank 25 to flow path 22. The remaining portion of the coolant flowing through flow path 21 and reaching tank 25 flows directly to flow path 22. Coolant flowing through flow path 22 and reaching tank 24 flows through tank 24 to flow path 22 and merges with the coolant flowing through tank 25 and reaching flow path 22. Furthermore, since the opening of tank 24 is blocked by elastic member 30a and the opening of tank 25 is blocked by elastic member 30b, leakage of coolant to the outside of bearing housing 20 can be suppressed.

[0044] The cover 40 is mounted on the outer peripheral surface 20b. More specifically, it is disposed within the groove 26. The thickness of the cover 40 is preferably less than the depth of the groove 26. By mounting the cover 40 on the outer peripheral surface 20b, it is possible to prevent the elastic members 30a and 30b from detaching from the grooves 24 and 25, respectively, due to the pressure of the coolant.

[0045] The bearing sleeve 50 has a first member 51 and a second member 52. The first member 51 and the second member 52 are cylindrical, extending along a central axis A. In a cross-sectional view orthogonal to the central axis A, the first member 51 and the second member 52 are annular in shape. The first member 51 has a first end 51a and a second end 51b in the direction of the central axis A. The second end 51b is located opposite to the first end 51a. The first end 51a is located on the side of the first end 10a, and the second end 51b is located on the side of the second end 10b. The second member 52 has a first end 52a and a second end 52b in the direction of the central axis A. The second end 52b is located opposite to the first end 52a. The first end 52a is located on the side of the second end 10b, and the second end 52b is located on the side of the first end 10a.

[0046] The first member 51 and the second member 52 are arranged along the direction of the central axis A, with their second ends 51b and 52b spaced apart from each other. The first member 51 has an inner peripheral surface 51c, an outer peripheral surface 51d, and an end face 51e. The end face 51e is the end face on the side of the first end 51a of the first member 51. The end face 51e is spaced apart and faces the enlarged diameter portion 11. The second member 52 has an inner peripheral surface 52c, an outer peripheral surface 52d, and an end face 52e. The end face 52e is the end face on the side of the first end 52a of the second member 52. The end face 52e is spaced apart and faces the enlarged diameter portion 12.

[0047] The first component 51 has an enlarged diameter portion 51f. The enlarged diameter portion 51f of the first component 51 extends in a direction orthogonal to the central axis A. Preferably, the outer diameter of the first component 51 at the enlarged diameter portion 51f is equal to the outer diameter of the rotating shaft 10 at the enlarged diameter portion 11. The second component 52 has an enlarged diameter portion 52f. The enlarged diameter portion 52f of the second component 52 extends in a direction orthogonal to the central axis A. Preferably, the outer diameter of the second component 52 at the enlarged diameter portion 52f is equal to the outer diameter of the rotating shaft 10 at the enlarged diameter portion 11.

[0048] The bearing sleeve 50 is mounted on the inner circumferential surface 20a. More specifically, the outer circumferential surfaces 51d and 52d are in contact with the inner circumferential surface 20a. Additionally, the expanded diameter portions 51f and 52f are inserted into the bearing housing 20 in the direction of the central axis A. The inner circumferential surfaces 51c and 52c are spaced apart and face the outer circumferential surface of the rotating shaft 10 (first part 13).

[0049] A flow path 53 is formed inside the first component 51, and a flow path 54 is formed inside the second component 52. Flow paths 27 and 28 are formed inside the bearing housing 20. Flow paths 53 and 54 are connected to flow path 27. Flow path 53 opens at its inner circumferential surface 51c and end face 51e. Flow path 54 opens at its inner circumferential surface 52c and end face 52e. Flow path 27 is connected to the outside of the bearing housing 20 on the side opposite to flow paths 53 and 54.

[0050] Air is supplied to flow paths 53 and 54 via flow path 27. The air supplied to flow path 53 is ejected from the inner peripheral surface 51c and the end face 51e, and the air supplied to flow path 54 is ejected from the inner peripheral surface 52c and the end face 52e. The pressure of this air supports the load applied to the rotating shaft 10 in the direction of the central axis A and in directions orthogonal to the central axis A while the rotating shaft 10 is rotating around the central axis A. That is, in the spindle assembly 100, the rotating shaft 10 is supported by a hydrostatic bearing so that it can rotate around the central axis A. Furthermore, the air ejected from the inner peripheral surface 51c, end face 51e, inner peripheral surface 52c, and end face 52e is discharged to the outside of the bearing housing 20 through the space between the first member 51 and the second member 52 and flow path 28.

[0051] The motor housing 60 is cylindrical, extending along the central axis A. In a cross-sectional view orthogonal to the central axis A, the motor housing 60 is annular. One end of the motor housing 60 along the central axis A is blocked by a cover 70. A through hole 71 is formed in the cover 70. The through hole 71 extends through the cover 70 along its thickness direction (the direction of the central axis A). The other end of the motor housing 60 along the central axis A is mounted to the bearing housing 20. The enlarged diameter portion 12 and the second portion 14 are located inside the motor housing 60. The second end 10b protrudes from the through hole 71.

[0052] The motor housing 60 has an inner peripheral surface 60a and an outer peripheral surface 60b. Figure 6 This is the first perspective view of the motor housing 60. Figure 7 From Figure 6 A second perspective view of the motor housing 60, viewed from direction VII. (See image below.) Figure 6 and Figure 7 As shown, a plurality of grooves 61 are formed on the outer peripheral surface 60b. The grooves 61 are circumferential grooves formed along the circumference of the motor housing 60. Adjacent grooves 61 are arranged at intervals in the direction of the central axis A.

[0053] A notch 62 is formed on the outer peripheral surface 60b between two adjacent grooves 61. The two adjacent grooves 61 are connected to each other through the notch 62. The notch 62 is formed, for example, along the direction of the central axis A.

[0054] The odd-numbered cutout 62, counted from one end of the motor housing 60 along the central axis A, is designated as cutout 62a, and the even-numbered cutout 62, counted from one end of the motor housing 60 along the central axis A, is designated as cutout 62b. Cutouts 62a and cutouts 62b are arranged in columns along the central axis A. The columns of cutouts 62a are located at different positions in the circumferential direction of the motor housing 60 than the columns of cutouts 62b. More specifically, the columns of cutouts 62a are located at positions symmetrical with respect to the central axis A compared to the column points of cutouts 62b.

[0055] A flow path 63 is formed inside the motor housing 60. The flow path 63 extends along the direction of the central axis A. The flow path 63 is connected to the groove 61 at one end and to the flow path 22 at the other end. Thus, the groove 61 and the flow path 22 are in fluid connection.

[0056] The electric motor 80 has a stator 81 and a rotor 82. The stator 81 is mounted on the inner circumferential surface 60a. The stator 81 is, for example, composed of a plurality of coil bodies arranged circumferentially along the motor housing 60. The rotor 82 is mounted on the rotating shaft 10 (second part 14) in a manner opposite to the stator 81 in the radial direction of the motor housing 60. The rotor 82 is, for example, a permanent magnet. The electric motor 80 sequentially excites the plurality of coil bodies constituting the stator 81 along the circumferential direction of the motor housing 60 by a signal from a motor drive circuit (not shown), thereby causing the rotor 82 to rotate. With this rotation, the rotating shaft 10 on which the rotor 82 is mounted rotates about the central axis A. The electric motor 80 is, for example, an induction motor or a PM (Permanent Magnet) motor. In the case that the electric motor 80 is an induction motor, the rotor 82 is an electromagnetic steel plate; in the case that the electric motor 80 is a PM motor, the rotor 82 is a permanent magnet.

[0057] The cover 90 is mounted on the outer peripheral surface 60b by covering the groove 61. A flow path is defined by the inner peripheral surface of the cover 90 and the groove 61. A drain outlet 91 is formed on the cover 90. The drain outlet 91 extends through the cover 90 in communication with the flow path defined by the inner peripheral surface of the cover 90 and the groove 61. Coolant flowing through the flow path 22 is supplied to the flow path defined by the inner peripheral surface of the cover 90 and the groove 61 via the flow path 63. The coolant flowing through this flow path is discharged from the drain outlet 91. Thus, the motor 80 is cooled.

[0058] (Effects of the spindle device in the implementation method)

[0059] The effects of the spindle assembly 100 will be explained.

[0060] In the spindle assembly 100, the flow path for the coolant used to cool the bearing sleeve 50 is defined by flow path 21, flow path 22, groove 24, groove 25, elastic member 30a, and elastic member 30b. Flow path 21 and flow path 22 are formed inside the bearing housing 20. Groove 24 and groove 25 are formed on the outer peripheral surface 20b. Elastic member 30a and elastic member 30b are respectively disposed in groove 24 and groove 25. Therefore, in the spindle assembly 100, by configuring the flow path for the coolant used to cool the bearing sleeve 50, the outer diameter dimension does not increase.

[0061] When the outer diameter of the spindle assembly is increased to form a flow path for the coolant to cool the bearing sleeve, it is necessary to maintain the outer diameter of the spindle assembly by reducing the outer diameter of the bearing housing. In this case, as the outer diameter of the bearing housing decreases, the outer diameter of the bearing sleeve also decreases, and the axial load (load in the direction of the central axis of the rotating shaft) that the bearing sleeve can support will decrease.

[0062] However, in the spindle assembly 100, the outer diameter does not need to be increased to form a flow path for the coolant to flow through the bearing sleeve 50, therefore, it is not necessary to reduce the outer diameter of the bearing housing 20. As a result, the axial load that the bearing sleeve 50 can support can be maintained according to the spindle assembly 100.

[0063] In the spindle assembly 100, since a cover 40 is installed on the outer peripheral surface 20b to cover the elastic members 30a and 30b, it is possible to prevent the elastic members 30a and 30b from falling off due to the pressure of the coolant. Furthermore, since the cover 40 is disposed within the groove 26 and its thickness is less than or equal to the depth of the groove 26, the overall dimensions of the spindle assembly 100 are not increased due to the installation of the cover 40 on the outer peripheral surface 20b.

[0064] When the groove 24 has a first part 24a and a second part 24b (and the groove 25 has a first part 25a and a second part 25b), since the elastic member 30a (elastic member 30b) stops at the layer difference between the first part 24a and the second part 24b (layer difference between the first part 25a and the second part 25b), the setting position of the elastic member 30a (elastic member 30b) can be stabilized.

[0065] In the spindle assembly 100, flow paths 21 and 22 are located symmetrically with respect to point A in a cross-sectional view orthogonal to the central axis A. Therefore, the flow of coolant through flow path 21 can be branched in two directions into channels 24 and 25.

[0066] In the spindle assembly 100, a plurality of grooves 61 are formed on the outer peripheral surface 60b, which are connected by cutouts 62 and fluidly connected to the flow path 22. Furthermore, a cover 90 is mounted on the outer peripheral surface 60b of the spindle assembly 100. Therefore, according to the spindle assembly 100, the motor 80 can be further cooled by the coolant used to cool the bearing sleeve 50.

[0067] When the groove 61 is a circumferential groove extending along the circumference of the motor housing 60, it is easy to perform the machining for forming the groove 61. When the rows of cuts 62a and 62b are located symmetrically with respect to the central axis A, coolant can be supplied evenly to the outer circumferential surface 60b, thus improving the cooling efficiency of the motor 80.

[0068] (First variation)

[0069] Figure 8 This is a first sectional view of the spindle assembly 100 of the first modified example. Figure 9 This is a second sectional view of the spindle assembly 100 in the second modified example. Figure 8 It shows the equivalent of Figure 1 The cross section at position II-II. Figure 9 It shows the equivalent of Figure 1 The cross-section at position III-III. For example... Figure 8 and Figure 9 As shown, partitions 24c and 25c are respectively provided in slots 24 and 25.

[0070] In the spindle assembly 100 of the first modified example, the flow path 21 and the flow path 22 are arranged such that, in a cross-sectional view orthogonal to the central axis A, the straight line connecting the center of the central axis A and the center of the flow path 21 forms an angle of 90° or less with the straight line connecting the center of the central axis A and the center of the flow path 22. This angle is preferably 45° or less.

[0071] A partition 24c is disposed circumferentially between flow paths 21 and 22 on the bearing housing 20. The partition 24c protrudes radially from the bottom surface of the groove 24 on the bearing housing 20. A partition 25c is disposed circumferentially between flow paths 21 and 22 on the bearing housing 20. The partition 25c protrudes radially from the bottom surface of the groove 24 on the bearing housing 20. Thus, the flow of coolant through grooves 24 and 25 becomes unidirectional. Furthermore, partitions 24c and 25c can be part of the bearing housing 20 or can be components distinct from the bearing housing 20.

[0072] (Second variation)

[0073] In the spindle assembly 100 of the second modification, the groove 61 may not be a circumferential groove, but a spiral groove. In addition, in the spindle assembly 100 of the second modification, no cut 62 is formed on the outer peripheral surface 60b.

[0074] (Third variation)

[0075] In the spindle assembly 100 of the third modification, instead of the bearing sleeve 50, one or more rolling bearings capable of rotatably supporting the rotating shaft 10 about the central axis A may be used. Furthermore, in the spindle assembly 100 of the third embodiment, the flow path 27 is not formed inside the bearing housing 20.

[0076] (Fourth and Fifth Variations)

[0077] Figure 10 This is a perspective view of the spindle assembly 100 in the fourth variation. (See diagram below.) Figure 10 As shown, the cover 40 can also be a plate-shaped component and rolled around the outer peripheral surface 20b (groove 26). In this case, the cover 40 can be easily installed. Figure 11 This is a perspective view of the spindle assembly 100 in the fifth variation. (See diagram below.) Figure 11 As shown, the cover 40 can also be divided into multiple parts in the circumferential direction. For example, the cover 40 can also be divided into two parts in the circumferential direction: a segmented cover 40a and a segmented cover 40b. However, the number of segments of the cover 40 is not limited to two. In this case, the cover 40 can be easily installed.

[0078] As described above, embodiments of the present invention have been presented, but various modifications can be made to these embodiments. Furthermore, the scope of the present invention is not limited to the above embodiments. The scope of the present invention is defined by the claims and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0079] Industrial availability

[0080] The above-described embodiments are particularly advantageous for use with air spindle devices for machining centers.

[0081] Symbol Explanation

[0082] 100 Spindle assembly, 10 Rotary shaft, 10a First end, 10b Second end, 11 Expanded diameter section, 12 Expanded diameter section, 13 First part, 14 Second part, 20 Bearing housing, 20a Inner circumferential surface, 20b Outer circumferential surface, 21 Flow path, 22 Flow path, 23 Supply port, 24 Groove, 24a First part, 24b Second part, 24c Separator, 25 Groove, 25a First part, 25b Second part, 25c Separator, 26 Groove, 27 Flow path, 28 Flow path, 30a Elastic member, 30b Elastic member, 40 Cover, 40a Dividing cover, 40b Dividing cover, 50 Bearing sleeve, 51 first component, 51a first end, 51b second end, 51c inner circumferential surface, 51d outer circumferential surface, 51e end face, 51f enlarged diameter section, 52 second component, 52a first end, 52b second end, 52c inner circumferential surface, 52d outer circumferential surface, 52e end face, 52f enlarged diameter section, 53 flow path, 54 flow path, 60 motor housing, 60a inner circumferential surface, 60b outer circumferential surface, 61 groove, 62 cut, 62a cut, 62b cut, 63 flow path, 70 cover, 71 through hole, 80 motor, 81 stator, 82 rotor, 90 cover, 91 outlet.

Claims

1. A spindle assembly, comprising: Rotation axis; A cylindrical bearing housing that extends along the central axis of the rotating shaft; A bearing, mounted on the inner circumferential surface of the bearing housing, and supporting the rotating shaft to enable rotation; and First elastic member, A first flow path and a second flow path extending along the central axis of the bearing housing are formed inside the bearing housing. A first groove is formed on the outer peripheral surface of the bearing housing, extending circumferentially along the bearing housing and connecting with the first flow path and the second flow path. The first elastic member seals the opening of the first groove. The spindle assembly further includes a first cover mounted on the outer peripheral surface of the bearing housing in a manner that covers the first elastic member.

2. The spindle device as described in claim 1, characterized in that, A separator is provided between the portion of the first slot that connects to the first flow path and the portion of the first slot that connects to the second flow path.

3. The spindle device as described in claim 1, characterized in that, The first flow path and the second flow path are located at different positions relative to each other in the circumferential direction of the bearing housing.

4. The spindle assembly as described in claim 1, characterized in that, The spindle assembly also includes a second elastic member. A second groove is formed on the outer peripheral surface of the bearing housing. The second groove extends circumferentially along the bearing housing, connects to the first flow path and the second flow path, and is separated from the first groove in the direction of the central axis of the bearing housing. The second elastic member seals the opening of the second groove.

5. The spindle apparatus of claim 1 wherein, Also includes: A cylindrical motor housing extending along the central axis of the bearing housing; Electric motor; as well as Second cover, The electric motor has a stator mounted on the inner circumferential surface of the motor housing and a rotor mounted on the rotating shaft in a radial direction opposite to the stator on the motor housing. At least one third groove is formed on the outer peripheral surface of the motor housing, the at least one third groove extending circumferentially along the motor housing and fluidly connected to the second flow path. The second cover is installed on the outer peripheral surface of the motor housing in such a way that it covers at least one or more third slots.

6. The spindle assembly as described in claim 5, characterized in that, At least one of the aforementioned third grooves are a plurality of circumferential grooves arranged at intervals from each other in the direction of the central axis of the rotation shaft. Two of the plurality of adjacent circumferential grooves are connected to each other in the direction of the central axis of the rotating shaft.

7. The spindle assembly as described in any one of claims 1 to 6, characterized in that, The bearing is a hydrostatic bearing that supports loads from the rotating shaft in the direction of the central axis of the rotating shaft and in a direction orthogonal to the central axis of the rotating shaft.

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