JP2007182947A - Coupling, machine tool provided with it, and method of aligning axial center - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To connect a motor shaft of a spindle motor to a spindle shaft of a spindle easily with precision so that they become concentric without using a special-purpose component for the alignment of axial centers. <P>SOLUTION: The coupling 50 is constituted of a hub 51 on the motor side and a hub 52 on the spindle side which are connected to each other through the medium of a leaf spring 53. A motor shaft hole 51f, which the motor shaft of the spindle motor can be inserted into and withdrawn from, is formed on the hub 51. Then a spindle shaft hole 52f, which the spindle shaft of the spindle larger than the motor shaft in diameter can be inserted into and withdrawn from, is formed on the hub 52. An axial center alignment hole 51i is formed at the leading end side of the motor shaft hole 51f of the hub 51 on the motor side. When the motor shaft and the spindle shaft become concentric with each other, the spindle shaft penetrates the spindle shaft hole 52f and is engaged with the axial center alignment hole 51i. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coupling that connects a rotation shaft of a driving unit and a rotation shaft of a driven unit so that the rotation shafts are concentric, a machine tool including the coupling, and an axis alignment method.

  Conventionally, in a machining center which is an example of a machine tool, a workpiece (work) is machined by a tool attached to a spindle (for example, “boring”, “milling”, “drilling”, “cutting”, etc.) Has been given. And in order to rotate the tool attached to the main shaft by the power of the main shaft motor, a driving method is used in which the spindle shaft provided inside the main shaft and the motor shaft of the main shaft motor are connected to rotate.

  Here, when the spindle shaft and the motor shaft are connected, if machining is performed in a state where the axes of the two axes do not match, vibration will occur due to the eccentricity of both axes, Detrimental effects such as degradation of machining accuracy and noise generation. Therefore, conventionally, it is known that the spindle shaft and the motor shaft are coupled via a coupling so that the eccentricity of both shafts is absorbed by the coupling so that the above-described adverse effects do not occur.

  However, in recent years, in order to improve the processing efficiency of machine tools, the rotation speed of the spindle has been increased. For this reason, the coupling alone cannot completely absorb the eccentricity of both shafts, and even a slight shaft misalignment causes vibration during machining. For this reason, conventionally, various methods have been proposed in which the spindle shaft and the motor shaft are aligned with each other so that both shafts are concentric.

  Specifically, the spindle motor is temporarily placed on the spindle without being fixed, and the spindle shaft and the motor shaft are coupled by a coupling. When the spindle motor is driven in this temporarily placed state, the center of the spindle and the center of the spindle motor gradually approach each other due to the vibration of the rotation. When there is no shaft misalignment between the rotating spindle shaft and motor shaft, the spindle motor is fixed at that position. As a result, it is known that the spindle shaft and the motor shaft can be connected to each other while being aligned.

  Also, a separate motor mounting plate for mounting the spindle motor to the spindle is prepared. Then, the motor mounting plate is attached to the spindle head by aligning the center of the spindle and the motor mounting plate with the small attached to the spindle. Then, it is known that the spindle motor and the spindle are aligned with each other by attaching the spindle motor to the motor mounting plate.

Further, the center of the motor shaft is aligned with the center of the through hole in the first mounting plate, while the center of the main shaft is aligned with the center of the through hole of the second mounting plate. The two mounting plates and the housing are fixed. Further, there is known one that can fit the peripheral wall and the through hole to fix the first mounting plate and the second mounting plate so that the center of the motor shaft and the center of the main shaft coincide with each other. (For example, refer to Patent Document 1).
Japanese Patent No. 3335550

  However, as in the prior art, the method of aligning the shaft center by driving the spindle motor temporarily placed on the spindle is a simple method that does not require other mounting parts or measuring instruments, but the spindle shaft and motor Accurate alignment of the shafts requires the skill and experience of the manufacturer, and a great deal of labor and labor has been required for position adjustment to make both shafts concentric. Also, even if the manufacturer intends to connect the spindle shaft and the motor shaft in a concentric manner, it cannot be guaranteed whether or not the two shafts are concentric, and there is actually a shaft misalignment. There was a thing.

  Also, if separate parts are used to connect the spindle shaft and motor shaft concentrically, such as a conventional motor mounting plate, the two shafts can be reliably aligned, but by adding another part, the main shaft There is a problem that the structure of the machine is complicated and the manufacturing cost of the machine tool increases. The invention described in Patent Document 1 also has a problem similar to the above because it is necessary to separately provide a dedicated mounting plate to which the motor side is fixed, a dedicated mounting plate to which the machine side is fixed, and the like.

  The present invention has been made to solve the above problems, and without using a dedicated component for axial alignment, the rotation shaft of the drive unit and the rotation shaft of the driven unit are concentric, It is an object of the present invention to provide a coupling capable of easily and accurately connecting each other, a machine tool including the same, and a method of aligning the axes.

  In order to achieve the above object, a coupling according to a first aspect of the present invention includes a drive-side hub formed with a first through hole into which the first rotation shaft of the drive unit can be inserted and removed, and the first rotation shaft. A driven-side hub formed with a second through hole into which the second rotating shaft of the driven portion having a larger diameter can be inserted and removed, and the first rotating shaft of the driving portion and the second rotating shaft of the driven portion are Couplings that connect each other so as to be concentric with each other, wherein the driving-side hub has the first through-hole communicating with a surface facing the driven-side hub, and a distal end side of the first through-hole. A hole having a shape into which the tip of the second rotation shaft can be fitted is formed, and the first rotation shaft inserted into the first through hole and the hole inserted into the second through hole. When the second rotating shaft is concentric, the second rotating shaft passes through the second through hole and is formed on the tip side of the first through hole. Characterized in that the fittable into the hole portion that is.

  In addition to the structure of the invention described in claim 1, the coupling of the invention according to claim 2 is provided in a gap between the driving side hub and the driven side hub to connect each other, and at least the first An elastic member having a third through hole into which the two rotation shafts can be inserted and removed is provided, and the first rotation shaft inserted into the first through hole and the second inserted into the second through hole. When the rotation shaft is concentric, the second rotation shaft can be fitted into the hole formed on the tip side of the first through hole through the second through hole and the third through hole. It is characterized by becoming.

  In addition to the configuration of the invention according to claim 2, the coupling of the invention according to claim 3 is one or a plurality of leaf springs in which the third through hole is formed in the central portion thereof. It is characterized by being.

  A machine tool according to a fourth aspect of the present invention is a machine tool including the coupling according to any one of the first to third aspects, wherein the first rotating shaft of the drive unit is a motor shaft of a main shaft motor. The second rotating shaft of the driven portion is a spindle shaft provided inside the main shaft.

  According to a fifth aspect of the present invention, there is provided a shaft alignment method using the coupling according to any one of the first to third aspects, and a first rotation shaft of the drive unit and a second rotation shaft of the driven unit. A method of aligning the shafts so as to be concentric with each other, wherein the driving portion and the driven portion are attached to each other via the coupling, and the first rotating shaft is connected to the first through-hole. A rotating shaft inserting step of inserting the second rotating shaft into the second through hole, while moving the coupling in the axial direction of the first rotating shaft and the second rotating shaft, The at least one of the driving unit and the driven unit is moved in a direction orthogonal to the axial direction, and the second rotating shaft is penetrated from the second through hole, and is formed on the tip side of the first through hole. A hole fitting step for fitting into the hole, and the drive unit; And a moving portion fixing step for fixing the driven portion, and the coupling is moved in the axial direction of the first rotating shaft and the second rotating shaft to position the first rotating shaft on the driving hub. A rotating shaft positioning step for positioning the second rotating shaft on the driven hub, and a coupling fixing for fixing the first rotating shaft to the driving hub while fixing the second rotating shaft to the driven hub. And a process.

  According to a sixth aspect of the present invention, there is provided a shaft alignment method according to the fourth aspect, wherein the spindle motor is disposed in a spindle head that communicates with the spindle, and the motor shaft and the spindle shaft are arranged. A method of aligning the shafts so as to be concentric with each other, wherein the spindle motor is attached to the spindle via the coupling, and the motor shaft is inserted into the first through hole. A rotating shaft inserting step of inserting the spindle shaft into the second through hole, and moving the coupling in an axial direction of the motor shaft and the spindle shaft, while moving the main shaft motor in a direction orthogonal to the axial direction. A hole fitting step of moving the spindle shaft through the second through hole and fitting into the hole formed on the tip side of the first through hole; and fixing the spindle motor. A motor fixing step, and the coupling is moved in the axial direction of the motor shaft and the spindle shaft to position the first rotating shaft on the driving hub, while the second rotating shaft is moved to the driven hub. The rotating shaft positioning step for positioning, and the coupling fixing step for fixing the spindle shaft to the driven hub while fixing the motor shaft to the driving hub.

  In the coupling according to the first aspect of the present invention, the drive-side hub has a hole formed on the tip end side of the first through hole, and the second rotating shaft is concentric with the second rotating shaft. The rotating shaft can pass through the second through hole and fit into the hole. Therefore, it is possible to easily and accurately connect the first rotating shaft of the driving unit and the second rotating shaft of the driven unit so that they are concentric without using a dedicated component for aligning the axes. it can.

  In addition to the effect of the invention according to claim 1, the coupling according to claim 2 includes an elastic member provided in the gap between the driving side hub and the driven side hub to connect each other. When the rotation shaft and the second rotation shaft are concentric, the second rotation shaft can be fitted into the hole portion through the second through hole and the third through hole. Therefore, the elastic member connecting the driving side hub and the driven side hub absorbs the shaft misalignment of the rotating shaft at the time of rotational driving, and blocks heat transmitted from the driving unit side to the driven unit side. Performance deterioration can be prevented.

  In the coupling according to the third aspect of the present invention, in addition to the effect of the second aspect of the invention, the elastic member is one or a plurality of leaf springs having a third through hole formed in the center thereof. Therefore, the elastic member can be mounted with a simple configuration using one or a plurality of leaf springs.

  In the machine tool of the invention according to claim 4, the first rotating shaft of the drive unit is a motor shaft of the main shaft motor, and the second rotating shaft of the driven unit is a spindle shaft provided inside the main shaft. Therefore, by using the coupling described above, the first rotating shaft of the driving unit and the second rotating shaft of the driven unit are concentric without using a dedicated component for axial alignment. Can be realized simply and accurately.

  In the shaft alignment method according to the fifth aspect of the present invention, the rotating shaft inserting step of attaching the driving portion and the driven portion with the coupling and inserting each rotating shaft into each through hole, and the second rotating shaft as the second A hole fitting step for penetrating from the through hole and fitting into the hole, a moving portion fixing step for fixing the driving portion and the driven portion, a rotating shaft positioning step for positioning each rotating shaft on each hub, and And a coupling fixing step of fixing the rotating shaft to each hub. Therefore, it is possible to easily and accurately connect the first rotating shaft of the driving unit and the second rotating shaft of the driven unit so that they are concentric without using a dedicated component for aligning the axes. it can.

  Further, in the shaft alignment method of the invention according to claim 6, a rotating shaft inserting step of attaching the main shaft motor to the main shaft by coupling and inserting each rotating shaft into each through hole, and the spindle shaft penetrating from the second through hole A hole fitting step for fitting into the hole portion, a motor fixing step for fixing the spindle motor, a rotation shaft positioning step for positioning each rotary shaft to each hub, and a cup for fixing each rotary shaft to each hub. A ring fixing step. Therefore, a machine that can easily and accurately connect the first rotating shaft of the driving unit and the second rotating shaft of the driven unit without using a dedicated component for aligning the axes. A machine can be realized.

  Hereinafter, a machining center 1 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of the machining center 1. FIG. 2 is an overall perspective view of the machining center 1 excluding the splash cover 3. FIG. 3 is a front view of the machining center 1 centering on the tool change mechanism 20 and the spindle head 7.

  First, the overall configuration of the machining center 1 will be described. As shown in FIG. 1, the machining center 1 moves a workpiece (not shown) and a tool 6 (see FIG. 3) relative to each other to perform desired machining (for example, “boring”, “milling”) on the workpiece. It is a machine tool that can perform cutting, drilling, cutting and the like. The machining center 1 includes a machine body that processes a workpiece, a bed 2 that serves as a base of the machine body, a box-shaped splash cover 3 that is provided on the bed 2 and surrounds the periphery of the machine body. It is mainly composed.

  As shown in FIG. 2, the bed 2 is an iron base, and leg portions 2a are respectively provided at the lower four corners thereof, and these four leg portions 2a are installed on a floor surface of a factory or the like. Thus, the machining center 1 is installed at a predetermined location. Furthermore, the core part of the bed 2 is so-called cut-out molding (frame structure with ribs) in order to reduce weight and increase strength.

  As shown in FIG. 1, the splash cover 3 is formed in a substantially rectangular parallelepiped box shape, and a machining area in which a workpiece is machined by a machine body is provided inside thereof. On the front surface of the splash cover 3, slide type opening and closing doors 4 and 5 for opening and closing the opening are provided. In addition, glass windows 4a and 5a are provided in the approximate center of the open / close doors 4 and 5, respectively, a handle 4b is provided in the vicinity of the right end of the open / close door 4, and the vicinity of the left end of the open / close door 5 is provided. Is provided with a handle portion 5b. Therefore, the openings are opened by opening these handle portions 4b and 5b away from each other. Then, the operator attaches / detaches the workpiece to / from the table 10 disposed inside the splash cover 3 through the opening.

  Although not shown, a maintenance inspection hatch is detachably provided on each of the left and right side wall portions of the splash cover 3. And the splash cover 3 having the above configuration surrounds the periphery of the machine body and protects it from the outside, and blocks the chips discharged from the machine body and splashes of the cutting fluid from scattering to the outside. It prevents the external environment from being polluted.

  On the other hand, on the right side of the front surface of the splash cover 3, an operation panel 80 having a substantially rectangular shape in front view for operating the machining center 1 is provided. A keyboard 81 having various keys is provided on the front surface of the operation panel 80, and a CRT (display) 89 for displaying a setting screen or an execution operation is provided above the keyboard 81.

  Next, the machine body of the machining center 1 will be described. As shown in FIG. 2, the machine body of the machining center 1 is housed inside the splash cover 3, is mounted and fixed on the upper surface of the column seat portion 17 a of the bed 2, and extends substantially vertically upward. A prismatic column 17b, a spindle head 7 provided so as to be movable up and down along the front surface of the column 17b, a spindle 9 projecting vertically downward from the lower front side of the spindle head 7, and a right side of the spindle head 7. A tool exchange mechanism (ATC) 20 for exchanging a tool 6 (described later) attached to the tip of the main shaft 9 with another tool 6, a table 10 provided on the upper portion of the bed 2 for detachably holding a workpiece, and a column A control panel 19 is provided mainly on the back side of 17b and incorporates each device such as a power supply device and a control board. A control device (not shown) that controls the machining center 1 is disposed inside the control panel 19.

  A pair of guide rails (not shown) extending in the vertical direction and guiding the spindle head 7 are fixed in the vertical direction on the front surface of the column 17b. A Z motor (not shown), which is a servo motor, is provided on the upper surface of the column 17b, and a feed screw (not shown) extending below the Z motor is selectively driven in the forward and reverse directions. Thus, the spindle head 7 moves in the vertical direction.

  A spindle 9 corresponding to a machining axis is rotatably mounted on the spindle head 7 and a spindle motor 8 for rotating the spindle 9 is provided at the top. A tool 6 (described later) is detachably attached to the tip of the main shaft 9, and the tool 6 is rotated by rotating the main shaft 9 by the main shaft motor 8, so that a workpiece fixed on the table 10 is processed. It has become.

  On the other hand, a table 10 is disposed below the main shaft 9. The table 10 has a work detachably fixed thereto, and is controlled to move in the X-axis direction (left-right direction) and the Y-axis direction (depth direction) by an X motor and a Y motor (not shown) that are servo motors. . A substantially rectangular parallelepiped support base 12 is provided below the table 10, and a pair of X-axis feed guides (not shown) extending along the X-axis direction are provided above the support base 12. Thus, the table 10 is movably supported on the X-axis feed guide. Further, the support 12 is supported on a pair of Y-axis feed guides extending along the longitudinal direction of the bed 2 so as to be movable. In this state, the table 10 is moved in the X-axis direction along the X-axis feed guide by the X motor provided on the bed 2, and the Y-axis feed is also provided by the Y motor provided on the bed 2. It moves in the Y-axis direction along the guide.

  As shown in FIG. 3, the tool change mechanism 20 includes a tool magazine 30 having a substantially oval shape in side view for storing a plurality of tool holders 60 to which the tool 6 is attached, and a tool holder 60 attached to the spindle 9. And a tool change arm 40 for gripping and transporting the other tool holder 60.

  The tool change arm 40 is an arm provided with gripping portions 41 and 41 capable of gripping the tool holder 60 at both ends at the lower end portion of a cylindrical arm turning shaft 43 that is rotatably and vertically movable. The part 42 is configured to be fixed. The arm turning shaft 43 is parallel to the Z-axis direction, and the arm portion 42 is rotatable about the arm turning shaft 43. A tool change motor 24 is provided above the tool change arm 40, and the tool change arm 40 is turned and moved up and down by the rotational drive of the tool change motor 24.

  In addition, the tool magazine 30 is provided with a transfer mechanism (not shown) in which a plurality of tool pots 31 each capable of storing a plurality of tools 6 are arranged. The attached tool 6 is maintained in a state (stored state) oriented in the lateral direction. A magazine motor 26 is provided on the upper part of the tool magazine 30, and a plurality of tool pots 31 are conveyed by a transfer mechanism by the rotation of the magazine motor 26.

  Further, a split outlet 32 is formed on the lower end side of the tool magazine 30 and the tool pot 31 extends from the retracted state to the state in which the tool 6 faces downward (changeable state) only at the position where the split outlet 32 is formed. It can be turned. A pot lifting mechanism (not shown) that is driven by an air cylinder (not shown) and rotates the tool pot 31 to a retracted state or a replaceable state is disposed at the tool change position.

  When the tool 6 mounted on the spindle 9 is exchanged, the tool exchange arm 40 first turns in a state where the tool exchange arm 40 is raised to the origin, and the tool holder 60 and the spindle 9 on the tool magazine 30 side are turned. The mounted tool holder 60 is gripped by the gripping portions 41 and 41, respectively. Next, the tool change arm 40 is lowered and a tool removal operation is performed. After that, the tool change arm 40 is turned and the tool holder 60 on the spindle 9 side and the tool holder 60 on the tool magazine 30 side are switched. At this time, the tool change arm 40 rotates 180 degrees. Thereafter, the tool change arm 40 is raised, and the tool 6 held by the tool change arm 40 is mounted on the tool pot 31 or the spindle 9 on the tool magazine 30 side. Then, the tool changing arm 40 turns by a predetermined angle, the tool holder 60 is released from the gripping portions 41, 41, and one cycle of the arm turning operation of the tool changing arm 40 is completed.

  Next, the configuration of the spindle head 7 will be described. 4 and 5 are enlarged side sectional views of the spindle head 7 as viewed from the right direction. 4 and 5 mainly show each member arranged on the axis of the main shaft 9 in the main shaft head 7 for easy understanding, and the configuration unnecessary for the description is omitted. FIG. 5 is a sectional view showing the housing cover of the spindle head 7 and the housing 25 and lid 39 of the spindle 9 in order to clarify the appearance of each member arranged on the axis of the spindle 9. Yes.

  As shown in FIGS. 4 and 5, a spindle motor 8 for rotating the spindle 27 included in the spindle 9 is provided on the upper part of the spindle head 7. A motor shaft 8 a that is an output shaft that protrudes downward from the lower surface of the spindle motor 8 is coupled to a spindle shaft 27 a that is an input shaft that protrudes upward from a spindle 27 provided inside the spindle 9 via a coupling 50. Are connected. With this configuration, when the motor shaft 8a rotates about the axis by driving the main shaft motor 8, the spindle shaft 27a also rotates through the coupling 50, so the spindle 27 of the main shaft 9 is driven to rotate about the axis. In the present embodiment, the spindle shaft 27a has a larger diameter than the motor shaft 8a. Details of the configuration centered on the coupling 50 will be described later.

  Although not shown, the spindle motor 8 has a configuration in which a braking unit and a driving unit are housed in a cylindrical motor frame. The drive unit of the main shaft motor 8 is an inner rotor type induction motor, and the motor shaft 8a is fixed to the inner peripheral surface of the rotor. The braking portion of the spindle motor 8 is a mechanical disc brake that applies a braking force to the motor shaft 8a.

  Further, the above-described main shaft 9 is provided at the lower portion of the main shaft head 7. The main shaft 9 includes a substantially cylindrical housing 25 that is long in the vertical direction. A spindle 27 is rotatably provided inside the housing 25. Further, bearing bearings 30 and 31 for rotatably supporting the spindle 27 are provided on the inner peripheral surface of the housing 25 in the axial direction front end side (lower end side). Similarly, bearing bearings 32 and 33 for rotatably supporting the spindle 27 are provided on the inner peripheral surface on the rear end side (upper end side) in the axial direction of the housing 25. A holder mounting hole 29 having a tapered inner peripheral surface is bored along the axis of the spindle 27 at the center of the tip of the spindle 27. And the taper-shaped outer peripheral surface of the shank part 61 of the tool holder 60 fits closely with the inner peripheral surface of the holder mounting hole 29.

  Furthermore, a wide diameter portion 34 that is continuous with the inner peripheral surface of the holder mounting hole 29 and has a slightly larger diameter is provided on the upper portion of the holder mounting hole 29 where the diameter is reduced. The upper portion of the wide-diameter portion 34 is continuous with the inner peripheral surface of the wide-diameter portion 34, and is oil mist (mixed with a small amount of coolant in high-pressure air in a mist shape) toward the tool holder 60 side. A flow path 35 is provided for supplying the liquid. Further, a chuck mechanism portion 37 that holds a pull stud 62 formed on the upper end portion of the tool holder 60 via a plurality of steel balls 38 is disposed on the lower inner peripheral surface of the flow path 35. Further, the front end portion (lower end portion) of the housing 25 holds the spindle 27 and the bearing bearings 30 and 31, and also has a ring in plan view that prevents chips and the like during cutting from entering the bearing bearings 30 and 31. A lid 39 is fixed with bolts 36.

  Next, the coupling 50 will be described in detail. 6 and 7 are external perspective views of the coupling 50. FIG. FIG. 8 is a plan view of the coupling 50. FIG. 9 is a left side view of the coupling 50. FIG. 10 is a front view of the coupling 50. FIG. 11 is a rear view of the coupling 50. FIG. 12 is a component development view of the coupling 50. FIG. 13 is a cross-sectional view in the arrow direction of the coupling 50 taken along the line AA (see FIG. 8). FIG. 14 is a cross-sectional view of the coupling 50 in the direction of the arrows, taken along line BB (see FIG. 9).

  8 to 14 are views of the coupling 50 in the state shown in FIG. 6 as seen from each direction. 6, 7, and 12, the right direction in FIGS. 8, 9, 13, and 14, the front direction in FIG. 10, and the depth direction in FIG. It is the front (front direction) facing the spindle motor 8. Further, the AA line shown in FIG. 8 and the BB line shown in FIG. 9 are axes passing through the center of the coupling 50. Further, the coupling 50 shown in FIG. 7 represents a state in which the coupling 50 shown in FIG. 6 is rotated 90 degrees clockwise around the axis when viewed from the front, but based on the state shown in FIG. 6 below. In order to describe the coupling 50, the description of FIG.

  First, the overall configuration of the coupling 50 will be described. As shown in FIGS. 6 and 8 to 11, the coupling 50 has a configuration in which a motor-side hub 51 and a spindle-side hub 52 are integrally connected via a leaf spring 53. The motor-side hub 51 has a cylindrical main body, and forms a hollow cylinder through which a shaft hole (motor shaft hole 51f) having a circular cross section into which the motor shaft 8a can be inserted in the axial direction is penetrated. Similarly, the spindle-side hub 52 has a cylindrical main body, and forms a hollow cylinder through which a shaft hole (spindle shaft hole 52f) having a circular cross section into which the spindle shaft 27a can be inserted in the axial direction is penetrated. . The leaf spring 53 has a substantially square thin plate shape when viewed from the front, and a circular through hole (shaft insertion / removal hole 53c) is formed at the center thereof. The motor-side hub 51 and the spindle-side hub 52 have substantially the same shape and size, and are attached via leaf springs 53 so that the respective axes coincide with each other, so that a coupling 50 that forms an integral hollow cylindrical member as a whole. Is formed. Each member (the motor side hub 51, the spindle side hub 52, and the leaf spring 53) constituting the coupling 50 is made of metal such as aluminum or titanium.

  The motor-side hub 51 is provided with a cut 51c in which a cylindrical main body is cut from the side surface perpendicularly to the axial direction at a substantially intermediate position in the front-rear direction so as to have elasticity in the bending direction. Specifically, the notch 51c is formed over a predetermined range of the cylindrical body of the motor-side hub 51. In the case of FIG. 6, it is formed over the range of the left side 2/3 of the motor-side hub 51 in the front view. Has been. Further, a slot 51d for reducing the inner diameter of the motor shaft hole 51f is formed in front of the notch 51c (in the upper right direction in FIG. 6) from the right end of the outer peripheral surface of the cylindrical body of the motor-side hub 51 in front view. It is cut to the right end of the circumferential surface and is formed in the circumferential direction so as to communicate with the cut 51c. Further, a bolt hole 51a is formed perpendicularly to the axial direction so as to communicate with the slit 51d from the upper side surface of the cylindrical body when viewed from the front, while it communicates with the slit 51d from the lower side surface of the cylindrical body. A screw hole 51b is formed perpendicular to the axial direction. The bolt hole 51a is a hole into which a reduced diameter bolt 80a described later is inserted, and the screw hole 51b is a female screw into which a shaft portion (male screw) of the reduced diameter bolt 80a is screwed.

  Similarly, the spindle-side hub 52 is provided with a notch 52c in which the cylindrical body is cut from the side surface perpendicularly to the axial direction at a substantially intermediate position in the front-rear direction so as to have elasticity in the bending direction. Yes. Specifically, the notch 52c is formed over a predetermined range of the cylindrical body of the spindle-side hub 52. In the case of FIG. 6, the rear-side view and the lower side 2/3 of the motor-side hub 51 are covered. Is formed. In addition, a slot 52d for reducing the inner diameter of the spindle shaft hole 52f is seen from the rear as viewed from the notch 52c (from the lower left in FIG. 6) from the lower end of the outer peripheral surface of the cylindrical body of the spindle-side hub 52. It is cut toward the lower end of the circumferential surface and is formed in the circumferential direction so as to communicate with the cut 52c. In addition, a bolt hole 52a (see FIG. 7) is drilled perpendicularly to the axial direction so as to communicate with the slit 52d from the left side surface of the cylindrical body when viewed from the rear, while the slot 52d is formed from the right side surface of the cylindrical body. A screw hole 52b is formed perpendicularly to the axial direction so as to communicate with each other. The bolt hole 52a is a hole into which a later-described reduced diameter bolt 80b is inserted, and the screw hole 52b is a female screw into which a shaft portion (male screw) of the reduced diameter bolt 80b is screwed.

  Further, the spindle-side hub 52 is formed with a plurality of adjustment screw holes 52e drilled in the circumferential direction at equal intervals in the cylindrical body in front of the notch 52c (upper right direction in FIG. 6). In the present embodiment, six adjustment screw holes 52e are penetrated from the outer peripheral surface of the cylindrical main body to the inner peripheral surface at intervals of 60 degrees. An adjustment bolt (not shown) can be inserted into and removed from these adjustment screw holes 52e from the outer peripheral direction, and the adjustment bolts screwed into the adjustment screw holes 52e adjust the rotation balance of the coupling 50. To act as a weight for. Therefore, the rotation balance of the coupling 50 can be arbitrarily adjusted by changing the mass of each adjustment bolt in the adjustment screw holes 52e.

  Further, as shown in FIG. 10, when the coupling 50 in the state shown in FIG. 6 is viewed from the front, the cylindrical body of the motor-side hub 51 has bolt holes 51h on the upper and lower edges of the circular cross section. While 51h is pierced in parallel with the axial direction, nut holes 51g and 51g are respectively pierced in parallel with the axial direction at the right and left end edges of the circular cross section. Similarly, as shown in FIG. 11, when the coupling 50 in the state shown in FIG. 6 is viewed from the back side, the cylindrical body of the spindle-side hub 52 has bolt holes 52h at the right end edge and left end edge of the circular cross section. , 52h are penetrated in parallel to the axial direction, and nut holes 52g, 52g are respectively penetrated in parallel to the axial direction at the upper edge and the lower edge of the circular cross section.

  That is, the upper and lower bolt holes 51h, 51h of the motor-side hub 51 and the upper and lower nut holes 52g, 52g of the spindle-side hub 52 are respectively formed at corresponding positions, and the left and right nut holes 51g, 51g and the left and right bolt holes 52h, 52h of the spindle-side hub 52 are formed at corresponding positions. The bolt holes 51h and 52h are holes into which connecting bolts 70a and 70b, which will be described later, are respectively inserted, and the nut holes 51g and 52g are holes into which connecting nuts 73b and 73a, which will be described later, are respectively accommodated.

  Here, the assembly structure of the coupling 50 will be described. As shown in FIGS. 12 to 14, in the coupling 50, the motor-side hub 51 and the leaf spring 53 are connected by two connecting bolts 70a and 70a, while the spindle-side hub 52 and the leaf spring 53 are two. It is connected to the two connecting bolts 70b, 70b. That is, the motor-side hub 51 and the spindle-side hub 52 have a structure that is indirectly connected via the leaf spring 53.

  First, as shown in FIGS. 12 and 13, two connecting bolts 70 a and 70 a are respectively inserted into the bolt holes 51 h and 51 h of the motor-side hub 51 from the front of the coupling 50. Each bolt hole 51h is reduced in diameter to form a stepped portion, and the head of each connecting bolt 70a is locked by this stepped portion. A washer 71a, a leaf spring 53, and a washer 72a are sequentially inserted into the shaft portion of each connecting bolt 70a that passes through each bolt hole 51h and protrudes from the back surface of the motor-side hub 51, and finally, at the tip of the shaft portion. The connecting nut 73a is fastened. The connection nut 73a fastened to the shaft portion of the connection bolt 70a is accommodated in the nut hole 52g of the spindle side hub 52 with some play.

  On the other hand, as shown in FIGS. 12 and 14, two coupling bolts 70 b and 70 b are respectively inserted into the bolt holes 52 h and 52 h of the spindle-side hub 52 from the rear of the coupling 50. Each bolt hole 52h is reduced in diameter to form a stepped portion, and the head of each connecting bolt 70b is locked by this stepped portion. Then, a washer 71b, a leaf spring 53, and a washer 72b are sequentially inserted into the shaft portion of each connecting bolt 70b that passes through each bolt hole 52h and protrudes from the front surface of the spindle-side hub 52, and finally, at the tip of the shaft portion. The connecting nut 73b is fastened. The connection nut 73b fastened to the shaft portion of the connection bolt 70b is accommodated in the nut hole 51g of the motor-side hub 51 with some play.

  Here, the connecting bolts 70a and 70b are hexagon socket head cap bolts in which a hexagon socket for tightening with a hexagon wrench is formed on a round plate-shaped head, and the connecting nuts 73a and 73b are connected to the connecting bolts 70a and 70b. It is a hex nut fastened to the tip of the shaft. The leaf spring 53 is a substantially square plate-like elastic member as viewed from the front. The plate-like main body of the leaf spring 53 has circular cross-sectional holes (bolt insertion holes 53a, 53b) through which the shaft portions of the connecting bolts 70a, 70b are inserted at the four corners, and the spindle shaft 27a is inserted at least in the center in the center. A shaft hole (shaft insertion / removal hole 53c) having a removable circular cross section is bored. The washers 71 a and 72 b function as a spacer that stabilizes the leaf spring 53 from the front side and holds a gap between the motor-side hub 51 and the leaf spring 53. On the other hand, the washers 71 b and 72 a function as a spacer that stabilizes the leaf spring 53 from the back side and holds the gap between the spindle-side hub 52 and the leaf spring 53.

  In the coupling 50 having the above-described configuration, the connection position (vertical direction of the vertical direction) of the leaf spring 53 using the two coupling bolts 70a and 70a that are opposed to the motor side hub 51 in the vertical direction with respect to the axial direction. It is connected to the bolt insertion holes 53a, 53a). On the other hand, using the two connecting bolts 70b, 70b facing the spindle-side hub 52 in the left-right direction with respect to the axial direction, the connecting positions facing the left-right direction of the leaf spring 53 (bolt insertion holes 53b, 53b in the left-right direction). It is linked to. In other words, the motor-side hub 51 and the spindle-side hub 52 are opposed to each other on the front side and the back side of the leaf spring 53 at connection positions that face each other about the axial direction of the coupling 50 and have a phase difference of 90 degrees. It is connected.

  With this structure, when the coupling 50 is mounted on the machining center 1, if the coupling 50 is bent or decentered during machining (when the spindle motor 8 and the spindle 9 are rotated), the leaf spring 53 is caused by the stress. Deform. That is, the bending or eccentricity of the coupling 50 is absorbed by the leaf spring 53 and does not affect other members (the motor-side hub 51 and the spindle-side hub 52). Even if heat is generated by the rotational drive of the spindle motor 8, the leaf spring 53 blocks the heat conducted from the motor-side hub 51 to the spindle-side hub 52 and transmits only the rotation of the spindle motor 8. For this reason, it is possible to prevent performance degradation during rotation of the coupling 50.

  Next, the attachment structure of the motor shaft 8a and the spindle shaft 27a to the coupling 50 will be described. As shown in FIG. 9, the bolt hole 51a and the screw hole 51b formed in the motor-side hub 51 communicate with each other in the vertical direction (the vertical direction in FIG. 9) with the slit 51d interposed therebetween. When the diameter-reduced bolt 80a is inserted into the bolt hole 51a from above (upward in FIG. 9), the head of the diameter-reduced bolt 80a is locked by a stepped portion having a diameter reduced inside the bolt hole 51a. The shaft portion of the reduced diameter bolt 80a can be screwed into the screw hole 51b via the slit 51d. The diameter-reduced bolt 80a is a hexagon socket head cap bolt in which a hexagon socket for tightening with a hexagon wrench is formed on a round plate head.

  When the motor shaft 8a is inserted into the motor shaft hole 51f from the front of the coupling 50 and the reduced diameter bolt 80a is tightened in the inserted state, the slot 51d becomes narrow in the motor-side hub 51 and the inner diameter of the motor shaft hole 51f is reduced. The inner diameter L1 shown in FIGS. 13 and 14 is reduced. The outer peripheral surface of the motor shaft 8 a is tightened by the inner peripheral surface of the motor shaft hole 51 f, and the motor shaft 8 a is fixed to the motor-side hub 51.

  Further, as shown in FIG. 8, the bolt hole 52a and the screw hole 52b formed in the spindle side hub 52 communicate with each other in the left-right direction (vertical direction in FIG. 8) with the slit 52d interposed therebetween. Yes. When the diameter-reduced bolt 80b is inserted into the bolt hole 52a from the right direction (upward in FIG. 8), the head of the diameter-reduced bolt 80b is locked by a stepped portion having a diameter reduced inside the bolt hole 52a. The shaft portion of the reduced diameter bolt 80b can be screwed into the screw hole 52b through the slit 52d. The diameter-reduced bolt 80b is a hexagon socket head cap bolt in which a hexagon socket for tightening with a hexagon wrench is formed on a round plate head.

  When the spindle shaft 27a is inserted into the spindle shaft hole 52f from the rear of the coupling 50 and the reduced diameter bolt 80b is tightened in the inserted state, the slot 52d is narrowed in the spindle-side hub 52, and the inner diameter of the spindle shaft hole 52f is reduced. The inner diameter L2 shown in FIGS. 13 and 14 is reduced. The outer peripheral surface of the spindle shaft 27 a is tightened by the inner peripheral surface of the spindle shaft hole 52 f, and the spindle shaft 27 a is fixed to the spindle side hub 52.

  As shown in FIGS. 13 and 14, in the coupling 50, the inner diameter L2 of the spindle shaft hole 52f is equal to the inner diameter L1 of the motor shaft hole 51f corresponding to the spindle shaft 27a having a larger diameter than the motor shaft 8a. It is formed larger than. In the motor-side hub 51, the motor shaft hole 51f is enlarged in the vicinity of the back surface, and a circular cross-sectional through hole (axial centering hole 51i) communicating with the motor shaft hole 51f is formed. The inner diameter of the centering hole 51i is equal to the inner diameter L2 of the spindle shaft hole 52f. Therefore, when the axis of the motor-side hub 51 and the axis of the spindle-side hub 52 are positioned on the same straight line (that is, in a concentric state), the tip of the spindle shaft 27a inserted into the spindle shaft hole 52f is moved to the plate. It is possible to fit the shaft centering hole 51i from behind via the shaft insertion / removal hole 53c formed in the spring 53.

  Finally, a method for attaching the coupling 50 to the machining center 1 will be described. 15 to 17 are enlarged views centering on the coupling 50 to which the motor shaft 8a and the spindle shaft 27a are attached in the spindle head 7. FIG. For ease of understanding, only the coupling 50 is shown as a cross-sectional view.

  In the machining center 1 of the present embodiment, the spindle motor 8 is disposed in the spindle head 7 communicating with the spindle 9, and the motor shaft 8a and the spindle shaft 27a are connected to each other so as to be concentric. Manufacturers, designers, and the like (hereinafter referred to as manufacturers) of the machining center 1 perform the center alignment using the coupling 50 in the following procedure.

  First, in the “rotary shaft insertion step”, the manufacturer or the like places the spindle motor 8 at a predetermined motor mounting position in the spindle head 7 with the motor shaft 8a facing downward. Then, the main shaft motor 8 is temporarily fixed with a fixing screw (not shown) so that the main shaft motor 8 does not move in the vertical direction and can be slid in the horizontal direction. On the other hand, when the spindle motor 8 is attached, the manufacturer or the like inserts the motor shaft 8a into the motor shaft hole 51f of the coupling 50 from above while inserting the spindle shaft 27a into the spindle shaft hole 52f from below. Then, the motor shaft 8a and the spindle shaft 27a are cupped using the reduced-diameter bolts 80a and 80b so that the coupling 50 does not fall even if the hand is released and the coupling 50 can be slid in the vertical direction. Temporarily fasten to the ring 50. In the present embodiment, the inner diameter L2 of the spindle shaft hole 52f is slightly larger than the diameter of the spindle shaft 27a so that the spindle shaft 27a can be easily inserted, and when the spindle shaft 27a is inserted into the spindle shaft hole 52f. Some play is formed.

  Next, in the “hole fitting step”, the manufacturer slides the coupling 50 in the vertical direction along the motor shaft 8a and the spindle shaft 27a while sliding the spindle motor 8 in the horizontal direction (see FIG. 15). Then, the spindle shaft 27a is passed through the spindle shaft hole 52f, and is fitted into an axis alignment hole 51i formed on the lower end side of the motor shaft hole 51f (see FIG. 16). Specifically, in order to position the axis of the motor shaft 8a of the motor-side hub 51 and the axis of the spindle shaft 27a of the spindle-side hub 52 in the same straight line (that is, in a concentric state), the manufacturer Or the like slides the temporarily fixed spindle motor 8 in the horizontal direction. If the motor shaft 8 a and the spindle shaft 27 a are concentric, when the coupling 50 is slid downward, the tip of the spindle shaft 27 a is lowered into the shaft alignment hole 51 i of the motor-side hub 51. Mates from the direction. On the other hand, if it is not in the coaxial state, even if the coupling 50 is slid downward, the tip of the spindle shaft 27a is hooked on the back surface (lower surface) of the motor-side hub 51, so that it does not fit into the shaft alignment hole 51i. . In other words, when the coupling 50 is slid in the vertical direction, the motor shaft 8a and the spindle shaft 27a are concentric if the tip of the spindle shaft 27a is fitted in the shaft alignment hole 51i. Yes. Therefore, the motor shaft 8a and the spindle shaft 27a can be easily and reliably concentric without using a dedicated component for axial alignment as in the prior art.

  Next, in the “motor fixing process”, the manufacturer cannot move the spindle motor 8 temporarily fixed in the horizontal direction in order to maintain the state where the motor shaft 8a and the spindle shaft 27a are concentric. So that it is completely fixed. As a result, the spindle motor 8 positioned in the spindle head 7 can be fixed, and the position of the coupling 50 in the horizontal direction can be fixed.

  Next, in the “rotating shaft positioning step”, the manufacturer or the like slides the coupling 50 in the vertical direction along the motor shaft 8 a and the spindle shaft 27 a to position the motor shaft 8 a on the motor-side hub 51, The spindle shaft 27a is positioned on the spindle-side hub 52 (see FIG. 17). That is, the coupling 50 is returned upward, and the motor shaft 8a and the spindle shaft 27a are positioned at appropriate attachment sites on the motor-side hub 51 and the spindle-side hub 52, respectively.

  Finally, in the “coupling fixing process”, in order to maintain a state where the coupling 50 is positioned at an appropriate attachment site, a manufacturer or the like cannot move the coupling 50 temporarily fixed in the vertical direction. To completely fix. Thereby, the coupling 50 can be integrally connected to the motor shaft 8a and the spindle shaft 27a, and the position of the coupling 50 in the vertical direction can be fixed.

  Through the above procedure, the spindle motor 8 is disposed in the spindle head 7 communicating with the spindle 9 in the machining center 1 and is coupled using the coupling 50 so that the motor shaft 8a and the spindle shaft 27a are concentric. be able to. Then, the rotational drive of the spindle motor 8 is transmitted to the spindle 27 via the coupling 50, and the spindle 9 can be rotated to perform machining with the tool 6. Further, since the motor shaft 8a and the spindle shaft 27a are concentric, the occurrence of vibration during machining due to shaft misalignment is suppressed, and even if eccentricity of both shafts occurs during machining, the coupling 50 absorbs them. Therefore, more accurate workpiece machining can be realized.

  As described above, according to the coupling 50 and the machining center 1 according to the present invention, the motor-side hub 51 has the shaft centering hole 51i formed on the tip side of the motor shaft hole 51f, and the motor shaft 8a and the spindle shaft 27a are connected to each other. When concentric, the spindle shaft 27a can be fitted into the shaft alignment hole 51i through the spindle shaft hole 52f. When the coupling 50 is attached to the machining center 1, the “rotating shaft insertion process” in which the motor shaft 8 a and the spindle shaft 27 a are inserted into the coupling 50, and the spindle shaft 27 a is passed through the spindle shaft hole 52 f to be aligned with each other. “Hole fitting process” for fitting into the hole 51i, “motor fixing process” for fixing the spindle motor 8 in the spindle head 7, and “rotation” for positioning the motor shaft 8a and the spindle shaft hole 52f in the coupling 50 The “axis positioning step” and the “coupling fixing step” for fixing the motor shaft 8a and the spindle shaft hole 52f to the coupling 50 are performed. Therefore, it is possible to easily and accurately connect the motor shaft 8a and the spindle shaft 27a so that the motor shaft 8a and the spindle shaft 27a are concentric without using a dedicated component for alignment.

  By the way, in the above embodiment, the main shaft motor 8 and the motor shaft 8a correspond to the “drive unit” and “first rotating shaft” of the present invention, and the motor side hub 51 and the motor shaft hole 51f correspond to the “drive side” of the present invention. It corresponds to “hub” and “first through hole”. Further, the spindle 27 and the spindle shaft 27a correspond to the “driven portion” and the “second rotating shaft” of the present invention, and the spindle side hub 52 and the spindle shaft hole 52f are the “driven side hub” and the “second through-hole” of the present invention. Corresponds to “hole”. The shaft centering hole 51i of the motor-side hub 51 corresponds to the “hole” of the present invention, and the leaf spring 53 and the shaft insertion / removal hole 53c correspond to the “elastic member” and the “third through hole” of the present invention. To do.

  In addition, this invention is not limited to the said embodiment, Of course, various improvement and deformation | transformation are possible within the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, the shaft centering hole 51i having an enlarged diameter is provided on the tip end side of the motor shaft hole 51f, and the spindle shaft 27a is fitted into the shaft centering hole 51i to perform the centering. Yes. However, the form of the shaft centering hole 51i and the spindle shaft 27a can be arbitrarily changed as long as the centering can be performed appropriately. 18 and 19 are other enlarged views centering on the coupling 50 to which the motor shaft 8a and the spindle shaft 27a are attached in the spindle head 7. FIG.

  In the example shown in FIG. 18, in the motor-side hub 51, the motor shaft hole 51 f penetrates from the upper end surface to the lower end surface of the motor-side hub 51. A ring-shaped groove portion that is cut into a substantially circular shape as an axial center alignment hole 51 i is formed on the outer periphery of the opening portion of the motor shaft hole 51 f formed on the lower end surface of the motor-side hub 51. On the other hand, the spindle shaft 27a is formed with a ring-shaped protrusion whose tip edge protrudes upward. Under such a configuration, the spindle may be aligned in the same manner as in the above embodiment by fitting the spindle shaft 27a into the shaft alignment hole 51i.

  In the example shown in FIG. 19, in the motor-side hub 51, the motor shaft hole 51 f penetrates from the upper end surface to the lower end surface of the motor-side hub 51. The front end side of the motor shaft hole 51f (near the lower end surface of the motor-side hub 51) functions as an axis alignment hole 51i having the same diameter as the motor shaft hole 51f. On the other hand, the spindle shaft 27a is formed with a columnar protrusion that protrudes upward with a reduced diameter at the tip edge. Under such a configuration, the spindle may be aligned in the same manner as in the above embodiment by fitting the spindle shaft 27a into the shaft alignment hole 51i.

  In the above-described embodiment, the case where the coupling 50 is mounted on the machining center 1 (corresponding to the “machine tool” of the present invention) is illustrated. However, the “first rotating shaft of the drive unit” is the motor of the main shaft motor 8. The “second rotational axis of the driven portion” is not limited to the spindle shaft 27 a of the spindle 27. Therefore, the “coupling” and the “axis alignment method” according to the present invention can be applied to other than the machining center 1 to connect the rotation shafts of various drive mechanisms and the rotation shafts of various driven mechanisms so as to be concentric. it can.

  In addition, the shape and size of the “coupling (drive side hub, driven side hub)” of the present invention can be arbitrarily changed within the scope of the present invention. For example, the inner diameter L1 of the motor shaft hole 51f can be changed according to the motor shaft 8a, or the inner diameter L2 of the spindle shaft hole 52f can be changed according to the spindle shaft 27a. Similarly, the inner diameter of the shaft centering hole 51i of the motor-side hub 51 may be changed according to the spindle shaft 27a.

  The “elastic member” of the present invention can arbitrarily change the shape and size of the leaf spring 53 as long as it can absorb the eccentricity in the coupling 50. For example, in the above embodiment, one leaf spring 53 is used, but a plurality of leaf springs 53 may be stacked and mounted.

  The coupling according to the present invention, the machine tool provided with the coupling, and the shaft centering method can be used as a coupling for connecting the rotating shaft of the driving unit and the rotating shaft of the driven unit so that they are concentric.

1 is a front view of a machining center 1. FIG. 1 is an overall perspective view of a machining center 1 excluding a splash cover 3. FIG. 2 is a front view of the machining center 1 centering on a tool change mechanism 20 and a spindle head 7. FIG. FIG. 3 is an enlarged side cross-sectional view of the spindle head 7 as viewed from the right direction. FIG. 3 is an enlarged side cross-sectional view of the spindle head 7 as viewed from the right direction. 2 is an external perspective view of a coupling 50. FIG. 2 is an external perspective view of a coupling 50. FIG. 3 is a plan view of the coupling 50. FIG. 3 is a left side view of the coupling 50. FIG. 3 is a front view of a coupling 50. FIG. 3 is a rear view of the coupling 50. FIG. FIG. 6 is a component development view of the coupling 50. It is an arrow directional cross-sectional view of the coupling 50 in an AA line (refer FIG. 8). FIG. 10 is a cross-sectional view in the arrow direction of the coupling 50 taken along the line BB (see FIG. 9). FIG. 3 is an enlarged view centering on a coupling 50 to which a motor shaft 8a and a spindle shaft 27a are attached in the spindle head 7. FIG. 3 is an enlarged view centering on a coupling 50 to which a motor shaft 8a and a spindle shaft 27a are attached in the spindle head 7. FIG. 3 is an enlarged view centering on a coupling 50 to which a motor shaft 8a and a spindle shaft 27a are attached in the spindle head 7. FIG. 6 is another enlarged view centering on a coupling 50 to which a motor shaft 8a and a spindle shaft 27a are attached in the main shaft head 7. FIG. 6 is another enlarged view centering on a coupling 50 to which a motor shaft 8a and a spindle shaft 27a are attached in the main shaft head 7.

Explanation of symbols

1 Machining Center 6 Tool 7 Spindle Head 8 Spindle Motor 8a Motor Shaft 9 Spindle 27 Spindle 27a Spindle Shaft 50 Coupling 51 Motor Side Hub 51f Motor Shaft Hole 51i Centering Hole 52 Spindle Side Hub 52f Spindle Shaft Hole 53 Plate Spring 53c Shaft Insertion Hole 70a Connection bolt 70b Connection bolt 71a Washer 71b Washer 72a Washer 72b Washer 73a Connection nut 73b Connection nut

Claims (6)

A drive-side hub formed with a first through hole into which the first rotary shaft of the drive unit can be inserted and removed, and a second through hole through which the second rotary shaft of the driven unit having a larger diameter than the first rotary shaft can be inserted and removed. A coupling comprising: a driven hub formed with a hole; and coupling each of the first rotating shaft of the driving unit and the second rotating shaft of the driven unit so as to be concentric with each other;
The drive-side hub has a shape in which the first through-hole communicates with a surface facing the driven-side hub, and the tip of the second rotating shaft can be fitted to the tip of the first through-hole. A hole is formed,
When the first rotating shaft inserted into the first through hole and the second rotating shaft inserted into the second through hole are concentric, the second rotating shaft passes through the second through hole. The coupling can be fitted into the hole formed on the tip side of the first through hole. And provided with an elastic member provided in a gap between the driving side hub and the driven side hub and connecting each other, and at least a third through hole into which the second rotating shaft can be inserted and removed,
When the first rotation shaft inserted into the first through hole and the second rotation shaft inserted into the second through hole are concentric, the second rotation shaft is connected to the second through hole and the second rotation shaft. 2. The coupling according to claim 1, wherein the coupling can be fitted into the hole formed through the three through-holes on the tip side of the first through-hole.   The coupling according to claim 2, wherein the elastic member is one or a plurality of leaf springs in which the third through hole is formed at a central portion thereof. A machine tool comprising the coupling according to claim 1,
The first rotation shaft of the drive unit is a motor shaft of a main shaft motor;
The machine tool according to claim 1, wherein the second rotating shaft of the driven portion is a spindle shaft provided inside the main shaft. A shaft center for connecting the first rotating shaft of the driving unit and the second rotating shaft of the driven unit so as to be concentric using the coupling according to claim 1. A combination method,
The drive unit and the driven unit are attached to each other via the coupling, and the first rotating shaft is inserted into the first through hole, while the second rotating shaft is inserted into the second through hole. Shaft insertion process;
The coupling is moved in the axial direction of the first rotating shaft and the second rotating shaft, while at least one of the driving portion and the driven portion is moved in a direction orthogonal to the axial direction to perform the second rotation. A hole fitting step in which a shaft is passed through the second through hole and fitted into the hole formed on the tip side of the first through hole;
A moving part fixing step of fixing the driving part and the driven part;
The coupling is moved in the axial direction of the first rotating shaft and the second rotating shaft to position the first rotating shaft on the drive side hub, while the second rotating shaft is positioned on the driven side hub. A rotary axis positioning step;
A shaft centering method comprising: a coupling fixing step of fixing the first rotating shaft to the drive side hub and fixing the second rotating shaft to the driven side hub. 5. The machine tool according to claim 4, wherein the spindle motor is disposed in a spindle head that communicates with the spindle and is connected to each other so that the motor shaft and the spindle shaft are concentric. A combination method,
A rotary shaft inserting step of attaching the spindle motor to the spindle through the coupling and inserting the motor shaft into the first through hole, while inserting the spindle shaft into the second through hole;
The coupling is moved in the axial direction of the motor shaft and the spindle shaft, while the main shaft motor is moved in a direction orthogonal to the axial direction so that the spindle shaft is penetrated from the second through hole. A hole fitting step for fitting into the hole formed on the tip side of one through hole;
A motor fixing step of fixing the spindle motor;
A rotating shaft positioning step of positioning the first rotating shaft on the driving hub while positioning the second rotating shaft on the driven hub by moving the coupling in the axial direction of the motor shaft and the spindle shaft. When,
A shaft centering method comprising: a coupling fixing step of fixing the motor shaft to the driving side hub and fixing the spindle shaft to the driven side hub.

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