JP4139971B2 - Spindle device - Google Patents

Description

  The present invention relates to a spindle device such as a machine tool.

  As a conventional spindle device for a machine tool or the like, a built-in motor spindle device as shown in FIG. 13 is known (see, for example, Patent Documents 1 and 2).

  The built-in motor spindle device 80 shown in FIG. 13 includes a motor housing 83 held by a unit support member 82 and a front housing 84 coupled to the front of the motor housing. The motor housing 83 and the front housing 84 are provided with a spindle main body 85 and a stator 86 fixed to the inner periphery of the intermediate portion of the motor housing 83. A rotor 87 is fixed to the outer periphery of the intermediate portion of the spindle main body 85. Has been.

The spindle body 85 has a hollow cylindrical shape, and a draw bar 89 that is urged by a disc spring 88 and is slidable in the cylinder is provided in the cylinder, and a chuck portion 89a is provided at the tip. Yes. Four front bearings 92 are interposed between the front housing 84 and the spindle body 85. A rear side bearing 93 that is a cylindrical roller bearing and a bearing sleeve 94 are fitted on the outer periphery of the rear portion of the spindle body 85, and a rear cover 95 is bolted to the rear portion of the motor housing 83.
JP-A-7-112303 (page 2-3, FIG. 1) JP 2003-159622 A (page 4-5, FIG. 1)

  By the way, in a machine tool, it is often the cause of a spindle failure by mainly damaging the bearing, which is caused by a bearing life, a spindle collision caused by a machining program error, or the like. It is important to reduce the time (downtime) from when a spindle breaks down until it returns, especially at parts machining sites that are directly connected to production lines such as automobile parts machining. In addition, the spindle speed of machine tools has been increased, and the life of spindle bearings has been infinite for 100,000 low-speed machines (less than 600,000 dmN), compared to 10,000 to 20,000 hours for high-speed machines. Therefore, it is considered that it is treated as a consumable, and there is a need to reduce maintenance costs.

The spindle device 80 disclosed in Patent Document 1 is configured such that the spindle main body 85 can be removed to improve maintainability. However, in this configuration, the spindle main body 85 comes off, but there is no description regarding replacement of the rear side bearing 93 which is a cylindrical roller bearing, and if the rear side bearing 93 is damaged, the maintenance work is not different from the conventional one. Further, since the protruding portion of the lubricating nozzle is not provided in order to remove the spindle body 85, inevitably, the running-in operation of the rear bearing 93 is required for about 2 to 10 hours after the assembly, so that the downtime is prolonged. There was a problem.
Further, in the main shaft device disclosed in Patent Document 2, when removing the main shaft, the pipe 73 is removed by turning to the rear portion, or when assembling, it is necessary to further align the phases of the bearing case 33 and the pipe 73. There was a problem that workability was bad.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a spindle device that can be easily assembled and removed during maintenance and is low in cost.

1) A main shaft device of the present invention includes an outer cylinder having a stator, a rotatable rotating shaft having a rotor, a front side bearing in which an outer ring is fixed to a front housing and an inner ring is fitted around one end of the rotating shaft. A bearing sleeve that is disposed on the other end side of the rotating shaft and is fitted to the outer cylinder and is movable in the axial direction of the rotating shaft; an inner ring is fitted on the other end of the rotating shaft; And a rear side bearing fixed to a bearing sleeve and cooperating with the front side bearing to rotatably support the rotary shaft, wherein the bearing sleeve is fitted in a sleeve housing. The outer diameter of the bearing sleeve is fitted with a clearance fit to the inner diameter of the sleeve housing, and the ratio between the fitting length of the bearing sleeve and the sleeve housing and the outer diameter of the bearing sleeve But, Gocho of / is set within a range of outside diameter = 0.45 to 0.8, the rear side bearing is a angular contact ball bearing and the rear combination position preloading, the inner circumference of the outer cylinder The inner diameter of the stator and the outer diameter of the bearing sleeve decrease in order, and the front housing, the subassembly comprising the rotating shaft and the bearing sleeve can be removed from the outer cylinder, and the bearing The diameter of the rotating body in an arbitrary cross section behind the sleeve is smaller than the minimum diameter of the non-rotating body between the cross section from the rear end of the bearing sleeve.

The bearing sleeve is fitted in the sleeve housing, the outer diameter of the bearing sleeve is fitted with a clearance fit to the inner diameter of the sleeve housing, and the rear side bearing is an angular ball bearing with a fixed position preload and a rear combination. Therefore, the role of the rear side bearing and the bearing sleeve is mainly to support the rotating shaft, but it is possible to absorb axial displacement such as thermal expansion due to heat generation by the rotor with a simple structure.
Further, since the ratio between the fitting length of the bearing sleeve and the sleeve housing and the outer diameter of the bearing sleeve is set within the range of fitting length / outer diameter = 0.45 to 0.8, the bearing Since the outer diameter of the sleeve and the length of the fitting portion with the sleeve housing are set in an appropriate relationship, a semi-assembly structure excellent in maintainability and performance as a machine tool can be obtained.
Here, as a front side bearing, a double row combination angular contact ball bearing can be illustrated.

In the main shaft device configured as described above, the subassembly including the front housing, the rotating shaft, and the bearing sleeve can be extracted from the outer cylinder. As a result, the ease of installation is improved and it can be quickly replaced when damaged. Further, since the bearing sleeve is in a state in which the rear side bearing is assembled, the state of the grease does not change when the subassembly is inserted or removed.
Therefore, in this main shaft device, the semi-assemblies are preconditioned using a different outer cylinder and then stocked, so that when the rotating shaft breaks, the semi-assemblies can be replaced and immediately normal operation can be performed. The downtime can be greatly reduced. Further, it is possible to reduce the cost compared to exchanging the entire spindle device, and it is possible to reduce the inventory cost. As a result, it becomes possible to eliminate the problem that the downtime becomes long because the grease lubrication which cannot reduce the maintenance work as in the conventional case requires the running-in operation of the bearing after the assembly.

  Also, the inner diameter of the outer cylinder, the inner diameter of the stator, and the outer diameter of the bearing sleeve become smaller in order, so that the non-rotating body does not become an obstacle when trying to remove the semi-assembly behind the bearing sleeve. The diameter of the rotating body in an arbitrary cross section is made smaller than the minimum diameter of the non-rotating body between the cross section from the rear end of the bearing sleeve so that the non-rotating body does not become an obstacle. Therefore, when trying to remove the semi-assembly, the piston mechanism, which is a non-rotating body that holds and releases the tool, does not become an obstacle.

2) The main shaft device of the present invention includes an outer cylinder having a stator, a rotatable rotating shaft having a rotor, a front side bearing in which an outer ring is fixed to a front housing and an inner ring is fitted around one end of the rotating shaft. A bearing sleeve that is disposed on the other end side of the rotating shaft and is fitted to the outer cylinder and is movable in the axial direction of the rotating shaft; an inner ring is fitted on the other end of the rotating shaft; And a rear side bearing fixed to a bearing sleeve and cooperating with the front side bearing to rotatably support the rotary shaft, wherein the bearing sleeve is fitted in a sleeve housing. The outer diameter of the bearing sleeve is fitted with a clearance fit to the inner diameter of the sleeve housing, and the ratio between the fitting length of the bearing sleeve and the sleeve housing and the outer diameter of the bearing sleeve But, Gocho of / is set within a range of outside diameter = 0.45 to 0.8, the rear side bearing is a angular contact ball bearing and the rear combination position preloading, and the front housing, the rotating A semi-assembly including a shaft and the bearing sleeve can be extracted from the outer cylinder, and an inner diameter part capable of changing tools is incorporated in the rotating shaft, and has a piston mechanism for changing tools. It is said.

In the main shaft device configured as described above, the subassembly including the front housing, the rotating shaft, and the bearing sleeve can be extracted from the outer cylinder. As a result, the ease of installation is improved and it can be quickly replaced when damaged. Further, since the bearing sleeve is in a state in which the rear side bearing is assembled, the state of the grease does not change when the subassembly is inserted or removed.
Therefore, in this main shaft device, the semi-assemblies are preconditioned using a different outer cylinder and then stocked, so that when the rotating shaft breaks, the semi-assemblies can be replaced and immediately normal operation can be performed. The downtime can be greatly reduced. Further, it is possible to reduce the cost compared to exchanging the entire spindle device, and it is possible to reduce the inventory cost.
Further, since the tool is exchanged by the inner diameter part incorporated in the rotating shaft via the piston mechanism, the tool can be exchanged with higher lubrication performance than that exposed to the outside.

  3) The spindle device of the present invention is the spindle device described in 2) above, wherein the distance between the mounting reference surface of the subassembly and the piston pressing surface of the inner diameter part is within ± 0.1 mm with respect to the reference dimension. It is characterized by being adjusted to.

  If it does in this way, since it can unclamp appropriately, when exchanging a subassembly, piston adjustment is unnecessary and maintenance nature can be improved.

  4) The spindle device according to the present invention is the spindle device according to 2), wherein the inner diameter component is incorporated so that a spring can be compressed, and an adjustment component is fixed to a rear portion of the inner diameter component. A piston pressing surface to the piston mechanism is formed on the adjustment part.

  In this way, the tool holder pressing amount can be set to a predetermined value by the adjustment part, so that the unclamping can be appropriately performed by adjusting the tolerance, and as a result, the inner diameter part. When exchanging the piston, it is possible to improve maintenance by eliminating the need for piston adjustment.

5) The spindle device of the present invention is the spindle device according to any one of 1) to 4) described above, wherein a labyrinth seal is provided on the front and rear of the front housing and on the front and rear of the bearing sleeve. It is characterized by.

Before and after the front housing and the bearing sleeve, there is always a boundary between the rotating part and the non-rotating part, and when this boundary is exposed to the outside air, it is necessary to prevent foreign matter from entering. Since the front side (tool side) of the front housing and the rear side (piston mechanism side) of the bearing sleeve are always exposed to the outside air, they are usually tightly sealed by a labyrinth seal or the like. On the other hand, the rear side of the front housing (rotor side) and the front side of the bearing sleeve (rotor side) are not directly exposed to the outside air in the finished state, but when they are stocked in a semi-assembled state In the case of replacement, since it is exposed to the outside air, foreign matter entry at this time can be prevented.

  6) The spindle device according to the present invention is the spindle device according to any one of 1) to 5), wherein the front housing is fitted to the outer cylinder by an interference fit. It is said.

  In this way, when the subassembly is disassembled or replaced, the shaft centers of the front housing and the outer cylinder are not displaced, and high accuracy can be maintained.

7) The spindle device of the present invention is the spindle device according to 6), wherein the length of the fitting portion between the front housing and the outer cylinder is 1/10 to 1/30 of the diameter of the fitting portion. The perpendicularity of the mating surfaces is 5 μm or less with respect to the axis.

In this case, if the fit between the front housing and the outer cylinder is an interference fit, the fitability is poor if the fit length is long, but the length of the fit portion is 1/10 of the diameter of the fit portion. By shortening to ~ 1/30, it is possible to easily tighten and assemble with built-in bolts. At this time, if the perpendicularity of the mating surface with respect to the shaft center is poor, the length of the fitting portion is short, and the assembly follows the mating surface, so the shaft center of the assembly of the front housing and the outer cylinder is not parallel. However, by setting each squareness to 5 μm or less, the parallelism can be maintained even if the length of the fitting portion is short.

8) The spindle device of the present invention is the spindle device according to any one of 2) to 7), wherein the mounting reference surface of the semi-assembly and the piston pressing surface of the inner diameter part are unclamped. The distance at is uniform regardless of the standard of the tool holder.

In general, there are many tool holder standards, which are selected by a machine tool user, and therefore machine tool manufacturers need to prepare machines having specifications conforming to these many tool holder standards. Since the stroke of the inner diameter part (drawer stroke) necessary for attaching and detaching the tool varies depending on the standard, it is usually necessary to change or adjust the piston mechanism in accordance with the tool holder standard. However, by adopting the configuration of 8), it is only necessary to change the subassembly, and it is not necessary to change or adjust the piston mechanism, and it is possible to reduce the type of inventory other than the subassembly and reduce the inventory cost. .

9) The spindle device of the present invention is the spindle device according to any one of 1) to 8) , wherein a plurality of pairs of O-rings are interposed between the outer diameter of the bearing sleeve and the inner diameter of the sleeve housing. It is characterized by being.

  In this case, lubricant leakage can be prevented by a plurality of pairs of O-rings between the outer diameter of the bearing sleeve and the inner diameter of the sleeve housing, and the vibration of the bearing sleeve can be damped by the damping effect due to the tightening margin of the O-ring. .

10) The spindle device according to the present invention is the spindle device according to any one of 1) to 9) , wherein a plurality of lubricant discharge holes are provided on a circumference of the bearing sleeve, and the outer circumference of the bearing sleeve. A circumferential groove provided on the fitting surface, and a radial lubricant supply path connected in communication with the circumferential groove.

  In this way, the lubricant can be discharged without any problem in any phase of the bearing sleeve. For example, a horizontally mounted spindle requires a discharge hole on the lower side, but discharge can be performed because one of the holes faces the lower side. Furthermore, the lubricant can be supplied at any position of the bearing sleeve. Therefore, it is not necessary to match the phases of the bearing sleeves, and maintenance workability is good.

11) The spindle device according to the present invention is characterized in that the spindle device according to any one of 1) to 10) is grease lubrication.

  In this way, it is easy to handle, and maintenance can be performed at low cost due to relatively inexpensive grease lubrication.

12) The spindle device according to the present invention is characterized in that the spindle device according to any one of 1) to 11) is provided with a grease replenishing device.

  In this way, the grease replenishing device can compensate for the shortage of grease, so that seizure or the like can be avoided.

13) The spindle device according to the present invention is characterized in that in the spindle device described in 12) , a mechanism is provided for discharging excess grease after replenishment of grease.

  In this way, the lubricant that is supplied to the inside of the bearing and is no longer needed is attached to a rotating member such as an outer ring spacer disposed in the vicinity of the bearing, and the lubricant attached to the rotating member is Played outward. Thereby, the lubricant that is no longer needed can be forcibly discharged to the outside of the bearing.

14) The spindle device of the present invention is characterized in that in the spindle device described in any one of 1) to 10) , a minute amount of lubrication of any one of oil air, oil mist, and direct injection lubrication is used. .

  In this way, efficient lubrication can be performed by any minute lubrication of oil-air, oil mist, and direct injection lubrication, so that seizure resistance can be further improved.

  According to the present invention, it is possible to provide a spindle apparatus that can be easily installed and removed during maintenance, can be operated immediately after replacement, and is low in cost.

  Hereinafter, a plurality of preferred embodiments according to the present invention will be described in detail with reference to the drawings. 1 is a longitudinal sectional view of a first embodiment of a spindle device according to the present invention, FIG. 2 is a longitudinal sectional view showing a subassembly in the spindle device shown in FIG. 1, and FIG. 3 is a front view showing a rear cover in FIG. 4 is a longitudinal sectional view of a second embodiment of the spindle device according to the present invention, FIG. 5 is a longitudinal sectional view showing a subassembly of the spindle device shown in FIG. 4, and FIG. 6 is a tool unscrew of the spindle device shown in FIG. FIG. 7 is an assembly view of the spindle device shown in FIG. 4 with the automatic tool changer machine, and FIG. 8 is a longitudinal section showing a semi-assembly of the third embodiment of the spindle device according to the present invention. FIG. 9 is a longitudinal sectional view showing a state in which the subassembly shown in FIG. 8 is inserted into the outer cylinder, and FIG. 10 is a characteristic diagram of bearing dimensions and surface pressure in the spindle device shown in FIG. (A) is a front view of the bearing sleeve in the fourth embodiment of the spindle device according to the present invention, and FIG. 11 (b) is a longitudinal section of (a). , 12 FIG. 11 (a), an essential part longitudinal cross sectional view showing a modified example of (b).

  As shown in FIG. 1, the main shaft device 1 according to the first embodiment of the present invention includes an outer cylinder 3 having a stator 4 and a sleeve housing 5, a rotatable rotating shaft 6 having a rotor 7, and an outer ring having a front housing. And a front-side bearing 12 that is a combined angular ball bearing that is fixed to 8 and has an inner ring fitted on one end of the rotating shaft 6. Further, a bearing sleeve 11 which is disposed on the other end side of the rotating shaft 6 and is fitted to the sleeve housing 5 and is movable in the axial direction of the rotating shaft 6, and an inner ring is fitted on the other end of the rotating shaft 6 and an outer ring Includes a rear side bearing 13 which is a pair of angular ball bearings which are fixed to the bearing sleeve 11 and cooperate with the front side bearing 12 to rotatably support the rotating shaft 6. Reference numeral 14 denotes a piston mechanism for tool change. The sleeve housing 5 and the outer cylinder 3 may be integrated.

  As shown in FIG. 2, the semi-assembly 2 including the front housing 8, the rotating shaft 6, and the bearing sleeve 11 is configured to be able to be extracted from the outer cylinder 3. That is, in the spindle device 1 of the present embodiment, the diameter decreases in the order of the inner peripheral diameter φA of the outer cylinder 3, the outer diameter φB of the rotor 7, and the outer diameter φC of the bearing sleeve 11 (φA> φB> φC). Further, instead of the rotor outer diameter φB, the stator inner diameter φB ′ (see FIG. 1) may be set to φA> φB ′> φC. Further, in the range L behind the bearing sleeve 11, the outer diameter of the subassembly 2 is set smaller than the outer diameter of the bearing sleeve 11. That is, when trying to pull out the main shaft in the direction of the arrow M, the outer diameter of the main shaft rotating body in an arbitrary cross section in the range L is set so that the non-rotating body does not become an obstacle. The outer diameter of the rotating body is defined so as to be smaller than the minimum inner peripheral diameter of the rotating body so that the non-rotating body does not become an obstacle. Therefore, when trying to pull out the subassembly 2 in the M direction in the figure, the piston mechanism 14 that is a non-rotating body that holds / releases the tool W mounted on the left end in the figure does not become an obstacle. .

  The spindle device 1 has a clearance fit in which the outer diameter of the bearing sleeve 11 is 5 to 30 μm with respect to the inner diameter of the sleeve housing 5. Further, the spindle device 1 is an angular ball bearing in which the rear side bearing 13 has a fixed position preload and a rear combination. As a result, the rear side bearing 13 and the bearing sleeve 11 are mainly responsible for supporting the rotating shaft 6, but can absorb axial displacement such as thermal expansion due to heat generated by the rotor with a simple structure.

Further, in the spindle device 1, an inlay portion 15 between the front housing 8 and the inner peripheral surface of the outer cylinder 3 is an interference fit of 0 to 20 μm. Thereby, the axial center of the front housing 8 and the outer cylinder 3 does not shift. Further, the mating surface 16 is finished with high accuracy at a right angle of 2 to 5 μm or less with respect to the axis of the front housing 8 and the outer cylinder 3. Thereby, even if the length LR of the inlay part 15 is short, both axial centers correspond. If the length of the inlay portion 15 is long, the assemblability is poor, but in this embodiment, the inlay length LR (the length of the fitting portion between the front housing 8 and the outer cylinder 3) is set to the inlay diameter φA (the fitting portion). The diameter is reduced to 1/10 to 1/30. Further, since the length LR of the inlay portion 15 is short, it can be assembled by being easily tightened by the built-in bolt 17. This eliminates the need for alignment work.

  Further, the subassembly 2 is formed with labyrinth seals L1 to L4 between outside air. When the spindle is used, foreign substances such as cutting water and chips are prevented from entering by the strong labyrinths L1 and L4. Further, when only the semi-assembly 2 is stocked, foreign substances such as dust are blocked by the labyrinths L1 to L4. The labyrinths L2 and L3 play a role of preventing entry of foreign matter even when the subassembly is replaced by maintenance. During maintenance, the labyrinth L2 and L3 are useful because an environment with little foreign matter such as a clean room cannot be expected. The structures of the labyrinths L3 and L4 can be realized by using the bearing sleeve 11.

  As shown in FIG. 3, the rear cover 9 has seven wiring lines (motor power line 25, motor temperature sensor line 26, rotary encoder line 27, etc.), and 14 pipe positions (bearing lubricating oil pipe 21, cooling oil pipe 22, tool Since the unclamping hydraulic pipe 23, the tool taper air blow pipe 24, and the air seal pipe 28) are connected to the outside, it is unnecessary to handle them at the time of maintenance, so the downtime is very short and the maintenance is good.

  According to the main shaft device 10 described above, the subassembly 2 including the front housing 8, the rotating shaft 6 and the bearing sleeve 11 can be extracted from the outer cylinder 3. As a result, the ease of installation is improved and it can be quickly replaced when damaged. Further, since the bearing sleeve 11 is in a state in which the rear side bearing 13 is assembled, the state of the grease does not change when the subassembly 2 is inserted or removed. Therefore, stocking the semi-assemblies 2 using a different outer cylinder in advance and stocking them makes it possible to replace the sub-assemblies when the rotating shaft breaks down and immediately perform normal operations, resulting in significant downtime. Can be shortened. Further, it is possible to reduce the cost compared to exchanging the entire spindle device 1, and to reduce the inventory cost.

  Next, a second embodiment of the spindle device according to the present invention will be described with reference to FIGS. In addition, in each embodiment following 2nd Embodiment, about the member etc. which have the structure and effect | action similar to the member already demonstrated, the description is simplified by attaching | subjecting the same code | symbol or an equivalent code | symbol in a figure. Omitted.

  As shown in FIG. 4, the spindle device 30 according to the second embodiment of the present invention has two springs 32 in the rotating shaft 6 that rotates together with the rotor 7 by energizing the stator 4 of the outer cylinder 3. An inner diameter part (also referred to as a drawbar) 31 that is compressible and tool-changeable is incorporated, and an inner diameter part side adjustment part 33 is attached to the rear end portion of the inner diameter part 31. A piston pressing surface 34 to the piston mechanism 14 is formed at the end of the inner diameter component side adjustment component 33. A piston-side adjustment component 36 that presses the inner-diameter component-side adjustment component 33 is attached to the end of the piston 35 of the piston mechanism 14.

  In the piston mechanism 14, the piston 35 is moved forward by introducing a pressure medium such as oil, water, air or the like into the forward movement pressure introducing portion 37, and the piston side adjustment component 36 of the piston 35 is changed to the inner diameter component adjustment component. The piston pressing surface 34 of 33 is pressed, the inner diameter part 31 is pressed and moved in the axial direction, the tool W is pushed out, and the tool is unclamped. On the other hand, the pressure of the forward side pressure introducing portion 37 is released and the pressure medium is introduced into the backward side pressure introducing portion 38, whereby the piston 35 is moved backward and the inner diameter part 31 is moved back in the axial direction. Let the tool clamp state.

  As shown in FIG. 5, the inner diameter component side adjustment component 33 has an axial dimension (distance) Z between the mounting reference surface 39 of the semi-assembly 2 and the piston pressing surface 34 of the inner diameter component 31 with respect to the reference dimension. It can be adjusted within 0.1 mm. That is, the subassembly 2 has a dimensional difference due to the stacking of a large number of components within the axial dimension Z from the attachment reference surface 39 to the piston pressing surface 34 of the inner diameter component 31. For this reason, if adjustment is not performed in advance, it is necessary to perform adjustment work of the piston stroke on site during maintenance. For example, if the movement amount (extrusion amount) of the inner diameter part 31 is reduced due to insufficient piston stroke, the tool holder cannot be unclamped. Conversely, if the inner diameter component 31 moves too much, the inner diameter component 31 pushes the tool holder forward further, so the automatic tool changer (ATC) 40 (see FIG. 7) grips the tool holder. Can not do. On the other hand, the inner diameter component side adjustment component 33 has a tool holder pushing amount (amount of the tool holder pushed out from the gripping position by the inner diameter component 31 when the piston 35 is pushed to the foremost end) of 0.4 mm to 0.00 mm. By adjusting the tolerance to within ± 0.1 mm, which is about 0.1 mm to 0.2 mm, it is possible to perform unclamping appropriately, and as a result, when replacing the subassembly Maintenance can be improved by eliminating piston adjustment.

  Here, the adjustment by the inner diameter component side adjustment component 33 is prepared in advance by a method of cutting (turning, grinding) with a margin in advance after dimension measurement, a method of sandwiching shims having different thicknesses in the gap S, and the like. Examples include a method of selecting an adjustment plate having several dimensions, a method of arranging the adjustment plate at a desired position with an adjustment screw, and fixing the plate with an anaerobic adhesive or the like. In order to simplify the adjustment work, a large jig is required to directly measure the axial dimension Z, and a heavy semi-assembly may have to be set on the jig. Some degree of dimensional control may be applied to each part. For example, dimension A, dimension B (both inner ring spacer and outer ring spacer), difference width C and dimension D of the inner and outer rings on the rear side of the front bearing 12 are managed, and the inner diameter component 31 is attached to the rotary shaft 6. The method of measuring and adjusting only the dimension ZZ in the attached state is mentioned. This method can reduce the cost of dimension management because it is not necessary to manage the axial dimension of the inner diameter part of the shaft that is the most difficult to manage (various dimensions of collet part, tool taper in / out, hole depth of inner diameter part 31, etc.) There is little burden of adjustment work. In order to simplify the management of the difference width C, universal combination bearings in which the front and rear difference widths are all individually adjusted may be used in the four rows of the front side bearings 12.

As shown in FIGS. 4 to 6, the tool holder pressing amount (see FIG. 5) E is adjusted using the subassembly 2 in which the axial dimension Z is controlled.
Tool holder push amount E = (piston stroke F) − (space G) − (space H)
Then, each amount on the right side is measured, or actually unclamped and the pushing amount E (the amount by which the tool holder advances) is measured. In this case, the piston side adjustment component 36 is adjusted so that E = 0.5 ± 0.1 mm. This determines the axial position of the clamp / unclamp stroke. As a result, since the positional relationship between the piston 35 and the inner diameter part 31 does not change if the subassemblies 2 adjusted with each other are exchanged thereafter, adjustment of the piston portion can be made unnecessary.

By doing in this way, the subassembly 2 allows the tool holder pushing amount E regardless of the tool holder standard regarding the tolerance of the axial dimension Z from the mounting reference surface 39 to the piston pressing surface 34 of the inner diameter part 31. The tolerance is controlled to a value smaller than 0.1 mm to 0.2 mm. When the piston mechanism 14 for tool change is assembled, the piston stroke F is adjusted in accordance with the managed subassembly 2. As a result, if the units of the semi-assemblies 2 in which the axial dimension Z is managed are replaced during maintenance, the axial phase relationship of the piston pressing surface 34 of the inner diameter part 31 does not change, so that the piston stroke readjustment is unnecessary. Become. Further, since the axial dimension Z is determined by stacking a large number of parts, the axial dimension tolerances of these parts may be set and managed so that the stacked value becomes a desired value or less. However, satisfying the tolerance of 0.1 to 0.2 mm in such a method, specifically, stacking 10 or more dimensional tolerances, increases the cost and increases the defect rate. It often happens. Therefore, the axial dimension Z can be managed at a very low cost by assembling after adjusting the inner diameter part-side adjustment part 33 after the inner diameter part 31 is assembled to the rear part of the inner diameter part 31.

  As shown in FIG. 6, in the piston mechanism 14, the piston 35 is moved forward by introducing a pressure medium into the forward movement pressure introducing portion 37, and the piston side adjustment component 36 is connected to the inner diameter component side adjustment component 33. The piston pressing surface 34 is pressed, the inner diameter component 31 is pressed and moved against the spring 32 in the axial direction, the tool W is pushed out, and the tool is unclamped.

  As shown in FIG. 7, at the time of automatic tool change of the spindle device 30, the operation of the automatic tool changer 40 is very fast for efficiency improvement, and the change time is usually about 0.2 seconds. . Therefore, it is necessary to keep the strength and rigidity of each part high. The automatic tool changer 40 unclamps the tool W of the rotary shaft 6 after the arm 41 grips the rotary shaft 6 and the tool holder 43 of the tool magazine 42, and the arm 41 moves up and down and swivels to perform tool change. To work. When gripping the tool W and unclamping the rotary shaft 6, if the pressing amount of the tool holder 43 is too large, the tool holder 43 has high rigidity and is held by the arm 41 as described above. Burden on the automatic tool changer 40. Therefore, the pressing amount of the tool holder 43 needs to be 0.5 to 0.6 mm or less. In the spindle device 30, even if the maintenance is performed and the subassembly 2 is replaced, the pressing amount of the tool holder 43 does not change, so that adjustment can be performed in a short time without adjustment.

Next, a third embodiment of the spindle device according to the present invention will be described with reference to FIG. In FIG. 8, the upper half in the drawing shows the tool unclamped state, and the lower half in the drawing shows the tool clamped state.
As shown in FIG. 8, the spindle device 50 according to the third embodiment of the present invention uses inner diameter parts 51 having different taper angles in the semi-assembly 2. At this time, the inner diameter part for the BT holder (JIS B6339) and the HSK holder (ISO-12164) vary in the target value Z1 with respect to the axial dimension Z to be managed according to the standard of the tool taper. It has been adjusted to be compatible with that shown in FIG. In other words, the axial dimension Z _UC2 when unclamped is adjusted to be the same as the unclamped state Z _UC1 shown in FIG. Note that the space G in FIG. 4 is set to a value larger than the minimum necessary amount for unclamping the BT holder in order to apply to the inner diameter parts having different axial dimensions Z as described above. Various tool taper standards may be used depending on the application, but as shown in this example, it is possible to change the specifications easily by maintaining compatibility so that unclamping is possible even with different tool standards. This makes it possible to reduce the cost by making inventory management of the inner cartridge easy.

As shown in FIG. 9, in the spindle device 30, the ratio between the outer diameter I of the bearing sleeve 11 and the length J of the fitting portion is J / I≈0.5. In this case, the relationship between the outer diameter I and the length J is J / I = 0.45 to 0.8. When the subassembly 2 is inserted into the outer cylinder 3, first, the bearing sleeve 11 is fitted into the inner diameter of the sleeve housing 5. Since the replacement of the subassembly 2 is normally performed at the work site of the machine tool user, a special jig cannot be used for the replacement work in many cases. In such a case, for example, when the subassembly 2 receives a force in the direction of arrow K such as its own weight, a moment load is applied to the rear bearing 13. At this time, if the length J is small, the span M of the two rows of the rear bearing 13 is shortened, and the contact surface pressure is increased, which may damage the rear bearing 13.

As shown in FIG. 10, in the spindle device 30, the relationship between the above-mentioned J / I and the bearing span and the relationship between the bearing contact surface pressure when the load K is applied were examined. The load K is a load that is generated due to the handling at the time of assembling in the exchange work at the site where the self-weight of the subassembly 2 is used and a jig cannot be used. The rear side bearing 13 is an angular ball bearing having an inner diameter of 55 mm. It is known that indentation occurs when the contact surface pressure of the bearing is 3.5 GPa or more in bearing steel having a hardness of Hv = 700. These show that J / I ≧ 0.45 is necessary. Further, if the span of the rear side bearing 13 is too long, the performance as a machine tool cannot be improved, and problems such as an increase in the moment of inertia of the shaft (increase in acceleration / deceleration time) and a decrease in the resonance point occur. shall be the J / I ≦ 0.8. Furthermore, by setting the J / I relationship as described above, it is possible to provide an O-ring (O-ring) having a vibration damping action described later without causing a sliding failure. Thus, by setting the relationship between the outer diameter I of the bearing sleeve 11 and the length J of the fitting portion and appropriately designing it, the semi-assembly 2 excellent in maintainability and performance as a machine tool. Can be obtained.

Next, with reference to FIGS. 11A and 11B, a fourth embodiment of the spindle device according to the present invention will be described.
As shown in FIGS. 11 (a) and 11 (b), the main shaft device 60 according to the fourth embodiment of the present invention has a lubrication supply and discharge structure arranged on the rear side bearing 13, and the semi-assembly 2 In order to enable easy removal and assembly, the structure does not need to be phased.
Moreover, the bearing sleeve 11 is a clearance fit with respect to the internal diameter of the sleeve housing 5 (refer FIG. 6). As a result, the bearing sleeve 11 easily rotates with respect to the rotating shaft 6 in a state where the inner diameter part 31 is assembled. Therefore, conventionally, when the lubricant is supplied to the rear side bearing 13, protrusions such as nozzles and keys are provided to determine the supply phase and the lubricant discharge hole phase. Therefore, there has been a problem that the assembly and separation of the semi-assembly 2 cannot be performed and the maintenance is difficult unless the phase alignment and the protruding parts are inserted and removed. On the other hand, since the semi-assembly 2 is not provided with a projection such as a lubrication nozzle from the outer peripheral side, the semi-assembly 2 can be removed simply by removing the built-in bolt 17.

  The lubrication supply structure is formed in the radial direction of the sleeve housing 61, and is connected to a lubricant supply inlet (lubricant supply path) 62 communicated with a lubricant supply machine (not shown), and a fitting surface on the outer periphery of the bearing sleeve 63. Through the outer ring of the rear-side bearing 13 through a circumferential groove 64 provided in the outer circumference of the bearing and a radial hole (lubricant supply path) 65 formed in communication with the circumferential groove 64 in the radial direction of the bearing sleeve 63. Lubricant is supplied into the bearing space. The sleeve housing 61 and the bearing sleeve 63 are sealed at the front end portions by front O-rings (O-rings) 66 and 66 and at the rear end portions by rear O-rings 67 and 67. At this time, even if the lubricant supply paths in the radial direction of the sleeve housing 61 and the bearing sleeve 63 are in the same phase, or both of them are rotated in the opposite phase by 180 °, the circumferential groove 64 causes the rear side bearing to The lubricating oil is smoothly supplied to 13. The circumferential groove 64 may be provided on the inner periphery of the sleeve housing 61.

  The discharge structure includes outer ring spacers 68 and 68 disposed between the rear side bearings 13, outer ring retainers 68 </ b> A and a bearing sleeve 63, radial discharge holes 69, 69, 69 formed in the radial direction, An axial discharge hole 70 formed to communicate with the radial discharge holes 69, 69, 69 in the axial direction of the sleeve 63, and a plurality at equal intervals in the circumferential direction of the bearing sleeve 63 communicated with the axial discharge hole 70. The six lubricant discharge holes 71, 71, 71, 71, 71, 71 are provided. Since the six lubricant discharge holes 71 are equally distributed, at least one lubricant discharge hole 71 is secured within ± 15 ° directly under any phase, so that discharge during horizontal mounting is possible. Is possible.

  The lubrication supply and discharge structure has a function of discharging excess grease after replenishing grease. As a result, the lubricant that is supplied to the inside of the bearing and is no longer needed is blown off to the outside of the bearing by the rotational force of the slinger portion 68B of FIG. 12 disposed in the vicinity of the bearing. As a result, lubricant can be discharged without any problems in any phase.For example, a horizontally mounted spindle requires a discharge hole on the lower side, but it can be discharged because one of the holes faces the lower side. it can. Further, since it is grease lubrication, it is easy to handle, and maintenance can be performed at low cost by relatively inexpensive grease lubrication. Further, since the lubricant supply machine (grease replenishing device) is provided, the shortage of grease can be compensated for, so that seizure or the like can be avoided. Further, a minute amount of any of oil-air, oil mist, and direct injection lubrication may be used. Then, efficient lubrication can be performed, so that seizure resistance can be further improved.

  Further, in order to prevent the O-ring from being cut off when the bearing sleeve 63 is inserted and removed between the sleeve housing 61 and the bearing sleeve 63, front-side O-rings 66 and 66 are arranged on the outer periphery on the front side of the bearing sleeve 63. Rear O-rings 67, 67 are arranged on the inner periphery of the rear side. As a result, when the bearing sleeve 63 slides on the inner periphery of the sleeve housing 61 by inserting or removing the subassembly 2, the sliding distance of each of the O-rings 66, 66, 67, 67 is minimized, and the O-ring is not cut. Since each O-ring 66, 66, 67, 67 does not pass through the step or hole that becomes a factor, the reliability of each O-ring 66, 66, 67, 67 can be remarkably improved.

  Each of the O-rings 66, 66, 67, 67 uses two O-rings, two on the front end side and two on the rear end side. This is intended to attenuate the vibration of the bearing sleeve 63 by a damping effect due to the tightening allowance of the O-rings 66, 66, 67, 67. Since the bearing sleeve 63 is a clearance fit with the sleeve housing 61, the bearing sleeve 63 vibrates in the gap without a damping element such as an O-ring. This is because the cutting performance and accuracy are deteriorated, and the inner diameter of the sleeve housing 61 or the outer diameter of the bearing sleeve 63 may be fretting worn. If fretting wear occurs, vibration further increases and slide failure occurs, and the entire spindle device must be replaced for repair. Further, since the restraining force is increased by using a plurality of O-rings, the bearing sleeve 63 does not rotate freely in the rotation direction, so that it is possible to prevent creep and to prevent fitting surface creep wear. Thus, a further effect can be obtained by using a plurality of O-rings.

  As shown in FIG. 12, in the modification of FIGS. 11A and 11B, only the rear side of the bearing sleeve 63 is a single O-ring 72 having a small diameter. By doing in this way, the number of O-rings can be reduced and an O-ring can be arranged compactly. However, FIGS. 11A and 11B are superior in that the bearing sleeve 63 does not receive an axial force due to the pressure of the lubricant.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

1 is a longitudinal sectional view of a first embodiment of a spindle device according to the present invention. It is a longitudinal cross-sectional view which shows the subassembly in the main axis | shaft apparatus shown in FIG. It is a front view which shows the rear cover in FIG. It is a longitudinal cross-sectional view of 2nd Embodiment of the spindle apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the subassembly of the main shaft apparatus shown in FIG. FIG. 5 is a longitudinal sectional view of the spindle device shown in FIG. 4 in a tool unclamped state. It is an assembly drawing with the automatic tool changer machine of the spindle device shown in FIG. It is a longitudinal cross-sectional view which shows the semi-assembly of 3rd Embodiment of the spindle apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the insertion state to the outer cylinder of the subassembly shown in FIG. FIG. 10 is a characteristic diagram of bearing dimensions and surface pressure in the spindle device shown in FIG. 9. (A) is a front view of the bearing sleeve in 4th Embodiment of the main axis | shaft apparatus based on this invention, (b) is a longitudinal cross-sectional view of (a). It is a principal part longitudinal cross-sectional view which shows the modification of Fig.11 (a), (b). It is a longitudinal cross-sectional view which shows the conventional main shaft apparatus.

Explanation of symbols

1, 30, 40, 50, 60 Main shaft device 2 Subassembly 3 Outer cylinder 4 Stator 5, 61 Sleeve housing 6 Rotating shaft 7 Rotor 8 Front housing 9 Rear cover 11, 63 Bearing sleeve 12 Front side bearing 13 Rear side bearing 14 Piston Mechanism 31 Internal part 32 Spring 33 Internal part adjustment part (Adjustment part)
34 Piston 39 Reference mounting surface 62 Lubricant supply inlet (lubricant supply path)
64 Circumferential groove 65 Radial hole (lubricant supply path)
66 Front O-ring (O-ring)
67 Rear O-ring (O-ring)
71 Lubricant discharge hole 72 O-ring

Claims (14)

An outer cylinder having a stator;
A rotatable rotating shaft having a rotor;
A front side bearing in which an outer ring is fixed to the front housing and an inner ring is fitted around one end of the rotating shaft;
A bearing sleeve disposed on the other end of the rotating shaft and fitted in the outer cylinder and movable in the axial direction of the rotating shaft;
A rear-side bearing in which an inner ring is fitted on the other end of the rotating shaft and an outer ring is fixed to the bearing sleeve and cooperates with the front-side bearing to rotatably support the rotating shaft;
A spindle device comprising:
The bearing sleeve is fitted in the sleeve housing, and the outer diameter of the bearing sleeve is fitted with a clearance fit to the inner diameter of the sleeve housing;
The ratio of the fitting length between the bearing sleeve and the sleeve housing and the outer diameter of the bearing sleeve is set within a range of fitting length / outer diameter = 0.45 to 0.8,
The rear side bearing is an angular ball bearing of a fixed position preload and a back surface combination,
The diameter decreases in the order of the inner diameter of the outer cylinder, the inner diameter of the stator, and the outer diameter of the bearing sleeve, and the subassembly including the front housing, the rotating shaft, and the bearing sleeve is extracted from the outer cylinder. A spindle device characterized in that the diameter of the rotating body in any cross section behind the bearing sleeve is smaller than the minimum diameter of the non-rotating body between the cross section from the rear end of the bearing sleeve. An outer cylinder having a stator;
A rotatable rotating shaft having a rotor;
A front side bearing in which an outer ring is fixed to the front housing and an inner ring is fitted around one end of the rotating shaft;
A bearing sleeve disposed on the other end of the rotating shaft and fitted in the outer cylinder and movable in the axial direction of the rotating shaft;
A rear-side bearing in which an inner ring is fitted on the other end of the rotating shaft and an outer ring is fixed to the bearing sleeve and cooperates with the front-side bearing to rotatably support the rotating shaft;
A spindle device comprising:
The bearing sleeve is fitted in the sleeve housing, and the outer diameter of the bearing sleeve is fitted with a clearance fit to the inner diameter of the sleeve housing;
The ratio of the fitting length between the bearing sleeve and the sleeve housing and the outer diameter of the bearing sleeve is set within a range of fitting length / outer diameter = 0.45 to 0.8,
The rear side bearing is an angular ball bearing of a fixed position preload and a back surface combination,
A semi-assembly comprising the front housing, the rotating shaft and the bearing sleeve can be removed from the outer cylinder;
A spindle device characterized in that an inner diameter part capable of tool change is incorporated in the rotating shaft and has a piston mechanism for tool change.   3. The spindle device according to claim 2, wherein a distance between an attachment reference surface of the semi-assembly and a piston pressing surface of the inner diameter part is adjusted within ± 0.1 mm with respect to a reference dimension.   The inner diameter part is incorporated so that a spring can be compressed, an adjustment part is fixed to the rear part of the inner diameter part, and a piston pressing surface to the piston mechanism is formed on the adjustment part. The spindle apparatus according to claim 2, wherein the spindle apparatus is characterized.   The spindle device according to any one of claims 1 to 4, wherein a labyrinth seal is provided on the front and rear of the front housing and on the front and rear of the bearing sleeve.   The spindle device according to any one of claims 1 to 5, wherein the front housing is fitted to the outer cylinder by an interference fit.   The length of the fitting portion between the front housing and the outer cylinder is 1/10 to 1/30 of the diameter of the fitting portion, and the perpendicularity of the mating surface is 5 μm or less with respect to the axis. The main shaft device according to claim 6, wherein the main shaft device is characterized by the following.   The distance in the unclamped state between the attachment reference surface of the semi-assembly and the piston pressing surface of the inner diameter part is unified regardless of the standard of the tool holder. The spindle device described in any one of the above. The spindle device according to any one of claims 1 to 8 , wherein a plurality of pairs of O-rings are interposed between the outer diameter of the bearing sleeve and the inner diameter of the sleeve housing. A plurality of lubricant discharge holes provided on the circumference of the bearing sleeve, a circumferential groove provided on a fitting surface on the outer periphery of the bearing sleeve, and a radial lubricant supply connected in communication with the circumferential groove A spindle device according to any one of claims 1 to 9 , wherein the spindle device has a path. It is grease lubrication, The spindle apparatus as described in any one of Claims 1-10 characterized by the above-mentioned. The spindle device according to any one of claims 1 to 11, further comprising a grease replenishing device. The spindle device according to claim 12 , further comprising a mechanism for discharging excess grease after replenishing with grease. 11. The spindle device according to claim 1, wherein a minute amount of any one of oil air, oil mist, and direct injection lubrication is used.

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