JP3448732B2 - Lead screw cooling system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed screw cooling device used as a table feed mechanism in a machine tool such as a machining center.

[0002]

2. Description of the Related Art In recent years, in a feed mechanism of a machine tool such as a machining center of this type, a feed screw shaft (ball screw shaft) is used as a feed screw shaft (ball screw shaft) due to a higher feed speed, a higher acceleration / deceleration, and an improved machine tool operating rate. In a feed system including a bearing portion that rotatably supports the feed screw shaft and a nut body that is screwed into the feed screw shaft, heat generation due to friction between the feed screw shaft, the bearing portion, and the nut body increases. Is coming. The increase in heat generation of the feeding system raises the temperature of each part of the feeding system, causes thermal deformation of each member of the feeding system, and causes a problem of deterioration of feeding accuracy.

By the way, as a conventional technique for solving this problem, a cooling device for a feed screw shaft described in Japanese Patent Publication No. 4-80265 is known. This conventional feed screw cooling device is provided with a shaft hole in the rotating screw shaft, and a cantilever-fixed hollow tube (pipe) that does not rotate is installed in the shaft hole. The screw shaft is cooled by circulating a cooling liquid in the space between the hollow pipe and the hollow pipe.

Further, in Japanese Patent Publication No. 4-80265, a shaft hole is provided in a rotating screw shaft, and a hollow pipe is fixed in the shaft hole to form a double pipe structure. A plurality of small holes are made in the radial direction in the section, and a pair of seals are slidably provided on the screw shafts on both sides of the small holes, and the cooling liquid is screwed through the small holes liquid-sealed by these seals. There is described a feed screw cooling device which supplies the cooling liquid passing through the inside of the hollow tube from the end of the hollow tube while supplying it to the space between the inner surface of the shaft hole and the hollow tube.

[0005]

However, among the above-described conventional feed screw cooling devices, the former one in which a non-rotating cantilever-fixed hollow tube is mounted in the shaft hole of the rotating screw shaft is used. Causes the following problems. (1) Since the elongated hollow tube that does not rotate together is cantilevered and fixed in the shaft hole of the long rotating screw shaft, the hollow tube moves radially outward at its free end. There is a problem that it easily shakes and easily contacts the inner surface of the shaft hole. (2) The cantilever-fixed hollow tube has a problem that it cannot be applied to a machine having a large feed stroke because vibration is likely to occur due to the natural frequency of the feed system or the hollow tube or the flow of the cooling fluid.

Of the above-mentioned conventional feed screw cooling devices, the latter one having a double pipe structure in which a hollow pipe rotates together with a screw shaft, has a plurality of radial end portions of the screw shaft. Small holes are made, a pair of seals is slidably provided on the screw shafts on both sides of these small holes, and cooling liquid is supplied into the shaft hole of the screw shaft through the small holes liquid-sealed by these seals. Because of this, the following problems occur. (3) Since the seal is directly slidably provided on the screw shaft, the diameter of the seal becomes large. Therefore, when the screw shaft is rotating at a high speed, the peripheral speed of the screw shaft that is in sliding contact with the seal portion increases, the seal easily wears, the life of the seal shortens, and the seal also forms on the outer periphery of the screw shaft. A wear mark appears due to sliding. Further, there is a problem that replacement is not easy when the screw shaft is worn. (4) Since the seal is directly slidably provided on the screw shaft, there is a problem that the diameter of the seal becomes large and the inertia (inertia) becomes large accordingly.

The present invention has been made in view of the above circumstances, and an object of the present invention is to smoothly rotate a screw shaft without hindering the rotation of the feed screw, and further to feed screw. Can be cooled smoothly and reliably, and problems such as wear do not easily occur even after long-term use, and the life can be greatly improved, but even if it wears, parts can be easily replaced. Another object of the present invention is to provide a cooling device for a feed screw which can be applied regardless of the length of the screw shaft.

[0008]

According to a first aspect of the present invention, at least one end of a screw shaft is rotatably supported, a nut body screwed into the screw shaft, and one end of the screw shaft. And a shaft hole formed along the axis of the screw shaft, the cooling device for the feed screw comprising:
The shaft hole of the screw shaft is partitioned into a fluid outward path and a fluid return path of the cooling fluid by a partition member mounted in the shaft hole, and the fluid outward path and the fluid of the cooling fluid are provided at the open end of the shaft hole of the screw shaft. An adapter having a communication passage communicating with the return passage is mounted, and a sealing means having a flow passage communicating with each communication passage of the adapter is slidably provided on the adapter. According to the first aspect of the present invention, when the screw shaft is rotating together with the adapter mounted at the open end of the shaft hole of the screw shaft, the screw means is slidably provided in the adapter through the flow passage of the sealing means. The cooling fluid supplied by the screw shaft is sent into the shaft hole through the communication passage of the adapter, and passes through the fluid outward path and the fluid return path partitioned by the partition member mounted in the shaft hole, and then the screw shaft. After cooling the (nut body, bearing portion), it returns to the communication passage of the adapter and is discharged to the fixed side via the flow passage of the sealing means.

According to a second aspect of the present invention, the partition member is composed of a pipe mounted in the shaft hole of the screw shaft, and a steady rest member is provided between the pipe and the screw shaft. According to the present invention, the pipe mounted inside the shaft hole of the screw shaft has a double shaft structure for the screw shaft, and a space between the inner wall surface of the shaft hole of the screw shaft and the outer peripheral surface of the pipe. And the space inside the pipe as cooling fluid passages for cooling the screw shaft, and supporting the pipe in the screw shaft by the steady rest member provided between the pipe and the screw shaft. , To prevent vibration during rotation of this pipe.
In this case, the space between the inner wall surface of the shaft hole of the screw shaft and the outer peripheral surface of the pipe is limited to either the fluid outward path or the fluid return path, and the cooling fluid flowing in this space is limited to one direction. The screw shaft can be cooled under the same conditions in the plane orthogonal to the axis of the shaft. Therefore, cooling unevenness does not occur around the axis of the screw shaft.

According to a third aspect of the present invention, the partition member is formed of a shape member which is in contact with the inner wall surface of the shaft hole of the screw shaft and has a plurality of spline grooves along the axis of the screw shaft. . According to the third aspect of the present invention, the shape member having a plurality of spline grooves is brought into contact with the inner wall surface of the shaft hole of the screw shaft to prevent rattling of the shape member, and to securely secure the shape member of the screw shaft. The screw shaft is cooled by mounting and fixing it in the shaft hole and circulating a cooling fluid through the plurality of spline grooves. In this case, in addition to directly cooling the inner wall surface of the shaft hole of the screw shaft that is in contact with the cooling fluid, the shape member is in contact with the inner wall surface. The more the above is used, the more the spline groove surface of the profile is cooled by the cooling fluid, so that the screw shaft is indirectly cooled through the profile. Therefore, the cooling area can be increased, which enables more efficient cooling.

According to a fourth aspect of the present invention, the partition member is formed of a shape member which is in contact with the inner wall surface of the shaft hole of the screw shaft and has a plurality of spiral grooves. According to the fourth aspect, the plurality of spiral grooves are used as the fluid passages (fluid forward path, fluid return path) of the cooling fluid, so that a longer flow path length can be obtained as compared with the case of the spline groove of the third aspect. Because it is secured
As a result, the cooling fluid and the screw shaft have been in contact with each other for a longer period of time, which allows better transfer of heat from the screw shaft to the cooling fluid, improves heat exchange efficiency, and effectively cools the screw shaft. To be done.

According to a fifth aspect of the present invention, the partition member is constituted by a shape member which is in contact with an inner wall surface of the shaft hole of the screw shaft and has a fluid passage between the inner wall surface and the inner wall surface. Hollow holes are formed. According to the present invention, the profile is brought into contact with the inner wall surface of the axial hole of the screw shaft to fix the profile within the screw shaft, and between the profile and the inner wall surface of the axial hole of the screw shaft. The cooling fluid is circulated using the space and the hollow hole of the profile to cool the screw shaft. In this case, the flow of the cooling fluid in the space between the screw shaft and the inner wall surface of the axial hole of the screw shaft can be limited to either the going or returning direction, like the pipe of the above-mentioned claim 2. It is cooled evenly around.

Further, if the profiled material according to claims 3 to 5 is made of aluminum or the like, the cooling efficiency is enhanced due to its high thermal conductivity, and the axial profile of the screw shaft is due to the softness. It is easy to apply the profile to the, and it is easy to firmly contact the inner wall surface of the shaft hole with the profile.

According to a sixth aspect of the present invention, the partition member is divided into a plurality of pieces along the length direction thereof, and these divided bodies are engaged with each other. According to the sixth aspect of the present invention, by configuring the partition member by a plurality of divided bodies that are engaged with each other, it is possible to add short parts (divided bodies) and insert and fix them in the shaft hole of the screw shaft. become.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 to 5 show a first embodiment of the present invention. In these figures, reference numeral 10 is a screw shaft of a ball screw. This screw shaft 10
It is rotatably supported by bearings 12 and 14 provided at both ends thereof. Then, the screw shaft 10
The output shaft 160 of the drive motor 16 is abutted to the base end of and is connected by a coupling 18. Further, the nut body 20 is screwed into the threaded portion formed in the intermediate portion of the screw shaft 10. By rotating the output shaft 160 of the drive motor 16, the nut body is rotated in accordance with the rotation of the screw shaft 10. 20 is configured to reciprocate along the axis of the screw shaft 10.

As shown in FIG. 1, the bearing portion 12 rotatably supporting the base end portion of the screw shaft 10 has a hollow support member 1 at a small diameter portion formed at the base end portion of the screw shaft 10.
4 bearings 121 mounted between the shaft 20 and the screw shaft 10
And pressing members 122 and 123 mounted on both sides of each bearing 121 of the screw shaft 10 and sandwiching inner ring members of these bearings 121, and mounted inside the supporting member 120 and each bearing 121. The fixing member 124 sandwiches the outer ring member with the support member 120.

The bearing portion 14 for rotatably supporting the tip end portion of the screw shaft 10 has a structure substantially similar to that of the bearing portion 12, and as shown in FIGS. In the small-diameter portion formed at the tip portion of 10, the two bearings 141 mounted between the hollow support member 140 and the screw shaft 10 and the bearings 141 of the screw shaft 10 mounted on both sides of the bearing 141, respectively. And the pressing members 143, 1 that hold the inner ring members of the bearings 141 therebetween.
44, a fixing member 145 that is mounted inside the support member 140 and a cover member 146 that covers the opening of the support member 140, and that holds the outer ring member of each bearing 141 together with the support member 140. ing.

A shaft hole 100 is formed along the axis of the screw shaft 10 at the center thereof, and a pipe 22 is mounted inside the shaft hole 100. Then, as shown in FIG. 5, the base end portion of the pipe 22 is fixed in the shaft hole 100 of the screw shaft 10 by a pipe retainer 24 inserted between the shaft hole 100 of the screw shaft 10 and the pipe 22. In addition, at the base end of the shaft hole 100 of the screw shaft 10,
A plug 26 that closes the base end is screwed. A plurality of small holes 220 are formed at the base end of the pipe 22.

Further, as shown in FIG. 4, three cylindrical steady rests 28 are fixed to the outer periphery of the central portion of the pipe 22 in the axial direction at equal intervals around the periphery of the pipe 22. The steady rests 28 come into contact with the inner wall surface of the shaft hole 100 of the screw shaft 10 to support the pipe 22.

At the tip of the shaft hole 100 of the screw shaft 10,
As shown in FIGS. 1 to 3, a base end portion of a hollow adapter 30 is inserted, and a flange portion 300 formed at an intermediate portion of the adapter 30 is in a liquid-tight state via an O-ring 305. While being held, it is attached to the tip end surface of the screw shaft 100 by a bolt 301. The center hole (communication passage) 302 formed in the adapter 30 is provided with a pair of groove portions (communication passage) 303 having a semicircular cross section, and is connected to these groove portions 303 and is open to the outside of the adapter 30. Small holes (communication passages) 304 are formed respectively. Further, the tip portion of the pipe 22 is inserted and fixed in the center hole 302 of the adapter 30.

Further, the cover member 1 of the bearing portion 140.
A pair of annular seal members 32 that seals both sides of the small hole 304 of the adapter 30 are mounted on 46, and the flow passage 34 that communicates with the space between these seal members 32.
And the flow passage 3 communicating with the space between the seal member 32 located on the tip side of the adapter 30 and the cover member 146.
6 and 6 are formed inside the cover member 146, respectively. The flow passages 34, 36 formed in the cover member 146 are respectively provided with the cooling fluid discharge pipe 38.
And the supply pipe 40.

Next, the case where the ball screw is cooled by using the cooling device configured as described above will be described.
First, when the drive motor 16 is driven to rotate the screw shaft 10 via the output shaft 160 thereof and the nut body 20 is moved along the axis of the screw shaft 10, the cooling fluid sent from the cooler ( (Cooling liquid) is supplied into the flow passage 36 in the cover member 146 via the supply pipe 40, the cooling fluid supplied to the flow passage 36 flows in the pipe 22 attached to the central hole 302 of the adapter 30. Passes through and reaches the base end of the pipe 22.

The cooling fluid is then passed through the pipe 22.
Through the small hole 220 formed at the base end of the pipe 22
Enters the space between the outer peripheral surface of the screw shaft 10 and the inner wall surface of the shaft hole 100 of the screw shaft 10, and returns to the tip of the screw shaft 10 through this space. Then, the cooling fluid that has returned to the tip of the screw shaft 10 passes through a pair of seals via the groove portion 303 of the adapter 30 mounted between the screw shaft 10 and the pipe 22 and the small hole 304 continuous to the groove portion 303. It enters the flow passage 34 of the cover member 146 through the space between the members 32, and is further returned to the cooler via the discharge pipe 38 connected to the flow passage 34.

As described above, in the cooling device of this embodiment, when the ball screw is operated, the cooling fluid is supplied to the inside of the pipe 22 and the pipe 22 and the screw shaft 10.
Since the space between the shaft hole 100 and the inner wall surface of the shaft hole 100 is circulated, the screw shaft 10, both bearing portions 12, 14 and the nut body 20 are smoothly and surely cooled, and the coupling 18 is used. Thus, the output shaft 160 of the drive motor 16 is cooled, and the cooling efficiency of the output shaft 160 is improved.

In this case, the pipe 22 comes into contact with the inner wall surface of the shaft hole 100 of the screw shaft 10 through the steadying member 28 at its central portion, and is reliably supported by this inner wall surface. When the shaft 10 is rotating, the internal pipe 22 does not swing, and problems such as contact with the inner wall surface of the shaft hole 100 do not occur. Therefore, even if the screw shaft 10 is long, the pipe 22 can be easily mounted inside.

Since the adapter 30 is detachably attached to the tip of the screw shaft 10 and the pair of seal members 32 is slidably provided on the adapter 30, the seal member 3 is provided.
Since the outer diameter of the adapter 30 which slides on the screw shaft 2 can be made smaller than the outer diameter of the screw shaft 10, the seal member 32 can be slid on the outer peripheral surface of the conventional screw shaft as compared with the structure in which the seal member is slidably provided. The diameter of can be reduced.

Therefore, since the peripheral speed of the adapter 30 sliding on the seal member 32 can be reduced when the screw shaft 10 rotates at a high speed, the adapter 3 of the seal member 32 can be reduced.
It is possible to reduce wear due to contact with zero and to significantly improve the life of the seal member 32.

The seal member 3 is used for a long period of time.
2 is worn, the cover member 146 of the bearing portion 14
To remove the new seal member 3 from the support member 140.
Replace with 2. In this case, the bearing portion 1 on the drive motor 16 side
Compared with No. 2, since there is no obstacle in the replacement work in the bearing portion 14, the replacement work of the seal member 32 can be carried out smoothly.

If the seal member 32 causes wear marks on the adapter 30, the cover member 146 will be used.
Since the seal member 32 is removed, the adapter 30 is removed from the screw shaft 10 and replaced with a new adapter 30, the replacement work can be performed very easily. Further, unlike the conventional configuration in which the seal member is slidably provided on the outer peripheral surface of the screw shaft, it is not necessary to perform difficult processing such as making a hole in the screw shaft 10 in the radial direction.

In the above embodiment, the pipe 2
2 has been described as a fluid outward path for the cooling fluid, and a space defined by the pipe 22 and the inner wall surface of the shaft hole 100 as a fluid return path has been described.
It goes without saying that the space formed by the inner wall surface of 0 may be used as the fluid outward path and the interior of the pipe 22 may be used as the fluid return path.

In this case, the space between the inner wall surface of the shaft hole 100 of the screw shaft 10 and the outer peripheral surface of the pipe 22 can be limited as a fluid return path (or fluid outward path), and the cooling fluid flowing in this space can be unidirectional. Therefore, cooling can be performed under the same condition over the entire circumference of the inner wall surface of the shaft hole 100 in the plane orthogonal to the axis of the screw shaft 10. Therefore, cooling unevenness does not occur around the axis of the screw shaft 10, and uniform cooling can be performed.

Further, in the present embodiment, the adapter 3
As shown in FIG. 3, the pair of groove portions 303 formed in the center hole 302 of the adapter 30 and the small holes 304 that are continuous with the groove portions 303 have been described as the communication passages of 0, but the shape, the number, etc. are not limited to this. In short, it suffices if a communication passage extending from the end surface of the adapter 30 to the outer peripheral surface can be secured. Further, in the present embodiment, as the steady rest member 28, three cylindrical members have been described as shown in FIG. 4, but the shape, the number, etc. are not limited to this, and the essential point is. , Pipe 22 and shaft hole 100 of screw shaft 10
It suffices that the structure is such that the pipe 22 can be smoothly supported by being interposed between and.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, instead of the pipe 22 and the adapter 30 of the first embodiment shown in FIGS. 1 to 5, a plurality (four in the drawing) are used.
Profile member 50 having spline groove 500 and adapter 52
Is provided on the screw shaft 10. Since the other configurations of the second embodiment are the same as those of the first embodiment, the same components are designated by the same reference numerals to simplify the description.

The shape member 50 has a plurality of spline grooves 500 at equal intervals on the outer peripheral surface of a cylindrical member formed of a soft metal having a high thermal conductivity such as aluminum, and the axis line of the cylindrical member. It is processed along the direction. And
Inside the shaft hole 100 of the screw shaft 10, a plurality of shape members 50
However, the end portions thereof are mounted in abutment with each other, and the outer peripheral surface of each shape member 50 is configured to abut the inner wall surface of the shaft hole 100, as shown in FIG.

The drive motor 1 among the above-mentioned shape members 50
As shown in FIG. 10, a protrusion 501 is formed at the base end of the profile member 50 on the 6 side, and the profile member 50 and the shaft hole 100 of the screw shaft 10 are provided outside the protrusion 501. A spring 54 that urges each shape member 50 toward the tip side (downward in FIG. 10) is mounted between the plug 26 and the plug 26.

Further, step portions 502 that engage with each other are formed at the end portions of the shape members 50 that are abutted against each other, and by engaging these step portions 502 with each other, the shape members 50 described above are formed. The spline grooves 500 are aligned with each other so that each of the shape members 50 does not rotate alone around its axis.

At the base end portion of the adapter 52 mounted at the tip end portion of the shaft hole 100 of the screw shaft 10, the shape member 50 is provided.
A step portion 520 that engages with the step portion 502 is formed. A flange portion 521 formed in the intermediate portion of the adapter 52 is attached to the tip end surface of the screw shaft 100 with a bolt 523 while maintaining a liquid-tight state via an O-ring 522.

Further, the adapter 52 has the profile 5
Straight and substantially L-shaped communication holes (communication passages) 524, 525 that communicate with the respective 0 spline grooves 500 are formed alternately around the axis of the adapter 52. Then, in the opening formed in the outer peripheral surface of the adapter 52 of the substantially L-shaped communication hole 525, the flow passage 3 of the cover member 146 is provided via the space between the seal members 32.
4 are communicated with each other, and the linear communication hole 524 has
A flow passage 36 is communicated with a space between the seal member 32 located on the tip end side of the adapter 52 and the cover member 146.

In the cooling device for a feed screw constructed as described above, when the ball screw is operated, the cooling fluid (cooling liquid) sent from the cooler is supplied to the supply pipe 40.
When the cooling fluid is supplied to the flow passage 36 in the cover member 146 via the communication passage 36, the cooling fluid supplied to the flow passage 36 is communicated with the communication hole 524 of the adapter 52 and the communication hole 524, and serves as a fluid outward path. It passes through the spline groove 500 of the shape member 50 to reach the base end portion of the shaft hole 100 of the screw shaft 10, and then passes through the space between the base end surface of the shape member 50 and the plug 26 to form a fluid return path. The flow path 34 of the cover member 146 is returned through the spline groove 500 of the shape member 50 and the space between the communication hole 525 of the adapter 52 and the pair of seal members 32.
And then returned to the cooler via a discharge pipe 38 connected to this flow passage 34.

In this case, in the second embodiment, similarly to the first embodiment, the driving is performed via the screw shaft 10, both bearing portions 12 and 14, the nut body 20, and the coupling 18. Since the output shaft 160 of the motor 16 is effectively cooled and the diameter of the seal member 32 can be reduced, the life of the seal member 32 can be improved, and wear marks on the screw shaft 10 can occur. There is no such a case, and there is an excellent effect that replacement work is easy when the seal member 32 or the adapter 52 is worn.

Further, in this embodiment, since the outer peripheral surface of the shape member 50 is in contact with the inner wall surface of the shaft hole 100 of the screw shaft 10, even if the screw shaft 10 rotates at a high speed, it is mounted inside. The shaped member 50 does not rattle, does not hinder the high speed rotation of the screw shaft 10 and the flow of the cooling fluid supplied into the screw shaft 10, and the shaped member 50 is not blocked in the shaft hole 100. Since it is supported and guided by the wall surface, by forming a rotation stop (step portion 502) on the shape members 50, a plurality of short shape members 50 are sequentially inserted into the shaft hole 100 to easily connect the shape members 50 to each other. It can be fixed in the closed state.

Moreover, since the profile 50 has a high thermal conductivity such as aluminum and is made of a soft metal, the cooling efficiency is improved and the profile of the shaft hole 100 of the screw shaft 10 is increased. It is easy to align 50, and the inner wall surface of the shaft hole 100 and the shape member 50 can be brought into close contact with each other. Therefore, in addition to directly cooling the inner wall surface of the shaft hole 100 of the screw shaft 10 that is in contact with the cooling fluid, the shape member 50 is in contact with the inner wall surface, so that the spline groove 500 of the shape member 50 is in contact. By cooling the surface with the cooling fluid, the screw shaft 10 is indirectly cooled via the profile 50. As a result, the cooling area can be increased, and more efficient cooling can be performed.

Regarding the structure of the second embodiment, in which a plurality of profile members 50 each having a detent (stepped portion 502) are sequentially inserted into the shaft hole 100 to connect the profile members 50, In the pipe 22 of the first embodiment, each pipe 22 is provided with a steadying member 28, and a plurality of pipes 22 are made to collide with each other, and the pipes 22 are engaged with each other by a whirl-stop provided at this colliding portion. You may. Accordingly, also in the pipe 22, it is possible to achieve the same operational effect as the profile 50 having the spline groove 500.

Furthermore, since the above-mentioned profile 50 need only be formed with the spline groove 500 on the outer peripheral surface thereof, it is easy to manufacture, and even a long profile can be processed accurately. Therefore, the gap between the outer peripheral surface of the profile 50 and the inner wall surface of the shaft hole 100 of the screw shaft 10 can be suppressed,
It is possible to cut off between the fluid outward path and the fluid return path, and use one continuous long shape member 50 without intentionally partitioning the shaft hole 100 with a structure in which a plurality of divided shape members 50 are connected to each other. May be.

Instead of the profile 50 having the spline groove 500 of the second embodiment, a profile 60 having two or more spiral grooves 600 may be used as shown in FIG. In this case, in addition to the same effect as the second embodiment, the plurality of spiral grooves 600 are used as the fluid passages of the cooling fluid (fluid outward passage, fluid return passage), so that the spline grooves 500 are formed into the fluid passages. Since a longer flow path length is ensured as compared with the case of, the cooling fluid and the screw shaft 10 are in contact with each other for a longer period of time, and the heat transfer from the screw shaft 10 to the cooling fluid is further increased. Good results and effective cooling of the screw shaft 10.

Instead of the profile members 50 and 60 having the spline groove 500 or the spiral groove 600, a square pipe 70 is attached to the shaft hole 100 of the screw shaft 10 as shown in FIG. The outer corner portion of 70 may be in contact with the inner wall surface of the shaft hole 100. Also, 1 on the outer circumference
It goes without saying that a configuration may be adopted in which a through hole is provided in the center of the shape members 60, 50 having the spiral groove 600 or the spline groove 500 having a number of lines or more.

These square pipes 70, or in the shape members 50 and 60 having a through hole in the central portion, the square pipes 7
0, the space between each of the shape members 50 and 60 and the inner wall surface of the shaft hole 100 is defined as the fluid return path (or the fluid return path), and the internal through hole is defined as the fluid return path (or the fluid return path). Similar to the embodiment, the screw shaft 10 can be cooled. In this case, as in the case of the pipe 22, the flow of the cooling fluid in the space between the screw shaft 10 and the inner wall surface of the shaft hole 100 can be limited to either going or returning. It can be cooled evenly around.

[0048]

According to the first aspect of the present invention, when the screw shaft rotates together with the adapter attached to the open end of the shaft hole of the screw shaft, the seal slidably provided on the adapter. Cooling fluid supplied through the flow passage of the means is fed into the shaft hole through the communication passage of the adapter, and the fluid forward path and the fluid return path are separated by the partition member mounted in the shaft hole. After cooling the screw shaft (nut body, bearing part) via the via, it returns to the communication passage of the adapter and is discharged to the fixed side via the flow passage of the sealing means, which hinders the rotation of the feed screw. It is possible to smoothly rotate the screw shaft, and to smoothly and surely cool the feed screw.

An adapter is provided at the open end of the screw shaft,
Since the sealing means is slidably provided on this adapter, the outer diameter of the adapter sliding on the sealing means can be made smaller than the outer diameter of the screw shaft, so that the outer peripheral surface of the conventional screw shaft is sealed. The diameter of the sealing means can be reduced as compared with the configuration in which the member is provided slidably.

Therefore, when the screw shaft is rotating at a high speed, the peripheral speed of the adapter sliding on the sealing means can be reduced, so that the wear of the sealing means due to the contact with the adapter can be reduced, and the seal can be reduced. The life of the means can be significantly improved, and problems such as wear do not easily occur even if it is used for a long time, and even if it is worn, parts can be easily replaced, and the length of the screw shaft is long. It can be applied regardless of.

According to the second aspect of the present invention, the pipe mounted in the shaft hole of the screw shaft forms the screw shaft in a double pipe structure, and the inner wall surface of the shaft hole of the screw shaft and the outer peripheral surface of the pipe. By using the space between the pipe and the space inside the pipe as the passages for the cooling fluid, respectively, the screw shaft can be efficiently cooled, and the runout provided between the pipe and the screw shaft can be achieved. By supporting the pipe in the screw shaft with the stop member, vibration during rotation of the pipe can be reliably prevented. In this case, the space between the inner wall surface of the shaft hole of the screw shaft and the outer peripheral surface of the pipe is limited to either the fluid outward path or the fluid return path, and the cooling fluid flowing in this space is limited to one direction. The screw shaft can be cooled under the same conditions in a plane orthogonal to the axis of the shaft. Therefore, cooling unevenness does not occur around the axis of the screw shaft, and uniform cooling can be achieved. .

According to the third aspect of the present invention, the shape member having a plurality of spline grooves is brought into contact with the inner wall surface of the shaft hole of the screw shaft, whereby the rattling of the shape member can be easily prevented. The shape member can be securely mounted and fixed in the shaft hole of the screw shaft, and the screw shaft can be effectively cooled by circulating the cooling fluid in the plurality of spline grooves. In this case, in addition to directly cooling the inner wall surface of the shaft hole of the screw shaft that is in contact with the cooling fluid, the shape member is in contact with the inner wall surface. The more the above is used, the more the spline groove surface of the profile is cooled by the cooling fluid, so that the screw shaft can be indirectly cooled through the profile. Therefore, since the cooling area can be increased, more efficient cooling can be performed.

According to the fourth aspect of the present invention, the plurality of spiral grooves are fluid passages (fluid forward path, fluid return path) for the cooling fluid, so that they are longer than the spline groove of the third aspect. Since the flow path length is secured, the cooling fluid and the screw shaft can be in contact with each other for a longer period of time, and the heat transfer from the screw shaft to the cooling fluid can be performed better, resulting in heat exchange. The efficiency can be improved and the screw shaft can be cooled smoothly.

According to claim 5 of the present invention, by abutting the profile on the inner wall surface of the shaft hole of the screw shaft, the profile can be firmly fixed in the screw shaft, and the profile and the screw By circulating the cooling fluid by utilizing the space between the shaft hole and the inner wall surface of the shaft hole and the hollow hole of the shape member, the screw shaft can be reliably cooled. In this case, the flow of the cooling fluid in the space between the screw shaft and the inner wall surface of the axial hole of the screw shaft can be limited to either going or returning, as in the case of the pipe according to the second aspect. Can be cooled evenly around.

According to the sixth aspect of the invention, the partition member is constituted by a plurality of divided bodies which are engaged with each other, so that a short component (divided body) is added to the partition member so that it is inserted into the axial hole of the screw shaft. Can be fixed. Therefore,
It can be applied smoothly even on long screw shafts,
Can be cooled effectively.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a bearing portion on the tip side of the screw shaft.

3 is a cross-sectional view taken along the line III-III of FIG.

4 is a cross-sectional view taken along line IV-IV of FIG.

FIG. 5 is a cross-sectional view showing a base end portion of a screw shaft.

FIG. 6 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a bearing portion on the tip side of the screw shaft.

8 is a cross-sectional view taken along the line VIII-VIII of FIG.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a cross-sectional view showing a base end portion of a screw shaft.

FIG. 11 is a perspective view showing an example of a shape member.

FIG. 12 is a perspective view showing another example of the shape member.

FIG. 13 is a cross-sectional view showing another example of the shape member.

[Explanation of symbols]

10 screw shaft 20 nut body 22 pipe 28 steady rest member 30, 52 adapter 32 seal member (sealing means) 34, 36 flow passage 50, 60 shape member 70 square pipe (shape member) 100 shaft hole 146 cover member (sealing means) 302 central hole (communication passage) 303 groove (communication passage) 304 small hole (communication passage) 500 spline groove 524, 525
Communication hole (communication passage) 600 spiral groove

Claims (6)

(57) [Claims] 1. A screw shaft having at least one end rotatably supported, a nut body screwed into the screw shaft, and an opening end provided at one end of the screw shaft to form an axis line of the screw shaft. In a cooling device for a feed screw having a shaft hole bored along the shaft hole, the shaft hole of the screw shaft is partitioned into a fluid forward path and a fluid return path for cooling fluid by a partition member mounted in the shaft hole. An adapter having communication passages that communicate with the fluid outward passage and the fluid return passage of the cooling fluid is attached to the opening end of the shaft hole of the screw shaft, and the adapter communicates with the communication passages of the adapter. A feed screw cooling device, characterized in that a sealing means having a passage is slidably provided. 2. The hole according to claim 1, wherein the partition member is composed of a pipe mounted in the shaft hole of the screw shaft, and a steady rest member is provided between the pipe and the screw shaft. Cooling device for feed screw shaft. 3. The partition member is constituted by a shape member which is in contact with the inner wall surface of the shaft hole of the screw shaft and has a plurality of spline grooves along the axis line of the screw shaft. Feed screw cooling system. 4. The cooling device for a feed screw according to claim 1, wherein the partition member is constituted by a shape member that is in contact with the inner wall surface of the shaft hole of the screw shaft and has a plurality of spiral grooves. 5. The partition member is made up of a shape member that abuts an inner wall surface of a shaft hole of a screw shaft and has a fluid passage between the inner wall surface and the inner wall surface, and a hollow hole is formed inside the shape member. The cooling device for a feed screw according to claim 1, characterized in that. 6. The partition member is divided into a plurality of pieces along the length direction thereof, and these divided bodies are configured to be engaged with each other. Alternatively, the cooling device for the feed screw according to item 5.