JPH1061668A - Main spindle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain thermal expansion and deformation by heating of a tool to the possible minimum level by improving rigidity of a main spindle while securing sealing performance, and practically eliminating positional dislocation of the tool installed on the main spindle even if the main spindle is rotated at high speed. SOLUTION: In a main spindle device having a main spindle 2 and a housing 10 to rotatably house the main spindle 2, a large diameter part 2A opposed to a grinding wheel T is arranged in the vicinity of an end part 2B on which the grinding wheel T of the main spindle 2 is installed, and a tool side injection port 12A and a large diameter part side injection port 12B to blow gas supplied from a gas supply source P in the shaft direction against the grinding wheel T and the large diameter part 2A by communicating with the gas supply source P and an exhaust passage 14A to communicate a clearance between the housing 10 and the large diameter part 2 with an external part, are arranged in the housing 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device in which a spindle is radially supported by bearings, for example, a spindle device used for a machine tool.

[0002]

Conventionally, for example, in a spindle device used for a machine tool, a journal bearing and a labyrinth seal are provided between a thrust bearing for axially supporting the spindle and an end of the spindle for mounting a tool. Since the shaft length must be ensured for arranging the spindle, the rigidity of the spindle is inevitably reduced.In addition, when the spindle is rotated at high speed, the thermal expansion of the spindle caused by the heat generated by the journal bearings causes There is a problem that the position may be greatly shifted.

Further, in the conventional spindle device, when the spindle is rotated at a high speed, there is also a problem that the tool may generate heat due to air friction and may be thermally expanded or deformed. It has been a conventional problem to solve these problems.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and achieves improved rigidity of a main shaft while ensuring sealing performance, and even when the main shaft is rotated at a high speed, the main shaft is rotated. It is an object of the present invention to provide a spindle device capable of almost eliminating the displacement of a tool mounted on a tool, and further suppressing thermal expansion and deformation due to heat generation of the tool as much as possible.

[0005]

According to a first aspect of the present invention, there is provided a spindle device including a spindle and a housing for rotatably housing the spindle, in the vicinity of an end of the spindle where a tool is mounted. Provided with a pressure receiving portion facing the tool,
A tool-side injection port and a pressure-receiving-portion-side injection port that communicates with the gas supply source and is supplied from the gas supply source to the housing to blow the gas axially to the tool and the pressure-receiving section; and the housing and the pressure-receiving section. An exhaust path for communicating the gap between the outside with the outside is provided. The structure of the spindle device is used as a means for solving the conventional problems, and the invention according to claim 2 of the present invention comprises a tool and a pressure receiving portion. And an exhaust path for communicating a gap between the housing and the end of the main shaft to the outside is provided in a main shaft end supporting portion of the housing located between the housing and the main shaft.

The spindle device according to claim 3 of the present invention has a structure in which gas cooling means is provided between a tool side injection port and a pressure receiving section side injection port and a gas supply source. The spindle device according to 4 has a configuration in which a liquid injection port that sprays a liquid supplied from a liquid supply source to a tool is provided at a position farther from the main shaft than the tool-side injection port and the pressure-receiving unit-side injection port of the housing, In the spindle device according to claim 5 of the present invention, an annular groove through which gas ejected from the tool-side injection port and the pressure-receiving section-side injection port flows in the circumferential direction of the main spindle is provided on a surface of the housing facing the tool and the pressure receiving portion. Each is provided with a configuration.

Further, according to a sixth aspect of the present invention, there is provided a spindle device in which a gas supplied from a gas supply source is supplied to a tool and a pressure receiving portion at a position farther from the main shaft than the tool side injection port and the pressure receiving portion side injection port of the housing. A tool-side auxiliary injection port and a pressure-receiving-portion-side auxiliary injection port that spray in the axial direction with respect to The pressure is lower than the pressure of the gas ejected from the side injection port.

[0008]

In the spindle device according to the first and second aspects of the present invention, the gas supplied from the gas supply source is supplied to the tool and the pressure receiving portion via the tool side injection port and the pressure receiving section side injection port. Respectively, and exhausted to the outside of the apparatus through a gap between the tool and the housing and an exhaust passage while supporting the main shaft in the axial direction. At this time, the gas blown to the tool is discharged between the end of the main shaft and the housing. The gas blown to the pressure receiving portion prevents the foreign matter from intruding from between, while the gas that is blown to the pressure receiving portion is located on the opposite side of the tool from the pressure receiving portion and supports the main shaft in the radial direction, for example, lubricating oil from the journal bearing Is prevented from leaking, so that the sealing property is ensured.

In other words, the cost can be reduced by not requiring the thrust bearing, and the sealing portion is formed between the tool having a short distance and the pressure receiving portion. The part is shortened, and therefore the rigidity of the spindle is improved, and the spindle is supported in the axial direction at a position close to the tool, so even if the spindle is rotated at high speed, the spindle caused by the heat generated by the journal bearings The displacement of the tool due to the thermal expansion of the tool can be extremely reduced.

[0010] Further, the gas blown from the tool-side injection port cools the tool and the portion supporting the spindle end of the housing, so that thermal expansion and deformation of the tool can be suppressed to a small extent.

In the spindle device according to claim 3 of the present invention,
Since the gas cooled by the gas cooling means is blown to the tool from the tool-side injection port, the part supporting the main shaft end of the tool and the housing is efficiently cooled, and the thermal expansion and deformation of the tool are further reduced. In the spindle device according to claim 4 of the present invention, in addition to the gas, the liquid supplied from the liquid supply source is blown from the liquid ejection port to the tool, so that the tool is efficiently cooled. This means that the thermal expansion and deformation of the tool can be further reduced.

In the spindle device according to a fifth aspect of the present invention, the gas ejected from the tool-side injection port and the pressure-receiving-portion-side injection port flows in the circumferential direction of the main shaft along the annular groove. And the pressure distribution between the pressure receiving portion and the housing become uniform in the circumferential direction. As a result, the main shaft is supported without being inclined with respect to the housing.

In the spindle device according to claim 6 of the present invention,
When gas is blown from the tool-side injection port and the pressure-receiving part-side injection port to the tool and the pressure-receiving part, respectively, the main shaft is supported in the axial direction, and in this state, the tool-side auxiliary injection port and the pressure-receiving part-side auxiliary injection port When gas is blown to the tool and the pressure receiving part, the tool-side auxiliary injection port and the pressure-receiving part-side auxiliary injection port are located at a position farther from the main axis than the tool-side injection port and the pressure-receiving part-side injection port. Since the gas ejected from the port and the pressure-receiving-port-side auxiliary ejection port has a lower pressure than the gas ejected from the tool-side ejection port and the pressure-receiving-port-side ejection port, a small amount of low-pressure gas is generated between the tool and the housing. The flow in the centrifugal direction of the main shaft is caused by the clearance and the slight clearance between the housing and the pressure receiving portion, and the sealing performance can be further improved without affecting the axial support force of the main shaft. To become.

[0014]

In the spindle device according to the first and second aspects of the present invention, since the above-described configuration is employed, the sealing property is ensured, and foreign matters enter the device and lubricating oil from a bearing, for example, a journal bearing. Leakage can be reliably prevented, and the cost can be reduced because thrust bearings are not required.In addition, the rigidity of the main shaft can be improved because the seal part can be formed in a short range in the axial direction. Since the spindle is supported in the axial direction at a position close to the tool, even when the spindle is rotated at high speed, the displacement of the tool due to the thermal expansion of the spindle caused by the heat generated by the journal bearings can be minimized. The part that supports the tool and the spindle end of the housing can be cooled by the gas blown from the tool-side injection port, minimizing thermal expansion and deformation of the tool. It leads to very excellent effect that it is possible.

According to the spindle device of the third aspect of the present invention, in addition to the same effects as obtained by the spindle device according to the first and second aspects, the gas cooled by the gas cooling means is blown to the tool. Therefore, the portion of the tool and the housing that supports the end of the spindle can be efficiently cooled, so that the thermal expansion and deformation of the tool can be further reduced, and the spindle device according to claim 4 of the present invention. Then
By spraying the liquid supplied from the liquid supply source onto the tool, efficient cooling of the tool can be realized, and a very excellent effect that the thermal expansion and deformation of the tool can be significantly reduced can be obtained.

Further, in the spindle device according to claim 5 of the present invention, the pressure distribution between the tool and the housing and the pressure distribution between the pressure receiving portion and the housing can be made uniform in the circumferential direction. A very excellent effect is obtained that the main shaft can be supported without tilting with respect to the housing.

Further, in the spindle device according to claim 6 of the present invention, the same effects as those of the spindle device according to claims 1 and 2 can be obtained, and the gas ejected from the tool side injection port and the pressure receiving section side injection port can be obtained. Supports the main shaft in the axial direction, and the lower-pressure gas ejected from the tool-side auxiliary injection port and the pressure-receiving-part-side auxiliary injection port prevents foreign matter from entering the inside of the device and leakage of lubricating oil from the journal bearing. Thus, a very excellent effect that the sealing property can be improved without hindering the function of the thrust bearing is brought about.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention.
6 shows an embodiment of a spindle device according to 2 and 5;

As shown in FIG. 1, the spindle device 1 includes a spindle 2, a housing 10 for accommodating the spindle 2, and a large-diameter portion (pressure receiving portion) provided in the housing 10 and provided on the spindle 2. The large-diameter portion 2A has an end face 2a near an end 2B of the main shaft 2 where a grindstone (tool) T is mounted. It is provided so as to face the end surface Ta of the grindstone T.

The housing 10 communicates with the gas supply source P via the supply passage 11 and faces the end face Ta of the grinding wheel T and the end face 2a of the large diameter portion 2A.
A and the large-diameter-portion-side injection port 12B, and the tool-side injection port which is provided along the circumferential direction on opposing surfaces 10a and 10b facing the end surface Ta of the grindstone T and the end surface 2a of the large-diameter portion 2A in the housing 10, respectively. 12A and the annular grooves 13A and 13B communicating with the large-diameter portion injection port 12B. The gas supplied through the supply path 11 is supplied from the tool-side injection port 12A and the large-diameter portion injection port 12B to the grindstone T. End face T
a and the end face 2a of the large-diameter portion 2A is axially sprayed, and flows in the circumferential direction of the main shaft 2 along the annular grooves 13A and 13B to axially support the main shaft 2 in a non-contact state by gas. It is supposed to.

In this case, the housing 10 is provided with an exhaust passage 14A for communicating a gap between the housing 10 and the large diameter portion 2A of the main shaft 2 to the outside, and the grinding wheel T and the large diameter portion of the housing 10 are provided. Part located between 2A (part supporting spindle end 2B of housing 10)
An exhaust passage 14B is provided for communicating a gap between the shaft end 2B and the outside to the outside, and the exhaust passage 14B communicates with the outside via an exhaust passage 14A.

In the main spindle device 1, the gas supplied from the gas supply source P via the supply path 11 is supplied to the housing 1.
0 is sprayed in the axial direction from the tool-side injection port 12A and the large-diameter portion-side injection port 12B to the end surface Ta of the grinding wheel T and the end surface 2a of the large-diameter portion 2A, and the annular grooves 13A, 13
When flowing in the circumferential direction of the main shaft 2 along B, the main shaft 2 is supported in the axial direction because an axial velocity component in the opposite direction and having the same magnitude is generated in the main shaft 2.

At this time, the gas ejected from the tool-side injection port 12A and the large-diameter portion-side injection port 12B flows into the annular groove 13A,
13B, and flows in the circumferential direction of the spindle 2 so that the grinding stone T
And the pressure distribution between the large-diameter portion 2A and the housing 10 become uniform in the circumferential direction, so that the main shaft 2 is supported without being inclined with respect to the housing 10. Become.

The gas flowing in the circumferential direction of the main shaft 2 along the annular grooves 13A and 13B is supplied to the grinding wheel T and the housing 1
0, and the gas exhausted to the outside of the apparatus through the exhaust passage 14A.
Foreign matter is prevented from entering between the end 2B and the housing 10, while the gas blown to the large-diameter portion 2A is
Since the lubricating oil is prevented from leaking from the journal bearing 3 located on the opposite side of the grindstone T from the large diameter portion 2A, the sealing property is ensured.

Therefore, in the spindle device 1, the cost is reduced by the amount that the thrust bearing is not required. In addition, the grinding wheel T and the large-diameter portion 2A whose sealing portion has a reduced distance are provided.
Formed between the main shaft 2 and the main shaft 2 as compared with the case where a labyrinth seal is provided.
The main shaft 2 is axially supported by the journal bearing 3 at a position close to the grindstone T. Thus, even when the main shaft 2 is rotated at high speed, the journal bearing 3 The displacement of the grindstone T in the axial direction due to the thermal expansion of the main shaft 2 caused by the heat generation of the main shaft 2 can be extremely suppressed.

Further, the gas blown from the tool-side injection port 12A cools the grinding wheel T and the portion supporting the main spindle end 2B of the housing 10, so that the thermal expansion and deformation of the grinding wheel T are suppressed to a small extent. It will be.

[Second Embodiment] FIG. 2 shows a first embodiment of the present invention.
3 shows an embodiment of a spindle device relating to 3 and 5;
As shown in FIG. 2, the main spindle device 21 according to this embodiment is different from the main spindle device 1 in the first embodiment in that the tool side injection port 12A and the large diameter portion side injection port 12B and the gas supply source P In between, ie, the supply path 11 and the gas supply source P
A cooling device (gas cooling means) C is provided between the first and second embodiments, and the other configuration is the same as that of the spindle device 1 in the first embodiment.

That is, in the spindle device 21 as well, the cost can be reduced by the amount that the thrust bearing is not required. In addition, the grinding wheel T having a shorter distance and the larger diameter can be used without the need for the labyrinth seal. Since the sealing portion is formed between the main shaft 2 and the portion 2A, the rigidity of the main shaft 2 is improved, and even if the main shaft 2 is rotated at a high speed, the position of the grindstone T in the axial direction due to the thermal expansion of the main shaft 2 is increased. The deviation can be kept extremely small.

In the spindle device 21, the cooling device C
The gas cooled by the grinding wheel T
Therefore, the portion supporting the grindstone T and the spindle end 2B of the housing 10 is efficiently cooled, and the thermal expansion and deformation of the grindstone T can be further reduced.

[Third Embodiment] FIG. 3 shows a third embodiment of the present invention.
FIG. 3 shows an embodiment of a spindle device according to 2, 4, and 5, and as shown in FIG. 3, a spindle device 3 according to this embodiment.
1 differs from the spindle device 1 in the first embodiment in that the liquid supply source PA and the supply passage 33 are located at a position farther from the spindle 2 than the tool-side injection port 12A and the large-diameter-portion-side injection port 12B of the housing 10. The configuration is the same as that of the spindle device 1 in the first embodiment except that a liquid ejection port 32 communicating with the main shaft device is provided.

Also in this spindle device 31, the cost can be reduced by the amount that the thrust bearing is not required.
Since the sealing portion is formed between the grindstone T whose distance has been shortened and the large diameter portion 2A, the rigidity of the main shaft 2 is improved, and the main shaft 2 thermally expands even when the main shaft 2 is rotated at high speed. The displacement of the grinding wheel T in the axial direction due to the above is extremely reduced.

Further, in the spindle device 31, in addition to the gas ejected from the tool-side ejection port 12A, the liquid supplied from the liquid supply source PA is blown from the liquid ejection port 32 to the grindstone T. Cooling is performed efficiently, and the thermal expansion and deformation of the grindstone T can be further reduced.

FIG. 4 shows a fourth embodiment of the present invention.
1 shows an embodiment of a spindle device relating to 2, 5 to 7;

As shown in FIG. 4, in the main spindle device 41, the gas supply source P and the supply path 51 are located at a position farther from the main shaft 2 than the tool-side injection port 12A and the large-diameter portion-side injection port 12B of the housing 10. A tool-side auxiliary injection port 5 which blows gas supplied from the gas supply source P in the axial direction to the end face Ta of the grinding wheel T and the end face 2a of the large diameter portion 2A through the
2A and the large diameter side auxiliary injection port 52B are provided,
On the opposing surfaces 10a and 10b of the housing 10, there are provided annular auxiliary grooves 53A and 53B for allowing gas ejected from the tool-side auxiliary injection port 52A and the large-diameter portion-side auxiliary injection port 52B to flow in the circumferential direction, respectively. The pressure of the gas ejected from the port 52A and the large-diameter portion auxiliary ejection port 52B is lower than the pressure of the gas ejected from the tool-side ejection port 12A and the large-diameter portion ejection port 12B. This is the same as the spindle device 1 in the embodiment.

In the spindle device 41, the gas supplied from the gas supply source P via the supply path 11 is supplied to the tool side injection port 1.
2A and the end face Ta of the grindstone T from the large diameter portion side injection port 12B.
When the main shaft 2 is blown in the axial direction against the end surface 2a of the large diameter portion 2A and flows in the circumferential direction of the main shaft 2 along the annular grooves 13A and 13B, the main shaft 2 is axially supported by the housing 10. Become.

During this time, the gas supplied from the gas supply source P via the supply path 51 is supplied from the tool side auxiliary injection port 52A and the large diameter side auxiliary injection port 52B to the end face Ta of the grinding wheel T and the end face of the large diameter section 2A. When the tool 2a is sprayed in the axial direction and flows in the circumferential direction of the main shaft 2 along the annular auxiliary grooves 53A and 53B, the tool-side auxiliary injection port 52A and the large-diameter portion-side auxiliary injection port 52B are turned into the tool-side injection ports. 12A and the large-diameter portion-side injection port 12B are located farther from the main shaft 2 than the tool-side auxiliary injection port 52A and the gas pressure ejected from the large-diameter-section side auxiliary injection port 52B.
Since the pressure of the gas ejected from the 2A and the large-diameter-portion-side injection port 12B is set to be lower than the pressure, the low-pressure gas is
In the small gap between the grindstone T and the housing 10 and in the small gap between the housing 10 and the large-diameter portion 2A, the fluid flows in the centrifugal direction of the main shaft 2, and as a result, the main shaft 2
Without influencing the axial supporting force, and the leakage of the lubricating oil from the journal bearing 3 located on the side opposite to the grindstone T is reliably prevented without affecting the foreign matter.

That is, in the spindle device 41, as in the spindle device 1 in the first embodiment, the cost can be reduced by not requiring the thrust bearing. Since the sealing portion is formed between the large-diameter portion 2A, the rigidity of the main shaft 2 is greatly improved, and even if the main shaft 2 is rotated at a high speed, the axial direction of the grindstone T due to the thermal expansion of the main shaft 2 is increased. The displacement is suppressed to a very small value.

Then, as described above, the tool-side injection port 12
A and the gas ejected from the large-diameter-portion-side injection port 12B are used for bearings in the axial direction, and the low-pressure gas jetted from the tool-side auxiliary injection port 52A and the large-diameter-portion auxiliary injection port 52B are used for sealing. Both the thrust bearing function and the sealing function are efficient.

The detailed structure of the spindle device according to the present invention is as follows.
The present invention is not limited to the above-described first to fourth embodiments.

[Brief description of the drawings]

FIGS. 1A and 1B are an explanatory sectional view showing a first embodiment of a spindle device according to the present invention and an explanatory sectional view taken along a line AA in FIG. 1A.

FIG. 2 is an explanatory sectional view showing a second embodiment of the spindle device according to the present invention.

FIG. 3 is an explanatory sectional view showing a third embodiment of the spindle device according to the present invention.

FIG. 4 is an explanatory sectional view showing a fourth embodiment of a spindle device according to the present invention.

[Explanation of symbols]

 1, 21, 31, 41 Spindle device 2 Spindle 2A Large diameter portion (pressure receiving portion) 2B Spindle end 10 Housing 10a, 10b Opposing surface 12A Tool side injection port 12B Large diameter portion side injection port (pressure receiving section side injection port) 13A , 13B Annular groove 14A, 14B Exhaust passage 32 Liquid injection port 52A Tool side auxiliary injection port 52B Large diameter side auxiliary injection port (pressure receiving section side auxiliary injection port) 53A, 53B Annular auxiliary groove C Cooling device (gas cooling means) P Gas supply source PA Liquid supply source T Whetstone (tool)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yu Owada Nissan Motor Co., Ltd. (2) 2 Takaracho, Kanagawa-ku, Yokohama, Nissan Motor Co., Ltd. (72) Toshikazu Otani 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Manabu Wakuda, Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor Minoru Ota 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture, Nissan Motor Co., Ltd. (72) Miya, Inventor Katsutoshi Hara 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd.

Claims (6)

[Claims] 1. A spindle device comprising: a spindle; and a housing rotatably accommodating the spindle, wherein a pressure receiving portion facing the tool is provided near an end of the spindle where a tool is mounted. A tool-side injection port and a pressure-receiving-port-side injection port that communicates with the gas supply source and supplies gas supplied from the gas supply source to the tool and the pressure-receiving section in the axial direction, and a gap between the housing and the pressure-receiving section. A main body device provided with an exhaust passage for communicating with the outside. 2. An exhaust passage for providing a gap between the housing and the end of the main shaft to the outside at a main shaft end supporting portion of the housing located between the tool and the pressure receiving portion. Spindle device. 3. A tool side injection port and a pressure receiving section side injection port,
3. The spindle device according to claim 1, wherein a gas cooling unit is provided between the main shaft device and the gas supply source. 4. A liquid injection port for spraying a liquid supplied from a liquid supply source to a tool at a position farther from the main shaft than the tool-side injection port and the pressure-receiving-portion-side injection port of the housing. The spindle device according to any one of the above. 5. An annular groove through which gas ejected from the tool-side injection port and the pressure-receiving section-side injection port flows in the circumferential direction of the main shaft is provided on a surface of the housing facing the tool and the pressure receiving section. 5. The spindle device according to any one of 4. 6. A tool-side auxiliary injection port that blows gas supplied from a gas supply source axially to a tool and a pressure-receiving section at a position farther from the main shaft than the tool-side injection port and the pressure-receiving section-side injection port of the housing. And a pressure receiving part side auxiliary injection port, the pressure of gas ejected from the tool side auxiliary injection port and the pressure receiving part side auxiliary injection port is lower than the pressure of gas ejected from the tool side injection port and the pressure receiving part side injection port. A spindle device according to any one of claims 1 to 5.