KR101183599B1 - thrust bearing cooling structure of superhigh speed air bearing - Google Patents

Abstract

The present invention provides a cylindrical housing cover (2), a cooling jacket (1) installed inside the housing cover (2), a radial bearing (3) installed inside the cooling jacket (1), and the lady. A rotating shaft 5 inserted into the inner bearing 3, a front cover 7 installed on the front of the rotating shaft 5 and the front of the housing cover 2, and having a through portion formed at the center thereof, and the front cover ( Trust bearing cooling of the ultra-high-speed air bearing spindle consisting of a thrust bearing (4) provided with a conduit inside the rear of the 7) and a spacer (6) installed in the rear of the thrust bearing (4) and provided with a conduit therein. Relates to a device.

Description

Thrust bearing cooling structure of superhigh speed air bearing

The present invention relates to an apparatus for a cooling system of an ultra-high speed air bearing spindle, and more particularly to a cooling system of a thrust bearing part to which a special pipe structure is applied in addition to a motor part and a radial bearing part inside the spindle.

As the industrial speed increases, high speed spindles are required for shortening the processing time and improving productivity. Increasingly, precise spindles with less vibration are required.

Generally, air bearing spindles are attached to CNC M / C, micro drill (PCB drill), dicing machine, optical lens and drum grinding, micro parts precision grinding and processing, etc. It is designed to achieve the effect of minimization and noise. It basically consists of stator and rotor of driving motor, radial bearing and thrust bearing, rotating shaft, cooling jacket, housing, etc. Cooling water can be circulated only outside the part where the motor part and the radial bearing are assembled.

For example, Korean Laid-Open Patent Publication No. 10-2004-0090280 discloses a spindle composed of a pulley connected to a belt or the like from a power source of a mechanical device, and a rotating shaft installed in a housing to rotate at high speed and a plurality of ball bearings supporting the same. The high-speed spindle for precision machining equipment is disclosed, which is characterized by installing an air pocket (7) to cool the heat due to the high-speed rotation and to prevent the inflow of foreign substances.

Korean Patent Publication No. 10-2003-0049640 discloses a motor housing 10 and a rotating shaft 20 installed on the motor housing 10 and a rotor 30 and a rotor 30 installed on the rotating shaft 20. It consists of a stator 40 is installed on the inner surface of the motor housing 10 so as to be arranged around the suction, the suction of the casing 50 and the casing 50 disposed at intervals around the motor housing 10 In the spindle motor of the machine tool including a cooling fan 60 installed in the seal 52 to cool the motor housing 10, an air passage 16 is provided between the motor housing 10 and the stator 40. A plurality of ribs 14 are formed on the inner circumferential surface of the motor housing 10 for heat dissipation of the motor housing 10, while the cooling fan 60 is formed on the outer surface of the motor housing 10. A suction hole 19 communicating with the suction chamber 52 so as to suck air from the air passage 16 and the outside air A spindle motor cooling structure of a machine tool is disclosed, characterized in that a plurality of through holes 18 are formed therethrough.

Publication No. 10-2007-0069324 discloses a cooling device of a spindle 20 embedded in a spindle housing 10 to rotate a tool, wherein the oil passage 103 is formed on the inner circumferential surface of the spindle housing 10. Cutting oil supply formed between the outer circumferential surface of the spindle bearing 30 outside the spindle 20 and consisting of a cutting oil tank 101 for storing cutting oil at room temperature and a pump 102 for supplying the cutting oil from the cutting oil tank 101. A spindle cooling apparatus using cutting oil is described, which leads the cutting oil supplied from the apparatus to a cutting oil injection hole 104 for injecting the cutting oil to a workpiece.

Korean Patent Publication No. 10-0367987 has a predetermined separation space coupled to the outer diameter surface 104 of the spindle 103 formed on one side of the motor and one side extension of the rotor 102, the spindle 103 Air to the outer diameter surface 104 of the nozzle body 106 provided with a plurality of first air nozzles 105 for causing the spindle 103 to slide in rotation with the air, and the air to the first air nozzles 105. In the structure of the air bearing spindle having a plurality of first housing (108) air supply for supplying the spindle housing 108 is formed and the other side of the spindle housing 108 is fixed by a fixed cap 110,

Buried in one inner surface of the fixed cap 110 is coupled to have a predetermined space from the other support shaft 110 of the rotor 102 to inject air to the outer surface of the support shaft 110 Air to the support shaft 111 of the rotor 102 through the auxiliary support 112 having a plurality of second air nozzles 105a formed thereon, and the second air nozzle 105a of the auxiliary support 112. A second air passage (107a) formed in the auxiliary support (112) to be connected to the fixing cap (107) to supply a; The structure of the air bearing spindle is characterized in that it comprises a ceramic layer 114 coated to prevent friction on the outer diameter surface of the spindle 103 friction with the air injected from the first air nozzle 105 It is

Publication No. 10-1001004 discloses a cooling device for a spindle motor 14, which is embedded in the spindle housing 16 and rotates the spindle 10, wherein the spindle housing 16 on which the spindle motor 14 is located. At least one cooling fluid inlet passage 101 and a cooling fluid outlet passage 102 in communication with the motor chamber 11 are formed in the motor chamber 11 in the longitudinal side wall of the main shaft, and the cooling fluid inlet passage ( 101 is connected to a pneumatic source 103 through which a cooling fluid of a predetermined pressure is discharged, and an annular groove 31 formed in the circumferential direction on the outlet side of the cooling fluid inlet passage 101 in communication with the corresponding outlet on one side thereof; Cooling of the spindle motor of the built-in spindle of the machine tool, characterized in that the distributor 30 having a plurality of perforated orifice holes 32 communicated with the annular groove 31 and arranged at equal intervals on the other side. The device is public,

Publication No. 10-0062957 discloses a work in which a spindle (3) with a hollow rod (2) having a socket (1) formed thereon is inserted into a head body (4) and rotated by a drive motor (5). In constructing a high speed spindle device of the machine, the spindle housing 6 is inserted into the head body 4 to insert the spindle 3, but the mill 8 operated by the cylinder 7 at the rear end of the rod 2. At the same time, the spindle 3 is coupled to the spline 10 coupled with the spline shaft 9 fixed on the shaft 5a of the motor 5 so that the motor 5 and the spindle 3 are directly connected to each other. A high speed spindle device of a machine tool is disclosed, which is configured to be connected,

No. 20-0190474 is registered in Korea Utility Model No. 20-0190474, the spindle unit is rotated and supported by the bearing assembly, the drawbar is pressed into the inside, and the spindle unit for processing the clamped material while rotating the spindle axis by the drive of the motor capable of rotation speed control In the spindle, on one side of the spindle to form an inlet conduit through which the lubricating oil penetrates the spindle axis to the rear side of the drawbar, and the lubricating oil of the inlet conduit is circulated in a spiral direction while being in contact with the inner surface of the spindle shaft. A spiral groove is formed, and the lubricating oil circulated to the double spiral groove is formed to penetrate through the bearing lubrication path so that the lubricating oil flows into the bearing assembly supporting the rotating support. The lubricating oil passing through the bearing lubrication path is discharged into the inlet pipe by pumping. Spindle axis, characterized in that it is circulated The lubricating device for peering, you can see that is open to the public.

Most air bearing spindles that rotate at high speeds of tens of thousands to hundreds of thousands of rpm consist of a device that can only cool the motor and the radial bearing, so that the thrust bearing in front of the spindle is not able to achieve cooling effect or cooling effect. It is more fragile than other parts. If heat is generated in the body of the spindle, it may lead to unstable operation during high-speed rotation due to thermal expansion of internal parts made of different materials.In particular, thermal expansion in technical parts that must maintain fine gaps (about 10㎛) due to the characteristics of air bearings. Errors may occur, which affects the machining quality during ultra-precision machining using air bearings. For this reason, the problem to affect the processing quality and the life of the spindle by setting the processing conditions according to the next best solution without deriving the optimum processing conditions is a problem to be solved by the present invention.

In order to solve the above problems, the present invention provides a special cooling water circulation conduit in front of the spindle where the thrust bearing is located to obtain an even cooling effect on the entire spindle so that the spindle is free from heat generation even at high speed rotation. It is an object of the present invention to provide a thrust bearing cooling device for an ultra-high-speed air bearing spindle, which is intended to contribute to the improvement of the quality of precision workpieces.

When rotating the air bearing spindle at tens of thousands of rpm, the spindle heats up the rotating shaft, bearing and housing by the heat of the motor.In addition to the motor part and the radial bearing part where the cooling conduits are formed, it also cools the thrust bearing part and generates it at high speed. It prevents thermal expansion of internal parts by protecting the spindle from high heat, and prevents the loss of air bearing effect because the spindle can structurally maintain internal clearance. There is an effect that can be utilized.

1 is an overall view of a thrust bearing cooling device of the ultra-high speed air bearing spindle of the present invention.
Figure 2 is a detailed view of a rotating shaft (spindle) of the present invention.
Figure 3 is a detailed view of the radial bearing and the thrust bearing connection of the present invention.
4 is a detailed view of a trust bearing of the present invention.
Figure 5 is a detailed view of the spacer of the present invention.
Figure 6 is a detailed view of a conventional thrust bearing cooling device of ultra-high air spindle.

In order to achieve the above object, the present invention provides a cylindrical housing cover (2), a cooling jacket (1) installed inside the housing cover (2), and a radial installed inside the cooling jacket (1). A bearing 3, a rotary shaft 5 inserted into the radial bearing 3, a front cover of the rotary shaft 5, which is installed on the front of the housing cover 2, and has a through portion formed at the center thereof; 7), a thrust bearing 4 having a conduit provided on the rear side of the front cover 7, and a spacer 6 installed on the rear of the thrust bearing 4 and having a conduit therein. A thrust bearing cooling device for an ultra-high speed air bearing spindle.

The ultra-high speed spindle used in the present invention is a spindle applied with a high frequency AC induction motor and an air static bearing, and is a technology related to a cooling method for an air bearing high frequency spindle suitable for chamfering glass for touch panels. The main specification is 60,000 rpm. It is capable of ultra high speed rotation, has a power of 2.8kW class, and has a static load capacity of 10kg, which is suitable for tempered glass processing.

The high speed spindle's static pressure air bearing uses compressed air to supply a very small gap with a clearance of 10 µm between the bearing and the rotating shaft to float the rotating shaft using air pressure. Built-in high frequency air bearing spins with a built-in high frequency motor are composed of stators and rotors of the high frequency motor to enable high speed rotation, and the rotor is assembled with the rotating shaft to be completed through final precision machining.

In order to rotate at 60,000rpm class, in addition to the precision processing technology, the technology to remove the unbalanced mass of the rotating shaft is very important to correct the precision balancing within 0.001g.mm. In front of the rotating shaft, a collet and a nut are fastened to mount the tool so that the air bearing spindle can work. The rotating shaft is supported by air bearing radial bearings and thrust bearings and floats in a non-contact state by the force of compressed air.

Outside the air bearing, the cooling jacket to cool the spindle and the housing secure the entire part.

The coolant can be circulated to the front of the thrust bearing through the hole through the radial bearing side, thrust bearing spacer, and thrust bearing part through the coolant pipe that circulated to the radial bearing part of the housing for cooling the thrust bearing. In order to maximize the cooling effect on the side of the thrust bearing, the inlet and the outlet were separated to form a groove of constant width and depth in the perimeter.

1 is an overall view of a thrust bearing cooling apparatus of an ultra-high speed air bearing spindle of the present invention, which is a device of an air bearing spindle to which a cooling conduit is applied to a thrust bearing portion, and a pipe line (X) is installed inside the thrust bearing portion, and a rotating shaft is provided. (Spindle) Radial bearings are connected to the cooling jacket (1) installed on the outside of the radial bearing (3) and the conduit (X) so that the coolant can circulate in the radial bearing (3), which is the front of the spindle. (3) The collar, spacer (6) and the thrust bearing (4) is made to be connected, and the thrust bearing (4) side has a pipe in the form of an arc almost close to a circle so that the coolant can be circulated to change direction. It is connected to the cooling jacket (1).

Figure 2 shows a detailed view of the rotating shaft (spindle) of the present invention,

Figure 3 is a detailed view of the radial bearing and the thrust bearing connection of the present invention, Figure 4 is a detailed view of the thrust bearing of the present invention, the cooling jacket (1) is formed up to the front of the rotating shaft spindle rotating shaft (spindle) ( 5) You can check the system that can give cooling effect with the distribution of the whole area.

Figure 4 is a detailed view of the thrust bearing of the present invention, Figure 5 is a detailed view of the spacer of the present invention, it can be seen that the cooling water movement passage (X) is installed inside.

FIG. 6 is a detailed view of a thrust bearing cooling device of a conventional high speed air spindle. As a general cooling jacket device of an air bearing spindle, cooling water is supplied to a C-IN position to circulate the cooling water along an outer groove. It is composed of a device that is discharged to the outside from the -OUT position, so that only the part where the motor and the radial bearing (3) are located can give a cooling effect.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 is an overall view of a thrust bearing cooling device of the ultra-high-speed air bearing spindle of the present invention, Figure 2 is a detailed view of the rotating shaft (spindle) of the present invention, Figure 3 is a radial bearing and a thrust bearing connection of the present invention, Figure 4 Detailed view of the thrust bearing of the present invention, Figure 5 is a detailed view of the spacer of the present invention, Figure 6 shows a detailed view of the conventional thrust bearing cooling device of the ultra-high air spindle, the cooling jacket (1), the housing cover (2), Radial bearings (3), thrust bearings (4), rotary shafts (5), spacers (6), front covers (7), rear covers (8), motor spacers (9), connector brackets (10), ring bolts ( 11), connector 12, stator 13, rotor 14, collet 15, collet nut 16, silencer 17, radial air bearing nozzle 30, cooling jacket coolant inlet (111) ), Cooling jacket cooling outlet 112, cooling jacket thrust bearing cooling water connection (114, 115), thrust bearing cooling outlet (114-1), It can be seen that the spacer cooling water outlet 114-2, the thrust bearing cooling water inlet 115-1, the spacer cooling water inlet 115-2, and the conduit X are shown.

Looking at the structure of the ultra-high-speed air bearing spindle thrust bearing cooling apparatus of the present invention, as shown in Figures 1 to 5,

A cylindrical housing cover 2, a cooling jacket 1 installed inside the housing cover 2, a radial bearing 3 installed inside the cooling jacket 1, and the radial bearing ( 3) a rotary shaft 5 inserted into the interior, a front cover 7 of the front surface of the rotary shaft 5, which is installed on the front of the housing cover 2, and has a penetrating portion in the center thereof, It consists of a thrust bearing (4) installed on the rear, and a spacer (6) installed on the rear of the thrust bearing (4),

As shown in Figure 3, the cooling jacket 1 is provided with a groove connected to the surface by a zigzag,

A cooling jacket cooling water inlet 111 penetrating to the outside of one side of the front groove of the cooling jacket 1 and a cooling jacket cooling water outlet 112 installed in a groove spaced at a predetermined distance from the cooling jacket cooling water inlet 111;

The rear side of the cooling jacket (1) is installed to penetrate through the outside of one side of the other groove

It consists of cooling jacket, thrust bearing and cooling water connection part (114, 115),

"형상의(X)로 구성되며,
3 and 4, the thrust bearing 4 has a plurality of radial air bearing nozzles 30 penetrating inward in a ring shape, and a thrust bearing cooling water inlet 115-1 installed at one side of the upper thrust bearing 4. And, the thrust bearing cooling water inlet (114-1) and the thrust bearing cooling water inlet (115-1) installed to be spaced apart from the thrust bearing cooling water inlet (115-1) and the thrust bearing cooling water inlet (115-1) Connected by a groove

"Consists of shape (X),

As shown in FIG. 5, the spacer 6 has a spacer cooling water inlet 115-2 installed at an upper side thereof, and a spacer ring cooling outlet 114-spaced apart from the spacer coolant inlet 115-2 at a predetermined interval. 2) and the spacer cooling water inlet 115-2 and the spacer cooling outlet 114-2.

Explain the assembly and use state,

After connecting the rotor fixing part (not shown) to the front of the cylindrical radial bearing (3), and installing the cooling jacket (1) on the outside of the radial bearing (3) and the rotor fixing part,

Connect the leader cover (not shown) to the rear of the rotor fixing part (not shown) with a bolt, and connect the coolant inlet and the cooling outlet to the coolant inlet and the outlet pipe to the leader cover, and the cooling jacket coolant inlet 111 is constant. Assemble and match with the cooling jacket cooling outlet 112 installed in the groove spaced apart,

After connecting the rotor to the rear of the rotary shaft (5) and inserted into the radial bearing (3),

The spacer 6 is positioned on the inserted front surface, and the cooling jacket thrust bearing cooling water connection part 114 and 115 and the spacer cooling water inlet 115-2 are penetrated to the outside of one side of the other groove of the rear side of the cooling jacket 1. And after connecting in conjunction with the spacer ring cooling outlet 114-2,

The thrust bearing 4 is connected to the rear surface of the spacer 6, but the spacer cooling water inlet 115-2 and the spacer ring cooling outlet 114-2 of the spacer 6 and the two bearing cooling water of the thrust bearing 4 are connected. After the inlet 115-1 and the thrust bearing cooling outlet 114-1 coincide,

After assembling by connecting the front cover (7) to the rear of the trust bearing (4),

The assembly was completed by connecting the collet 15 to the front of the rotating shaft (5) with collel nuts.

The operating method is to open the valve of the coolant inlet and outlet, turn on the power,

As the coolant flows into the cooling jacket 1, the rotor 14 is rotated and the rotating shaft 5 connected to the rotor 14 is rotated, and a radial air bearing nozzle installed outside the rotating shaft 5 ( Air is supplied to the rotating shaft (5) to rotate without resistance in 30), and the cooling water is supplied to the cooling jacket (1) to supply the cooling water to the thrust bearing (4) and the spacer (6) installed at the front of the rotating shaft (5). It is a method of operating by maintaining the desired temperature throughout the rotating shaft (5).

At this time, the cooling water supply of the cooling jacket (1) is the cooling water through the cooling jacket cooling water inlet 111, the cooling jacket groove, the spacer cooling water inlet (115-2), the thrust bearing cooling water inlet (115-1), pipe (X). After being supplied, the thrust bearing cooling outlet 114-1. Cooling water is discharged through the spacer cooling outlet 115-1, the cooling jacket groove, and the cooling jacket cooling outlet 112.

Cooling jacket (1), housing cover (2), radial bearing (3), thrust bearing (4), rotary shaft (5), spacer (6), front cover (7), rear cover (8), motor spacer ( 9), connector bracket (10), ring bolt (11), connector (12), stator (13), rotor (14), collet (15), collet nut (16), silencer (17), cooling jacket Inlet (111), cooling jacket cooling outlet (112), cooling jacket trust bearing cooling water connection passage (114, 115), trust bearing cooling outlet (114-1), spacer cooling outlet (114-2), trust bearing cooling water inlet (115) -1), spacer coolant inlet 115-2), pipeline (X)

Claims (1)

In a thrust bearing cooling device of an ultra-high speed air bearing spindle,
A cylindrical housing cover 2, a cooling jacket 1 installed inside the housing cover 2, a radial bearing 3 installed inside the cooling jacket 1, and the radial bearing ( 3) a rotary shaft 5 inserted into the interior, a front cover 7 of the front surface of the rotary shaft 5, which is installed on the front of the housing cover 2, and has a penetrating portion in the center thereof, It consists of a thrust bearing (4) installed on the rear, and a spacer (6) installed on the rear of the thrust bearing (4),

The cooling jacket (1) is installed with a groove connected to the surface zigzag,
A cooling jacket cooling water inlet 111 penetrating to the outside of one side of the front groove of the cooling jacket 1 and a cooling jacket cooling water outlet 112 installed in a groove spaced at a predetermined distance from the cooling jacket cooling water inlet 111;
The cooling jacket (1) consists of a cooling jacket thrust bearing cooling water connecting portion (114, 115) penetrated to the outside of the other groove on the rear side of the cooling jacket (1),

The thrust bearing 4 has a plurality of radial air bearing nozzles 30 penetrating inward in a ring shape, a thrust bearing cooling water inlet 115-1 provided at one side of the upper part, and the thrust bearing cooling water inlet 115-1. ) And the thrust bearing cooling outlet 114-1 installed at a predetermined interval, and connected to the thrust bearing cooling water inlet 115-1 and the thrust bearing cooling outlet 114-1 by a groove.

"Consists of shape thrust bearing cooling water pipe (X),

The spacer 6 includes a spacer cooling water inlet 115-2 installed at one side of the upper portion, a spacer ring cooling outlet 114-2 installed at a predetermined distance from the spacer cooling water inlet 115-2, and the spacer cooling water inlet. A thrust bearing cooling device for an ultra-high speed air bearing spindle, comprising: 115-2 and a spacer cooling outlet 114-2.

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