KR20080005766U - Spindle unit - Google Patents

Abstract

The present invention relates to a spindle unit using air bearings as a means for supporting a spindle shaft rotating above the spindle unit. The spindle unit comprises a cooling system capable of cooling the drill end of the spindle shaft and the surrounding area of the actuator coil, in particular the cooling system using coolant (water or oil) as a cooling medium to provide contact cooling function in the area. I use it. The cooling system is integrated within the spindle unit so that the structural unity and precision of the unit can be maintained. The air bearing of the spindle unit includes a suction slot and an inlet for increasing the air suction amount to provide the spindle shaft with axial and radial support rotation. The air bearing is configured such that coolant flows through it so that the area adjacent the drill end of the spindle shaft can be cooled. The spindle unit of the present invention is suitable for use in drilling machines, in particular high speed drilling machines such as PCB drilling machines. As the parts of the spindle unit operate according to their own function, the spindle unit can be easily assembled, reassembled, repaired and repaired.

Air bearing, spindle unit

Description

Spindle Unit {SPINDLE UNIT}

The present invention relates to a spindle unit, and more particularly to a spindle device using an air bearing as a means for supporting the spindle, which spindle unit can be used on a high speed drilling machine such as a printed circuit board (PCB) drilling machine.

As technology advances and improves, the requirements of high-precision electronic devices have increased. Due to this increased requirement, the drilling process of major components in the device has become more important. In practice, PCBs are one of the underlying elements of most electronic devices. The drilling process of the PCB is more important and must have high precision to have a good return. Spindle units comprising drills rotating at high speed are the essence of high speed drilling. At present, the use of an air bearing as a means for supporting a rotating spindle in the spindle unit makes it possible to effectively perform high speed and high precision drilling.

1 shows a cross-sectional view of a known spindle drilling apparatus using air bearings A, B, C to support rotation of the spindle 1 in a chamber 11 formed inside the housing 10. The spindle device comprises a cylindrical motor for rotationally driving the spindle 1. When power is supplied to the actuator motor coil 12 (starter) in the housing 1, the spindle 1 with an outer ring 9 (rotor) made of a conductive material such as copper or metal rotates on axis O Drive. The drill 3 attached to the end 2 of the spindle 1 can be driven to rotate with the rotation of the spindle 1.

Pressurized air or gas is supplied to the air inlets 14, 16 of the spindle device, and then pressurized air is supported by the cushion of air while the spindle 1 rotates in the chamber 11. It discharges from the air discharge parts 13 and 15 of (A, B, C). The air bearings A, B (radial bearings) can support the spindle 1 in the radial direction, while the air bearing C (axial bearings) can hold the spindle 1 from the air outlet 15. The spindle 1 is supported in the axial direction by discharging the pressurized air to the flange 4 of. The spindle 1 can be supported or supported to rotate radially and axially. The spindle device may be mounted or attached to a drilling device (not shown), to carry out the drilling process of a workpiece (not shown), such as a PCB, located below and to move it up and down in the axial direction of the spindle. It can be further driven by a linear motor. As the spindle device rotates at high speeds of thousands or tens of thousands of revolutions per minute, the precision, structural integrity and stability of the parts are becoming more important factors in their manufacture and construction.

Drilling devices or spindle devices have advantages and disadvantages. As is known to those skilled in the art, the heat generated during the drilling process has a significant impact on the life and performance of the spindle. This heat is mainly generated by the friction between the actuator motor coil 12 during operation and the workpiece 2 and the drill 2 of the spindle during the drilling process. As most parts in the spindle device are made of metal or metal alloys, heat and high temperatures can significantly affect the mechanical properties of these parts and reduce their lifespan. As these parts wear out, the precision of the drill holes and grilling process is degraded, and the drill may crack or break during the drilling process. The effects of heat and high temperature on the rigidity and mechanical properties of the spindle device, in particular the parts of the motor 12, air bearings A, B, C and drill 3, are carefully controlled to prevent undesired operation. Should be done. Therefore, an effective cooling system must be provided for the spindle unit, while maintaining the component precision and structural integrity of the unit.

U.S. Patent 5,798,587 describes a "cooling spindle of a high speed spindle" which provides three groups of cooling loops of the cooling zone, wherein the first group is the front bearing cooling zone and the second group is Motor cooling zone, and the third group is the rear bearing cooling zone. Cooling fluid supplied from the outlet of the cooling device flows through the rear end of the spindle to the front bearing cooling zone and then to the motor cooling zone before entering the rear bearing cooling zone. The cooling fluid again travels to the inlet of the cooling device to form a temperature-controlled cooling loop. The cooling loop may provide a cooling function to the bearing and actuator motor. However, due to the structural limitations of the loop, the cooling loop must be configured to surround the internal components of the spindle device in order to achieve the preferred cooling function. This requires considerable precision in the space between the parts and is undesirable for spindle units using air bearings. In particular, the spiral cooling loop made of metal or conductive material must be formed in a precise shape that matches the parts of the spindle unit, thereby reducing the manufacturing costs and providing additional parts and complexity, thereby providing the overall structural integrity of the unit ( integrity is reduced. In addition, the cooling loop does not provide a practical solution for spindle devices using air bearings. In particular, the outer periphery of the air bearing has an air inlet through which air can be introduced, and the cooling loop can prevent air intake of the air bearing by the loop surrounding the bearing surface of the bearing. The provision of a cooling loop in the spindle arrangement including the air bearings can have a significant impact on the performance of the bearings and reduce the stiffness of the bearings. In addition, the circuit of the cooling fluid can be interrupted when the loop breaks, and leakage of the cooling fluid causes the spindle unit to malfunction. There is therefore a need to provide a more efficient cooling system for the spindle unit while maintaining the structural integrity of the device.

U. S. Patent No. 6,373, 158 discloses a "motor shaft provided with rapid cooling means," and according to the disclosure of the patent, a micro-pin provided to aid heat transfer, in order to prevent overheating of the spindle or main shaft during movement. A plurality of micro pins configured therein is provided. The micro pins are arranged adjacent to the bearings and actuator motor coils (starters) in the housing such that these micro pins provide a relatively large surface area for better heat dissipation. However, using these micro fins or their shape does not provide efficient and cost-effective heat dissipation. The micro fins are arranged in a spindle device with a relatively small air circulation and transfer section to limit the heat transfer and dissipation performed by the micro fins. In addition, these micro pins are mainly suitable for wheel bearings and, as they are used in spindles with air bearings, interfere with the attachment of air bearings to the housing and to the air intakes from the surroundings, thereby reducing the rigidity, performance and accuracy of the bearings. Is reduced. More manufacturing and maintenance costs are required to form and configure the micro pins on the inner surface of the housing, which is undesirable.

In order to use a high speed spindle device using air bearings, it is preferred to increase the air intake of the air bearings. In other words, it is necessary to increase the amount of air introduced into the air bearing in order to increase the stability of the spindle shaft rotating at high speed inside the apparatus.

As is known to those skilled in the art, air bearings use air or gas even though air bearings using air or gas as the support medium have a cleaner working environment than any other type of bearing, such as wheel bearings using oil as lubricant. It will be susceptible to damage by prolonged exposure to debris and impurities. There is therefore a need to provide a spindle unit with a structure that is easy to assemble, reassemble, repair and repair.

One feature of the present invention is to provide a spindle unit having a cooling system capable of cooling a high speed spindle including an air bearing.

Another feature of the present invention is to provide a cooling system in which a cooling system is integrally configured within a spindle including an air bearing to cool an actuator motor coil (starter), a spindle end with a drill and / or an air bearing adjacent the end of the spindle shaft. There is. Such cooling systems utilize any known coolant, including water or oil. As such a cooling system is provided, the spindle unit of the present invention is provided with an improved structure with an air bearing capable of providing increased air flow for supporting the spindle. In addition, the spindle device can be configured to allow coolant to flow through its components. The spindle unit can be attached to a drilling machine, for example a high speed drilling machine for a PCB.

According to one feature of the invention, the spindle unit is provided with a cooling system capable of cooling the components of the spindle unit, in particular the air bearing and the actuator coil. In particular, the area surrounding the actuator coil can be cooled by contact cooling. Air bearings, in particular bearings adjacent to the ends of the spindle shafts rotatably supported in the spindle unit, can be cooled as they flow into the bearings with a coolant chamber configured such that the coolant surrounds the ends of the spindle shafts through the coolant channels.

According to one embodiment of the invention, the spindle unit comprises a housing, a cooling cylinder attached within the housing, an actuator coil (starter) covering at least a portion of the inner surface of the housing, a spindle shaft rotatably arranged in the actuator motor coil within the housing. (Rotor) and a plurality of air bearings mounted within the housing, wherein the housing includes one or more air inlets, one or more coolant inlets and one or more coolant outlets, wherein the cooling cylinder supplies air to the plurality of air bearings. And an air conduit having one or more air openings fluidly connected to the air inlet of the housing to flow therethrough, the cooling cylinder allowing coolant to flow from the coolant inlet of the housing to the plurality of air bearings. Bearing cooling channels. In one embodiment of the present invention, each of the air bearings includes a plurality of intake and outlet ports connected in fluid communication with the air inlet of the housing and the air opening of the cooling cylinder, wherein the one or more air bearings increase air intake. Slots on the outer surface to make them easy. In one embodiment, the cooling cylinder and the air bearing can be configured to allow air to flow from the air inlet of the housing to the inlet of the air bearing while at the same time preventing the coolant flowing through the cooling cylinder from entering or blocking the inlet of the air bearing. Can be. In another embodiment, an outer ring of actuator coil may be attached to the cooling cylinder and configured to function as an interface for guiding the coolant flowing therethrough. In one embodiment of the housing, the housing may further comprise a joining base for attaching to a drilling machine. In another embodiment, the coolant inlet, outlet and air inlet of the housing are arranged on its base. In one embodiment of the present invention, at least a portion of the spindle shaft is made of a conductive material to assist startup initiated by the actuator coil.

In another embodiment of the present invention, the spindle unit comprises a front bearing, a rear bearing, a thrust bearing, the rear bearing can support the spindle shaft transversely within the housing, the front bearing together with the thrust bearing in the housing It is not only provided for supporting the spindle shaft in the axial direction but also for supporting the shaft in the housing in the transverse direction. The inlet and outlet of the bearing are connected for fluid communication. In one embodiment, preferably, the diameter of the inlet can be made smaller than the diameter of the corresponding outlet in order to cause or produce a nozzle effect. In one embodiment of a thrust bearing, one side of the thrust bearing includes a coolant opening in which coolant flows through the coolant chamber adjacent the end of the spindle shaft and is in fluid communication with the bearing cooling channel of the cooling cylinder, and thus the spindle shaft. The drilling end of is cooled conductively. In another embodiment, the thrust bearing includes an air slot connected to allow fluid to flow through the intake port so that the air intake amount is increased. In one embodiment of the spindle shaft, the spindle shaft comprises a flange between the thrust bearing and the front bearing, the flange in a spacer ring having a thickness that is greater than or substantially equal to the thickness of the flange to receive the flange thereto. Are arranged. In one embodiment, the spacer ring further includes one or more coolant through holes connected in fluid communication with the coolant conduit of the bearing.

According to another feature of the invention, the spindle unit can increase the air intake of the air bearing as the coolant system is provided. In one embodiment of the present invention, the spindle unit includes one or more axial bearings for supporting the spindle shaft axially in the housing and one or more radial bearings for supporting the spindle shaft transversely, the outer side of the bearing The peripheral surface includes slots for increasing the air receiving space and alternately increasing the air intake, and the outer surface of the bearing is configured to attach to the cooling cylinder. In another embodiment, the spindle unit comprises a front bearing, a rear bearing and a thrust bearing, the front bearing being capable of supporting the spindle shaft axially and transversely together with the thrust bearing, the outside of the rear and front bearings. The peripheral surface further includes a slot for increasing the air intake amount, and the thrust bearing further includes an air slot connected to allow fluid to flow through the inlet of the bearing to effectively discharge air from the outlet.

According to another feature of the invention, the spindle unit is provided with a cooling system that maintains the mechanical properties and structural integrity of the unit. According to the above-mentioned embodiment, the cooling system can be integrated with the spindle unit, in particular the cooling cylinder, the air bearing and the actuator coil are configured to provide the integrity of the cooling system in the spindle unit. As a result of integrity, overall structural unity and precision are maintained. In addition, the rigidity of the air bearings is maintained and the air intake is increased.

The present invention provides a spindle unit with a high precision component and structure. The spindle unit uses air bearings and can be used in high speed drilling machines at rotation speeds of 20,000 to 160,000 RPM or more.

According to another feature of the invention, there is provided a spindle unit that is easy to assemble, reassemble, repair and repair. No external or additional pipes, pins or structures are provided in the spindle unit to increase the complexity of the unit or to reduce the overall integrity. The overall structure of the spindle unit can be easily assembled by detachably connecting or attaching parts of the spindle unit to each other, maintaining high precision on the respective parts, and arranging the respective parts according to their respective functions.

The foregoing description describes preferred embodiments of the present invention and is not intended to limit the present invention. The above-mentioned embodiments can be configured in various ways that are considered to be within the scope of the present invention. Details of the above-mentioned embodiments are provided below to further describe the present invention.

The present invention relates to a spindle unit for a drilling machine. The spindle unit uses an air bearing as a means for rotatably supporting a spindle shaft integrally formed with the cooling system. The spindle unit provides an ultra precision spindle that can rotate at high speed and can be used on high speed drilling machines such as PCB drilling machines. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, details of preferred embodiments of the present invention are described, and for the sake of clarity, reference is made to the accompanying drawings. The technical details of the preferred embodiments are provided only as illustrative embodiments, and any modifications or variations of the above embodiments may be configured within the scope of the present invention.

2 shows a cross-sectional view of a preferred embodiment of the spindle unit 10 according to the present invention. The spindle unit 10 comprises a housing 20 comprising an air inlet 22, a coolant inlet 24 and a coolant outlet 26. The cooling cylinder 30 including the outer surface 31 has an air opening 32 and an air conduit 39 attached to the housing 20 and connected in fluid communication with the air inlet 22 of the housing 20. The cooling cylinder 30 further includes a coil cooling channel 34 and a bearing cooling channel 36 connected to fluid communication with the coolant inlet 24 as well as the coolant outlet 26 of the housing 20. (The coolant outlet is arranged adjacent to the coolant inlet on the other side as shown in FIG. 2). The actuator coil (starter) 40 is attached to the interior of the cooling cylinder 30 and includes an outer ring 42 configured to form an interface between the coil cooling channels 34 of the cooling cylinder 30. do. The spindle shaft 50 (rotor) rotatably supported by the air bearings 70, 80, 90 is arranged inside the actuator coil 40 and transversely from the outer surface 51 of the spindle shaft 50. A flange portion 52 extending into the groove. The air bearings 70, 80, 90 have an axial bearing 90 and a spindle shaft 50 arranged around the flange portion 52 of the spindle shaft 50 for axially supporting the spindle shaft 50. Radial bearings 70, 80 arranged at two separate ends 43, 45 of the actuator coil 40 to laterally support.

In one embodiment, each of the radial bearings 70, 80 may include an inner peripheral surface comprising a plurality of outlets 75, 85, respectively, and an outer peripheral surface having air inlets 73, 83, respectively. have. The inlets 73, 83 of the bearing are connected to allow the fluid to pass through the air opening 32 and the air conduit 39 of the cooling cylinder 30, and the inlets 73, 83 connect the corresponding outlets 75, on the bearing. 85) for fluid communication. In one embodiment, the outlets are formed substantially parallel to the transverse or radial direction of the spindle 50 such that the air discharged from the outlets 75, 85 provides a lateral support for the spindle shaft 50. do. The axial bearing 90 may include a plurality of outlets 95 and a plurality of inlets 93. Similarly, the inlet 93 of the axial bearing 90 is connected in fluid communication with the air opening 32 and the air conduit 39 of the cooling cylinder 30, and the inlet 93 is connected to the outlet 95. The fluid is connected through. In one embodiment, the openings of the outlet 95 of the axial bearing 90 are such that the air discharged from the outlet 95 can support the shaft 50 in the axial or rotational direction within the housing 20. It is formed substantially perpendicular to the flange portion 52 of the spindle shaft 50. In order to lower the temperature of the spindle shaft 50 including the drill 55 attached to the end 57 during the operation of the spindle shaft, the axial bearing 90 has a bearing cooling channel 36 of the cooling cylinder 30. And a coolant chamber 91 and a coolant conduit 96 connected to and in fluid communication with each other. The coolant from the coolant inlet 24 of the housing 20 may thus be moved through the cooling cylinder 30 and may enter the axial bearing 90, in particular the cooling channel 91, such that the cooling chamber 91 Adjacent areas of the spindle unit 10 can be cooled continuously during operation of the spindle unit 10, ie the temperature at the end 57 of the spindle shaft 50 is through this in the cooling chamber 91 of the axial bearing 90. The coolant may be lowered by conductive cooling and / or contact as it flows.

In one embodiment according to the operation of the air bearing of the spindle unit, the pressurized air moves through the air conduit 39 and the cooling cylinder 30 because pressurized air enters the air inlet 22 of the housing 20. Is discharged from the air opening 32. Air then flows to the radial bearings 70 and 80 attached to the cooling cylinder 30 and to the axial bearing 90 arranged around the flange portion 52 of the spindle shaft 50. Pressurized air enters the radial bearings 70, 80 from the inlets 73, 83 to the corresponding outlets 75, 85 on the outer peripheral surface. Similarly entrained air enters the axial bearing 90 from the inlet 93 of the intake surface 92 and then exits the outlet 95. Thus, as the air is discharged from the outlets 75, 85 of the radial bearing 70 toward the outer surface 51 of the spindle shaft 50, the spindle shaft 50 is driven by an air cushion in the radial or transverse direction. Supported. As air is discharged toward the upper and lower surfaces 58, 59 of the flange portion 52 through the outlet 95 of the axial bearing 90, the spindle shaft 50 is axial or rotary axis during its operation. O can be properly supported. In another embodiment of the present invention, the spindle unit 10 includes a plurality of axial bearings and three or more radial bearings. In another embodiment, spindle shaft 50 includes a single axial bearing and a single radial bearing. In other embodiments, the spindle shaft 50 may include two or more flange portions 52 adjacent to the axial bearing 90. The above-mentioned outlets 75, 83, 95 may be formed with a diameter smaller than the diameter of the inlet 73, 83, 93 in order to realize the "nozzle effect." In another embodiment of the present invention The air bearings may additionally include front bearings, rear bearings and thrust bearings to implement the effects of radial and axial bearings, which are described in detail below.

During operation of the spindle unit 10, a power supply, such as an AC power supply (not shown), is made of or covered with a conductive material 54 (rotor) as it transfers current to the actuator coil 40 (starter). The spindle shaft 50, which includes at least a portion of the true outer surface 51, can be driven by the coil 40 to rotate on axis O. As the spindle shaft 50 rotates, the spindle shaft may be suspended or supported inside the actuator coil 40 and the cooling cylinder 30 due to the pressurized air discharged from the air bearings 70, 80, 90. . The above mentioned conductive materials include materials composed of copper, metal alloys or other conductive materials. 3 shows a cross-sectional view according to an embodiment of the spindle shaft 50 of the present invention. In one embodiment, the conductive material is coated with the outer surface 51 of the spindle shaft 50 to form the conductive region 54. In another embodiment, the outer surface 51 of the spindle shaft 50 is entirely coated with a conductive material. In another embodiment the spindle shaft 50 is made entirely of conductive material. The spindle shaft can thus be driven by the actuator coil 40 to rotate on axis O. In another embodiment, the conductive region 54 is configured to form a plurality of strips extending along axis O on the outer surface 51 of the spindle shaft 50. In one embodiment, each said strip surrounding the outer surface 51 is inclined at a certain angle, preferably 5 °, relative to axis O such that the drive rotation of the conducting region 54 is initiated, and thus the spindle shaft 50 ) Is formed smoothly or is easy to operate. The drill 55 attached to one end 57 of the spindle shaft 50 can be driven to rotate on axis O to perform a high speed drilling operation on a workpiece (not shown) located directly below the spindle.

As mentioned above, the actuator coil 40 is one of the main heat sources for raising the temperature of the spindle. It is therefore essential to provide a cooling system for the spindle unit. In another embodiment of the present invention, the spindle unit 10 is integrated with a cooling system that includes a cooling cylinder 40 as shown in FIGS. 2, 4 and 5. 2 shows a preferred embodiment of the spindle unit 10, in which the housing 20 of the spindle unit 10 comprises a coolant inlet 24 and a coolant outlet 26. As the coolant is supplied from the cooling device (not shown) to the outside of the spindle unit 10, the coolant flows by the coolant inlet 24 to the outer surface 31 of the cooling cylinder 30. That is, the coolant flows between the inner surface 21 of the housing 20 and the outer surface 31 of the cooling cylinder 30. In a preferred embodiment of the cooling cylinder 30, the outer surface 31 of the cooling cylinder 30 includes two opposing ends 33, 37 attached to the inner surface of the housing 20. For example, as shown in FIGS. 2 and 4, the two ends 33, 37 of the cooling cylinder 30 are connected to the inner surface 21 of the housing 20 and the outer surface of the cooling cylinder 30. 31) may comprise an O-ring, which functions as a connecting means and is arranged thereon. In another embodiment, the O-ring and the connecting means are detachably attached to the inner surface 31 of the housing 20 rather than the ends 33, 37 of the cooling cylinder 30. In one embodiment, the O-ring can function as a seal that restricts the flow of coolant between the housing 20 and the cooling cylinder 30. The cooling cylinder 30 is provided with a housing 20 by compression fit or close dimensional fitting such that the outer surface 31 of the cooling cylinder 30 is connected with the inner surface 21 of the housing without an O-ring. ) Can be attached.

As shown in FIG. 4, the coolant flowing between the outer surface 31 of the cooling cylinder and the inner surface 21 of the housing 20 allows the actuator coil 40 to be cooled by contact cooling during its operation. Guide 34, whereby the coolant enters the cooling cylinder 30 and reaches the outer ring 42 of the actuator coil 40. In one embodiment, the cooling cylinder 30 may additionally include a bearing cooling channel 36 capable of flowing the coolant through the coolant conduit 96 of the axial bearing 90 and into the coolant chamber 91. have. As shown in FIG. 4, the outer surface 31 of the cooling cylinder 30 further includes a coolant slot 38 for guiding and assisting the coolant flowing therethrough. In another embodiment of the cooling cylinder 30, the inlet or opening of the bearing cooling channel 36 and the coil cooling channel 34 is arranged in the coolant slot 38. The cooling cylinder 30 further includes an air opening 32 connected in fluid communication with an air conduit 39 arranged between the outer and inner surfaces 31, 35 of the cooling cylinder 30. The air conduit 39 of the cooling cylinder 30 is connected to allow fluid to pass through the air opening 32 and the air inlet 22 of the housing 20 so that air can move within the cooling cylinder 30. . As the path of coolant and air is separated, air can flow in the cooling cylinder 30, and at the same time coolant can be introduced into the cooling cylinder 30 by the coil cooling channel 34. As described above, the O-ring may consist of connecting means and / or seals between the housing 20 and the cooling cylinder 30. The coolant may thus flow by the coolant inlet 24 through the cooling cylinder 30 attached to the housing 20, and is discharged from the coolant outlet 26 during operation. In another embodiment of the cooling cylinder 30, the outer or outer surface 31 of the cooling cylinder 30 may be additionally coated with metallic or non-metallic paint to better aid the flow of coolant on the cooling cylinder 30. Can be.

5 shows a preferred embodiment of the actuator coil 40. As mentioned above, the actuator coil 40 may be one of the main heat sources during operation of the spindle unit 10. The coolant from the cooling device (not shown) flows into the coil cooling channel 34 of the cooling cylinder 3 by the coolant inlet 24 of the housing 20, and the coolant flows out of the outer ring of the actuator coil 40. 42 and flow through the outer ring before being discharged to the housing 20 and the cooling cylinder 3 by the coolant outlet 26, whereby a cooling loop integrally formed with the spindle unit 10 is provided. Is formed. As shown in the figure, the outer ring 42 forms an interface between the coil cooling channels 34 of the cooling cylinder 30. In one embodiment, the outer ring 42 may further include a coolant slot 48 for guiding and assisting the coolant flowing therethrough. In addition, one embodiment of the cooling cylinder 3 may include a bearing cooling channel 36 to allow coolant to flow into the axial bearing 90 arranged at one end 57 of the spindle shaft 50. In another embodiment, the coil cooling channel 34 of the cooling cylinder 30 has the slot 48 on the outer ring 42 of the actuator coil 40 such that coolant directly reaches and flows through the slot 48. It is arranged in the above area. As a result, the actuator coil 40 is effectively cooled by direct or contact cooling as the coolant flows through it.

Tables 1 and 2 show the effects and differences of "contacts" where the coolant is cooled as it flows directly through the outer surface of the actuator coil 40. In particular, the data described in Table 1 represent an embodiment in which the coolant flows through the outer surface 31 of the cooling cylinder 30 only without the coolant flowing into the coil cooling channel 34 and in direct contact with the actuator coil 4. Table 2, on the other hand, relates to an embodiment of the spindle unit 10 in which the coolant is in direct contact with the outer ring 42 for "contacting" cooling and flows through the coil cooling channel 34 of the cooling cylinder 30. will be. The temperature of actuator coil 40 is then measured and recorded as described below.

Coolant temperature (° C) Measured Coil Resistance (Ohms) Converted Coil Temperature (° C)  The temperature of the actuator coil (the coolant and the coil are not in direct contact) 18.2 2.01 66 18.5 1.98 67 18.7 1.93 67 18.8 1.95 67 19.1 1.93 67 19.5 1.91 68 19.8 1.89 68 20.2 1.87 68 19 1.88 68 18 1.92 67 16.9 1.98 67

Table 1: Actuator coil temperature (coil is not in direct contact with the coolant)

Coolant temperature (° C) Measured Coil Resistance (Ohms) Converted Coil Temperature (° C)            The temperature of the actuator coil (the coolant and the coil are in direct contact) 16.6 3.62 50 16.8 3.57 50 17 3.52 51 17.2 3.49 51 17.4 3.45 51 17.7 3.43 51 17.9 3.4 52 18.1 3.38 52 18.3 3.36 52 18.5 3.32 52 18.7 3.3 52 18.9 3.28 53 19.1 3.26 53 19.4 3.22 53 19.6 3.2 53 19.7 3.19 53 19.5 3.19 53 19.3 3.2 53 19.1 3.21 53 18.9 3.23 53 18.7 3.25 53 18.5 3.26 53 18.3 3.29 52 18 3.32 52 17.7 3.34 52 17.6 3.37 52 17.4 3.38 52 17.2 3.41 51

Table 2: Actuator coil temperature (coil is in direct contact with the coolant)

The results in Tables 1 and 2 represent the efficiency with the coolant flowing directly through the actuator coil 40 to dissipate the heat generated by the actuator coil 40 in accordance with "contact" cooling. For example, as highlighted in Table 1, the temperature of the coil is 67 ° C when the temperature of the coolant from the cooling device is 19.1 ° C. As shown in Table 2, the temperature of the coil drops to 53 ° C. (highlighted in bold) while the temperature of the coolant is 19.1 ° C. while the coil is cooled by contact cooling. These results show a difference greater than 10 ° C. The method of conversion and temperature measurement used relates to the principle of "thermal resistance measurement". The resistance of the actuator coil 40 is measured based on the R-T relationship of the coil material and known material properties. The corresponding temperature of the resistance value can be calculated and converted. Measurement values formed using a thermal resistive sensor are within the scope of the present invention. In addition, the above-mentioned coolant may be formed of any type of cooling medium including cooling oil or water, and the temperature of the coolant is one of the key properties. The measurements and data indicate the effect of contact cooling of the coil. Any type of coolant may be used, and the scope of the present invention is not limited to any of the values shown in the table.

6 to 11 show another preferred embodiment according to the present invention. 6 is a cross-sectional view according to an embodiment of the spindle unit 110. According to the aforementioned embodiment of the spindle unit 10, the main difference between the embodiments lies in the structure of the air bearings 70, 80, 90, 170, 180, 190 and the housing 20, 120. According to one feature of the invention, the structure of the spindle unit has a cooling system integrally formed thereon while being easily formed for maintenance and assembly. In one embodiment, the housings 20, 120 of the spindle units 10, 110 may be formed to improve the overall structure. In another embodiment, the amount of air sucked on the air bearings 70, 80, 90, 170, 180, 190 is increased to provide a better air cushion effect or support effect for the spindle shafts 50, 150. In another embodiment, the at least one air bearing, in particular the air bearings 90, 190, has a contiguous area comprising end portions 57, 157 of the spindle shafts 50, 150 with drills 55, 155. It is formed in a structure that can flow through the coolant so that the air bearing is continuously cooled. Details are described below.

In one embodiment, spindle unit 110 includes cooling cylinder 130, actuator coil 140, coolant inlet 124, coolant outlet 126 as well as other similar elements mentioned above. A coil cooling system. As further shown in FIGS. 2 and 6, one embodiment of the spindle shafts 50, 150 of the spindle units 10, 110 is a hollow tube in which pneumatic or hydraulic piston rods 60, 160 can be arranged. It is formed in the form. Pneumatic or hydraulic piston rods 60, 160 are mechanisms provided for the operation of drills 55, 155 attached to the ends of spindle shaft 50, whereby drills 55, 155 are removed from the spindle for replacement. Can be. In other embodiments, spindle shafts 50 and 150 may be formed without hollow tube shapes and / or piston loaders 60 and 160.

In one embodiment according to the housing 120 of the spindle unit 110, the housing 120 includes an outer shell 123 and a joining base 125 as shown in FIG. 7. In a preferred embodiment, the outer shell 123 may substantially cover the entirety of the air cylinders 170, 180 and the cooling cylinder 130 arranged at two opposing ends 127, 129. The outer shell 120 further surrounds an actuator coil 140 attached to the interior of the cooling cylinder 130 and may cover at least a portion of the spindle shaft 150 arranged thereon. In one embodiment, the air bearings 170, 180, 190 may be detachably secured to the outer shell 123 by, for example, screws, bolts or adhesives to increase the stability and rigidity of the bearings. In one embodiment of the housing 120, the joining base 125 is detachably secured to one end 129 of the shell 123 by, for example, a screw, bolt, or bonding agent. In another embodiment, the air inlet 122, the coolant inlet 124, and the coolant outlet 126 are arranged on the junction base 125. As shown in the figure, the spindle unit 110 may be configured to have a structure formed well with the lay-out parts according to its function, whereby the entire structure can be easily assembled or reassembled, Parts can be easily removed for replacement and maintenance purposes. The risk of replacing the spindle unit as a whole in the event of a component failure is thus significantly reduced. In other embodiments, the housing 120 may be formed to be integral with the cooling cylinders 30, 130, and in other embodiments the outer shell 123, the bonding base 125, the cooling cylinder 130. ) And the actuator coil 140 may be integrated into a single part.

The following description relates to air bearings 170, 180, 190 (as well as 70, 80, 90), and a mechanism is provided for increasing air intake of the bearings within spindle unit 110 (as well as 10). 8A and 8B show a preferred embodiment of the air bearing 170, as mentioned above the air bearing may be a radial bearing. Accordingly, as the inlet 173 is formed on the outer peripheral surface 173 of the air bearing 170, the air flows into the bearing so that the discharged air can provide a radial support for the spindle shaft 150 inside the bearing. And discharge from corresponding outlet 175 arranged on the inner peripheral surface of the bearing. In one embodiment of the air bearing 170, the air bearing may be a rear bearing in the spindle unit 110. As shown in FIG. 7, in one embodiment, the rear bearing 170 may be positioned adjacent the end 129 of the outer shell 123 and / or adjacent the end 159 of the spindle shaft 150. Can be. In a preferred embodiment, the outer peripheral surface 172 of the air bearing 170 further includes a suction slot 177. In another embodiment, at least a plurality of inlets 173 are arranged on the suction slots 177. The outer peripheral surface 172 of the air bearing 170 may further include an O-ring for connecting with the cooling cylinder 130. The components of the spindle unit 110 are formed with high precision and the outer peripheral surface 172 is arranged at a position adjacent to the cooling cylinder 130. Suction slot 177 can effectively increase the air receiving space, thereby increasing the amount of air sucked in the bearing. In another embodiment, the air bearing 170 further includes a flange 179 on one end to further reinforce the connecting function of the cooling cylinder. The above description is an embodiment with respect to the air bearing 170, which may be applied to a radial bearing comprising the air bearing 80 as described above.

9A and 9B show an embodiment of the air bearing 180 of the present invention. In one embodiment, the air bearing 180 serves as part of the axial support by axially providing thrust air to the spindle shaft and is capable of providing a radial support to the spindle shaft 150. bearing). In some embodiments of the spindle unit 100, the air bearing 180 has a plurality of outlets 185 and outer surfaces 182 on the inner surface 184 to provide axial support to the spindle shaft 150. It includes a plurality of suction ports 183. In one embodiment, the front bearing 180 further includes a thrust plane 189 that is substantially parallel to the flange 152 of the spindle shaft 150, and the thrust plate 189 has air in the spindle shaft ( It may further include a plurality of outlets 185 substantially perpendicular to the flange 152 to be discharged axially with respect to 150. Similarly, the outer peripheral surface of the air bearing 180 may additionally include an intake slot 187, and in some embodiments, at least the plurality of intake ports 183 may have an intake slot 187 to increase the amount of intake air. ) Is arranged on. In another embodiment, the outer peripheral surface 182 of the air bearing 180 may include an O-ring for connecting with the cooling cylinder 130. Preferably in some embodiments, the air bearing 180 is arranged near the end 157 of the spindle shaft 150. As shown in FIGS. 9A and 9B, the air bearing 180 is coolant-penetrating to flow coolant from the bearing cooling channel 136 of the cooling cylinder 130 into the interior of the front bearing or air bearing 180. Sphere 186 may additionally be included. In one embodiment, the coolant through hole 186 is in fluid communication with the bearing cooling channel 136 of the cooling cylinder 130 as it passes through at least a portion of the air bearing 180.

10A and 10B show a preferred embodiment of the air bearing 190 of the present invention. Air bearing 190 includes an axial opening 198 to allow drilling therethrough and to receive end 157 of spindle shaft 150. In one embodiment, the air bearing 190 may be a thrust bearing and may be configured with the aforementioned embodiments of the air bearing 180 to provide axial support to the spindle shaft 150. As shown in the figure, the thrust bearing 190 includes an upper surface 192 and a lower surface 194, the upper surface being formed adjacent to and parallel to the flange 152 of the spindle shaft 150. . The upper surface 192 additionally includes a plurality of outlets perpendicular to the flange 152 of the spindle shaft 150, while the lower surface may be arranged to include an inlet. In one embodiment, the upper surface 192 may also include a suction port. To increase the amount of intake air, the air bearing 190 additionally includes an air-convection slot 197 to increase the air receiving space in the bearing, thus allowing more air to exit the outlet 195. May be discharged from Preferably thrust bearing 190 provides spindle unit 150 to provide axial support in a direction opposite to the direction of front bearing 180 mentioned above such that flange 152 is axially supported by thrust and front bearings. End 157). In addition, in one embodiment, a spacer ring 200 may be arranged between the thrust bearing 190 and the front bearing 180. In a preferred embodiment, the spacer ring can be configured to have an axial thickness that can accommodate the flange 152 therein for passing the drill end of the spindle shaft 150.

In one embodiment, the air bearing 190 additionally includes a coolant conduit 196 and a coolant chamber 191 as shown in FIGS. 10A and 10B to provide cooling to the end 157 of the spindle shaft 150. Include. As the coolant flows from the bearing cooling channel 136, the coolant enters the coolant opening 206 of the spacer ring 200 and the coolant through-hole 186 of the air bearing 180, through which the coolant conduit 196. It moves to the inside of the air bearing 190 via). In one embodiment, the interior of the air bearing 190 further includes a coolant chamber 191 in fluid communication with the coolant conduit 196, whereby the coolant is coupled to the drill end of the spindle shaft 150. It can flow through the coolant chamber 191 arranged adjacently, thereby cooling the support and the surrounding area to which the drill is attached. In addition, as shown in the figure, in one embodiment of the coolant chamber 191, the coolant chamber is configured to be separated from the air delivery slot 197. That is, the coolant chamber and the air delivery slot are completely separated from each other so that air can move through the air delivery slot while the coolant flows through the cooling chamber 191 at the same time during operation of the spindle unit 110, in particular the spindle unit 110. It is not connected to pass through. In one embodiment, the coolant chamber 191 is formed adjacent to the axial openings 98, 198 mentioned above.

11 illustrates another preferred embodiment of the air bearing 190 ′. In one embodiment, the thrust bearing 190 'sends a signal to a feedback system (not shown) to control the drive rotational speed of the spindle shaft 150 and the power supplied to the actuator coil 140 (starter). It further includes a rotational speed sensor (not shown) capable of sensing the rotational speed of the spindle shaft (rotor) 150. As shown in the figure, one embodiment of the thrust bearing 190 'may include a sensor receptacle 199' suitable for receiving a sensor. Preferably the receiver 199 'is arranged at the upper surface 192' of the thrust bearing 190 'opposite the flange 152 of the spindle shaft 150. In one embodiment, the attached sensor and the receiver 199 'are arranged on the lateral side of the coolant chamber 191' and the axial opening 198 '. More preferably the receiver is arranged at a distance away from the coolant conduit 191 ′ and the inlet 193 ′ and on the transverse side of the air delivery slot 197 ′. In one embodiment, the rotational speed sensor is a magnetorelectric sensor, such as a hall sensor or a magnetoresistive component. According to one embodiment of the present invention, the sensor receptacle 199 'of the thrust bearing 190' is suitable for receiving a Hall sensor or Hall component, so that the position of the rotor and the magnetic field of the spindle shaft (rotor) It may be sensed, and signals may be generated and further processed to control the speed of rotation of the spindle shaft 150. In one embodiment, the sensor receiver 199 'is preferably formed in a size or diameter that does not substantially affect the stiffness of the bearing. The above mentioned rotational speed sensor may comprise other types of sensors, including for example optical sensors. Additionally in accordance with one embodiment of the present invention, the sensor may be arranged on the thrust face 89 of the axial bearing, such as the air bearing 90.

The invention is described according to the above detailed examples and preferred embodiments, but such embodiments are not intended to limit the invention and are provided for the purpose of description. For example, the term “air” described in the specification above is not limited to air but relates to gaseous fluids including air. Furthermore, the term "one" described in the specification and claims means "one or more". Modifications and combinations are apparent to those of ordinary skill in the art and are configured within the scope of the appended claims and the spirit of the present invention.

The present invention can be configured in various forms and details of preferred embodiments described in accordance with the accompanying drawings. The drawings show and represent preferred embodiments of the invention without being limited in scope.

1 is a cross-sectional view of a known spindle drilling apparatus.

2 is a cross-sectional view showing a preferred embodiment of the spindle unit of the present invention.

3 shows a cross-sectional view of a preferred embodiment of the spindle shaft of the spindle unit cut along the axis of rotation O;

4 is a cross-sectional view showing a preferred embodiment of the housing of the spindle shaft cut along the axis;

5 is a side view of a preferred embodiment of the actuator coil of the spindle unit.

6 is a cross-sectional view of a preferred embodiment of the spindle unit.

7 shows another preferred embodiment of the spindle unit.

8A is a top view of a preferred embodiment of the air bearing / rear bearing of the spindle unit.

8B is a cross-sectional view of the air bearing / rear bearing shown in FIG. 8A along line A-A.

9A is a top view of a preferred embodiment of the air bearing / rear bearing of the spindle unit.

9B is a cross-sectional view of the air bearing / rear bearing shown in FIG. 9A along line A-A.

10A is a top view of a preferred embodiment of an air bearing / thrust bearing of a spindle unit.

10B is a cross-sectional view of the air bearing / thrust bearing shown in FIG. 10A along line A-A.

FIG. 11 is a top view of another preferred embodiment of the air bearing / thrust bearing of the spindle unit. FIG.

Claims (30)

In a spindle unit for a drilling machine, the spindle unit A housing having at least one air inlet, at least one coolant inlet and at least one coolant outlet, Cooling attached to the housing, including one or more air openings and air conduits connected to allow fluid to pass through the air inlet of the housing, one or more coil cooling channels and one or more bearing cooling channels connected to allow the fluid to pass through the coolant inlet of the housing; Including a cylinder, An actuator coil (starter) surrounded by a cooling cylinder, having an outer ring comprising at least a portion forming an interface between one or more coil cooling channels of the cooling cylinder, A spindle shaft (rotor) rotatably arranged in an actuator coil, the flange including an flange extending outwardly from the outer surface, the outer surface including at least a portion covered with a conductive material, At least one radial bearing attached to the cooling cylinder, the inner peripheral surface having a plurality of outlets and the outer peripheral surface having a plurality of inlets, the inlet having fluid passing through the at least one air opening of the cooling cylinder. Connected to the outlet and the outlet is formed parallel to the radial direction of the spindle shaft, At least one axial bearing attached to the cooling cylinder, including a suction surface with a plurality of inlets, a thrust face with a plurality of outlets, and at least one coolant conduit, said inlet having a fluid flow through the air opening of the cooling cylinder; The outlet is formed perpendicular to the flange of the spindle shaft, the coolant conduit is connected in fluid communication with the bearing cooling panel of the cooling cylinder, The coolant is discharged to the spindle unit by the coolant inlet, at least a portion of the coolant is moved through the coil cooling channel to the outer ring of the actuator coil enclosed by the cooling cylinder, and the other portion of the coolant is transferred through the bearing cooling channel. And a cooling chamber that flows into the coolant conduit of the directional bearing, wherein the axial bearing further comprises a cooling chamber connected in fluid communication with the coolant conduit. The spindle unit of claim 1, wherein the housing further comprises a joining base configured to be attached to the drilling machine. 3. A spindle unit according to claim 2, wherein said at least one air inlet, at least one coolant inlet and at least one coolant outlet are arranged on a joining base. The spindle unit of claim 1, wherein the cooling cylinder has an outer surface including at least a portion formed with a coolant slot to direct the flow of coolant. 5. The spindle unit of claim 4, wherein a coil cooling channel and a bearing cooling channel are arranged in the coolant slot. The spindle unit of claim 4, wherein the outer surface of the cooling cylinder further comprises one or more O-rings for connecting the housing. The spindle unit of claim 1, wherein the interface formed on the outer ring of the actuator coil is a slot for guiding the coolant flowing therethrough. The spindle unit of claim 1, wherein the outer ring of the actuator coil further comprises one or more O-rings for connecting a cooling cylinder. 2. A spindle unit according to claim 1, wherein the conductive material on the outer surface of the spindle shaft is formed of a plurality of strips which are inclined to form an angle with the axis of rotation of the spindle shaft and extend axially along the outer surface. The spindle unit of claim 1, wherein the outer peripheral surface of the radial bearing further comprises one or more suction slots in which a plurality of said suction ports are arranged. The spindle unit of claim 1, wherein the outer peripheral surface of the radial bearing further comprises one or more O-rings for connecting a cooling cylinder. The spindle unit of claim 1, wherein the axial bearing further comprises an axial opening for receiving an end of the spindle shaft therethrough. The spindle unit of claim 1, wherein the axial bearing further comprises an air transfer slot connected to the fluid inlet thereof. The spindle unit of claim 1, wherein the outlet port is formed to have a diameter smaller than that of the suction port. 2. The axial bearing of claim 1 wherein the axial bearing comprises a pair of thrust bearings in which the outlet of the thrust bearing is arranged on the opposite side of the flange of the spindle shaft for axially supporting the spindle shaft. Spindle unit, characterized in that. 16. The spindle unit of claim 15, wherein the pair of thrust bearings are spaced by spacer rings having a thickness for passing through an end of the spindle shaft therethrough and at least receiving a flange of the spindle shaft. 18. The spindle unit of claim 16, wherein said spacer ring further comprises a coolant opening connected to fluid communication with the coolant conduit of the axial bearing. The spindle unit of claim 1, wherein the thrust face of the axial bearing further comprises a sensor receiver for receiving one or more rotational speed sensors. 19. The spindle unit of claim 18, wherein said rotational speed sensor is a hall sensor. In a spindle unit for a drilling machine, the spindle unit Includes an outer shell, A joining base detachably connected to the outer shell, including one or more air inlets, one or more coolant inlets and one or more coolant outlets, -At least one air opening and air conduit connected to fluid communication at the air inlet of the junction base, at least one coil cooling channel and at least one bearing cooling channel connected to fluid communication at the coolant inlet at the junction base. Includes an attached cooling cylinder, An actuator coil (starter) surrounded by a cooling cylinder, including an outer ring having at least a portion forming an interface between said one or more coil coolant channels of the cooling cylinder, A spindle shaft (rotor) rotatably arranged in an actuator coil, the flange extending outwardly from the outer surface and having an outer surface having at least a portion coated with a conductive material, At least one front bearing attached to the cooling cylinder, the outer peripheral surface having a plurality of inlets, the inner peripheral surface and a thrust face having a plurality of outlets and at least one coolant through-hole, said inlets having an outlet and a cooling cylinder Fluidly connected to one or more air openings of the outlet, the outlet on the inner peripheral surface is formed parallel to the radial direction of the spindle shaft while the outlet on the thrust face is formed perpendicular to the flange of the spindle shaft, and the coolant The through hole is connected for fluid communication to the bearing cooling channel of the cooling cylinder, At least one rear bearing attached to the cooling cylinder, the outer peripheral surface having a plurality of inlets and an inner peripheral surface having a plurality of outlets, said inlets having fluid flow through at least one air opening and outlet of the cooling cylinders; The outlet is formed parallel to the radial direction of the spindle shaft, At least one thrust bearing facing the front bearing, including a suction surface with a plurality of inlets, a thrust face with a plurality of outlets, and at least one coolant conduit, the outlet being formed perpendicular to the flange of the spindle shaft; The coolant conduit is in fluid communication with the coolant through hole of the front bearing, A spacer ring arranged between the front bearing and the thrust bearing for passing and rotating the end of the spindle shaft, As the coolant is discharged to the spindle unit by the coolant inlet, at least a portion of the coolant moves through the coil cooling channel to the outer ring of the actuator coil, and the rest of the coolant is passed through the bearing cooling channel to the coolant through hole of the front bearing. And a coolant conduit which then flows into the coolant conduit of the thrust bearing, the thrust bearing further comprising a cooling chamber connected in fluid communication with the coolant conduit. 21. The spindle unit of claim 20, wherein the cooling cylinder has an outer surface including at least a portion formed with a coolant slot to direct the flow of coolant. 21. The spindle unit of claim 20, wherein a coil cooling channel and a bearing cooling channel are arranged in the coolant slot. 21. The spindle unit of claim 20, wherein the outer surface of the cooling cylinder further comprises one or more O-rings for connecting the outer shell. 21. The spindle unit of claim 20, wherein said interface formed on an outer ring of an actuator coil is a slot for guiding coolant flowing therethrough. 21. The spindle unit of claim 20, wherein said outer ring of actuator coil further comprises one or more O-rings for connecting a cooling cylinder. 21. The spindle unit of claim 20, wherein the conductive material on the outer surface of the spindle shaft is formed of a plurality of strips inclined to form an angle with the axis of rotation of the spindle shaft and extending axially along the outer surface. 21. The spindle unit of claim 20, wherein the outer peripheral surfaces of the front and rear bearings further comprise one or more suction slots. 21. The spindle unit of claim 20, wherein the thrust face of the thrust bearing further comprises an air transfer slot connected to allow fluid to pass through its inlet. 21. The spindle unit of claim 20, wherein the spacer ring further comprises a coolant opening in fluid communication with the coolant conduit of the thrust bearing and the coolant through hole of the front bearing. 21. The spindle unit of claim 20, wherein the thrust face of the thrust bearing further comprises a sensor receptacle for receiving one or more rotational speed sensors.

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