Cooling main shaft and circular saw

Abstract

The invention provides a cooling main shaft and a circular saw. The cooling main shaft and the circular saw are used for at least solving the technical problem of main shaft heat dissipation in the prior art. The cooling main shaft comprises a cutter mounting part, a heat dissipation part, a bearing part and a transmission part, the cutter mounting part is provided with a detachable structure capable of mounting and dismounting a machining cutter, the transmission part and the driving device achieve transmission, the bearing part is provided with a bearing so that the main shaft body can rotate, the heat dissipation part is arranged close to the cutter mounting part, and a cooling box is arranged on the periphery of the heat dissipation part; the cooling box is provided with a liquid inlet and a liquid outlet, cooling liquid enters the cooling box from the liquid inlet, and the cooling liquid leaves the cooling box from the liquid outlet after making contact with the heat dissipation part; or the cooling box is provided with a refrigerating device which can reduce the temperature of the cooling liquid in the cooling box. The temperature close to the tool mounting part is high, and the heat conductivity coefficient of the solid is far higher than that of the liquid, so that a large part of heat of tool machining is transmitted through the spindle body, the spindle body is directly connected with the machining tool, the temperature of the machining tool can be reduced, and the cutting speed is increased.

Description

Technical Field

[0001] This application relates to the field of machine tools, and more particularly to a cooling spindle and a circular saw. Background Technology

[0002] Machine tools typically process materials using cutting methods, which generate a large amount of heat. For example, when a saw cuts hard steel, the temperature can reach hundreds of degrees Celsius. Therefore, cutting fluid is usually needed for cooling and the rotation speed must be controlled. Most circular saws operate at around 100 revolutions per minute. The larger the diameter of the saw blade, the lower the rotation speed. The rotation speed determines the processing efficiency. High rotation speed inevitably leads to an increase in the temperature of the saw blade. Currently, even the best-performing circular saw blades on the market, made of high-cobalt ultra-hard high-speed tool steel, can only withstand temperatures up to around 600 degrees Celsius. Furthermore, high-temperature cutting generates oil fumes that pollute the air, negatively impacting the working environment of the entire workshop. Cutting fluid has good fluidity, but as a liquid, its thermal conductivity is much lower than that of a solid, typically below 1 W / (m·K). The thermal conductivity of steel is around 40 W / (m·K), while pure copper can reach 400 W / (m·K). Cutting fluid is usually added to the cutting position, which has the highest temperature and the best cooling effect. However, due to heat conduction, the spindle temperature usually exceeds 50°C. In high-temperature workshops or under long-term high-load operation, the spindle temperature can even exceed 90°C. Therefore, spindle cooling is absolutely necessary. Lowering the spindle temperature will also lower the saw blade temperature, thereby increasing the saw blade speed and improving processing efficiency.

[0003] Chinese patent application CN219945483U, entitled "A Cooling Device for a Sawing Machine," discloses a cooling device for a sawing machine. The device includes a cooling chamber within the spindle box, containing cooling lubricant. A drive spindle, which drives the saw blade assembly, is rotatably mounted within the spindle box. A support sleeve is also located within the spindle box, and the drive spindle is rotatably mounted within the support sleeve via a rotating bearing assembly. Sealing devices are located at both ends of the support sleeve. A cooling circuit communicating with the cooling chamber is located within the support sleeve. A circulating inlet and outlet are located on the top of the spindle box. An inlet pipe is connected to the circulating inlet, and an outlet pipe is connected to the circulating outlet. A suction pump and a radiator are fixed to the spindle box. The outlet pipe is connected to the inlet of the suction pump, and the outlet of the suction pump is connected to the cooling inlet of the radiator. The cooling outlet of the radiator is connected to the inlet pipe. This device can effectively cool the rotating bearings on the drive spindle when it rotates, thereby aiding in heat dissipation and lubrication of the drive spindle and rotating bearings, improving performance. However, this design uses a bearing between the spindle and the cooling chamber, resulting in low thermal conductivity, high spindle temperature, and difficulty in increasing spindle speed.

[0004] Chinese patent application CN107470977A, entitled "A Cooling System for the Spindle and Sawing of a CNC Horizontal Circular Saw," discloses a cooling system for the spindle and sawing of a CNC horizontal circular saw. The system includes a sawing section and a saw blade spindle with an internal axial central through hole. One end of the saw blade spindle is connected to a coolant pipe via a connector, and the other end is fixedly connected to the sawing section. The sawing section includes an outer pressure plate, an inner pressure plate, and a saw blade located between the outer and inner pressure plates. A coolant cavity is formed at the center of the outer and inner pressure plates, and outlet channels communicating with the coolant cavity are respectively formed on the inner and outer pressure plates. However, this design results in coolant splashing everywhere, making it difficult to control. Furthermore, the rotary joint is prone to wear, causing coolant leakage.

[0005] Chinese patent application CN219648837U, entitled "A Cooling Device for the Spindle and Sawing of a Horizontal CNC Circular Saw," discloses a cooling device for the spindle and sawing of a horizontal CNC circular saw. The device includes a protective shell, a mounting component on the left side of the protective shell, a saw blade mounted on the left side of the mounting component, and through holes evenly spaced on the outer surface of the mounting component. A mounting shell is located on the right side of the protective shell, and a conveying pipe is connected to the lower surface of the mounting shell. A water pump is connected to the end of the conveying pipe, and a water inlet pipe is connected to the input end of the water pump. A fixing plate is fixed to the upper surface of the mounting shell, and the spindle body is housed inside the mounting shell. However, this design suffers from the risk of wear on the sealing ring due to long-term spindle rotation, leading to coolant leakage. Summary of the Invention

[0006] This application provides a cooling spindle and circular saw to at least solve the spindle heat dissipation technology problem existing in the prior art.

[0007] According to a first aspect of this application, a cooling spindle is provided, including a tool mounting section, a heat dissipation section, a support section, and a transmission section. The tool mounting section has a detachable structure for mounting and removing machining tools. The transmission section is connected to a drive device for transmission. The support section has a bearing that allows the spindle body to rotate. The heat dissipation section is located near the tool mounting section. A cooling box is provided on the outer periphery of the heat dissipation section. The cooling box has an inlet and an outlet. Coolant enters the cooling box from the inlet and leaves the cooling box from the outlet after contacting the heat dissipation section. Alternatively, the cooling box is provided with a refrigeration device to reduce the temperature of the coolant inside the cooling box.

[0008] Compared with the prior art, the cooling spindle of this application has the following beneficial effects: The area near the tool mounting point has a high temperature, and the thermal conductivity of solids is much higher than that of liquids. Therefore, a large portion of the heat generated during tool machining is transferred through the spindle body. Traditional cooling methods only apply cooling fluid to the machining area. Since cutting fluid has a low thermal conductivity, especially in circular saws, coolant nozzles are not installed on non-machined surfaces to prevent splashing. This results in a short cooling time, making it difficult to achieve sufficient cooling. The average temperature of the saw blade can reach hundreds of degrees Celsius, and the only way to avoid damage is to reduce the sawing speed. The cooling spindle of this application uses a cooling tank to maintain the spindle body temperature at a low level, even below zero. This reduces the temperature of the machining tool and improves machining efficiency. Lowering the temperature of the cutting fluid affects its flow properties. Cutting fluid not only has a cooling function but also a lubricating function, primarily acting at the cutting position with a relatively small range of action. Therefore, the cooling effect of room-temperature cutting fluid is quite similar to that of low-temperature cutting fluid. This application provides cooling for the spindle body, eliminating the need for lubrication. Low-freezing-point antifreeze can be used, and a high-efficiency refrigeration device can cool the antifreeze to minus forty degrees Celsius, thus lowering the spindle body temperature to below zero. The spindle body is directly connected to the machining tool, reducing the tool temperature. For circular saws, this allows for increased saw blade speed and faster cutting speed.

[0009] In one embodiment, the heat dissipation section has multiple disc-shaped heat dissipation fins axially arranged on the main shaft body, with the diameter of the heat dissipation fins near the outer ends being smaller than the diameter of the heat dissipation fins near the center. Multiple disc-shaped heat dissipation fins can increase the heat dissipation area and improve heat exchange efficiency.

[0010] In one embodiment, the cooling box is provided with heat-conducting fins, with heat-conducting fins spaced apart between the heat dissipation fins. Compared with solids, liquids have a lower thermal conductivity and poorer thermal conductivity. In addition, when the spacing between heat dissipation fins is small, the coolant tends to rotate with the heat dissipation fins, reducing heat exchange efficiency. By providing heat-conducting fins, the coolant can flow back and forth between the stationary and moving heat-conducting fins and the heat dissipation fins, greatly improving heat exchange efficiency.

[0011] In one embodiment, the cooling tank is annular and surrounds the spindle body. When the spindle body rotates, an annular heat exchange zone is formed outside the spindle body. That is, the coolant overcomes gravity under the action of centrifugal force to form a near-annular coolant ring, reducing coolant leakage between the spindle body and the cooling tank body.

[0012] In one embodiment, the cooling tank is connected to a negative pressure pipe, creating a negative pressure environment inside the cooling tank. This ensures that even if a small amount of coolant reaches between the cooling tank and the spindle body, it will flow within the cooling tank under negative pressure, preventing coolant leakage even without a seal between the cooling tank and the spindle body.

[0013] In one embodiment, the cooling tank inlet is equipped with a circulation pipe, which is connected to the circulation pool. The circulation pool obtains coolant from the cooling tank through a negative pressure pipe connected to the outlet, and then delivers coolant to the cooling tank through the circulation pipe. This allows the coolant to be recycled, and further improves the heat exchange efficiency during the circulation process.

[0014] In one embodiment, the circulation tank is equipped with a cooling device to reduce the temperature of the coolant. The cooling device utilizes the evaporation of compressed refrigerant or employs semiconductors for cooling. If an ethylene glycol antifreeze with a concentration greater than 60% is used as the coolant, it can ensure that the coolant does not solidify at -50 degrees Celsius, thus significantly reducing the temperature of the spindle body. The temperature should be selected according to the specific application scenario. Especially for large circular saws, where the entire processing line costs over a million, the working efficiency of the circular saw greatly affects its processing cost. The processing speed of a circular saw is greatly affected by the saw blade temperature; increasing the saw blade speed increases the temperature of the saw blade during processing. Therefore, increasing the cooling rate can increase the circular saw blade speed, thereby improving processing efficiency. Different cooling temperatures can be set for different processing equipment.

[0015] In one embodiment, the inlet is located at the highest point directly above the heat dissipation unit, and the outlet is located below the spindle body, near the spindle body. This allows for top-to-bottom cooling of the spindle body's heat dissipation unit. As the spindle body rotates, the coolant distributes in a ring shape. Under centrifugal force, less coolant is present near the spindle, and excess coolant can flow out from the outlet near the spindle body, preventing coolant leakage.

[0016] In one embodiment, the machining tool is a circular saw blade. The transmission unit and the drive device transmit power and provide axial and circumferential forces. A tapered roller bearing is provided on the bearing unit near the tool mounting part. The tapered roller bearing has an outer ring, an inner ring, and rollers. The inner side of the outer ring and the outer side of the inner ring are provided with tapered surfaces. The tapered surfaces of the outer or inner ring of the tapered roller bearing on the spindle body are oriented in the same direction as the axial force provided by the drive device. This allows the spindle body to move axially a certain distance under the axial force provided by the drive device, reducing the clearance between the inner ring, outer ring, and rollers. This reduces radial runout and improves machining accuracy.

[0017] According to a second aspect of this application, a circular saw with a cooled spindle is provided, wherein the aforementioned cooled spindle is used and a circular saw blade is mounted in the tool mounting section. This improves the machining efficiency of the circular saw.

[0018] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0019] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. Several embodiments of this application are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0020] Figure 1 This paper shows a three-dimensional schematic diagram of the composition structure of the cooling spindle in Embodiment 1 of this application; Figure 2 A half-sectional schematic diagram of the cooling spindle of Embodiment 1 of this application is shown; Figure 3 This diagram illustrates the cooling spindle in Embodiment 1 of this application with the lower half of the housing removed. Figure 4 A three-dimensional schematic diagram of the upper half of the cooling spindle of Embodiment 1 of this application is shown; Figure 5 A three-dimensional schematic diagram of the lower half of the cooling spindle of Embodiment 1 of this application is shown; Figure 6 A schematic diagram of the circulation pool connection for the cooling spindle in Embodiment 1 of this application is shown; Figure 7 A schematic diagram of the transmission structure for cooling the spindle in Embodiment 1 of this application is shown; Figure 8 A perspective view of the cooling spindle of Embodiment 2 of this application is shown; Figure 9 This shows a half-sectional view of the first extreme position of the cooling spindle in Embodiment 2 of this application; Figure 10 This shows a half-sectional view of the second extreme position of the cooling spindle in Embodiment 2 of this application; Figure 11 A schematic diagram of the composition structure of the circular saw of Embodiment 3 of this application is shown; Figure 12 This invention provides a schematic diagram of the internal structure of the casing after the circular saw removes a portion of the casing in Embodiment 3 of this application. Figure 13 A schematic diagram of the transmission structure of the circular saw according to Embodiment 3 of this application is shown; Figure 14 A schematic diagram of the installation position of the cooling spindle in Embodiment 3 of this application is shown; Figure 15 A half-sectional schematic diagram of the cooling spindle of Embodiment 3 of this application is shown.

[0021] The same reference numerals are used in different embodiments, and the reference numerals in the figure are explained as follows: X, first direction; Y, second direction; Z, third direction; 1. Spindle body; 2. Circular saw blade; 3. Drive unit; 4. Bearing section; 5. First clamping section; 6. Second clamping section; 7. Braking device; 8. Housing; 9. Shell; 11. Heat dissipation section; 12. Tool mounting section; 13. Bearing section; 14. Transmission section; 31. First drive unit; 32. Second drive unit; 51. Linear track; 52. Track drive motor; 81. Friction disc; 103. Coolant chamber; 104. Coolant pipe; 105. Journal neck; 106. Evaporation channel; 107. Flywheel; 108. Brake disc; 109. Heat-conducting fins ; 110. Cooling box; 111. Liquid inlet; 112. Liquid outlet; 113. Heat dissipation fins; 114. Upper half box; 115. Lower half box; 116. Sealing groove; 117. Circulation pipe; 118. Circulation pool; 119. Refrigeration device; 120. Negative pressure pipe; 130. Tapered roller bearing; 131. Inner ring; 132. Outer ring; 133. Roller; 134. Sleeve section; 135. Inner cylinder section; 136. Cylindrical roller bearing; 137. Conical surface; 141. Helical gear; 142. Gear ring; 143. Second transmission section; 144. First transmission section. Detailed Implementation

[0022] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Example 1: like Figure 1 and Figure 2 As shown, a cooling spindle can be used in circular saws, milling machines, and drilling machines. However, milling machines and drilling machines have relatively concentrated machining positions and temperature distributions, resulting in lower heat transfer efficiency through the spindle. Circular saws, on the other hand, have more dispersed machining positions compared to milling and drilling machines, allowing for sufficient cooling time. Therefore, using a cooling spindle effectively improves machining efficiency. In the figure, the first direction is the axial direction of the spindle body 1, which is horizontal; the second direction is radial, also horizontal; and the third direction is vertical, pointing upwards.

[0024] like Figure 1 and Figure 2As shown, this embodiment takes a circular saw as an example. The processing tool is a circular saw blade 2. The cooling spindle includes a tool mounting part 12, a heat dissipation part 11, a support part 13, and a transmission part 14. The tool mounting part 12 has a detachable structure that can install and remove the processing tool, i.e., the circular saw blade 2. The transmission part 14 is connected to the drive device 3 for transmission. The transmission structure of the transmission part 14 can be a gear, a pulley, a sprocket, or a combination thereof. The support part 13 is provided with a bearing so that the spindle body 1 can rotate. The heat dissipation part 11 is located close to the tool mounting part 12. The closer the heat dissipation part 11 is to the tool mounting part 12, the better the heat dissipation effect. Considering the force problem, the spindle body 1 has a small diameter and limited load-bearing capacity. If the spindle body 1 has a large diameter, the effective processing radius will be reduced. The support part 13 is located between the heat dissipation part 11 and the tool mounting part 12, which can reduce the radius of the spindle body 1. In some embodiments, for small circular saws, the tool mounting part 12 and the heat dissipation part 11 can be arranged adjacent to each other. A cooling tank 110 is provided around the outer periphery of the heat dissipation unit 11. The cooling tank 110 has an inlet 111 and an outlet 112. Coolant enters the cooling tank 110 through the inlet 111 and leaves the cooling tank 110 through the outlet 112 after contacting the heat dissipation unit 11. Heat conduction is achieved through the coolant, eliminating the need for direct contact, reducing wear, extending service life, and improving processing stability, thus reducing the failure rate.

[0025] like Figure 1 and Figure 2 As shown, in one embodiment, the heat dissipation unit 11 has a plurality of disc-shaped heat dissipation fins 113 axially arranged on the spindle body 1. The heat dissipation fins 113 can be welded to the outside of the spindle body 1, and the diameter of the edge heat dissipation fins 113 near the outer ends is smaller than the diameter of the heat dissipation fins 113 near the center. The heat dissipation fins 113 at both outer ends mainly use centrifugal force to prevent coolant leakage from the cooling tank 110. Therefore, the edge heat dissipation fins 113 do not come into contact with the coolant during normal operation, and control the coolant within the cooling tank 110 when coolant splashes. In this way, coolant leakage is not likely to occur between the cooling tank 110 and the spindle body 1 even without a sealing ring.

[0026] like Figure 2 and Figure 3 As shown, in one possible embodiment, the cooling box 110 is provided with heat-conducting fins 109, and heat-conducting fins 113 are spaced apart by heat-conducting fins 109. The heat-conducting fins 109 are also annular and are arranged corresponding to the heat-conducting fins 113. The heat-conducting fins 109 may be provided with through holes to ensure that the two sides of the heat-conducting fins 109 are connected.

[0027] like Figure 3 , Figure 4 and Figure 5As shown, in one embodiment, the cooling box 110 is annular and surrounds the spindle body 1. The cooling box 110 includes an upper half box 114 and a lower half box 115. The upper half box 114 and the lower half box 115 are provided with sealing grooves 116 for installing sealing rings. The split design facilitates installation.

[0028] like Figure 2 and Figure 5 As shown, in one embodiment, the cooling box 110 is connected to the negative pressure pipe 120 so that the inside of the cooling box 110 is in a negative pressure state.

[0029] like Figure 2 , Figure 4 and Figure 6 As shown, in one embodiment, the inlet 111 of the cooling tank 110 is provided with a circulation pipe 117, which is connected to the circulation pool 118. The circulation pool 118 obtains coolant from the cooling tank 110 through a negative pressure pipe 120 connected to the outlet 112, and delivers coolant to the cooling tank 110 through the circulation pipe 117.

[0030] like Figure 2 , Figure 4 and Figure 6 As shown, in one embodiment, the circulation tank 118 is equipped with a cooling device 119, which lowers the temperature of the coolant. The cooling device 119 utilizes the evaporation of compressed refrigerant or a semiconductor to achieve cooling. If an ethylene glycol antifreeze with a concentration greater than 60% is used as the coolant, it can ensure that the coolant does not solidify at -50 degrees Celsius, thus significantly reducing the temperature of the spindle body 1. The temperature is selected according to the specific application scenario. Especially for large circular saws, where the entire processing line equipment costs over a million, the working efficiency of the circular saw greatly affects its processing cost. The processing speed of the circular saw is greatly affected by the saw blade temperature; increasing the saw blade speed increases the temperature of the saw blade during processing. Therefore, increasing the cooling speed can increase the speed of the circular saw blade 2, thereby improving processing efficiency. Different cooling temperatures can be set for different processing equipment. For high-power circular saws, the coolant temperature can be set at -40 degrees Celsius, so the temperature of the spindle body 1 during operation is close to -30 degrees Celsius. The spindle temperature of a conventional circular saw exceeds 50 degrees Celsius during operation, a temperature difference of 80 degrees Celsius, resulting in completely different heat dissipation efficiencies. The circular saw blade 2 is installed at completely different processing temperatures. At the same temperature, the spindle body 1 of this application can increase its rotation speed by 20%, resulting in higher processing efficiency.

[0031] like Figure 1 , Figure 4 and Figure 5As shown, in one possible embodiment, the liquid inlet 111 is located at the highest point directly above the heat dissipation section 11, and the coolant can enter the cooling tank 110 from the liquid inlet 111 under the action of gravity. The liquid outlet 112 is located below the spindle body 1 and close to the spindle body 1.

[0032] For high-power machine tools, copper or aluminum can be plated on the surfaces of the circular saw blade 2, the spindle body 1, and other components in contact with the saw blade. This can further improve the conductivity of each component and achieve efficient heat conduction. Silicone grease can be used to fill the gaps between the components to increase heat transfer performance, especially between the circular saw blade 2 and the spindle body 1.

[0033] like Figure 1 and Figure 2 As shown, in one embodiment, the transmission unit 14 transmits power to the drive device 3 and provides axial and circumferential forces. The bearing unit 13 is provided with a tapered roller bearing 130 near the tool mounting unit 12. The tapered roller bearing 130 has an outer ring 132, an inner ring 131, and rollers 133. The inner side of the outer ring 132 and the outer side of the inner ring 131 are provided with a tapered surface 137. The tapered surface 137 of the outer ring 132 or the inner ring 131 of the tapered roller bearing 130 provided on the spindle body 1 faces the same direction as the axial force provided by the drive device 3. In the figure, the axial force provided by the drive device 3 is opposite to the first direction, and the tapered surface 137 also faces the opposite direction to the first direction. This makes the spindle body 1 move axially a certain distance under the axial force provided by the drive device 3, and the clearance between the inner ring 131, the outer ring 132, and the rollers 133 is reduced.

[0034] Due to the significant temperature variations between the machining and non-machining states of the spindle body 1, a certain temperature difference exists between the inner ring 131 and the outer ring 132 of the bearing. Therefore, the bearing clearance variation is relatively larger than that of ordinary bearings. In this embodiment, the clearance between the inner ring 131, outer ring 132, and roller 133 is related to the axial force provided by the drive device 3 and the contact angle of the tapered roller bearing 130. The contact angle of the tapered roller bearing 130 has a significant impact on radial runout. When the axial force provided by the drive device 3 is constant, the smaller the contact angle of the tapered roller bearing 130, the smaller the radial runout. Under the same axial direction... The smaller the clearance under the applied force, the greater the rotational resistance. Therefore, the contact angle of the tapered roller bearing 130 needs to be selected within a suitable range. The spindle body 1 automatically generates axial force under the drive of the drive device 3. By controlling the axial force within a reasonable range, the corresponding clearance can be obtained. In this way, even if the bearing wears continuously, the spindle body 1 will move axially under the axial force and automatically adjust the clearance to obtain a suitable clearance, thereby reducing radial runout and increasing the machining accuracy of the machine tool. In addition, even if the temperature of the spindle body 1 changes during the machining process, it will not affect the clearance size or the machining accuracy.

[0035] like Figure 1 and Figure 2 As shown, in one embodiment, the outer ring 132 is fixed to the spindle body 1, and the inner ring 131 is mounted to the bearing portion 4 of the machine tool. The bearing portion 4 can be integrated with the machine tool housing 8. This results in a larger bearing radius and stronger load-bearing capacity. The rollers 133 are mounted on the inner ring 131 via cages, and the inner ring 131 is more stably fixed to the bearing portion 4.

[0036] like Figure 1 and Figure 2 As shown, in one embodiment, the spindle body 1 is provided with a sleeve portion 134, the outer ring 132 is fixed inside the sleeve portion 134, and the bearing portion 4 is provided with an inner cylinder portion 135, the inner ring 131 is installed outside the inner cylinder portion 135. The inner cylinder 135 is an integral structure with the housing 8 or is fixed to the housing 8 by screws. This can increase the size of the tapered roller bearing 130 and increase the load capacity of the tapered roller bearing 130. The roller 133 is usually fixed to the inner ring 131 by a cage. After the cage wears, the roller 133 is easy to fall off the inner ring 131. The inner ring 131 is installed on the spindle body 1 and will rotate with it. The roller 133 is easy to fall off the inner ring 131 under the action of centrifugal force. However, the inner ring 131 is installed on the bearing part 4. When the clearance is large, the roller 133 can fall off the outer ring 132 and stop rotating, preventing further rotation and separation from the inner ring 131. When the clearance is small, the roller 133 is in close contact with the outer ring 132, stabilizing the spindle body 1 and reducing the radial runout of the spindle body 1.

[0037] like Figure 1 and Figure 2 As shown, in one embodiment, the transmission part 14 is provided with a gear ring 142, which is fixed to the main shaft body 1 by means of threads. Whether the gear ring 142 has straight teeth or helical teeth, it can decompose a part of the circumferential force to the axial direction, so that the tapered roller bearing 130 can be subjected to a stable axial force, ensuring the clearance of the tapered roller bearing 130 and making the radial runout smaller.

[0038] like Figure 1 and Figure 2 As shown, in one embodiment, the contact angle of the tapered roller bearing 130 is less than or equal to the helix angle of the thread. This ensures a larger radial support force and keeps radial runout within a smaller range.

[0039] like Figure 1 and Figure 7As shown, in one embodiment, the transmission unit 14 includes a first transmission unit 144 and a second transmission unit 143. When the first transmission unit 144 and the second transmission unit 143 are in transmission, the axial forces they generate on the spindle body 1 are in opposite directions. The first transmission unit 144 and the second transmission unit 143 are driven by independent first drive devices 31 and second drive devices 32. For example, the first drive device 31 of the first transmission unit 144 is driven by a 15 kW motor, and the second drive device 32 of the second transmission unit 143 is driven by a 10 kW motor, with a rotational speed of 1440 rpm. For the helical gear 141, the pitch circle radius is 50 mm and the helix angle β = 15 degrees. When the first drive device 31 and the second drive device 32 drive the spindle body 1 to rotate, they generate opposite axial forces on the spindle body 1, and the axial forces can be controlled within 4 kN.

[0040] like Figure 1 and Figure 2 As shown, in one embodiment, the bearing portion 13 is provided with multiple cylindrical roller bearings 136 or needle roller bearings and at least one tapered roller bearing 130. Different machine tools have different power ratings; some machine tools have higher power and generate greater axial forces. Using a single cylindrical roller bearing 136 or needle roller bearing is insufficient to handle circumferential forces. The cylindrical roller bearings 136 or needle roller bearings mainly bear radial loads. For large machine tools, the radial load is large. To ensure axial movement, the inner ring 131 or outer ring 132 of the cylindrical roller bearings 136 or needle roller bearings are not provided with flanges, ensuring that the spindle body 1 can move axially within a certain range when subjected to axial forces.

[0041] Example 2: like Figure 8 and Figure 9 As shown, the difference from Embodiment 1 is that the cooling box 110 is equipped with a refrigeration device 119 to reduce the temperature of the coolant inside the cooling box 110. The refrigeration device 119 can utilize compressor refrigeration or semiconductor refrigeration. If semiconductor refrigeration is used, the cold end of the semiconductor is placed inside the cooling box 110 to cool the coolant, and the hot end is placed outside the cooling box 110 to dissipate heat. If compressor refrigeration is used, the refrigeration device 119 includes a compressor, an evaporator, a condenser, and a control circuit. The cooling box 110 is provided with an evaporation channel 106, and the evaporator is connected to the evaporation channel 106. The compressor compresses the refrigerant and delivers it to the evaporation channel 106. The refrigerant in the evaporation channel 106 evaporates, thus carrying away heat. In this way, the refrigerant can be efficiently reduced to a sub-zero temperature, and the temperature is transferred to the spindle body 1 through the coolant inside the cooling box 110, so that the spindle body 1 has a low temperature. The cooling box 110 is provided with a coolant chamber 103 for filling with coolant. The cooling fins 109 are located in the coolant chamber 103. The coolant chamber 103 is connected to the coolant pipe 104 for easy filling with coolant.

[0042] like Figure 9 and Figure 10 As shown, in one embodiment, the machining tool is a circular saw blade 2. The transmission part 14 and the drive device 3 transmit power and provide axial and circumferential forces. The bearing part 13 is provided with a tapered roller bearing 130 near the tool mounting part 12. The tapered roller bearing 130 is provided with an outer ring 132, an inner ring 131 and rollers 133. The inner side of the outer ring 132 and the outer side of the inner ring 131 are provided with a tapered surface 137. The tapered surface 137 of the outer ring 132 or the inner ring 131 of the tapered roller bearing 130 provided on the spindle body 1 faces the same direction as the axial force provided by the drive device 3. In the figure, the axial force provided by the drive device 3 is opposite to the first direction, and the tapered surface 137 also faces the opposite direction to the first direction. This makes the spindle body 1 move axially a certain distance under the axial force provided by the drive device 3, and the clearance between the inner ring 131, the outer ring 132 and the rollers 133 is reduced.

[0043] Due to the significant temperature variations between the machining and non-machining states of the spindle body 1, a certain temperature difference exists between the inner ring 131 and the outer ring 132 of the bearing. Therefore, the bearing clearance variation is relatively larger than that of ordinary bearings. In this embodiment, the clearance between the inner ring 131, outer ring 132, and roller 133 is related to the axial force provided by the drive device 3 and the contact angle of the tapered roller bearing 130. The contact angle of the tapered roller bearing 130 has a significant impact on radial runout. When the axial force provided by the drive device 3 is constant, the smaller the contact angle of the tapered roller bearing 130, the smaller the radial runout. Under the same axial direction... The smaller the clearance under the applied force, the greater the rotational resistance. Therefore, the contact angle of the tapered roller bearing 130 needs to be selected within a suitable range. The spindle body 1 automatically generates axial force under the drive of the drive device 3. By controlling the axial force within a reasonable range, the corresponding clearance can be obtained. In this way, even if the bearing wears continuously, the spindle body 1 will move axially under the axial force and automatically adjust the clearance to obtain a suitable clearance, thereby reducing radial runout and increasing the machining accuracy of the machine tool. In addition, even if the temperature of the spindle body 1 changes during the machining process, it will not affect the clearance size or the machining accuracy.

[0044] like Figure 8 and Figure 9 As shown, in one embodiment, the inner ring 131 is fixed to the spindle body 1, and the outer ring 132 is installed to the bearing portion 4 of the machine tool. This installation method is more convenient.

[0045] like Figure 8 and Figure 9 As shown, in one embodiment, the spindle body 1 is provided with a journal 105, and the inner ring 131 is fixed outside the journal 105 or is an integral structure with the journal 105. The bearing part 4 is provided with a support part 41, and the outer ring 132 is installed inside the support part 41.

[0046] like Figure 8 and Figure 9 As shown, in one embodiment, the transmission unit 14 transmits power to the drive device 3 via a helical gear 141. The helical gear 141 can decompose a portion of the circumferential force into the axial force, ensuring that the tapered roller bearing 130 is subjected to a stable axial force, thus ensuring the clearance of the tapered roller bearing 130 and reducing radial runout. The thread has a relatively large selection range for the helix angle of the helical gear 141. While the helix angle of the helical gear 141 is limited, it can be directly machined into the spindle body 1 according to standards, resulting in lower costs. The thread, however, needs to be machined separately according to the design.

[0047] like Figure 8 and Figure 9 As shown, in one embodiment, the contact angle of the tapered roller bearing 130 is less than or equal to the helix angle of the helical gear 141. This ensures a larger radial support force and keeps radial runout within a smaller range.

[0048] like Figure 8 and Figure 9 As shown, in one embodiment, the spindle body 1 is equipped with a flywheel 107. Although the circular saw blade 2 generates rotational inertia when it rotates, the flywheel 107 can further increase the rotational inertia. Utilizing the principle of a gyroscope, the direction pointed to by the axis of rotation of a rotating object will not change when not affected by external forces. Therefore, even if the spindle body 1 moves axially, the rollers 133 of the tapered roller bearing 130 temporarily disengage from the outer ring 132, without affecting the rotation of the spindle body 1. The flywheel 107 can be integrated with the heat dissipation fins 113 or the brake disc 108, thus allowing the heat dissipation fins 113 to be thickened for better heat conduction.

[0049] like Figure 9 and Figure 10 As shown, in one possible embodiment, the transmission unit 14 transmits power to the drive device 3 and provides axial and circumferential forces, and the axial force provided by the drive device 3 during acceleration is opposite in direction to the axial force provided by the drive device 3 during deceleration. Figure 9 As shown, the axial force provided by the drive device 3 during acceleration is opposite to the first direction, and the spindle body 1 moves to the first limit position in the opposite direction to the first direction. Figure 10 As shown, the axial force provided by the drive device 3 during deceleration is the same as that in the first direction, and the spindle body 1 moves to the second limit position along the first direction. The axial distance between the first limit position and the second limit position is greater than 1 mm. Preferably, the axial distance between the first limit position and the second limit position is 5 mm for larger circular saws and 2 mm for smaller circular saws.

[0050] like Figure 7 and Figure 10As shown, in one embodiment, the transmission unit 14 includes a first transmission unit 144 and a second transmission unit 143. When the first transmission unit 144 and the second transmission unit 143 are in transmission, the axial forces they generate on the spindle body 1 are in opposite directions. The first transmission unit 144 and the second transmission unit 143 use independent drive devices 3. There are multiple scenarios where the axial forces are opposite. In one scenario, both the first transmission unit 144 and the second transmission unit 143 provide power to the spindle body 1 with opposite axial forces. For example, the first transmission unit 144 uses a left-hand helical gear 141, and the second transmission unit 143 uses a right-hand helical gear 141. The first drive device 31 of the first transmission unit 144 is driven by a 15 kW motor, and the second drive device 32 of the second transmission unit 143 is driven by a 10 kW motor. The rotational speed is 1440 revolutions per minute. The pitch circle radius of the helical gear 141 is 50 mm, and the helix angle β = 15°. When the first transmission unit 144 and the second transmission unit 143 work simultaneously, they can generate an axial force of more than 3 kN, ensuring that the bearing clearance is within a small range, realizing axial movement and reducing radial runout. In addition, the circular saw blade 2 has a large radius and a large inertia, and the resistance changes greatly under no-load and load conditions. In order to ensure processing efficiency, the circular saw blade 2 must have a certain speed before cutting the material and maintain a certain speed during material cutting. The dual drive device 3 can realize the use of one drive device 3 when no-load and the use of two drive devices 3 to maintain speed under load, avoiding large speed fluctuations. In the second scenario, the driving forces of the first transmission unit 144 and the second transmission unit 143 are in the same direction, but the output speeds of the control circuits of the drive devices 3 of the first transmission unit 144 and the second transmission unit 143 are different, resulting in opposite axial forces. This structure is more complex and requires an energy storage structure in the motor drive circuit, such as a large-capacity capacitor. The slower transmission unit 14 recovers energy and eventually achieves balance. In the third scenario, when the first transmission unit 144 or the second transmission unit provides power to the spindle body 1 alone, the axial forces of the first transmission unit 144 or the second transmission unit 143 that does not provide power are opposite to those of the first transmission unit 144 or the second transmission unit 143 that provides power. Processing different materials will generate different loads. To ensure the stability of the spindle body 1, the first transmission unit 144 and the second transmission unit 143 can balance the axial forces and output a constant axial force under different loads.

[0051] In one embodiment, the first transmission unit 144 and the second transmission unit 143 are driven by a variable frequency motor, and the power can be adjusted according to the load size. The magnitude of the axial force can also be adjusted by changing the power of the drive motors of the first transmission unit 144 and the second transmission unit 143. In this way, the axial force of the tapered roller bearing 130 can be adjusted as needed. For applications requiring high machining accuracy, the axial force can be increased and the radial runout can be decreased. For applications requiring lower machining accuracy, the axial force can be decreased and the rotational resistance can be decreased.

[0052] In one embodiment, the first transmission unit 144 serves as the main drive structure when unloaded, while the second transmission unit 143 stops working when unloaded. Therefore, the gear ring 142 of the first transmission unit 144 is fixed to the spindle body 1 by threads, which can provide a large axial force. The second transmission unit 143 uses spur gear transmission or helical gear 141 with a small helix angle transmission, which makes the axial force of the second transmission unit 143 smaller. The first transmission unit 144 uses a 1 kW servo motor, and the second transmission unit 143 uses a 15 kW motor. The motor of the second transmission unit 143 is started when there is a load.

[0053] Example 3: like Figure 11 and Figure 12 As shown, the difference from Embodiment 2 is that this embodiment of the circular saw for cooling the spindle also includes a housing 9. Inside the housing 9, a first clamping part 5 and a second clamping part 6 are provided. The first clamping part 5 has a linear track 51 that can move axially along the spindle under the drive of a track drive motor 52. Since the spindle body 1 will axially move, the position of the circular saw blade 2 needs to be calibrated periodically to ensure processing accuracy. Furthermore, different loads, i.e., different driving forces, will also cause changes in axial position; therefore, the position needs to be recalibrated when changing the material being cut.

[0054] like Figure 12 and Figure 13 As shown, in one embodiment, the transmission unit 14 transmits power to the drive device 3 and the braking device 7, and the axial force provided by the drive device 3 is opposite to the axial force provided by the braking device 7. Under the axial force, the main shaft body 1 moves axially in the direction of the greater force. The braking device 7 is a brake coupler, which can achieve rapid braking. When the circular saw has finished cutting the material, the feed end does not need to move. When the drive device 3 decelerates, it provides the opposite axial force direction, and the braking device 7 provides the opposite axial force, causing the main shaft body 1 to move axially. This allows the saw blade to detach from the material at the feed end. For the material at the discharge end, it can slide down under gravity, or a movable track can be provided to move the material axially, so that the material separates from the circular saw blade 2.

[0055] like Figure 12 and Figure 13As shown, in one embodiment, the drive device 3 and the braking device 7 are connected for transmission. The axial force generated by the drive device 3 on the spindle body 1 when it drives is opposite in direction to the axial force generated by the drive device 3 on the spindle body 1 when the braking device 7 brakes the drive device 3. After the circular saw finishes cutting the material, the circular saw blade 2 cannot stop rotating in time. It is necessary to use a brake coupler or other braking device 7 to achieve braking. The forces of the drive device 3 and the braking device 7 are opposite. When they act at the same position, they can generate opposite axial forces. Under the opposite axial forces, the spindle body 1 can be axially moved. The direction of the movement is the same as the direction of the larger axial force. When braking, the drive device 3 has no output force or outputs a reverse force, which can realize the reverse movement of the spindle body 1.

[0056] like Figure 14 As shown, in one embodiment, the spindle body 1 is provided with a brake disc 108. The spindle body 1 is mounted on the housing 8 via a support part 13. The housing 8 is provided with a friction disc 81. When the spindle body 1 moves axially in a first direction, the brake disc 108 disengages from the friction disc 81. When the spindle body 1 moves in a second direction, the brake disc 108 contacts the friction disc 81. This provides a better braking effect and enables axial movement during braking, causing the circular saw blade 2 to detach from the material and avoiding damage to the material.

[0057] like Figure 14 and Figure 15 As shown, in one embodiment, the bearing portion 13 is provided with a plurality of cylindrical roller bearings 136 or needle roller bearings and two tapered roller bearings 130. The cylindrical roller bearings 136 or needle roller bearings have a large clearance and can move axially, while the tapered roller bearings 130 bear axial and radial forces. Under the action of axial and radial forces, the bearing clearance is smaller, the radial runout is also smaller, and the operation is more stable.

[0058] like Figure 15 As shown, in one embodiment, the contact angle of the tapered roller bearing 130 is greater than or equal to the helix angle of the helical gear 141 or the helix angle of the thread of the gear ring 142. This ensures a larger axial support force and guarantees the stability of the axial position of the spindle body 1. For example, if the drive unit uses a 15 kW motor with a speed of 1440 rpm, a transmission efficiency of 0.9, a transmission ratio of 8, and an output torque of 716 N·m, and the pitch circle radius of the helical gear 141 is 75 mm with a helix angle β = 15 degrees, then the circumferential force is 9547 N and the axial force is 2558 N. Selecting a tapered roller bearing 130 with a shaft diameter of 40 mm or more can meet the working life of tens of thousands of hours. Since the bearing clearance of this application is adjustable, its actual service life is longer and the radial runout is smaller.

[0059] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0061] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A cooling spindle, comprising a tool mounting section (12), a heat dissipation section (11), a support section (13), and a transmission section (14), wherein the tool mounting section (12) is provided with a detachable structure for mounting and dismounting machining tools, the transmission section (14) is connected to a drive device (3) for transmission, and the support section (13) is provided with a bearing to allow the spindle body (1) to rotate, characterized in that, The heat dissipation part (11) is located near the tool mounting part (12). A cooling box (110) is provided on the outer periphery of the heat dissipation part (11). The cooling box (110) is provided with an inlet (111) and an outlet (112). Coolant enters the cooling box (110) from the inlet (111). After the coolant comes into contact with the heat dissipation part (11), it leaves the cooling box (110) from the outlet (112). Alternatively, the cooling box (110) is provided with a refrigeration device (119) that can reduce the temperature of the coolant in the cooling box (110).

2. The cooling spindle according to claim 1, characterized in that, The heat dissipation part (11) is provided with a plurality of disc-shaped heat dissipation fins (113) axially arranged on the main shaft body (1), and the diameter of the heat dissipation fins (113) near the outer ends is smaller than the diameter of the heat dissipation fins (113) near the center.

3. The cooling spindle according to claim 1, characterized in that, The cooling box (110) is provided with heat-conducting fins (109), and the heat dissipation fins (113) are spaced apart by the heat-conducting fins (109).

4. The cooling spindle according to claim 1, characterized in that, The cooling box (110) is annular and surrounds the spindle body (1).

5. The cooling spindle according to claim 1, characterized in that, The cooling box (110) is connected to the negative pressure pipe (120) so that the inside of the cooling box (110) is in a negative pressure state.

6. The cooling spindle according to claim 1, characterized in that, The inlet (111) of the cooling tank (110) is provided with a circulation pipe (117), which is connected to the circulation pool (118). The circulation pool (118) obtains coolant from the cooling tank (110) through a negative pressure pipe (120) connected to the outlet (112), and delivers coolant to the cooling tank (110) through the circulation pipe (117).

7. The cooling spindle according to claim 6, characterized in that, The circulation tank (118) is equipped with a refrigeration device (119) and the refrigeration device (119) reduces the temperature of the coolant. The refrigeration device (119) uses compressed refrigerant evaporation or semiconductor to achieve refrigeration.

8. The cooling spindle according to claim 1, characterized in that, The liquid inlet (111) is located at the highest point directly above the heat dissipation part (11), and the liquid outlet (112) is located below the spindle body (1) near the spindle body (1).

9. The cooling spindle according to any one of claims 1-8, characterized in that, The machining tool is a circular saw blade (2). The transmission part (14) and the driving device (3) realize transmission and provide axial force and circumferential force. The bearing part (13) is provided with a tapered roller bearing (130) near the tool mounting part (12). The tapered roller bearing (130) is provided with an outer ring (132), an inner ring (131) and a roller (133). The inner side of the outer ring (132) and the outer side of the inner ring (131) are provided with a tapered surface (137). The tapered surface (137) of the outer ring (132) or the inner ring (131) of the tapered roller bearing (130) provided on the spindle body (1) is oriented in the same direction as the axial force provided by the driving device (3), so that under the axial force provided by the driving device (3), the spindle body (1) moves axially a certain distance, and the clearance between the inner ring (131), the outer ring (132) and the roller (133) is reduced.

10. A circular saw with a cooling spindle, using the cooling spindle described in any one of claims 1-9, characterized in that, A circular saw blade (2) is installed in the tool mounting part (12).

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