Main shaft for axial movement of circular saw and circular saw

Abstract

The invention provides a main shaft for axial movement of a circular saw and the circular saw, and aims to at least solve the technical problem of scraping of a circular saw blade in the prior art. The main shaft for axial movement of the circular saw comprises a cutter mounting part, a bearing part and a transmission part, the cutter mounting part is provided with a detachable structure capable of mounting and dismounting a circular saw blade, the bearing part is provided with a bearing so that a main shaft body can axially move and rotate, and the transmission part and a driving device achieve transmission and provide axial acting force and circumferential acting force. The axial acting force provided by the driving device during acceleration is opposite to the axial acting force provided by the driving device during deceleration; or the axial acting force provided by the driving device is opposite to the axial acting force provided by the braking device, and the main shaft body axially moves in the direction with large stress under the axial acting force. When the circular saw cuts materials, the feeding end does not need to move, the driving device or the braking device provides opposite axial acting force, the main shaft body axially moves, and the materials are separated from the circular saw blade.

Description

Technical Field

[0001] This application relates to the field of circular saws, and more particularly to a circular saw spindle with axial movement and a circular saw. Background Technology

[0002] Compared to band saws, circular saws have the advantage of higher processing precision, which can reduce material waste. Especially for large bars, even a one-millimeter deviation or a one-degree tilt will further increase the processing allowance. If the precision can be well controlled, the saw cut surface can even be used as the final processing surface. The difference in raw material waste between the two can be several kilograms.

[0003] When a circular saw blade finishes cutting material, the reduced resistance and increased rotational speed lead to intensified vibration, causing axial wobble and scraping against the material. To protect the saw blade and the cut surface, and to prevent scraping, the material is usually moved axially to detach from the blade. The unloading end is generally lighter and easier to remove, but moving the feed end affects feeding accuracy and is more difficult due to its weight (potentially several tons). Alternatively, the saw blade can be moved axially a certain distance, thus avoiding scraping. The circular saw blade is mounted on the spindle, which is mounted on the worktable. The worktable needs to move perpendicular to the axial direction to complete the sawing. The entire worktable weighs close to one ton, and some large saws can weigh several tons. Directly moving the worktable consumes a lot of energy, affects processing accuracy, and requires a high-power motor, resulting in higher costs. The spindle that is directly mounted on the saw blade is a better choice. However, it is difficult to move the spindle so that it can move axially a certain distance after sawing the material. Due to the high speed of the spindle, the large wear will reduce the machining accuracy of the spindle. It is also difficult to achieve axial transmission between the high-speed rotating spindle and other components.

[0004] Chinese patent application CN101474806B, entitled "Preferred Saw Shaft Structure for a Longitudinal Circular Saw," discloses a preferred saw shaft structure for a longitudinal slitting circular saw. It includes a saw shaft and a saw shaft seat for supporting the saw shaft. At least one saw blade sleeve, movable axially and rotating with the saw shaft, is fitted onto the saw shaft. At least one movable circular saw blade is fixedly mounted on the saw blade sleeve. A circular saw blade sliding fork is movably connected to the saw blade sleeve and connected to a lead screw and nut pair. At least one fixed circular saw blade is fixedly mounted on the saw shaft. At least one saw shaft key is provided on the saw shaft, and at least one keyway is provided in the shaft hole of the saw blade sleeve, corresponding to the keyway on the saw blade sleeve. This saw shaft structure allows for convenient and flexible axial sliding adjustment of the circular saw blade. However, the machining accuracy of the saw blade is determined by the sliding fork. If the gap between the sliding fork and the circular saw blade is too small, it may affect the rotation of the circular saw blade. The axial sliding of the circular saw blade will also cause wear, increasing the gap. If the gap is too large, the axial movement of the saw blade during processing will affect the machining accuracy.

[0005] German patent application number “DE1809997A1” entitled “Workpiece Clamping Device on a Circular Saw” discloses a circular saw in which the workpiece and the scrap to be cut are clamped by separate clamps, and at least one clamp can move linearly along an axis extending transversely to the plane of the saw blade, or pivot about an axis located outside the plane of the saw blade, to remove the workpiece and / or scrap from the saw after cutting. In the illustrated embodiment, the clamps can slide in axial guides of the saw blade, and at least one of them slides off the saw blade after cutting. In another embodiment, at least one clamp can swing about a horizontal or vertical pivot. In a further embodiment, after cutting, one of the clamps slides off or swings from the saw blade, and the saw blade slides axially away from the other clamp by a small distance. This patent only discloses some embodiments of material detachment from the saw blade, providing a specific scheme for how the spindle moves. Summary of the Invention

[0006] This application provides a main shaft for axial movement of a circular saw and a circular saw, so as to at least solve the problem of circular saw blade scraping technology in the prior art.

[0007] According to a first aspect of this application, a main shaft for axial movement of a circular saw is provided, comprising a tool mounting part, a bearing part, and a transmission part. The tool mounting part is provided with a detachable structure for mounting and dismounting the circular saw blade. The bearing part is provided with a bearing so that the main shaft body can move and rotate axially. The transmission part transmits power to a drive device and provides axial force and circumferential force, and the axial force provided by the drive device during acceleration is opposite in direction to the axial force provided by the drive device during deceleration; or, the transmission part transmits power to a drive device and a braking device, and the axial force provided by the drive device is opposite to the axial force provided by the braking device, and the main shaft body moves axially in the direction of greater force under the axial force.

[0008] Compared with the prior art, the axially moving spindle of the circular saw in this application has the following advantages: When the circular saw finishes cutting the material, the feed end does not need to move. When the drive device decelerates, it provides the opposite axial force direction, and the braking device provides the opposite axial force, causing the main shaft body 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 the action of gravity, or a movable track can be set to move the material axially, so that the material separates from the circular saw blade.

[0009] In one embodiment, the transmission unit includes a first transmission unit and a second transmission unit, and the axial forces generated by the first and second transmission units on the spindle body are in opposite directions when they are in operation. The first and second transmission units use independent drive devices, and there are several scenarios where the axial forces are opposite. First, when both the first and second transmission units provide power to the spindle body, the axial forces are opposite. Second, although the driving forces of the first and second transmission units are in the same direction, the output speeds of the control circuits of the drive devices of the first and second transmission units are different, resulting in opposite axial forces. Additionally, when either the first or second transmission unit provides power to the spindle body alone, the axial forces are opposite to those of the first and second transmission units that are not providing power. Processing different materials generates different loads. To ensure the positional stability of the spindle body, the first and second transmission units can balance the axial forces, allowing a constant axial force to be output under different loads.

[0010] In one embodiment, the drive device and the braking device are connected for transmission. The axial force generated by the drive device on the spindle body when it drives is opposite in direction to the axial force generated by the braking device on the spindle body when it brakes the drive device. After the circular saw finishes cutting the material, the saw blade cannot stop rotating in time and needs to be braked using a brake coupler or other braking device. The forces of the drive device and the braking device are opposite, and when they act at the same position, they can generate opposite axial forces. Under the opposite axial forces, the spindle body can move axially. The direction of the movement is the same as the direction of the larger axial force. When braking, the drive device has no output force or outputs a reverse force, which can achieve the reverse movement of the spindle body.

[0011] In one embodiment, the transmission unit is provided with a gear ring, which is fixed to the main shaft body by threads. Whether the gear ring has straight or helical teeth, it can decompose a portion of the circumferential force into the axial force, so that the tapered roller bearing can be subjected to a stable axial force, ensuring the clearance of the tapered roller bearing and reducing radial runout.

[0012] In one embodiment, the transmission unit communicates with the drive unit via helical gears. Helical gears can decompose a portion of the circumferential force into the axial force, ensuring stable axial force on the tapered roller bearings, guaranteeing bearing clearance, and reducing radial runout. The thread has a wider range of selectable helix angles compared to helical gears, while the helix angle of helical gears is limited but can be directly machined into the spindle body according to standards, resulting in lower costs. Threads, on the other hand, need to be machined separately according to the design.

[0013] In one embodiment, the spindle body is equipped with a brake disc, and the spindle body is mounted on a housing via a support portion. The housing is equipped with a friction disc. When the spindle body moves axially in a first direction, the brake disc disengages from the friction disc; when the spindle body moves in a second direction, the brake disc contacts the friction disc. This provides better braking effect and achieves axial movement during braking, causing the circular saw blade to detach from the material and preventing damage to the material.

[0014] In one embodiment, the bearing portion is provided with multiple cylindrical roller bearings or needle roller bearings and at least one tapered roller bearing. Different machine tools have different power ratings; some machine tools have higher power and generate larger axial forces. Using a single cylindrical roller bearing or needle roller bearing is insufficient to handle circumferential forces. The cylindrical roller bearings or needle roller bearings primarily bear radial loads. For large machine tools, the radial load is significant. To ensure axial movement, the inner or outer ring of the cylindrical roller bearings or needle roller bearings is not fitted with flanges, ensuring that the spindle body can move axially within a certain range when subjected to axial forces.

[0015] In one embodiment, the contact angle of the tapered roller bearing is greater than or equal to the helix angle of the helical gear or the helix angle of the gear ring thread. This ensures a larger axial support force and guarantees the stability of the spindle body's axial position.

[0016] In one embodiment, the spindle body is equipped with a flywheel. Although the circular saw blade generates rotational inertia when it rotates, the flywheel 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 it is not affected by external forces. Therefore, even if the spindle body moves axially, the rollers of the tapered roller bearing temporarily disengage from the outer ring, which does not affect the rotation of the spindle body.

[0017] According to a second aspect of this application, a circular saw with an axially moving spindle is provided, comprising a spindle for axial movement of the circular saw, and a first clamping part and a second clamping part. The first clamping part is provided with a linear track that can move along the axial direction of the spindle under the drive of a driving device.

[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 from the following detailed description taken in conjunction with 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 A three-dimensional schematic diagram of the main shaft of the circular saw with axial movement according to Embodiment 1 of this application is shown; Figure 2 This shows a half-sectional schematic diagram of the main shaft of the circular saw in Embodiment 1 of this application, which is axially moving. Figure 3 This diagram illustrates the state of the main shaft of the circular saw in Embodiment 1 of this application, where the lower half of the box is removed due to axial movement. Figure 4 This paper shows a three-dimensional schematic diagram of the upper half of the main shaft of the circular saw in Embodiment 1 of this application, which exhibits axial movement. Figure 5 This paper shows a three-dimensional schematic diagram of the lower half of the main shaft of the circular saw in Embodiment 1 of this application, which exhibits axial movement. Figure 6 This paper shows a schematic diagram of the circulation tank connection of the main shaft of the circular saw in Embodiment 1 of this application, which is axially moving. Figure 7 A schematic diagram of the transmission structure of the main shaft of the circular saw in Embodiment 1 of this application is shown; Figure 8 A perspective view of the axial movement of the main shaft of the circular saw in Embodiment 2 of this application is shown; Figure 9This shows a half-sectional schematic diagram of the first extreme position of the spindle of the circular saw in Embodiment 2 of this application, indicating axial movement. Figure 10 This shows a half-sectional schematic diagram of the second extreme position of the spindle of the circular saw in Embodiment 2 of this application, indicating the axial movement of the spindle. Figure 11 A schematic diagram of the composition structure of the circular saw with an axially moving spindle according to Embodiment 3 of this application is shown; Figure 12 This invention provides a schematic diagram of the internal structure of the housing for the circular saw removal portion of the axially moving spindle in Embodiment 3 of this application. Figure 13 A schematic diagram of the transmission structure of the circular saw with an axially moving spindle according to Embodiment 3 of this application is shown; Figure 14 A schematic diagram showing the installation position of the spindle of the circular saw in Embodiment 3 of this application is provided. Figure 15 A half-sectional schematic diagram of the axial movement of the main shaft of the circular saw in 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 circular saw spindle with axial movement includes a tool mounting part 12, a bearing part 13, and a transmission part 14. The tool mounting part 12 has a detachable structure for mounting and dismounting the circular saw blade 2. The bearing part 13 has a bearing that allows the spindle body 1 to move and rotate axially. The transmission part 14 transmits power to the drive device 3 and provides axial and circumferential forces. 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. Under the axial force, the spindle body 1 moves axially along the direction with greater force. In the figure, the first direction is the axial direction of the spindle body 1, which is in a horizontal plane; the second direction is radial, which is also in a horizontal plane; and the third direction is vertical, which is vertically upward.

[0024] like Figure 1 and Figure 7 As 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 generated 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. Under the drive of the 10 kW motor, the axial force in the first direction can be controlled at about 2.5 kN. Under the action of the 15 kW motor, the axial force in the opposite direction can be controlled within 4 kN. Since the spindle body 1 is rotating, the spindle body 1 can be moved axially to achieve axial movement. The specific direction of movement is affected by the drive of the first transmission unit 144 and the second transmission unit 143.

[0025] like Figure 1 and Figure 2As 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 fitted with flanges. This ensures that the spindle body 1 can move axially within a certain range when subjected to axial forces, requiring at least an additional axial movement of 2mm.

[0026] 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.

[0027] 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.

[0028] like Figure 1 and Figure 2 As shown, in one embodiment, the transmission unit 14 is provided with a gear ring 142, which is fixed to the main shaft body 1 by a thread. Whether the gear ring 142 has spur or helical teeth, it can decompose a portion of the circumferential force into the axial direction, allowing the tapered roller bearing 130 to receive a stable axial force and achieve axial movement. Furthermore, it can ensure the clearance of the tapered roller bearing 130, resulting in less radial runout. When a 15 kW motor is used in the drive unit… like Figure 1 and Figure 2As 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.

[0029] like Figure 1 and Figure 2 As shown, the axially rotating spindle of the circular saw includes a tool mounting section 12, a heat dissipation section 11, a support section 13, and a transmission section 14. The tool mounting section 12 has a detachable structure that allows for the mounting and dismounting of the machining tool, i.e., the circular saw blade 2. The transmission section 14 is connected to the drive device 3 for transmission. The transmission structure of the transmission section 14 can be a gear, a pulley, a sprocket, or a combination thereof. The support section 13 has a bearing that allows the spindle body 1 to rotate. The heat dissipation section 11 is located close to the tool mounting section 12. The closer the heat dissipation section 11 is to the tool mounting section 12, the better the heat dissipation effect. Considering the force issue, the spindle body 1 has a small diameter and limited load-bearing capacity. If the spindle body 1 has a large diameter, the effective machining radius will be reduced. The support section 13 is located between the heat dissipation section 11 and the tool mounting section 12, which can reduce the radius of the spindle body 1. In some embodiments, for small circular saws, the tool mounting section 12 and the heat dissipation section 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.

[0030] The area near the tool mounting section 12 has a high temperature. Since the thermal conductivity of solids is much higher than that of liquids, a large portion of the heat generated during tool machining is transferred through the spindle body 1. Traditional cooling methods only apply cooling fluid to the machining area. Given the low thermal conductivity of cutting fluid, 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, requiring a reduction in sawing speed to prevent damage to the circular saw blade 2. The cooling spindle of this application maintains the spindle body 1 at a low temperature, even below zero, by incorporating a cooling tank 110. 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 cooling but also lubricating functions, 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 cools the spindle body 1 without considering lubrication, and can use antifreeze with a low freezing point. In addition, the antifreeze can be cooled to minus forty degrees Celsius by using a high-efficiency refrigeration device 119, so the temperature of the spindle body 1 can also be reduced to below zero. The spindle body 1 is directly connected to the machining tool, which can reduce the temperature of the machining tool. For a circular saw, the rotation speed of the circular saw blade 2 can be increased, and the cutting speed can be accelerated.

[0031] like Figure 1 and Figure 2 As shown, the axially moving spindle of a circular saw can also be used on milling machines and drilling machines. However, the machining positions on milling machines and drilling machines are relatively concentrated, and the temperature distribution is also relatively concentrated. Therefore, the efficiency of heat transfer through the spindle is relatively low. But compared to milling machines and drilling machines, the machining positions of a circular saw are more dispersed, and there is enough cooling time. Using a cooling spindle can effectively improve machining efficiency.

[0032] like Figure 1 and Figure 2 As shown, in one embodiment, the heat dissipation unit 11 has multiple 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. Multiple disc-shaped heat dissipation fins 113 can increase the heat dissipation area and improve heat exchange efficiency.

[0033] like Figure 2 and Figure 3As shown, in one embodiment, the cooling box 110 is provided with heat-conducting fins 109, and heat dissipation fins 113 are spaced apart by the heat-conducting fins 109. The heat-conducting fins 109 are also annular and are arranged correspondingly to the heat dissipation 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. Compared with solids, liquids have a lower thermal conductivity and poorer thermal conductivity. In addition, when the spacing between the heat dissipation fins 113 is small, the coolant tends to rotate with the heat dissipation fins 113, reducing the heat exchange efficiency. By providing heat-conducting fins 109, the coolant can flow back and forth between the stationary and moving heat-conducting fins 109 and the heat dissipation fins 113, which greatly improves the heat exchange efficiency.

[0034] like Figure 3 , Figure 4 and Figure 5 As shown, in one embodiment, the cooling box 110 is annular and surrounds the spindle body 1. The cooling box 110 includes an upper half 114 and a lower half 115. The upper half 114 and the lower half 115 are provided with sealing grooves 116 for installing sealing rings. The split design facilitates installation. When the spindle body 1 rotates, an annular heat exchange zone can be formed outside the spindle body 1. That is, the coolant overcomes the effect of gravity under the action of centrifugal force to form a near-annular coolant ring, reducing coolant leakage between the spindle body 1 and the main body of the cooling box 110.

[0035] like Figure 2 and Figure 5 As shown, in one embodiment, the cooling tank 110 is connected to the negative pressure pipe 120, so that the inside of the cooling tank 110 is under negative pressure. In this way, even if a small amount of coolant reaches between the cooling tank 110 and the spindle body 1, it will flow into the cooling tank 110 under the action of negative pressure, and no coolant leakage will occur even if a sealing ring is not used between the cooling tank 110 and the spindle body 1.

[0036] 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. This enables the coolant to be recycled, and further improves the heat exchange efficiency during the circulation process.

[0037] like Figure 2 , Figure 4 and Figure 6As 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.

[0038] like Figure 1 , Figure 4 and Figure 5 As shown, in one embodiment, the inlet 111 is located at the highest point directly above the heat dissipation section 11. Coolant can enter the cooling tank 110 from the inlet 111 under gravity. The outlet 112 is located below the spindle body 1, near the spindle body 1. This cooling process from top to bottom cools the heat dissipation section 11 of the spindle body 1. As the spindle body 1 rotates, the coolant is distributed in a ring shape. Under centrifugal force, less coolant is near the spindle, and excess coolant can flow out from the outlet 112 near the spindle body 1, preventing coolant leakage.

[0039] 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.

[0040] like Figure 1 and Figure 2As 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.

[0041] 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.

[0042] Example 2: like Figure 8 and Figure 9 As shown, the difference from Embodiment 1 is that 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, allowing the tapered roller bearing 130 to receive a stable axial force, ensuring the clearance of the tapered roller bearing 130, and thus reducing radial runout. The thread has a wider range of selectable helix angles compared to 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.

[0043] like Figure 8 and Figure 9As 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] like Figure 8 and Figure 9 As shown, in one embodiment, 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. This can efficiently reduce the refrigerant temperature to below zero, and the temperature is transferred to the spindle body 1 through the coolant inside the cooling box 110, resulting in a lower temperature for the spindle body 1. The cooling box 110 is provided with a coolant chamber 103 for filling with coolant. Cooling fins 109 are located in the coolant chamber 103, and the coolant chamber 103 is connected to the coolant pipe 104 for convenient filling with coolant.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] Example 3: like Figure 11 and Figure 12 As shown, the difference from Embodiment 2 is that in this embodiment, a circular saw with an axially moving spindle is provided. Because the spindle body 1 moves axially, the position of the circular saw blade 2 needs to be calibrated periodically to ensure processing accuracy. In addition, different loads, i.e., different driving forces, will also cause changes in axial position, so the position needs to be recalibrated when changing the material to be cut.

[0055] 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 greater force. The braking device 7 is a brake coupler, which can achieve rapid braking.

[0056] like Figure 12 and Figure 13 As shown, in one possible embodiment, the drive device 3 and the brake device 7 achieve 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 brake device 7 brakes the drive device 3.

[0057] 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 bearing 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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 main shaft for axial movement of a circular saw, comprising a tool mounting part (12), a bearing part (13), and a transmission part (14), wherein the tool mounting part (12) is provided with a detachable structure for mounting and dismounting a circular saw blade (2), characterized in that, The bearing part (13) is provided with a bearing so that the spindle body (1) can move and rotate axially. The transmission part (14) and the drive device (3) realize transmission and provide axial force and circumferential force. The axial force provided by the drive device (3) when accelerating is opposite to the axial force provided by the drive device (3) when decelerating. Alternatively, the transmission part (14) and the drive device (3) and the braking device (7) realize transmission. The axial force provided by the drive device (3) is opposite to the axial force provided by the braking device (7). The spindle body (1) moves axially in the direction of greater force under the axial force.

2. The axially moving spindle of the circular saw according to claim 1, characterized in that, 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 generated on the main shaft body (1) are in opposite directions.

3. The axially moving spindle of the circular saw according to claim 1, characterized in that, The drive device (3) and the brake device (7) are connected by transmission. The axial force generated by the drive device (3) on the spindle body (1) when the drive device (3) is driven is opposite in direction to the axial force generated by the drive device (3) on the spindle body (1) when the brake device (7) brakes the drive device (3).

4. The axially moving spindle of the circular saw according to claim 1, characterized in that, The transmission part (14) is provided with a gear ring (142), which is fixed to the main shaft body (1) by means of threads.

5. The axially moving spindle of the circular saw according to claim 1, characterized in that, The transmission unit (14) is connected to the drive device (3) via a helical gear (141).

6. The axially oriented spindle of the circular saw according to any one of claims 1-5, characterized in that, The spindle body (1) is provided with a brake disc (108). The spindle body (1) is mounted on the housing (8) via a bearing part (13). The housing (8) is provided with a friction disc (81). When the spindle body (1) moves axially in the first direction, the brake disc (108) disengages from the friction disc (81). When the spindle body (1) moves in the second direction, the brake disc (108) contacts the friction disc (81).

7. The axially oriented spindle of the circular saw according to claim 6, characterized in that, The main shaft body (1) is provided with at least one tapered roller bearing (130) and multiple cylindrical roller bearings (136) or needle roller bearings.

8. The axially moving spindle of the circular saw according to claim 7, characterized in that, 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).

9. The axially moving spindle of the circular saw according to claim 8, characterized in that, The main shaft body (1) is equipped with a flywheel (107).

10. A circular saw with an axially moving spindle, comprising an axially moving spindle as described in any one of claims 1-9, characterized in that, The circular saw is provided with a first clamping part (5) and a second clamping part (6). The first clamping part (5) is provided with a linear track (51) which can move along the axial direction of the main shaft under the drive of the track drive motor (52).

Images