A forced-cooling lubrication-free type power head for a drift drill

Abstract

The present invention discloses a forced cooling and lubrication maintenance-free power head for a tunnel drilling rig, which comprises a housing. A main shaft rotating around its own axis and a driving device for driving the main shaft to rotate are arranged on the housing. A hollow chuck device for clamping the main shaft is sleeved outside the main shaft. A first cooling cavity communicated with the inner cavity of the chuck device is formed by enclosing the housing and the main shaft. One of the chuck device and the housing is provided with a liquid inlet, and the other is provided with a liquid outlet. Both the liquid inlet and the liquid outlet are communicated with the first cooling cavity. The forced cooling and lubrication maintenance-free power head for the tunnel drilling rig injects a coolant into the chuck device and the first cooling cavity through a liquid injection port. The coolant is discharged from the liquid outlet, taking away the heat and debris impurities on the surfaces of the chuck device and the main shaft, realizing the cooling and lubrication of the power head, keeping the inside of the equipment clean and maintaining it within a suitable temperature range, reducing thermal deformation, ensuring the sealing effect, exempting the equipment from maintenance, and greatly prolonging its service life.

Description

Technical Field

[0001] The present invention relates to the technical field of power heads, and more particularly to a forced-cooling lubrication maintenance-free tunnel drilling rig power head. Background Art

[0002] The power head of a tunnel drilling rig mainly includes two functional components. One is a speed reduction component for driving the main shaft to rotate, and the other is an oil distribution component for clamping or loosening the drill pipe by the movement of the slip.

[0003] Existing power heads usually also use a skeleton oil seal to isolate the lubricated chuck component to prevent lubricating oil leakage. However, after the equipment has been running for a long time, due to friction, the skeleton oil seal and the slip seat heat up rapidly, and the components are prone to thermal deformation, resulting in weakened sealing performance. Moreover, due to the harsh operating environment of the equipment and the uneven professional skill levels of the operators, they often forget to perform maintenance on time or perform improper maintenance, resulting in a significant reduction in the service life of the power head; the slip seat and the main shaft are prone to wear and need to be replaced regularly, resulting in increased usage costs for customers, reduced work efficiency, and increased labor intensity of the workers; not only that, when the equipment is running, the vibration of the main shaft drives the vibration of the chuck component, causing the oil cylinder that drives the axial displacement of the chuck component to vibrate, shortening the service life of the oil cylinder seal; in addition, in existing power heads, the slips are usually fixed to the slip seat with screws, and the loading and unloading operations are troublesome and not conducive to replacement.

[0004] Therefore, it is necessary to improve the power head of the tunnel drilling rig in the prior art. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects existing in the prior art, and provide a forced-cooling lubrication maintenance-free tunnel drilling rig power head that prolongs the service life, ensures the sealing effect, reduces the workload of workers, improves work efficiency, reduces usage costs, and is convenient for replacing the slips.

[0006] To achieve the above technical effects, the technical solution of the present invention is: a forced-cooling lubrication maintenance-free tunnel drilling rig power head, including a housing, a main shaft rotatable around its own axis is provided on the housing, and a driving device for driving the main shaft to rotate, a hollow chuck device for clamping the main shaft is sleeved outside the main shaft, a first cooling cavity communicating with the inner cavity of the chuck device is formed by enclosing the housing and the main shaft, a liquid inlet is provided on one of the chuck device and the housing, and a liquid outlet is provided on the other, and both the liquid inlet and the liquid outlet communicate with the first cooling cavity.

[0007] When the power head of the tunnel drilling rig in the above technical solution is in use, the driving device operates to drive the main shaft to rotate, and the drill pipe is clamped by the chuck device. During the operation of the equipment, coolant (usually hydraulic oil) is introduced into the liquid injection port. The coolant flows inside the chuck device and in the first cooling cavity, and then is discharged from the liquid outlet. When the coolant flows inside the chuck device and in the first cooling cavity, on the one hand, it absorbs the heat of the main shaft and the chuck device, delays the heating rate, and avoids thermal deformation at high temperatures, thereby stabilizing the operation of the equipment at a suitable temperature, extending the service life of the device, and ensuring the sealing performance. At the same time, during the flow of the coolant, the debris and impurities generated due to relative friction are also carried away, further reducing the wear of the equipment. And when the coolant is hydraulic oil, it can also play a lubricating role in the operation of the equipment. As described above, the cooling effect on the power head is achieved through the flowing coolant, and the debris generated during the operation of the equipment is carried away, reducing wear, maintaining the operation of the equipment at a stable and suitable temperature, avoiding thermal deformation at high temperatures from affecting the sealing performance and service life of the equipment, enabling the equipment to be free from maintenance, thereby reducing the workload of workers, improving work efficiency, and reducing the use cost of the equipment.

[0008] Preferably, a bearing seat sleeved outside the main shaft is further provided between the housing and the chuck device. A bearing sleeved outside the main shaft is provided on the bearing seat. A second cooling cavity communicating with the inner cavity of the chuck device and the first cooling cavity is formed by enclosing the bearing seat and the main shaft.

[0009] By adopting the above technical solution, the bearing on the bearing seat is used to support the main shaft for stable rotation, and through the communication between the second cooling cavity and the inner cavity of the chuck device, the coolant can enter between the main shaft and the bearing seat, increasing the contact area between the coolant and the main shaft, improving the cooling effect of the main shaft, and ensuring the stable operation of the equipment.

[0010] Preferably, at least one of the housing and the bearing seat is provided with a first wear-resistant ring sleeved outside the main shaft between it and the main shaft.

[0011] By adopting the above technical solution, the first wear-resistant ring can be used to reduce the wear of the main shaft, thereby reducing the replacement cost of parts. Specifically, when the parts are worn, only the first wear-resistant ring needs to be replaced, rather than the high-cost large parts such as the main shaft. On the one hand, the replacement difficulty is reduced, thereby reducing the replacement workload of workers, which is beneficial to improving labor efficiency. On the other hand, there is no need to replace the main shaft, and only small parts such as the first wear-resistant ring need to be replaced, so the replacement cost is low, that is, the use cost of customers is reduced.

[0012] Preferably, at least one of the housing and the bearing seat is provided with a diversion spray hole with an oil inlet communicating with the first cooling cavity and an oil outlet facing the main shaft.

[0013] By adopting the above technical solution, the flow direction of the coolant is guided by the diversion spray holes, so that after the coolant flows inside the chuck device and in the first cooling cavity, it is sprayed on the main shaft through the diversion through holes, ensuring that the coolant can take away heat in the first time and further improving the cooling effect.

[0014] Preferably, a first wear-resistant ring sleeved outside the main shaft is arranged between the housing and the bearing seat and the main shaft, and diversion spray holes are arranged on both the housing and the bearing seat, and the oil outlet of the diversion spray hole faces the sealing contact surface of the first wear-resistant ring.

[0015] By adopting the above technical solution, the wear-resistant performance of the main shaft is further enhanced, the maintenance cost is reduced, the workload of workers is reduced, and the work efficiency is improved. In addition, the diversion spray holes at two places can respectively guide the coolant to accurately spray on the two first wear-resistant rings, and this position is exactly the place where the oil seal rubs and generates heat, further ensuring that the coolant can take away the heat and debris generated by friction in the first time, making the device free from maintenance and extending the service life.

[0016] Preferably, a plurality of the diversion spray holes are arranged and evenly distributed on a circumference centered on the center of the cross-section of the main shaft.

[0017] By adopting the above technical solution, by using a plurality of evenly distributed diversion spray holes, the coolant can be evenly sprayed on the first wear-resistant ring, thereby realizing multi-point simultaneous cooling, balancing thermal deformation, and extending the service life of the wear-resistant ring and the device.

[0018] Preferably, the chuck device includes a collet seat sleeved outside the main shaft, at least three collets arranged between the collet seat and the main shaft, and a translation assembly for driving the collet seat to move axially along the main shaft. The inner surface of the collet seat is in a flared shape facing away from the driving device or a constricted shape facing the driving device. The collets are distributed on a circumference centered on the center of the cross-section of the main shaft. An outer bearing housing is hermetically sleeved outside the collet seat, and an inner cavity of the chuck device is formed by enclosing the collet seat and the outer bearing housing.

[0019] By adopting the above technical solution, after the main shaft rotates, the collet seat and the collets are driven to rotate to realize the rotation function. Then, the translation assembly drives the collet seat to move. By using the design that the inner surface of the collet seat is in a flared shape or a constricted shape, the collet seat is made to push the collets to move radially towards the main shaft to clamp the drill pipe. The coolant flows in the inner cavity formed by the collet seat and the outer bearing housing to realize the cooling of the collet seat and prevent its thermal deformation, thereby extending the service life of the collet seat.

[0020] Preferably, a second wear-resistant ring sleeved outside the collet seat is arranged between the outer bearing housing and the collet seat.

[0021] By adopting the above technical solution, the second wear-resistant ring is used to prevent the slip seat from being worn. After the second wear-resistant ring is worn, only the second wear-resistant ring needs to be replaced, instead of replacing the slip seat. Therefore, it not only facilitates the replacement work, reduces the workload of workers and improves labor efficiency, but also reduces the replacement cost and the usage cost.

[0022] Preferably, the translation assembly includes an oil cylinder. The cylinder barrel of the oil cylinder is fixedly connected to the housing. One end of the piston rod of the oil cylinder connected to the bearing housing is provided with a spherical protrusion, and one side of the bearing housing connected to the protrusion is provided with a recess adapted to the protrusion.

[0023] By adopting the above technical solution, the design of the matching spherical protrusion and recess reduces the vibration transmitted from the chuck device to the oil cylinder, thereby prolonging the service life of the oil cylinder seal.

[0024] Preferably, the slip is fixedly connected to the slip seat through a magnetic attraction member.

[0025] By adopting the above technical solution, the magnetic attraction member is used to realize the fixed connection between the slip seat and the slip. Compared with the traditional screw connection method, this connection method is more conducive to the convenient disassembly and replacement of the slip, reducing the workload of workers.

[0026] In summary, for the power head of the forced cooling lubrication and maintenance-free tunnel drilling rig of the present invention, the coolant is injected into the chuck device and the first cooling cavity through the liquid injection port, and the coolant is discharged from the liquid outlet, taking away the heat and debris impurities on the surfaces of the chuck device and the main shaft, realizing the cooling and lubrication of the power head, keeping the interior of the equipment clean and maintaining it within a suitable temperature range, reducing thermal deformation, ensuring the sealing effect, exempting the equipment from maintenance, and greatly prolonging its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the present invention;

[0028] Figure 2 is Figure 1 an enlarged view of part A of

[0029] Figure 3 is Figure 1 an enlarged view of part B of

[0030] Figure 4 is Figure 1 an enlarged view of part C of

[0031] Figure 5 is a schematic structural diagram of the connection between the translation assembly of the present invention and the bearing housing;

[0032] Figure 6It is a partial sectional view of the front cover of the present invention;

[0033] Figure 7 It is a schematic structural diagram of the flow dividing sleeve of the present invention;

[0034] Figure 8 It is a sectional view of the flow dividing sleeve of the present invention;

[0035] Figure 9 It is Figure 8 an enlarged view of part D of

[0036] Figure 10 It is a sectional view of the gland of the present invention;

[0037] In the figure: 1. housing, 2. main shaft, 3. driving device, 3a. hydraulic motor, 3b. driving gear, 3c. driven gear, 4. liquid inlet, 5. liquid outlet, 6. first cooling cavity, 7. bearing seat, 8. bearing, 9. second cooling cavity, 10. first wear-resistant ring, 11. diversion spray hole, 12. chuck, 13. chuck seat, 14. second wear-resistant ring, 15. oil cylinder, 16. protrusion, 17. depression, 18. magnetic part, 19. flow dividing sleeve, 20. gland, 21. reduction housing, 22. annular groove, 23. drain port, 24. first diversion port, 25. second diversion port, 26. bearing housing, 27. front cover, 28. rear cover. Specific embodiments

[0038] The following combines the drawings and embodiments to further describe the specific embodiments of the present invention. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0039] As Figures 1-10 shown, the forced cooling and lubrication maintenance-free type tunnel drilling rig power head of the present invention includes a housing 1, a main shaft 2 that rotates around its own axis is arranged on the housing 1, and a driving device 3 for driving the main shaft 2 to rotate. A hollow chuck device for clamping the main shaft 2 is sleeved outside the main shaft 2. A first cooling cavity 6 communicating with the inner cavity of the chuck device is formed by enclosing the housing 1 and the main shaft 2. A liquid inlet 4 is arranged on the chuck device, and a liquid outlet 5 is arranged on the housing 1. Both the liquid inlet 4 and the liquid outlet 5 are communicated with the first cooling cavity 6.

[0040] When the tunnel drilling rig of the present invention is in use, the driving device 3 is started, the driving main shaft 2 rotates around its axis, and the drill pipe is clamped by the chuck device; at the same time, hydraulic oil is injected into the chuck device through the liquid injection port 4. After the hydraulic oil passes through the inner cavity of the chuck device and the first cooling cavity in sequence, it flows out from the liquid outlet 5. During the flowing process of the hydraulic oil, the heat on the surfaces of the chuck device and the main shaft 2, as well as the debris and impurities generated due to friction, are carried away, and then flow out from the liquid outlet 5, so that the outside of the main shaft 2 and the inside of the chuck device are kept clean, avoiding the wear caused by debris. At the same time, the hydraulic oil is used to carry away heat, cooling and lubricating the main shaft 2 and the chuck device, reducing the thermal deformation of the main shaft 2 and the chuck device, thereby ensuring the sealing effect and extending the service life of the equipment, and making the equipment free from maintenance. Of course, the liquid outlet 5 can also be arranged on the chuck device, and correspondingly, the liquid inlet 4 is arranged on the housing 1 at this time.

[0041] As Figure 1 shown, the housing 1 includes a reduction housing 21. The driving device 3 includes a hydraulic motor 3a fixed on the reduction housing 21, a driving gear 3b coaxially fixed on the output end of the hydraulic motor 3a, and two driven gears 3c coaxially connected to the main shaft 2. The outer diameters of the two driven gears 3c are different, and the driving gear 3b is a double gear meshing with one of the driven gears 3c.

[0042] When the driving device 3 operates, the hydraulic motor 3a is started to drive the driving gear 3b to rotate. The driving gear 3b acts on one of the driven gears 3c meshing with it, so as to drive the main shaft 2 to rotate through the driven gear 3c; since the driving gear 3b is a double gear and the outer diameters of the two driven gears 3c are different, by controlling the driving gear 3b to mesh with the other driven gear 3c, the rotation speed of the main shaft 2 can be changed. Thus, according to different needs, the driving gear 3b is selected to mesh with one of the driven gears 3c to adjust the rotation speed of the main shaft 2.

[0043] As Figure 2 shown, the chuck device includes a chuck seat 13 sleeved outside the main shaft 2, at least three chucks 12 arranged between the chuck seat 13 and the main shaft 2, and a translation assembly for driving the chuck seat 13 to move axially along the main shaft 2. The inner surface of the chuck seat 13 is a flared shape facing away from the hydraulic motor 3a. The chucks 12 are evenly distributed on the circumference with the center of the cross-section of the main shaft 2 as the center. An outer bearing housing 26 is hermetically sleeved outside the chuck seat 13. The chuck seat 13 and the outer bearing housing 26 enclose to form the inner cavity of the chuck device; a second wear-resistant ring 14 is hermetically sleeved outside the chuck seat 13 between the outer bearing housing 26 and the chuck seat 13.

[0044] The main shaft 2 is drivingly connected to the collet seat 13 in the chuck device. After the main shaft 2 is driven to rotate by the driving device 3, it drives the collet seat 13 and the collet 12 to rotate around the axis of the main shaft 2, realizing the rotation function; the collet seat 13 is driven to move axially along the main shaft 2 by the translation assembly, and the collet 12 is driven to move radially closer to the main shaft 2 along the inner wall of the flared collet seat 13, and finally the collet 12 abuts against the main shaft 2, thereby clamping the drill pipe; when the hydraulic oil enters the inner cavity formed by enclosing the collet seat 13 and the bearing housing 26, it takes away the impurities in the inner cavity and the heat on the surface of the collet seat 13, keeps the surface of the inner cavity clean, reduces wear, cools the collet seat 13, prevents its thermal deformation, ensures the sealing effect, and prolongs the service life of the collet seat 13; the second wear-resistant ring 14 can prevent the wear between the collet seat 13 and the bearing housing 26. When the wear-resistant ring 14 is damaged, only alignment and replacement are required, without replacing the installed collet seat 13. On the one hand, the replacement cost is reduced, and on the other hand, the replacement is more convenient, reducing the workload of the workers, thus being beneficial to improving work efficiency. It should be noted that the inner surface of the collet seat 13 can also be designed into a converging shape facing the hydraulic motor 3a, and the above technical effects can also be achieved.

[0045] The collet 12 is fixedly connected to the collet seat 13 through the magnetic attraction member 18. The fixed connection between the collet 12 and the collet seat 13 is realized through the magnetic attraction member 18, and compared with the traditional screw fixing method, the installation method of the collet 12 is more conducive to quickly replacing and installing it, improving the replacement efficiency and reducing the replacement workload.

[0046] As Figure 5 and Figure 6 shown, the translation assembly includes an oil cylinder 15. The cylinder barrel of the oil cylinder 15 is fixedly connected to the housing 1. A spherical protrusion 16 is provided at one end of the piston rod of the oil cylinder 15 connected to the bearing housing 26. A front cover 27 and a rear cover 28 fixedly connected by bolts are provided on one side of the collet seat 13 and the protrusion 16. The front cover 27 and the rear cover 28 enclose a recess 17 adapted to the protrusion 16.

[0047] By adopting the above design, the recess 17 formed by combining the front cover 27 and the rear cover 28 is adapted to the spherical protrusion 16 at the end of the piston rod of the oil cylinder 15, so that when the equipment is running, the vibration transmitted from the chuck device to the oil cylinder 15 can be reduced, thereby prolonging the service life of the sealing member of the oil cylinder 15.

[0048] As Figure 1 shown, a bearing seat 7 sleeved on the main shaft 2 is further provided between the housing 1 and the chuck device. A bearing 8 sleeved on the main shaft 2 is provided on the bearing seat 7. The bearing seat 7 and the main shaft 2 enclose a second cooling cavity 9 communicating with the inner cavity of the chuck device and the first cooling cavity 6; As Figure 3 and Figure 4 、 Figures 7-10As shown, at one end of the housing 1 facing away from the chuck device, there is a flow dividing sleeve 19 sleeved outside the main shaft 2. At one end of the bearing housing 7 adjacent to the chuck device, there is a gland 20 sleeved outside the main shaft 2. Between the flow dividing sleeve 19 and the main shaft 2, and between the gland 20 and the main shaft 2, there are first wear-resistant rings sleeved outside the main shaft 2 for sealing. Both the flow dividing sleeve 19 and the gland 20 are provided with annular grooves 29 and diversion spray holes 11 communicating with the inside of the annular grooves. Among them, the annular groove 29 on the flow dividing sleeve 19 communicates with the first cooling cavity 6, and the liquid outlet of the diversion spray hole 11 faces the sealing contact surface of the first wear-resistant ring 10 between the flow dividing sleeve 19 and the main shaft 2. The annular groove 29 on the gland 20 communicates with the second cooling cavity 9, and the liquid outlet of the diversion spray hole 11 faces the sealing contact surface of the first wear-resistant ring 10 between the bearing housing 7 and the main shaft 2. As Figure 1 and Figure 4 shown, the bearing housing 26 is provided with a liquid inlet 4 and a liquid outlet 23 communicating with the inner cavity of the chuck device. The bearing housing 7 is provided with a first diversion port 24 communicating with the second cooling cavity 9 and the liquid outlet 23. The reduction housing 21 is provided with a second diversion port 25 communicating with the liquid outlet 23 and the first cooling cavity 6 and a liquid outlet 5 communicating with the first cooling cavity 6.

[0049] The bearing 8 on the bearing housing 9 is used to support the support 2 for stable rotation, reducing the vibration generated during its rotation. When the hydraulic oil flows, it first enters the inner cavity formed by the bearing housing 26 and the collet seat 13 through the liquid inlet 4, and then is discharged through the liquid outlet 23, dividing into two cooling flow channels. One of them enters the second cooling cavity 9 through the first diversion port 24, and the other enters the first cooling cavity 6 through the second diversion port 25. Finally, the hydraulic oil in the two cooling flow channels is discharged through the liquid outlet 5. During the flow of the hydraulic oil, the heat on the surface of the main shaft 2 and the debris and impurities generated by friction are carried away, ensuring that the internal environment of the equipment is maintained at a relatively high cleanliness level. At the same time, the heat generated by friction is carried away through the flow of the hydraulic oil, thereby stabilizing the operation of the equipment at a suitable temperature, extending the service life of the equipment, and exempting the equipment from maintenance.

[0050] Moreover, the first wear-resistant ring 10 can prevent wear between the main shaft 2 and the bearing housing 7 and the housing 1 during the rotation of the main shaft 2, ensuring that the main shaft 2 has a sufficiently long service life and exempting the equipment from maintenance. When the first wear-resistant ring 10 is damaged, the workers only need to replace the first wear-resistant ring 10, without disassembling and assembling the main shaft 2 for maintenance. On the one hand, it makes the equipment maintenance more convenient and reduces the workload. On the other hand, since only the first wear-resistant ring 10 needs to be replaced, the maintenance cost is greatly reduced, thus significantly reducing the customer's usage cost.

[0051] There are multiple diversion spray holes 11 on the diversion sleeve 19 and the gland 20, and they are evenly distributed on the circumference centered on the center of the cross-section of the main shaft 2 and face the first wear-resistant ring 10. After adopting the above structure, the hydraulic oil in the two cooling channels entering the second cooling cavity 9 and the first cooling cavity 6 can be evenly sprayed on the first wear-resistant rings 10 at the two places through the multiple diversion spray holes 11. And the first wear-resistant ring is exactly at the oil seal friction and heat generation place of the main shaft 2. Therefore, it can ensure that the hydraulic oil takes away heat and impurities in the first time and lubricates the main shaft 2. The multi-point uniform design is beneficial to evenly absorb heat from the first wear-resistant ring 10 and the outer periphery of the main shaft 9, avoiding thermal deformation caused by inconsistent temperatures everywhere. In this way, the cooling effect is improved by evenly absorbing heat, and the service life of the main shaft 2 and the equipment is further extended.

[0052] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the technical principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A forced-cooling and lubrication maintenance-free power head for a drift drill, comprising a housing (1), a main shaft (2) rotatable about its own axis is arranged on the housing (1), and a driving device (3) for driving the main shaft (2) to rotate, a hollow chuck device for clamping the main shaft (2) is sleeved outside the main shaft (2). Characterized in that: A first cooling chamber (6) communicating with the inner cavity of the chuck device is formed by enclosing the housing (1) and the main shaft (2), one of the chuck device and the housing (1) is provided with a liquid inlet (4), and the other is provided with a liquid outlet (5), and both the liquid inlet (4) and the liquid outlet (5) communicate with the first cooling chamber (6).

2. The forced-cooling and lubrication maintenance-free power head for a drift drill according to claim 1, Characterized in that: A bearing seat (7) sleeved outside the main shaft (2) is further arranged between the housing (1) and the chuck device, a bearing (8) sleeved outside the main shaft (2) is arranged on the bearing seat (7), and a second cooling chamber (9) communicating with the inner cavity of the chuck device and the first cooling chamber (6) is formed by enclosing the bearing seat (7) and the main shaft (2).

3. The forced-cooling and lubrication maintenance-free power head for a drift drill according to claim 2, Characterized in that: At least one of the housing (1) and the bearing seat (7) is provided with a first wear-resistant ring (10) sleeved outside the main shaft (2) between it and the main shaft (2).

4. The forced-cooling and lubrication maintenance-free power head for a drift drill according to claim 3, Characterized in that: At least one of the housing (1) and the bearing seat (7) is provided with a diversion spray hole (11) whose oil inlet communicates with the first cooling chamber (6) and whose oil outlet faces the main shaft (2).

5. The forced-cooling and lubrication maintenance-free power head for a drift drill according to claim 4, Characterized in that: First wear-resistant rings (10) sleeved outside the main shaft (2) are arranged between both the housing (1) and the bearing seat (7) and the main shaft (2), diversion spray holes (11) are arranged on both the housing (1) and the bearing seat (7), and the oil outlet of the diversion spray hole (11) faces the sealing contact surface of the first wear-resistant ring (10).

6. The forced-cooling and lubrication maintenance-free power head for a drift drill according to claim 4, Characterized in that: A plurality of the diversion spray holes (11) are provided and are evenly distributed on a circumference with the center of the cross-section of the main shaft (2) as the center of the circle.

7. The forced-cooling and lubrication maintenance-free power head for a drift drill according to claim 1, Characterized in that: The chuck device includes a collet seat (13) sleeved outside the main shaft (2), at least three collets (12) arranged between the collet seat (13) and the main shaft (2), and a translation assembly for driving the collet seat (13) to move axially along the main shaft (2). The inner surface of the collet seat (13) is in a flared shape facing away from the driving device (3) or a constricted shape facing the driving device (3). The collets (12) are distributed on a circumference centered on the center of the cross-section of the main shaft (2). An outer bearing housing (26) is hermetically sleeved outside the collet seat (13). The collet seat (13) and the bearing housing (26) enclose to form the inner cavity of the chuck device.

8. The forced cooling and lubrication maintenance-free power head of a tunnel drilling rig according to claim 7, characterized in that: A second wear-resistant ring (14) hermetically sleeved outside the collet seat (13) is arranged between the bearing housing (26) and the collet seat (13).

9. The forced cooling and lubrication maintenance-free power head of a tunnel drilling rig according to claim 7, characterized in that: The translation assembly includes an oil cylinder (15). The cylinder barrel of the oil cylinder (15) is fixedly connected to the housing (1). A spherical protrusion (16) is arranged at one end of the piston rod of the oil cylinder (15) connected to the bearing housing (26). A recess (17) adapted to the protrusion (16) is arranged on one side of the bearing housing (26) connected to the protrusion (16).

10. The forced cooling and lubrication maintenance-free power head of a tunnel drilling rig according to claim 7, characterized in that: The collet (12) is fixedly connected to the collet seat (13) through a magnetic attraction member (18).

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