High-power rocker arm cooling system of coal mining machine

Abstract

The present application relates to a kind of high-power rocker arm cooling systems of coal mining machine, including rocker arm shell and planetary mechanism, high, low speed section cutting transmission mechanism installation cavity being equipped with left and right communication in rocker arm shell, high-speed section cutting transmission mechanism installation cavity is close to machine body connecting end and coal wall side, its below is equipped with front lower cavity, both are communicated, planetary mechanism axis extends and is installed in the coal wall side of the drum connecting end of rocker arm shell, the planetary carrier of planetary mechanism includes planetary carrier body, the inside of planetary carrier body forms the sun gear installation cavity and planetary gear installation cavity located at rear and oil cavity located at front, interval wall between oil cavity and sun gear installation cavity is equipped with central through hole and multiple axial oil holes around central through hole, the diameter of oil cavity is not less than the diameter of sun gear installation cavity, first, second forced cooling device is respectively installed in front lower cavity and oil cavity.The present application can solve the problem that the lubrication deficiency phenomenon of high-power rocker arm is prominent when working at an angle.

Description

Technical Field

[0001] This invention relates to a high-power rocker arm cooling system for a coal mining machine, which can better meet the cooling and lubrication requirements of the rocker arm when it is in its respective tilt angle. Background Technology

[0002] With increasingly complex mining conditions, such as the increasing presence of interbedded rock and faults, the frequency of rock cutting has greatly increased. Therefore, the demand for and development of high-power thin coal seam mining machines is constantly being raised and upgraded. Currently, the power of a single rocker arm has increased from the early 100KW to the current 500KW. In the design process of increasing the power of the rocker arm, the main consideration is the lifespan of the transmission system gears and bearings. However, due to the limitations of existing rocker arm housings (see...) Figure 18 Limited internal space often brings new problems, such as: the efficiency loss caused by high power and the heating problem of rocker arm caused by oil stirring loss cannot be well solved, and insufficient cooling leads to weakened lubrication effect; the effective oil holding space in the inner cavity of the rocker arm housing is small and cannot meet the lubrication needs, especially when the rocker arm housing is working at an angle, the phenomenon of insufficient lubrication is more prominent, but this tilted working state is the normal state when the rocker arm housing is working. Summary of the Invention

[0003] The purpose of this invention is to provide a cooling system for a high-power rocker arm of a coal mining machine, which solves the problems of overheating, poor lubrication, and insufficient lubrication when the high-power rocker arm is working at an angle.

[0004] The main technical solutions of this invention are as follows:

[0005] A high-power rocker arm cooling system for a coal mining machine includes a rocker arm housing and a planetary mechanism. The two ends of the rocker arm housing along its length are a machine body connection end and a drum connection end, respectively. The rocker arm housing contains a high-speed section cutting transmission mechanism mounting cavity and a low-speed section cutting transmission mechanism mounting cavity that are connected horizontally. The high-speed section cutting transmission mechanism mounting cavity is located near the machine body connection end and the coal wall side. A lower front cavity is located below the high-speed section cutting transmission mechanism mounting cavity, and the high-speed section cutting transmission mechanism mounting cavity is vertically connected to the lower front cavity. A first forced cooling device assembly is installed in the lower front cavity. The planetary mechanism... The mechanism's axis extends forward and backward and is installed on the coal wall side of the roller connection end of the rocker arm housing. The planetary carrier of the planetary mechanism includes a planetary carrier body with a rotating structure. The interior of the planetary carrier body forms a sun gear mounting cavity and a planet gear mounting cavity at the rear, and an oil cavity at the front. The planet gear mounting cavity surrounds the sun gear mounting cavity and communicates with it. The partition wall between the oil cavity and the sun gear mounting cavity is provided with a central through hole and multiple axial oil holes surrounding the central through hole. The diameter of the oil cavity is not less than the diameter of the sun gear mounting cavity. A second forced cooling device is installed in the oil cavity.

[0006] The first forced cooling device group includes one or more first forced cooling devices. Each first forced cooling device includes a cooling medium flow pipe group, a cooling medium inlet / outlet seat, and a connecting seat. The cooling medium flow pipe group includes multiple inlet pipes and multiple outlet pipes extending in the same direction and spaced apart from each other. The two ends of the cooling medium flow pipe group are respectively installed on the cooling medium inlet / outlet seat and the connecting seat. The cooling medium inlet / outlet seat is provided with multiple inlet channels and multiple outlet channels. The outlets of all inlet channels and the inlets of all outlet channels are on the same end face of the cooling medium inlet / outlet seat. Each component converges and occupies half of the end face. The outlet of the inflow channel and the inlet of the outflow channel are connected one-to-one with the corresponding ends of the inflow and outflow pipes, respectively. Both the inlet and outlet of the inflow channel lead to the radial outer side of the cooling medium inlet / outlet seat. The end of the connecting seat near the cooling medium flow pipe assembly has multiple internally interconnected channel interfaces, which are connected one-to-one with the corresponding end of each cooling medium flow pipe in the cooling medium flow pipe assembly. The cooling medium inlet / outlet seat has a stepped shaft structure, including at least large, medium, and small... The three-tiered cylindrical surface has a radial seal on each tier. Each pair of adjacent radial seals divides the tiered cylindrical surface into a region. The inlet of the inflow channel and the outlet of the outflow channel are separately located in two different regions. The cooling medium inlet / outlet seat and the connecting seat are both installed on the rocker arm housing. When there is one first forced cooling device, the inlet of the inflow channel and the outlet of the outflow channel of the first forced cooling device constitute the medium inlet and medium outlet of the first forced cooling device group, respectively. When there are multiple first forced cooling devices, the multiple first forced cooling devices are connected in series according to the flow direction of the cooling medium. The inlet of the inflow channel of the first forced cooling device and the outlet of the outflow channel of the last forced cooling device constitute the medium inlet and medium outlet of the first forced cooling device group, respectively. The rocker arm housing has a medium inlet hole and a medium outlet hole, which are connected and communicate with the medium inlet and medium outlet of the first forced cooling device group, respectively. Alternatively, the rocker arm housing has a water jacket, and the first forced cooling device group is connected in series in the water channel of the water jacket.

[0007] The first forced cooling device also includes a welding seat. The end of the connecting seat away from the cooling medium flow pipe assembly is inserted into one end of the welding seat and is clearance-fitted with the shaft hole of the welding seat. The other end of the welding seat is provided with an inclined plane. The bottom cavity wall of the front lower cavity near the roller connection end is an inclined transition cavity wall. The inclined transition cavity wall is higher as it gets closer to the roller connection end. The cooling medium inlet / outlet seat is installed on the oil cylinder connecting arm of the rocker arm housing. The welding seat is welded to the inclined transition cavity wall with its inclined plane.

[0008] The outer cylindrical surface of the connecting seat that mates with the shaft hole of the welding seat is provided with multiple annular grooves, and vibration damping O-rings are installed in the annular grooves.

[0009] The stepped cylindrical surface of the cooling medium inlet / outlet seat is provided with an inlet flat-bottomed groove and an outlet flat-bottomed groove. The inlets of all inflow channels are opened on the bottom surface of the inlet flat-bottomed groove, and the outlets of all outflow channels are opened on the bottom surface of the outlet flat-bottomed groove.

[0010] The high-speed section cutting transmission mechanism mounting cavity inside the rocker arm housing has two motor mounting cavities extending forward and backward on the goaf side. The spacer between the two motor mounting cavities has a motor inter-cavity. The high-speed section cutting transmission mechanism mounting cavity and the motor inter-cavity are connected forward and backward. The outer side of the motor mounting cavity near the roller connection end has a clutch cavity. The high-speed section cutting transmission mechanism mounting cavity and the clutch cavity are connected forward and backward. The lower front part of the motor mounting cavity also has a lower rear cavity. The lower front cavity and the lower rear cavity are connected forward and backward.

[0011] The second forced cooling device includes a cooling base, a cooling jacket, and a cooling medium flow pipe. The cooling jacket is a hollow tubular structure. The front part of the cooling jacket is inserted into and fixedly installed in the cooling base, while the middle and rear parts extend outwards. The front wall of the cooling jacket has a cooling medium inflow groove and a cooling medium outflow groove, which communicates with the cooling medium outflow channel in the cooling base. The cooling jacket also has several cooling medium inflow outlet holes and several cooling medium outflow outlet holes extending forward and backward within its wall. The front ends of the cooling medium inflow outlet holes and cooling medium outflow outlet holes communicate with the cooling medium inflow groove and cooling medium outflow groove, respectively. The rear end of the hole and the outlet of the cooling medium communicate with the annular groove located in the rear tube wall of the cooling jacket. The front shaft hole of the cooling medium flow pipe is fitted and fixedly installed in the inner hole of the cooling jacket. The middle part is located inside the cooling jacket and is spaced apart from the cooling jacket. The rear part extends out of the cooling jacket. The front end of the cooling medium flow pipe is closed. A lateral through hole is provided on the front tube wall of the cooling medium flow pipe. The lateral through hole communicates with the cooling medium inflow groove. The rear end of the cooling medium flow pipe and the cooling medium outlet channel in the cooling seat respectively constitute the cooling medium inflow channel and the cooling medium outlet channel of the second forced cooling device.

[0012] The outlet of the cooling medium outflow channel in the cooling base is connected to a connector, which extends radially along the cooling base.

[0013] The outer and inner surfaces of the middle and rear portion of the cooling jacket are both provided with a corrugated structure.

[0014] The rocker arm housing is equipped with a water jacket. High-speed end bearing seats and low-speed end bearing seats are respectively installed on the coal wall side cavity wall of the high-speed section cutting transmission mechanism installation cavity and the goaf side cavity wall of the low-speed section cutting transmission mechanism installation cavity. Both the high-speed end bearing seat and the low-speed end bearing seat are equipped with an annular cooling groove and two connecting grooves. The annular cooling groove is connected to the water circuit of the water jacket through the two connecting grooves on the same bearing seat.

[0015] The beneficial effects of this invention are:

[0016] By setting up the lower front cavity, not only is a larger oil capacity provided for the boom, but also a larger space for the heat dissipation of the high-power rocker arm. It can also be used as a cooling device installation cavity. By adding a forced cooling device in it, the cooling efficiency of the lubricating oil in the boom cavity can be improved, the lubrication condition can be improved, and thus the cooling and lubrication needs of the high-power rocker arm can be met.

[0017] By setting a lower front cavity below the mounting cavity of the high-speed cutting transmission mechanism, more oil can be stored in the boom without changing the standard oil filling amount. When the rocker arm is working at a large tilt angle, especially when the low-speed end is below and the high-speed end is above, a higher oil level can still be maintained. This ensures that the high-speed cutting transmission mechanism is immersed in the oil to a sufficient depth, avoiding poor lubrication caused by the high-speed end gear being too high above the oil surface. This enhances or at least prevents the cooling and lubrication effect from being weakened due to angled operation, ensuring that the rocker arm can meet the cooling and lubrication needs of a high-power rocker arm regardless of its state.

[0018] The lower front cavity is located at the lower part of the rocker arm housing near the fuselage connection end. When a forced cooling device is installed therein, the forced cooling device is located below the line connecting the lowest position of the gears of the high-speed section cutting transmission mechanism. It does not affect the arrangement of the cutting transmission mechanism, nor does it occupy the loading channel under the low-speed end boom.

[0019] The bottom cavity wall of the lower front cavity near the roller connection end is configured as a sloping transition cavity wall, and the sloping transition cavity wall is higher the closer it is to the roller connection end. When the lower front cavity is used as a cooling device mounting cavity, the sloping transition cavity wall can serve as a welding base surface at one end for the corresponding cooling device during installation, facilitating the installation of cooling devices of different lengths.

[0020] The motor cavity and the clutch cavity are both located within the solid structure of the rocker arm housing with a relatively thick local wall. This not only avoids increasing the occupation of the original internal space of the rocker arm housing, but also expands the new effective oil-containing space within the rocker arm housing.

[0021] By adding a rear lower cavity, the front and rear width of the newly added oil-containing space at the lower part of the rocker arm housing near the fuselage connection end is further widened, which means that the oil-containing space and heat release space are further expanded, and the cooling and lubrication effect of the boom is further improved.

[0022] The motor cavity, clutch cavity, connecting end cavity, and connecting end side cavity can all be seen as further expansions of the boom's internal oil space, further ensuring sufficient lubrication of the boom cavity.

[0023] This invention increases the oil storage space in the lower part of the boom as much as possible. When the rocker arm of the coal mining machine is working at an angle, regardless of whether the machine body connection end or the drum connection end is on top, the oil level rises, reducing the vertical distance between the oil level and the highest transmission component. Even without adding a cooling device, this invention can improve the lubrication of the transmission component at the highest point to a certain extent.

[0024] Because the planetary carrier has a larger oil cavity space than the existing planetary carrier, it can hold more lubricating oil and can install a cooling device therein, ensuring the overall oil storage capacity of the planetary mechanism where the planetary carrier is located, ensuring sufficient lubrication of the end transmission mechanism where the planetary carrier is located, and greatly improving the cooling effect of the end transmission mechanism.

[0025] Because the oil chamber wall has radial oil holes penetrating the chamber wall, and the partition wall between the oil chamber and the sun gear mounting chamber has axial oil holes, the oil in the gear meshing area, bearing rolling contact area, and floating seal ring contact area between the roller connecting sleeve and the planetary carrier of the end transmission mechanism can freely flow and exchange with the oil in the oil chamber. Therefore, the heat generated in the gear meshing area, bearing rolling contact area, floating seal ring contact area, and oil churning loss of the planetary mechanism can be dissipated in a timely and effective manner. When a second forced cooling device is installed in the oil chamber, excessively high temperatures can be avoided, ensuring the normal and reliable operation of the end transmission mechanism where the planetary carrier is located.

[0026] By incorporating axial oil holes, heat exchange is facilitated between the meshing chamber and the oil chamber, promoting cooling at the meshing point of the planetary gears and the sun gear. Shallow grooves on the front walls of the sun gear mounting chamber and the planetary gear mounting chamber extend the heat exchange between the meshing chamber and the oil chamber to the multiple rows of support bearings inside the planetary gears, enabling rapid cooling of these bearings. Therefore, the design of the large-volume oil chamber, radial oil holes, and axial oil holes ensures sufficient cooling of the entire internal cavity of the planetary mechanism containing the planet carrier.

[0027] The first forced cooling device has a compact structure, which can save a lot of axial installation space. The cooling medium inlet and outlet seats adopt a multi-step cylindrical surface, which facilitates the installation and removal of the sealing ring. A radial seal is set on each step cylindrical surface. Every two adjacent radial seals divide the step cylindrical surface into a region. The inlet of the inflow channel and the outlet of the outflow channel are set in two different regions. This arrangement can effectively isolate and seal the water.

[0028] By setting an inclined plane on the welding base, when installing the first forced cooling device, the inclined plane on the welding base is welded to the inclined transition cavity wall. The inclined plane cooperation can better ensure the smooth installation of the cooling medium flow pipe assembly on the rocker arm housing blank surface without jamming, and also facilitates the installation of cooling devices of different lengths.

[0029] The second forced cooling device is small in size and installed inside the oil chamber of the planetary carrier, without occupying any additional installation space. It can effectively cool the planetary mechanism, and its operation is not affected by whether a cavity structure is used between the rocker arm housing and the planetary mechanism. Compared with conventional cooling devices with water outlet connectors at the ends, the second forced cooling device occupies less axial space, making the roller more compact axially.

[0030] The high-speed and low-speed end cooling plates are used for auxiliary cooling. When the rocker arm is working at a large tilt angle, the cooling effect of other cooling methods at the high-speed end or low-speed end of the rocker arm may be weakened. At this time, the cooling plate at the corresponding end will play a role in enhancing the cooling of the corresponding end. Attached Figure Description

[0031] Figure 1 This is a front view of an embodiment of the rocker arm of the present invention;

[0032] Figure 2 for Figure 1 Top view;

[0033] Figure 3 for Figure 2 AA section view;

[0034] Figure 4 for Figure 2 BB section view;

[0035] Figure 5 for Figure 1 A partial sectional view from a top-down perspective;

[0036] Figure 6 for Figure 5 CC section view;

[0037] Figure 7 A schematic diagram showing the water circuit configuration in the high-speed end cooling plate;

[0038] Figure 8 A schematic diagram showing the water circuit configuration in the low-speed end cooling plate;

[0039] Figure 9 This is a schematic diagram showing the state of the rocker arm of a coal mining machine when it is working at an angle (low speed end down, high speed end up);

[0040] Figure 10 This is a schematic diagram showing the state of the rocker arm of a coal mining machine when it is working at an angle (high-speed end down, low-speed end up);

[0041] Figure 11 This is a schematic diagram of one embodiment of the first forced cooling device;

[0042] Figure 12 for Figure 11 DD stepped sectional view;

[0043] Figure 13 A partial enlarged view of one embodiment of the mounting structure for the first forced cooling device;

[0044] Figure 14 This is a structural schematic diagram of one embodiment of the planetary carrier;

[0045] Figure 15 This is a schematic diagram of one embodiment of the end transmission mechanism where the planetary carrier is located;

[0046] Figure 16 A schematic diagram of one embodiment of the second forced cooling device;

[0047] Figure 17 for Figure 16 EE sectional view;

[0048] Figure 18 This is a schematic diagram of the structure of an existing coal mining machine rocker arm;

[0049] Figure 19 This is a schematic diagram of the planetary carrier used in the rocker arm of an existing coal mining machine.

[0050] Figure label:

[0051] 1. Rocker arm housing; 101. Water inlet; 103. Water outlet; 104. Connecting hole; 11. Lower front cavity; 111. Sloping transition cavity wall; 112. Lower front housing of motor mounting cavity; 12. Connecting end cavity; 13. Connecting end side cavity; 14. Inter-motor cavity; 15. Clutch cavity; 17. Lower rear cavity; 18. Motor mounting cavity;

[0052] 2. Electric motor;

[0053] 31. The line connecting the lowest positions of the gears in the high-speed section cutting transmission mechanism;

[0054] 44. Planetary carrier; 440. Planetary gear shaft mounting hole; 441. Journal; 442. Radial oil hole; 443. Oil cavity wall; 444. Axial oil hole; 445. Sun gear mounting cavity; 446. Planetary gear mounting cavity; 447. Oil cavity; 448. Central through hole; 449. External spline;

[0055] 45. Front bearing; 48. Roller connecting sleeve; 481. End face floating seal;

[0056] 5. Roller; 51. Roller connecting disc; 52. Roller end cover;

[0057] 61. First forced cooling device; 611. Cooling medium flow pipe assembly; 612. Cooling medium inlet / outlet seat; 6121. Stepped cylindrical surface; 6122. Sealing ring; 6123. Flat-bottomed groove; 613. Connecting seat; 614. Welding seat; 6141. Inclined plane; 615. Vibration-damping O-ring; 62. Second forced cooling device; 620. Cooling medium flow pipe; 6201. Lateral through hole; 621. Cooling jacket; 6211. Cooling medium inlet groove; 6212. Cooling medium inlet outlet hole; 6213. Ring 6214. Cooling medium outlet hole; 6215. Cooling medium outlet groove; 6216. Cooling jacket external thread; 6217. Cooling jacket internal thread; 6218. Connecting hole; 6219. Annular groove; 622. Cooling seat; 6222. Connector; 63. High-speed end cooling plate; 631. High-speed end bearing seat; 6311. Annular cooling groove; 6312. Connecting groove; 64. Low-speed end cooling plate; 641. Low-speed end bearing seat; 6411. Annular cooling groove; 6412. Connecting groove; 65. Water jacket;

[0058] 1'. Existing rocker arm housing. Detailed Implementation

[0059] This invention discloses a high-power rocker arm cooling system for a coal mining machine, such as... Figure 1-17 As shown, the device includes a rocker arm housing 1 and a planetary mechanism. The two ends of the rocker arm housing along its length are the machine body connection end and the drum connection end, respectively. The rocker arm housing has a high-speed cutting transmission mechanism mounting cavity and a low-speed cutting transmission mechanism mounting cavity that are connected horizontally. The high-speed cutting transmission mechanism mounting cavity is located near the machine body connection end and the coal wall side, while the low-speed cutting transmission mechanism mounting cavity is located near the drum connection end. Below the high-speed cutting transmission mechanism mounting cavity is a lower front cavity 11, which is vertically connected to the lower front cavity. A first forced cooling device assembly is installed in the lower front cavity. The first forced cooling device assembly is used for cooling the high-speed end of the rocker arm.

[0060] By setting the lower front cavity, not only is a larger oil-holding space provided for the rocker arm, but also a larger space for the heat dissipation of the high-power rocker arm. It can also be used as a cooling device mounting cavity. By setting the first forced cooling device group in it, the cooling efficiency of the lubricating oil in the rocker arm cavity is improved, the lubrication condition is improved, and thus the cooling and lubrication needs of the high-power rocker arm are met.

[0061] By setting a lower front cavity below the mounting cavity of the high-speed cutting transmission mechanism, more oil is stored in the rocker arm cavity while the standard oil filling amount remains unchanged. When the rocker arm is working at a large tilt angle, especially when the low-speed end is at the bottom and the high-speed end is at the top, a higher oil level can still be maintained. This ensures that the high-speed cutting transmission mechanism is immersed in the oil to a sufficient depth, avoiding poor lubrication caused by the high-speed end gear being too high above the liquid surface. This enhances or at least prevents the cooling and lubrication effect from being weakened due to angled operation, ensuring that the rocker arm can meet the cooling and lubrication needs of a high-power rocker arm regardless of its state.

[0062] The lower front cavity is located at the lower part of the rocker arm housing near the fuselage connection end. When the first forced cooling device group is installed therein, the first forced cooling device group is located below the lowest position connection line 31 of the gear of the high-speed section cutting transmission mechanism. It does not affect the arrangement of the cutting transmission mechanism, nor does it occupy the loading channel under the low-speed end boom.

[0063] The planetary mechanism (a core component of the rocker arm's end-drive mechanism) extends longitudinally and is mounted on the coal wall side of the drum connection end of the rocker arm housing. For example... Figure 2 , 14 As shown in Figure 15, the planetary carrier 44 of the planetary mechanism includes a planetary carrier body with a rotating structure. The interior of the planetary carrier body forms a sun gear mounting cavity 445 and a planet gear mounting cavity 446 at the rear, and an oil cavity 447 at the front. The planet gear mounting cavities surround and communicate with the sun gear mounting cavity, and the junction of the sun gear mounting cavity and the planet gear mounting cavity forms a meshing cavity between the sun gear and the planet gears. A central through-hole 448 and multiple axial oil holes 444 surrounding the central through-hole are provided on the partition wall between the oil cavity and the sun gear mounting cavity. The central through-hole is used to pass through a cooling medium flow pipe. The oil cavity and the sun gear mounting cavity communicate through the central through-hole and the axial oil holes, allowing heat exchange between the meshing cavity and the oil cavity, promoting cooling at the meshing point of the planet gear and the sun gear. Shallow grooves are also provided on the front walls of the sun gear mounting cavity and the planet gear mounting cavity, allowing the heat exchange between the meshing cavity and the oil cavity to extend to the multiple rows of support bearings inside the planet gears, enabling rapid cooling of the multiple rows of support bearings. The diameter of the oil chamber is not less than the diameter of the sun gear mounting chamber, compared to existing planetary carriers (see...). Figure 19 This allows for a larger oil cavity space, facilitating the holding of more lubricating oil and enabling better heat dissipation. A second forced cooling device 62 is installed within the oil cavity, which significantly improves the cooling effect of the transmission mechanism containing the planetary carrier.

[0064] The oil cavity wall 443 is provided with a radial oil hole 442 penetrating the cavity wall. The outer cylindrical surface of the oil cavity wall is divided by the radial oil hole. The front part of the radial oil hole is provided with an external spline 449 for forming a spline connection with the roller connecting sleeve 48, and the rear part is a journal 441 for installing the front bearing 45. The radial oil hole can connect the inner and outer spaces of the oil cavity, allowing the local hot oil caused by frictional heat at the end face floating seal 481 between the roller connecting sleeve and the inner cavity planetary carrier and the front bearing to exchange heat with the large amount of cooled oil in the oil cavity. The internal gear ring is fixed on the rocker arm housing. The rear part of the inner cavity planetary carrier is rotatably supported on the rocker arm housing through the rear bearing. The sun gear and planet gears are respectively installed in the sun gear mounting cavity and the planet gear mounting cavity. The planet gears mesh externally with the sun gear and internally with the internal gear ring.

[0065] The front and rear walls of the planetary gear mounting cavity are provided with pairs of planetary gear shaft mounting holes 440. There are multiple pairs of planetary gear shaft mounting holes, which are evenly distributed in a circle around the central through hole. Correspondingly, one planetary gear is installed at each pair of planetary gear shaft mounting holes. The diameter of the journal is preferably not less than the diameter of the distribution circle of the planetary gear shaft mounting holes.

[0066] The second forced cooling unit is used for cooling the end drive mechanism of the rocker arm.

[0067] The first forced cooling device group includes one or more first forced cooling devices 61. Each first forced cooling device includes a cooling medium flow pipe group 611, a cooling medium inlet / outlet seat 612, and a connecting seat 613. The cooling medium flow pipe group includes multiple inflow pipes extending in the same direction and spaced apart from each other, and multiple outflow pipes. Both ends of the cooling medium flow pipe group are fixedly installed on the cooling medium inlet / outlet seat and the connecting seat, respectively. Because multiple pipes are connected in parallel between the cooling medium inlet / outlet seat and the connecting seat, the cooling device structure is very compact and has high structural strength. The cooling medium inlet / outlet seat has multiple inflow channels and multiple outflow channels. The outlets of all inflow channels and the inlets of all outflow channels converge on the same end face of the cooling medium inlet / outlet seat and each occupy half of that end face. In the embodiment shown in the attached drawings, there are two outlets for each inflow channel and two inlets for each outflow channel, and each outlet for each inflow channel and each inlet for each outflow channel occupies a semicircular surface. The outlet of the inlet channel and the inlet of the outlet channel are connected one-to-one with the corresponding ends of the inlet and outlet pipes, respectively. Both the inlet and outlet of the inlet channel lead to the radial outer surface of the cooling medium inlet / outlet seat. Compared to existing cooling devices that require connecting cooling medium inlet / outlet channels at the ends, this design saves significant axial installation space. The connecting seat near the end of the cooling medium flow pipe assembly has multiple internally interconnected channel interfaces, each connected one-to-one with the corresponding end of each cooling medium flow pipe in the assembly. The cooling medium enters the inlet pipe through the inlet channel, then passes through the connecting seat into the outlet pipe, and finally flows out through the outlet channel. The cooling medium inlet / outlet seat is a stepped shaft structure, comprising at least three stepped cylindrical surfaces: large, medium, and small. Each stepped cylindrical surface 6121 has a radial seal, such as a sealing ring 6122. Each pair of adjacent radial seals divides the stepped cylindrical surface into a region, with the inlet of the inlet channel and the outlet of the outlet channel separately located in two different regions. The multi-step cylindrical surface facilitates the installation and removal of the sealing ring. Setting the sealing ring on the multi-step cylindrical surface in the manner described above can effectively seal the water, including preventing the cooling medium from leaking into the oil sump and preventing cross-contamination between the inlet and outlet pipes, thus ensuring an effective series connection between the inlet and outlet pipes.

[0068] The cooling medium inlet / outlet seat and the connecting seat are both mounted on the rocker arm housing. When there is one first forced cooling device, the inlet of the inflow channel and the outlet of the outflow channel of the first forced cooling device constitute the medium inlet and medium outlet of the first forced cooling device group, respectively. When there are multiple first forced cooling devices (the attached figure shows two first forced cooling devices connected in series), the multiple first forced cooling devices are connected in series according to the flow direction of the cooling medium therein, and the inlet of the inflow channel of the first first forced cooling device and the outlet of the outflow channel of the last first forced cooling device constitute the medium inlet and medium outlet of the first forced cooling device group, respectively. The outlet of the outflow channel of the preceding cooling device and the inlet of the inflow channel of the following cooling device are connected through a connecting hole provided in the rocker arm housing.

[0069] Regarding the configuration of the cooling medium inlet and outlet channels outside the first forced cooling device group, one configuration involves a medium inlet hole and a medium outlet hole within the rocker arm housing. These holes are connected to and communicate with the medium inlet and outlet of the first forced cooling device group, respectively, allowing the first forced cooling device group to be integrated into a cooling medium circulation loop. The cooling medium is introduced into the first forced cooling device group through the rocker arm housing and ultimately discharged through it. Another configuration involves a water jacket 65 within the rocker arm housing, with the first forced cooling device group connected in series in the water path of the water jacket. The first forced cooling device group directly utilizes the cooling water in the water jacket and the water circulation established by the water jacket, eliminating the need for a separate cooling medium circulation pipeline. Figure 13 The first forced cooling device group introduces cooling water from the water jacket through the water inlet hole 101, and the water outlet of the first forced cooling device group enters the water jacket in sequence through the water outlet hole 103 and the connecting hole 104.

[0070] The first forced cooling device may further include a welding seat 614. The end of the connecting seat away from the cooling medium flow pipe assembly is inserted into one end of the welding seat and clearance-fitted with the shaft hole of the welding seat. The other end of the welding seat is provided with an inclined plane 6141. The bottom cavity wall of the lower front cavity near the roller connection end is an inclined transition cavity wall, and the height of the inclined transition cavity wall increases as it approaches the roller connection end. The cooling medium inlet / outlet seat is installed on the cylinder connecting arm of the rocker arm housing, and the welding seat is welded to the inclined transition cavity wall with its inclined plane.

[0071] The outer cylindrical surface of the connecting seat, which mates with the shaft hole of the welding seat, is provided with multiple annular grooves, and vibration-damping O-rings 615 are installed in the annular grooves. The insertion depth of the connecting seat into the welding seat is determined according to specific circumstances, and a certain axial safety clearance is usually maintained between the connecting seat and the bottom of the shaft hole of the welding seat.

[0072] The stepped cylindrical surface of the cooling medium inlet / outlet seat is provided with an inlet flat-bottomed groove and an outlet flat-bottomed groove (collectively referred to as flat-bottomed groove 6123). The inlets of all inflow channels are located on the bottom surface of the inlet flat-bottomed groove, and the outlets of all outflow channels are located on the bottom surface of the outlet flat-bottomed groove. The inlet flat-bottomed groove facilitates the even distribution of the incoming cooling medium to all inflow pipes, while the outlet flat-bottomed groove facilitates the smooth convergence and outflow of the cooling medium from each outflow pipe.

[0073] The rocker arm housing has two motor mounting cavities 18, each extending forward and backward, located on the goaf side of the high-speed section cutting transmission mechanism mounting cavity, for mounting motors 2. A motor inter-cavity 14 is located within the partition wall between the two motor mounting cavities. The high-speed section cutting transmission mechanism mounting cavity communicates with the motor inter-cavity but not with the motor mounting cavities. A clutch cavity 15 is located on the outer side of the motor mounting cavity near the drum connection end. The high-speed section cutting transmission mechanism mounting cavity communicates with the clutch cavity. Both the motor inter-cavity and the clutch cavity are located within a locally thicker solid structure of the rocker arm housing, thus avoiding increased occupancy of the original internal space of the rocker arm housing while simultaneously creating new effective oil-containing space within the rocker arm housing.

[0074] A rear lower cavity 17 is also provided below the front part of the motor mounting cavity, and the front lower cavity and the rear lower cavity are connected front and rear. The rear lower cavity is located below the front lower housing 112 of the motor mounting cavity. By setting the rear lower cavity, the front and rear width of the newly added oil-containing space at the lower part of the rocker arm housing near the fuselage connection end is further widened, which means that the oil-containing space and heat release space are further expanded, and the cooling and lubrication effect of the boom is further improved.

[0075] A connecting end cavity 12 is also provided on the outer side of the high-speed section cutting transmission mechanism mounting cavity and the lower front cavity, near the connecting end of the machine body. The high-speed section cutting transmission mechanism mounting cavity and the lower front cavity are both connected to the connecting end cavity laterally. A connecting end side cavity 13 is also provided on the outer side of the front part of the motor mounting cavity and the lower rear cavity, near the connecting end of the machine body. The connecting end cavity and the connecting end side cavity are connected front and rear. The motor cavity, clutch cavity, connecting end cavity, and connecting end side cavity can all be regarded as a further expansion of the oil space inside the boom, further ensuring sufficient lubrication of the boom cavity.

[0076] This invention increases the oil storage space in the lower part of the rocker arm as much as possible. When the rocker arm of the coal mining machine is working at an angle, regardless of whether the machine body connection end or the drum connection end is on top, the oil level rises, reducing the vertical distance between the oil level and the highest transmission component. Even without adding a cooling device, it can improve the lubrication of the transmission component at the highest point to a certain extent.

[0077] The second forced cooling device 62 includes a cooling base 622, a cooling sleeve 621, and a cooling medium flow pipe 620. The cooling sleeve is a hollow tubular structure, with its front part inserted and fixedly installed in the cooling base, and its middle and rear parts extending outwards. The front wall of the cooling sleeve has a cooling medium inflow groove 6211 and a cooling medium outflow groove 6215, which communicates with the cooling medium outflow channel in the cooling base. The cooling sleeve also has several cooling medium inflow outlet holes 6212 and several cooling medium outflow outlet holes 6214 extending forward and backward. The front ends of the cooling medium inflow outlet holes and cooling medium outflow outlet holes communicate with the cooling medium inflow groove and cooling medium outflow groove, respectively, and the rear ends communicate with an annular groove 6213 located in the rear wall of the cooling sleeve. The front of the cooling medium flow pipe is fitted with and relatively fixedly installed in the inner hole of the cooling sleeve, its middle part is located inside the cooling sleeve and maintains a gap from it, and its rear part extends outwards from the cooling sleeve. The front end of the cooling medium flow pipe is closed, and a lateral through hole 6201 is provided on the front wall of the cooling medium flow pipe. The lateral through hole communicates with the cooling medium inflow groove and is used to introduce the cooling medium from the cooling medium flow pipe into the cooling medium inflow groove of the cooling jacket. The rear end of the cooling medium flow pipe and the cooling medium outflow channel in the cooling seat constitute the cooling medium inflow channel and cooling medium outflow channel of the second forced cooling device, respectively. The cooling medium flows into the barrel-shaped cooling device from the rear end of the cooling medium flow pipe, passes sequentially through the lateral through hole, the cooling medium inflow groove on the cooling jacket, the cooling medium inflow outlet hole, the annular groove, the cooling medium outflow outlet hole, and the cooling medium outflow groove on the cooling jacket, and finally exits from the cooling medium outflow channel in the cooling seat.

[0078] When the second forced cooling device is installed, the cooling seat is fixed to the front end of the planetary carrier. The rest of the second forced cooling device is located in the oil cavity of the planetary carrier. Under normal working conditions, it is always immersed in the oil in the oil cavity to force-cool the oil, so that the corresponding planetary mechanism is cooled more fully, making up for the lack of water jacket cooling of the rocker arm shell of the existing coal mining machine.

[0079] Typically, the cooling medium is water. The cooling medium inflow channel of the second forced cooling device can be connected to the water circuit of the water jacket on the rocker arm housing, so that the water in the water jacket is introduced into the second forced cooling device and effectively exchanges heat with the hot oil in the oil chamber of the planetary carrier 44 before being discharged.

[0080] The second forced cooling device is small in size and is installed inside the oil chamber of the planetary carrier, without occupying any other additional installation space.

[0081] Since the water in the cooling medium flow pipe of the second forced cooling device comes from the boom water jacket, most of the second forced cooling device is immersed below the oil level in the oil chamber of the planetary carrier when the rocker arm housing is in various tilt angles, and can effectively cool the planetary mechanism. Therefore, the operation of the second forced cooling device is not affected by whether a cavity structure is used between the rocker arm housing and the planetary mechanism.

[0082] In this embodiment, both the cooling medium inflow groove and the cooling medium outflow groove are arc-shaped grooves extending circumferentially along the cooling jacket, with the groove openings facing the radial outer side of the cooling jacket.

[0083] Furthermore, the front tube wall of the cooling jacket is provided with a connecting hole 6218. One end of the connecting hole is open on the inner side of the tube wall of the cooling jacket and communicates with the lateral through hole, and the other end communicates with the cooling medium inflow groove so as to lead the cooling medium from the lateral through hole to the cooling medium inflow groove.

[0084] Preferably, an annular groove 6219 is provided on the inner side of the front tube wall of the cooling jacket, and one end of the connecting hole communicates with the lateral through hole through the annular groove. With the annular groove, circumferential positioning is not required between the cooling jacket and the cooling medium flow pipe to ensure communication between the connecting hole and the lateral through hole, thus simplifying assembly. In this embodiment, the lateral through hole is a through hole that radially penetrates both sides of the cooling medium flow pipe to increase the flow rate of the cooling medium exiting the cooling medium flow pipe.

[0085] The outlet of the cooling medium outlet channel in the cooling seat is connected to a connector 6222. This connector extends radially along the cooling seat and, in the installed state, is located between the drum connecting plate 51 and the drum end cover 52. Compared to conventional cooling devices with end-connected water outlet connectors, this design occupies less axial space, making the drum 5 more compact axially. The outlet of the connector can be connected to the water path of the drum's cooling / spraying system, allowing the water that has absorbed heat from the hot oil in the planetary carrier's oil chamber to be discharged through the drum's cooling / spraying system. This greatly simplifies the composition, structure, and installation of the forced cooling system centered on the second forced cooling device and saves significant space. The cooling medium outlet channel in the cooling seat can have multiple branches, each branch having one outlet, and each outlet connected to a connector 6222.

[0086] The outer and inner surfaces of the middle and rear portion of the cooling jacket are preferably provided with corrugated structures to increase the contact area between the cooling jacket and the oil and improve cooling efficiency. In this embodiment, for ease of processing, the corrugated structure is provided by threads, including an external thread 6216 and an internal thread 6217.

[0087] High-speed end bearing housing 631 and low-speed end bearing housing 641 are respectively installed on the coal wall side cavity wall of the high-speed section cutting transmission mechanism installation cavity and the goaf side cavity wall of the low-speed section cutting transmission mechanism installation cavity. Both the high-speed end bearing housing and the low-speed end bearing housing are equipped with annular cooling grooves 6311 and 6411 and two connecting grooves 6312 and 6412. When a water jacket is installed inside the rocker arm housing, the annular cooling grooves are connected in series to the water path of the water jacket through the two connecting grooves on the same bearing housing. The annular cooling grooves and connecting grooves are machined from the original bearing housing. To distinguish them from the original bearing housing, the bearing housing with the annular cooling grooves and connecting grooves can be called a cooling plate, namely the high-speed end cooling plate 63 and the low-speed end cooling plate 64.

[0088] The high-speed and low-speed end cooling plates are used for auxiliary cooling. When the rocker arm operates at a large tilt angle, the cooling effect of other cooling methods on the high-speed end or low-speed end of the rocker arm, which is in a higher position, may be weakened. At this time, the cooling plate on the corresponding end will enhance the cooling effect on the corresponding end. For example, when the rocker arm housing is tilted upwards at the high-speed end and downwards at the low-speed end, the enhanced cooling effect of the cooling water circuit in the high-speed end cooling plate on the high-speed end oil can compensate for the weakened cooling effect of the first forced cooling device group.

Claims

1. A high-power rocker arm cooling system for a coal mining machine, characterized in that: The system includes a rocker arm housing and a planetary mechanism. The rocker arm housing has a machine body connection end and a drum connection end at its two ends along its length. The rocker arm housing contains a high-speed section cutting transmission mechanism mounting cavity and a low-speed section cutting transmission mechanism mounting cavity that are connected horizontally. The high-speed section cutting transmission mechanism mounting cavity is located near the machine body connection end and the coal wall side. A lower front cavity is located below the high-speed section cutting transmission mechanism mounting cavity, and the high-speed section cutting transmission mechanism mounting cavity is vertically connected to the lower front cavity. A first forced cooling device assembly is installed in the lower front cavity. The planetary mechanism's axis extends forward and backward and is installed on the coal wall side of the drum connection end of the rocker arm housing. The planetary carrier includes a planetary carrier body with a rotating structure. The interior of the planetary carrier body forms a sun gear mounting cavity and a planet gear mounting cavity at the rear, and an oil cavity at the front. The planet gear mounting cavity surrounds the sun gear mounting cavity and communicates with it. The partition wall between the oil cavity and the sun gear mounting cavity is provided with a central through hole and multiple axial oil holes surrounding the central through hole. The diameter of the oil cavity is not less than the diameter of the sun gear mounting cavity. A second forced cooling device is installed in the oil cavity. The wall of the oil cavity is provided with radial oil holes penetrating the cavity wall. The outer cylindrical surface of the oil cavity wall is divided by the radial oil holes. The front part of the radial oil holes is provided with an external spline, and the rear part is a journal.

2. The high-power rocker arm cooling system for a coal mining machine as described in claim 1, characterized in that: The first forced cooling device group includes one or more first forced cooling devices. Each first forced cooling device includes a cooling medium flow pipe group, a cooling medium inlet / outlet seat, and a connecting seat. The cooling medium flow pipe group includes multiple inlet pipes and multiple outlet pipes extending in the same direction and spaced apart from each other. The two ends of the cooling medium flow pipe group are respectively installed on the cooling medium inlet / outlet seat and the connecting seat. The cooling medium inlet / outlet seat is provided with multiple inlet channels and multiple outlet channels. The outlets of all inlet channels and the inlets of all outlet channels are on the same end face of the cooling medium inlet / outlet seat. Each component converges and occupies half of the end face. The outlet of the inflow channel and the inlet of the outflow channel are connected one-to-one with the corresponding ends of the inflow and outflow pipes, respectively. Both the inlet and outlet of the inflow channel lead to the radial outer side of the cooling medium inlet / outlet seat. The end of the connecting seat near the cooling medium flow pipe assembly has multiple internally interconnected channel interfaces, which are connected one-to-one with the corresponding end of each cooling medium flow pipe in the cooling medium flow pipe assembly. The cooling medium inlet / outlet seat has a stepped shaft structure, including at least large, medium, and small... The three-tiered cylindrical surface has a radial seal on each tier. Each pair of adjacent radial seals divides the tiered cylindrical surface into a region. The inlet of the inflow channel and the outlet of the outflow channel are separately located in two different regions. The cooling medium inlet / outlet seat and the connecting seat are both installed on the rocker arm housing. When there is one first forced cooling device, the inlet of the inflow channel and the outlet of the outflow channel of the first forced cooling device constitute the medium inlet and medium outlet of the first forced cooling device group, respectively. When there are multiple first forced cooling devices, the multiple first forced cooling devices are connected in series according to the flow direction of the cooling medium. The inlet of the inflow channel of the first forced cooling device and the outlet of the outflow channel of the last forced cooling device constitute the medium inlet and medium outlet of the first forced cooling device group, respectively. The rocker arm housing has a medium inlet hole and a medium outlet hole, which are connected and communicate with the medium inlet and medium outlet of the first forced cooling device group, respectively. Alternatively, the rocker arm housing has a water jacket, and the first forced cooling device group is connected in series in the water channel of the water jacket.

3. The high-power rocker arm cooling system for a coal mining machine as described in claim 2, characterized in that: The first forced cooling device also includes a welding seat. The end of the connecting seat away from the cooling medium flow pipe assembly is inserted into one end of the welding seat and is clearance-fitted with the shaft hole of the welding seat. The other end of the welding seat is provided with an inclined plane. The bottom cavity wall of the front lower cavity near the roller connection end is an inclined transition cavity wall. The inclined transition cavity wall is higher as it gets closer to the roller connection end. The cooling medium inlet / outlet seat is installed on the oil cylinder connecting arm of the rocker arm housing. The welding seat is welded to the inclined transition cavity wall with its inclined plane.

4. The high-power rocker arm cooling system for a coal mining machine as described in claim 3, characterized in that: The outer cylindrical surface of the connecting seat that mates with the shaft hole of the welding seat is provided with multiple annular grooves, and vibration damping O-rings are installed in the annular grooves.

5. The high-power rocker arm cooling system for a coal mining machine as described in claim 2, 3, or 4, characterized in that: The stepped cylindrical surface of the cooling medium inlet / outlet seat is provided with an inlet flat-bottomed groove and an outlet flat-bottomed groove. The inlets of all inflow channels are opened on the bottom surface of the inlet flat-bottomed groove, and the outlets of all outflow channels are opened on the bottom surface of the outlet flat-bottomed groove.

6. The high-power rocker arm cooling system for a coal mining machine as described in claim 5, characterized in that: The high-speed section cutting transmission mechanism mounting cavity inside the rocker arm housing has two motor mounting cavities extending forward and backward on the goaf side. The spacer between the two motor mounting cavities has a motor inter-cavity. The high-speed section cutting transmission mechanism mounting cavity and the motor inter-cavity are connected forward and backward. The outer side of the motor mounting cavity near the roller connection end has a clutch cavity. The high-speed section cutting transmission mechanism mounting cavity and the clutch cavity are connected forward and backward. The lower front part of the motor mounting cavity also has a lower rear cavity. The lower front cavity and the lower rear cavity are connected forward and backward.

7. The high-power rocker arm cooling system for a coal mining machine as described in claim 1, 2, 3, or 4, characterized in that: The second forced cooling device includes a cooling base, a cooling jacket, and a cooling medium flow pipe. The cooling jacket is a hollow tubular structure. The front part of the cooling jacket is inserted into and fixedly installed in the cooling base, while the middle and rear parts extend outwards. The front wall of the cooling jacket has a cooling medium inflow groove and a cooling medium outflow groove, which communicates with the cooling medium outflow channel in the cooling base. The cooling jacket also has several cooling medium inflow outlet holes and several cooling medium outflow outlet holes extending forward and backward within its wall. The front ends of the cooling medium inflow outlet holes and cooling medium outflow outlet holes communicate with the cooling medium inflow groove and cooling medium outflow groove, respectively. The rear end of the hole and the outlet of the cooling medium communicate with the annular groove located in the rear tube wall of the cooling jacket. The front shaft hole of the cooling medium flow pipe is fitted and fixedly installed in the inner hole of the cooling jacket. The middle part is located inside the cooling jacket and is spaced apart from the cooling jacket. The rear part extends out of the cooling jacket. The front end of the cooling medium flow pipe is closed. A lateral through hole is provided on the front tube wall of the cooling medium flow pipe. The lateral through hole communicates with the cooling medium inflow groove. The rear end of the cooling medium flow pipe and the cooling medium outlet channel in the cooling seat respectively constitute the cooling medium inflow channel and the cooling medium outlet channel of the second forced cooling device.

8. The high-power rocker arm cooling system for a coal mining machine as described in claim 7, characterized in that: The outlet of the cooling medium outflow channel in the cooling base is connected to a connector, which extends radially along the cooling base.

9. The high-power rocker arm cooling system for a coal mining machine as described in claim 7, characterized in that: The outer and inner surfaces of the middle and rear portion of the cooling jacket are both provided with a corrugated structure.

10. The high-power rocker arm cooling system for a coal mining machine as described in claim 7, characterized in that: The rocker arm housing is equipped with a water jacket. High-speed end bearing seats and low-speed end bearing seats are respectively installed on the coal wall side cavity wall of the high-speed section cutting transmission mechanism installation cavity and the goaf side cavity wall of the low-speed section cutting transmission mechanism installation cavity. Both the high-speed end bearing seat and the low-speed end bearing seat are equipped with an annular cooling groove and two connecting grooves. The annular cooling groove is connected to the water circuit of the water jacket through the two connecting grooves on the same bearing seat.

11. The high-power rocker arm cooling system for a coal mining machine as described in claim 5, characterized in that: The second forced cooling device includes a cooling base, a cooling jacket, and a cooling medium flow pipe. The cooling jacket is a hollow tubular structure. The front part of the cooling jacket is inserted into and fixedly installed in the cooling base, while the middle and rear parts extend outwards. The front wall of the cooling jacket has a cooling medium inflow groove and a cooling medium outflow groove, which communicates with the cooling medium outflow channel in the cooling base. The cooling jacket also has several cooling medium inflow outlet holes and several cooling medium outflow outlet holes extending forward and backward within its wall. The front ends of the cooling medium inflow outlet holes and cooling medium outflow outlet holes communicate with the cooling medium inflow groove and cooling medium outflow groove, respectively. The rear end of the hole and the outlet of the cooling medium communicate with the annular groove located in the rear tube wall of the cooling jacket. The front shaft hole of the cooling medium flow pipe is fitted and fixedly installed in the inner hole of the cooling jacket. The middle part is located inside the cooling jacket and is spaced apart from the cooling jacket. The rear part extends out of the cooling jacket. The front end of the cooling medium flow pipe is closed. A lateral through hole is provided on the front tube wall of the cooling medium flow pipe. The lateral through hole communicates with the cooling medium inflow groove. The rear end of the cooling medium flow pipe and the cooling medium outlet channel in the cooling seat respectively constitute the cooling medium inflow channel and the cooling medium outlet channel of the second forced cooling device.

12. The high-power rocker arm cooling system for a coal mining machine as described in claim 6, characterized in that: The second forced cooling device includes a cooling base, a cooling jacket, and a cooling medium flow pipe. The cooling jacket is a hollow tubular structure. The front part of the cooling jacket is inserted into and fixedly installed in the cooling base, while the middle and rear parts extend outwards. The front wall of the cooling jacket has a cooling medium inflow groove and a cooling medium outflow groove, which communicates with the cooling medium outflow channel in the cooling base. The cooling jacket also has several cooling medium inflow outlet holes and several cooling medium outflow outlet holes extending forward and backward within its wall. The front ends of the cooling medium inflow outlet holes and cooling medium outflow outlet holes communicate with the cooling medium inflow groove and cooling medium outflow groove, respectively. The rear end of the hole and the outlet of the cooling medium communicate with the annular groove located in the rear tube wall of the cooling jacket. The front shaft hole of the cooling medium flow pipe is fitted and fixedly installed in the inner hole of the cooling jacket. The middle part is located inside the cooling jacket and is spaced apart from the cooling jacket. The rear part extends out of the cooling jacket. The front end of the cooling medium flow pipe is closed. A lateral through hole is provided on the front tube wall of the cooling medium flow pipe. The lateral through hole communicates with the cooling medium inflow groove. The rear end of the cooling medium flow pipe and the cooling medium outlet channel in the cooling seat respectively constitute the cooling medium inflow channel and the cooling medium outlet channel of the second forced cooling device.

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