Grinding head device of sharpening machine

Abstract

The grinding head device of the sharpening machine comprises a supporting rod, a grinding rod and a grinding wheel, the grinding rod is arranged on the supporting rod in a sleeved mode, the supporting rod is rotationally connected into the grinding rod, the grinding wheel is arranged at one end of the supporting rod in a sleeved mode, and the end, close to the grinding wheel, of the supporting rod is sleeved with a shaft sleeve. The grinding rod comprises a first rod and a second rod, and one end of the first rod is detachably connected with one end of the second rod. The shaft sleeve is easy to damage after being used for a long time, the first rod is detached from the second rod, and the rotating rod is detached from the connecting rod, so that an operator can conveniently overhaul the shaft sleeve.

Description

Technical Field

[0001] This application relates to the field of grinding machines, and in particular to a grinding head device for a grinding machine. Background Art

[0002] During the production process of seamless steel pipes, it is usually necessary to grind the inner surface of the steel pipes with a grinding machine to remove defects.

[0003] Chinese Patent with the authorization announcement number CN218427315U discloses a grinding rod structure for an internal grinding machine of a steel pipe, which includes a grinding rod. An inner bearing installation cavity and a wire soft shaft installation cavity are coaxially arranged on the grinding rod. There is a through hole in the form of a perforation between the inner bearing installation cavity and the wire soft shaft installation cavity. A liquid flow channel is arranged axially along the grinding rod inside the grinding rod, and a pipe interface communicating with the liquid flow channel is arranged at one end of the grinding rod far from the inner bearing installation cavity. A communication hole communicating with the liquid flow channel is arranged at the other end of the grinding rod. A liquid spraying seat is sleeved on the grinding rod. A liquid storage cavity communicating with the communication hole is coaxially arranged inside the liquid spraying seat. A plurality of liquid spraying holes communicating with the liquid storage cavity are arranged on the outer edge of the liquid spraying seat. The cutting fluid enters the liquid storage cavity through the communication hole, and then is sprayed onto the inner surface of the steel pipe through the liquid spraying holes, so as to add cutting fluid to the grinding position of the grinding wheel, reduce the roughness of the grinding position of the steel pipe, improve the surface finish, and in addition, reduce the wear of the grinding wheel, and the cutting fluid adding position is relatively fixed with the position of the grinding wheel.

[0004] In view of the above related technologies, after long-term use, the bearing ages, which is likely to affect the rotation of the grinding wheel. When overhauling the bearing, the entire grinding rod needs to be disassembled. The grinding rod is usually relatively long, and the disassembly is rather inconvenient, thus making it inconvenient for the overhaul of the bearing. Summary of the Utility Model

[0005] In order to facilitate the overhaul of the bushing, this application provides a grinding head device for a grinding machine.

[0006] The grinding head device for a grinding machine provided by this application adopts the following technical solution:

[0007] A grinding head device of a grinding machine, comprising a support rod, a grinding rod, and a grinding wheel. The grinding rod is sleeved on the support rod, and the central axis of the grinding rod is collinear with the central axis of the support rod. The support rod is rotatably connected within the grinding rod. The grinding wheel is sleeved on one end of the support rod, and the central axis of the grinding wheel is collinear with the central axis of the support rod. A bushing is sleeved on the support rod near the grinding wheel end, and the outer circle of the bushing is connected to the inner wall of the grinding rod. The support rod includes a rotating rod and a connecting rod. The length direction of the rotating rod is the same as that of the connecting rod. One end of the rotating rod is detachably connected to one end of the connecting rod. The grinding wheel is sleeved on the end of the rotating rod away from the connecting rod. The bushing is sleeved on the rotating rod, and the central axis of the grinding wheel is collinear with the central axis of the rotating rod. The grinding rod includes a first rod and a second rod. The length direction of the first rod is the same as that of the second rod. One end of the first rod is detachably connected to one end of the second rod. The first rod is sleeved on the rotating rod, and the rotating rod is rotatably connected to the first rod. The second rod is sleeved on the connecting rod, and the connecting rod is rotatably connected to the second rod. The central axis of the first rod is collinear with the central axis of the rotating rod.

[0008] By adopting the above technical solution, during long-term use, the bushing is prone to damage. By detaching the first rod from the second rod and the rotating rod from the connecting rod, it is convenient for the operator to repair the bushing.

[0009] Optionally, the connecting rod and the rotating rod are detachably connected by a spline.

[0010] By adopting the above technical solution, the connecting rod and the rotating rod are detachably connected by a spline, making the disassembly of the connecting rod and the rotating rod more convenient.

[0011] Optionally, the first rod and the second rod are detachably connected by bolts and nuts.

[0012] By adopting the above technical solution, the first rod and the second rod are detachably connected by bolts and nuts, making the disassembly of the first rod and the second rod more convenient.

[0013] Optionally, a mounting seat is sleeved on the end of the rotating rod away from the connecting rod. The central axis of the mounting seat is collinear with the central axis of the rotating rod. The grinding wheel is sleeved on the rotating rod, and the grinding wheel is detachably connected to the mounting seat by bolts.

[0014] By adopting the above technical solution, the grinding wheel is detachably connected to the mounting seat, facilitating the cleaning or replacement of the grinding wheel and improving the grinding effect of the grinding wheel on the steel pipe.

[0015] Optionally, a circulation channel is provided inside the grinding rod. The length direction of the circulation channel is the same as that of the grinding rod. One end of the circulation channel away from the grinding wheel is connected to a liquid inlet pipe, which is used to input cutting fluid into the circulation channel. The grinding rod is provided with an annular channel, whose circumferential direction is the same as that of the grinding rod. The annular channel is arranged at one end of the first rod close to the grinding wheel and is connected to the circulation channel. A plurality of spray heads are connected to the circumferential side of the first rod, and the plurality of spray heads are sequentially and spaced apart along the circumferential direction of the first rod. The spray heads are connected to the annular channel.

[0016] By adopting the above technical solution, when the grinding wheel grinds the inner surface of the steel pipe, the liquid inlet pipe inputs cutting fluid into the circulation channel, and the cutting fluid enters the annular channel along the circulation channel. The cutting fluid is sprayed onto the inner wall of the steel pipe through the spray heads, thereby reducing the temperature of the grinding wheel during grinding and reducing the wear of the grinding wheel.

[0017] Optionally, a connecting sleeve is sleeved on the first rod. The central axis of the connecting sleeve is collinear with the central axis of the first rod. A connecting hole is provided on the circumferential side of the first rod, which connects the connecting sleeve and the annular channel. The spray heads are connected to the connecting sleeve and communicate with the connecting sleeve. The plurality of spray heads are spaced apart along the circumferential direction of the connecting sleeve. The connecting sleeve is detachably connected to the first rod.

[0018] By adopting the above technical solution, during long-term use, it is easy for metal debris to block the spray heads, and the connecting sleeve is detachably connected to the first hole, so as to facilitate the cleaning or replacement of the spray heads.

[0019] Optionally, the connecting sleeve includes a first ring and a second ring. The central axis of the first ring is collinear with the central axis of the second ring. The circumferential direction of the first ring is the same as that of the first rod, and the circumferential direction of the second ring is the same as that of the first rod. The first ring and the second ring are connected end to end, and the first ring and the second ring form a gap for the first rod to pass through. The inner circle of the first ring contacts the circumferential side of the first rod, and the inner circle of the second ring contacts the circumferential side of the first rod. One end of the first ring is detachably connected to one end of the second ring, and the other end of the first ring is detachably connected to the other end of the second ring.

[0020] By adopting the above technical solution, when disassembling the connecting sleeve, detach the first ring from the second ring and move the first ring and the second ring away from each other, so as to facilitate the cleaning or replacement of the spray heads.

[0021] Optionally, limiting grooves are formed on the circumferential side of the first rod. The limiting grooves are arranged as annular grooves. The circumferential direction of the limiting grooves is the same as that of the first rod. There are two limiting grooves, and the two limiting grooves are sequentially and spaced apart along the length direction of the first rod. The two limiting grooves are respectively arranged on both sides of the annular channel along the length direction of the first rod. The two axial ends of the first ring are respectively embedded in the two limiting grooves, and the two axial ends of the second ring are respectively embedded in the two limiting grooves. The first ring and the second ring are respectively embedded on both sides of the limiting groove along the radial direction of the first rod. Sealing layers are connected to the inner walls of the limiting grooves. The sealing layers are arranged in an annular shape. The circumferential direction of the sealing layers is the same as that of the first rod. The first ring and the second ring are respectively in contact with the sealing layers on both sides of the first rod along the radial direction.

[0022] By adopting the above technical solution, when installing the connecting sleeve, the two axial ends of the first ring are respectively embedded in the two limiting grooves, the two axial ends of the second ring are respectively embedded in the two limiting grooves, and the first ring and the second ring are connected end to end, and both the first ring and the second ring are in contact with the sealing layer, so as to improve the connection stability between the connecting sleeve and the first rod.

[0023] In summary, the present application includes at least one of the following beneficial technical effects:

[0024] 1. Under long-term use, the bushing is prone to damage. By detaching the first rod from the second rod and the rotating rod from the connecting rod, it is convenient for the operator to repair the bushing.

[0025] 2. The grinding wheel is detachably connected to the mounting seat, so as to facilitate the cleaning or replacement of the grinding wheel, thereby improving the grinding effect of the grinding wheel on the steel pipe.

[0026] 3. When installing the connecting sleeve, the two axial ends of the first ring are respectively embedded in the two limiting grooves, the two axial ends of the second ring are respectively embedded in the two limiting grooves, and the first ring and the second ring are connected end to end, and both the first ring and the second ring are in contact with the sealing layer, so as to improve the connection stability between the connecting sleeve and the first rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a three-dimensional structure diagram of this embodiment.

[0028] Figure 2 is a cross-sectional view of this embodiment, used to show the connecting rod and the rotating rod.

[0029] Figure 3 is this embodiment Figure 2 an enlarged view of part A in.

[0030] Figure 4 is this embodiment Figure 1 an enlarged view of part B in.

[0031] Description of reference numerals: 100, support rod; 110, rotating rod; 120, connecting rod; 200, grinding rod; 210, first rod; 211, first groove; 212, limiting groove; 213, sealing layer; 220, second rod; 221, second groove; 230, bushing; 240, end cap; 300, grinding wheel; 310, mounting seat; 400, flow channel; 410, first channel; 420, second channel; 430, liquid inlet pipe; 440, annular channel; 450, connection hole; 500, connecting sleeve; 510, first ring; 511, first mounting plate; 520, second ring; 521, second mounting plate; 530, nozzle. Detailed implementation manners

[0032] The following further describes the present application in detail with reference to the Figures 1-4 accompanying drawings.

[0033] An embodiment of the present application discloses a grinding head device of a grinding machine. Refer to Figure 1 and Figure 2 , a grinding head device of a grinding machine includes a support rod 100, a grinding rod 200, and a grinding wheel 300. The support rod 100 is horizontally arranged, the grinding rod 200 is sleeved on the support rod 100, the support rod 100 is rotatably connected inside the grinding rod 200, and the central axes of the grinding rod 200 and the support rod 100 are collinear.

[0034] Refer to Figure 1 and Figure 2 , the grinding rod 200 includes a first rod 210 and a second rod 220. The length direction of the first rod 210 is the same as that of the second rod 220, the central axes of the first rod 210 and the second rod 220 are collinear, the first rod 210 and the second rod 220 are arranged in sequence along the length direction of the first rod 210, and one end of the first rod 210 is detachably connected to one end of the second rod 220. The support rod 100 includes a connecting rod 120 and a rotating rod 110. The connecting rod 120 and the rotating rod 110 are horizontally arranged, the length direction of the connecting rod 120 is the same as that of the rotating rod 110, the rotating rod 110 and the connecting rod 120 are arranged in sequence along the length direction of the rotating rod 110, the central axes of the connecting rod 120 and the rotating rod 110 are collinear, and one end of the connecting rod 120 is detachably connected to one end of the rotating rod 110.

[0035] Refer to Figure 1 and Figure 2, the first rod 210 is sleeved on the rotating rod 110. The rotating rod 110 is rotatably connected to the first rod 210, and there is a gap between the inner wall of the first rod 210 and the outer wall of the rotating rod 110. The central axis of the first rod 210 is collinear with the central axis of the rotating rod 110. Four bushings 230 are sleeved on the rotating rod 110, and the central axis of the bushing 230 is collinear with the central axis of the first rod 210. The inner ring of the bushing 230 is connected to the circumferential side of the rotating rod 110, and the outer ring of the bushing 230 is connected to the inner wall of the first rod 210. The second rod 220 is sleeved on the connecting rod 120. The connecting rod 120 is rotatably connected to the second rod 220, and there is a gap between the inner wall of the second rod 220 and the outer wall of the connecting rod 120. The central axis of the first rod 210 is collinear with the central axis of the rotating rod 110. The grinding wheel 300 is sleeved on one end of the rotating rod 110 away from the connecting rod 120. The central axis of the grinding wheel 300 is collinear with the central axis of the support rod 100, and the central axis of the grinding wheel 300 is collinear with the central axis of the rotating rod 110.

[0036] Referring to Figure 1 and Figure 2 , both ends of the grinding rod 200 are open along its length direction. One end of the grinding rod 200 close to the grinding wheel 300 is connected with an end cover 240. The end cover 240 covers the opening at one end of the grinding rod 200 close to the grinding wheel 300. The rotating rod 110 passes through and is rotatably connected to the end cover 240 along its length direction. The central axis of the end cover 240 is collinear with the central axis of the first rod 210, and the end cover 240 is detachably connected to the first rod 210 by bolts. The bolts pass through the end cover 240 along the length direction of the first rod 210 and are threadedly connected to the first rod 210.

[0037] Referring to Figure 2 , a mounting seat 310 is threadedly sleeved on one end of the rotating rod 110 away from the connecting rod 120. The central axis of the mounting seat 310 is collinear with the central axis of the rotating rod 110, and the mounting seat 310 is arranged at one end of the first rod 210 away from the grinding wheel 300. The grinding wheel 300 is sleeved on the rotating rod 110. The grinding wheel 300 is arranged on one side of the mounting seat 310 away from the connecting rod 120, and the grinding wheel 300 is detachably connected to the mounting seat 310 by bolts. The bolts pass through the grinding wheel 300 along the length direction of the first rod 210 and are threadedly connected to the mounting seat 310.

[0038] Referring to Figure 1 and Figure 2, the first rod 210 and the second rod 220 are detachably connected by bolts and nuts. A plurality of first grooves 211 are formed on the circumferential side of one end of the first rod 210 close to the second rod 220. There are five first grooves 211, and the five first grooves 211 are evenly spaced along the circumferential direction of the first rod 210. A plurality of second grooves 221 are formed on the circumferential side of one end of the second rod 220 close to the first rod 210. There are five second grooves 221, and the five second grooves 221 are evenly spaced along the axial direction of the second rod 220. The first grooves 211 and the second grooves 221 correspond to each other one by one. The bolt passes through the inner wall of one end of the second groove 221 close to the first rod 210 and the inner wall of one end of the first groove 211 close to the second rod 220 along the length direction of the first rod 210 and is threadedly connected to the nut. The nut is arranged in the first groove 211. One end of the connecting rod 120 and one end of the rotating rod 110 are detachably connected by a spline.

[0039] Referring to Figure 2 and Figure 3 , a circulation channel 400 is formed in the grinding rod 200. The length direction of the circulation channel 400 is consistent with the length direction of the grinding rod 200. The circulation channel 400 includes a first channel 410 and a second channel 420. The length direction of the first channel 410 is consistent with the length direction of the first rod 210, and the length direction of the second channel 420 is consistent with the length direction of the second rod 220. The first channel 410 is formed in the first rod 210, the second channel 420 is formed in the second rod 220, and one end of the first channel 410 is communicated with one end of the second channel 420.

[0040] Referring to Figure 2 and Figure 3 , a liquid inlet pipe 430 is communicated with one end of the second channel 420 far from the first channel 410. The liquid inlet pipe 430 is used for inputting cutting fluid into the circulation channel 400. The grinding rod 200 is provided with an annular channel 440. The outer circumferential wall of the annular channel 440 is open. The circumferential direction of the annular channel 440 is consistent with the circumferential direction of the grinding rod 200. The annular channel 440 is arranged at one end of the first channel 410 far from the second channel 420, and the first channel 410 is communicated with the annular channel 440.

[0041] Referring to Figure 3 and Figure 4 , a connecting sleeve 500 is sleeved on the first rod 210. The central axis of the connecting sleeve 500 is collinear with the central axis of the first rod 210. A plurality of connecting holes 450 are formed on the circumferential side of the first rod 210. The connecting holes 450 are sequentially and spaced along the circumferential direction of the first rod 210 on the first rod 210. The connecting holes 450 communicate the connecting sleeve 500 with the annular channel 440.

[0042] Referring to Figure 2 and Figure 3, a limiting groove 212 is provided on the circumferential side of the first rod 210. There are two limiting grooves 212, and the limiting grooves 212 are arranged as annular grooves. The circumferential direction of the limiting grooves 212 is the same as the circumferential direction of the first rod 210. The two limiting grooves 212 are sequentially and spaced apart along the length direction of the first rod 210. An annular channel 440 is arranged between the two limiting grooves 212. The depth direction of the limiting grooves 212 is the same as the radial direction of the first rod 210.

[0043] Refer to Figure 3 , the connecting sleeve 500 is respectively embedded in the two limiting grooves 212 along both axial ends thereof. Sealing layers 213 are connected to the inner walls on both sides of the limiting grooves 212 along the length direction of the first rod 210. The sealing layers 213 are arranged in a ring shape. The circumferential direction of the sealing layers 213 is the same as the circumferential direction of the first rod 210. The sealing layers 213 are in contact with the connecting sleeve 500, and the sealing layers 213 are used to reduce the gap between the connecting sleeve 500 and the inner wall of the limiting grooves 212.

[0044] Refer to Figure 3 and Figure 4 , the connecting sleeve 500 includes a first ring 510 and a second ring 520. The central axis of the first ring 510 is collinear with the central axis of the second ring 520. Both the first ring 510 and the second ring 520 are arranged in a semicircular shape. The first ring 510 and the second ring 520 form a gap for the first rod 210 to pass through. The circumferential direction of the first ring 510 is the same as the circumferential direction of the first rod 210. The circumferential direction of the second ring 520 is the same as the circumferential direction of the first rod 210. The first ring 510 and the second ring 520 are connected end to end. The two axial ends of the first ring 510 are respectively embedded in the two limiting grooves 212, and the two axial ends of the second ring 520 are respectively embedded in the two limiting grooves 212.

[0045] Refer to Figure 4 , both circumferential ends of the first ring 510 are connected with first mounting plates 511, and both circumferential ends of the second ring 520 are connected with second mounting plates 521. The first mounting plates 511 and the second mounting plates 521 correspond to each other one by one. The first mounting plates 511 and the second mounting plates 521 are detachably connected by bolts and nuts. The bolts pass through the first mounting plates 511 and the second mounting plates 521 along the radial direction of the first rod 210 and are threadedly connected with the nuts. A plurality of spray nozzles 530 are communicated with both the first ring 510 and the second ring 520. The plurality of spray nozzles 530 are evenly spaced along the circumferential direction of the first ring 510 on the first ring 510, and the plurality of spray nozzles 530 are evenly spaced along the circumferential direction of the second ring 520 on the second ring 520.

[0046] The implementation principle of the grinding head device of a grinding machine in an embodiment of the present application is as follows: during maintenance, the first rod 210 is detached from the second rod 220, and the rotating rod 110 is detached from the connecting rod 120, so that the connecting rod 120 and the rotating rod 110 move away from each other, and the first rod 210 and the second rod 220 move away from each other. The end cover 240 is detached from one end of the first rod 210, so as to facilitate the maintenance of the bushing 230 by the operator.

[0047] The above are all the preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A grinding head device of a grinding machine, comprising a support rod (100), a grinding rod (200), and a grinding wheel (300). The grinding rod (200) is sleeved on the support rod (100), and the central axis of the grinding rod (200) is collinear with the central axis of the support rod (100). The support rod (100) is rotatably connected inside the grinding rod (200). The grinding wheel (300) is sleeved on one end of the support rod (100), and the central axis of the grinding wheel (300) is collinear with the central axis of the support rod (100). A bushing (230) is sleeved on one end of the support rod (100) close to the grinding wheel (300), and the outer circle of the bushing (230) is connected to the inner wall of the grinding rod (200). It is characterized in that: The support rod (100) includes a rotating rod (110) and a connecting rod (120). The length direction of the rotating rod (110) is the same as that of the connecting rod (120). One end of the rotating rod (110) is detachably connected to one end of the connecting rod (120). The grinding wheel (300) is sleeved on the end of the rotating rod (110) away from the connecting rod (120). The sleeve (230) is sleeved on the rotating rod (110). The central axis of the grinding wheel (300) is collinear with the central axis of the rotating rod (110). The grinding rod (200) includes a first rod (210) and a second rod (220). The length direction of the first rod (210) is the same as that of the second rod (220). One end of the first rod (210) is detachably connected to one end of the second rod (220). The first rod (210) is sleeved on the rotating rod (110). The rotating rod (110) is rotatably connected to the first rod (210). The second rod (220) is sleeved on the connecting rod (120). The connecting rod (120) is rotatably connected to the second rod (220). The central axis of the first rod (210) is collinear with the central axis of the rotating rod (110).

2. The grinding head device of a grinding machine according to claim 1, characterized in that: The connecting rod (120) and the rotating rod (110) are detachably connected by splines.

3. The grinding head device of a grinding machine according to claim 1, characterized in that: The first rod (210) and the second rod (220) are detachably connected by bolts and nuts.

4. The grinding head device of a grinding machine according to claim 1, characterized in that: An installation seat (310) is sleeved on the end of the rotating rod (110) away from the connecting rod (120). The central axis of the installation seat (310) is collinear with the central axis of the rotating rod (110). The grinding wheel (300) is sleeved on the rotating rod (110). The grinding wheel (300) is detachably connected to the installation seat (310) by bolts.

5. The grinding head device of a grinding machine according to claim 1, characterized in that: A flow channel (400) is formed in the grinding rod (200). The length direction of the flow channel (400) is the same as that of the grinding rod (200). One end of the flow channel (400) away from the grinding wheel (300) is communicated with a liquid inlet pipe (430). The liquid inlet pipe (430) is used to input cutting fluid into the flow channel (400). The grinding rod (200) is provided with an annular channel (440). The circumferential direction of the annular channel (440) is the same as that of the grinding rod (200). The annular channel (440) is arranged at one end of the first rod (210) close to the grinding wheel (300). The annular channel (440) is communicated with the flow channel (400). A plurality of spray heads (530) are connected to the circumferential side of the first rod (210). The plurality of spray heads (530) are sequentially and spaced apart along the circumferential direction of the first rod (210). The spray heads (530) are communicated with the annular channel (440).

6. The grinding head device of a grinding machine according to claim 5, characterized in that: A connecting sleeve (500) is sleeved on the first rod (210). The central axis of the connecting sleeve (500) is collinear with the central axis of the first rod (210). Connecting holes (450) are formed on the circumferential side of the first rod (210). The connecting holes (450) communicate the connecting sleeve (500) with the annular channel (440). The nozzle (530) is connected to the connecting sleeve (500). The nozzle (530) is in communication with the connecting sleeve (500). A plurality of the nozzles (530) are circumferentially and spaced apart along the connecting sleeve (500). The connecting sleeve (500) is detachably connected to the first rod (210).

7. The grinding head device of a grinding machine according to claim 6, characterized in that: The connecting sleeve (500) includes a first ring (510) and a second ring (520). The central axis of the first ring (510) is collinear with the central axis of the second ring (520). The circumferential direction of the first ring (510) is the same as the circumferential direction of the first rod (210). The circumferential direction of the second ring (520) is the same as the circumferential direction of the first rod (210). The first ring (510) and the second ring (520) are connected end to end. The first ring (510) and the second ring (520) form a gap for the first rod (210) to pass through. The inner circle of the first ring (510) contacts the circumferential side of the first rod (210). The inner circle of the second ring (520) contacts the circumferential side of the first rod (210). One end of the first ring (510) is detachably connected to one end of the second ring (520). The other end of the first ring (510) is detachably connected to the other end of the second ring (520).

8. The grinding head device of a grinding machine according to claim 7, characterized in that: Limiting grooves (212) are formed on the circumferential side of the first rod (210). The limiting grooves (212) are arranged as annular grooves. The circumferential direction of the limiting grooves (212) is the same as the circumferential direction of the first rod (210). There are two limiting grooves (212). The two limiting grooves (212) are sequentially and spaced apart along the length direction of the first rod (210). The two limiting grooves (212) are respectively arranged on both sides of the annular channel (440) along the length direction of the first rod (210). Axial ends of the first ring (510) are respectively embedded in the two limiting grooves (212). Axial ends of the second ring (520) are respectively embedded in the two limiting grooves (212). The first ring (510) and the second ring (520) are respectively embedded on both sides of the limiting groove (212) along the radial direction of the first rod (210). Sealing layers (213) are connected to the inner walls of the limiting grooves (212). The sealing layers (213) are arranged in an annular shape. The circumferential direction of the sealing layers (213) is the same as the circumferential direction of the first rod (210). The first ring (510) and the second ring (520) respectively contact the sealing layers (213) on both sides along the radial direction of the first rod (210).

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