Spherical pilot valve for hydraulic adjustment

Abstract

The utility model relates to the technical field of pilot valves, and discloses a spherical pilot valve for hydraulic adjustment, which comprises a coil assembly, an electromagnet assembly and a main valve sleeve assembly, the main valve sleeve assembly comprises a main valve sleeve, a piston sleeve, a pilot valve sleeve and a pilot valve core, the piston sleeve is fixed in the main valve sleeve, the outer wall of the piston sleeve is attached to the inner wall of the main valve sleeve to form sealing, and the pilot valve core is fixed in the main valve sleeve. A pilot valve sleeve is fixed to the end, close to the electromagnet assembly, of the piston sleeve, a pilot valve element is assembled in the main valve sleeve in a clearance mode, the pilot valve element has the freedom degree of axial movement along the main valve sleeve, the pilot valve sleeve is located between the pilot valve element and the piston sleeve, and a piston rod is coaxially fixed to the end, close to the pilot valve sleeve, of the pilot valve element. A piston cavity is formed in the end, close to the pilot valve sleeve, of the piston sleeve, a sealing face is formed on the inner wall of the piston cavity, the piston rod movably penetrates through the pilot valve sleeve and makes contact with the sealing face in a matched mode to form a first sealing face, the pilot valve element makes contact with the pilot valve sleeve to form second sealing, control parameters are reduced, assembly is easy, and machining difficulty is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of pilot valves, in particular to a ball-type pilot valve for hydraulic regulation. Background Art

[0002] The automobile suspension system is an important component related to automobile safety, and the key component of suspension damping control is the pilot valve. The pilot valve has the characteristics of large flow and large pressure regulation. Most pilot valves on the market are divided into built-in and external types. At present, the main problem of the external pilot valve is the unstable product performance, which is mainly manifested in the unstable pressure relief and the inability to form a controllable flow pressure regulation mechanism. Secondly, the structure is complex, the assembly is difficult, the cost is high, and it is not convenient for mass production. Utility Model Content

[0003] The utility model aims to overcome the deficiencies of the prior art and provide a ball-type pilot valve for hydraulic regulation, which has reduced control parameters, simple assembly, reduced processing difficulty, convenient mass production and reduced costs.

[0004] The purpose of the utility model is achieved through the following technical solutions: a ball-type pilot valve for hydraulic regulation, comprising a coil assembly, an electromagnet assembly and a main valve sleeve assembly, the two ends of the electromagnet assembly are respectively equipped with the coil assembly and the main valve sleeve assembly, the main valve sleeve assembly comprises a main valve sleeve, a piston sleeve, a pilot valve sleeve and a pilot valve core, the piston sleeve is fixed in the main valve sleeve, the outer wall of the piston sleeve is in contact with the inner wall of the main valve sleeve to form a seal, the pilot valve sleeve is fixed to one end of the piston sleeve close to the electromagnet assembly, and the pilot valve sleeve is fixed to the pilot valve sleeve. The core gap is assembled in the main valve sleeve, the pilot valve core has the freedom to move axially along the main valve sleeve, the pilot valve sleeve is located between the pilot valve core and the piston sleeve, the end of the pilot valve core close to the pilot valve sleeve is coaxially fixed with a piston rod, the end of the piston sleeve close to the pilot valve sleeve is provided with a piston cavity, the inner wall of the piston cavity is formed with a sealing surface, the piston rod moves through the pilot valve sleeve, the piston rod contacts and cooperates with the sealing surface to form a first sealing surface, and the pilot valve core contacts with the pilot valve sleeve to form a second seal.

[0005] In some embodiments, a steel ball is provided at one end of the piston rod away from the pilot valve core, the sealing surface is an annular step surface, and the steel ball blocks the annular step surface to form a first sealing surface.

[0006] In some embodiments, a conical head is fixed to one end of the piston rod away from the pilot valve core, the sealing surface is a conical surface, and the inclined surface of the conical head cooperates with the sealing surface to form a first sealing surface.

[0007] In some embodiments, a T-shaped head is fixed to one end of the piston rod away from the pilot valve core, the sealing surface is a stepped table, and the T-shaped head cooperates with the stepped table to form a first sealing surface.

[0008] In some embodiments, the piston sleeve is in a stepped shape, and a plurality of first flow holes are provided on the side wall of the piston sleeve along its circumferential direction, the first flow holes are connected to the piston cavity, and the sealing surface is located between the first flow hole and the steel ball. The pilot valve sleeve is in a stepped shape, and the large diameter end of the pilot valve sleeve is fixedly connected to the large diameter end of the piston sleeve, and a mounting groove is provided on the large diameter end of the pilot valve sleeve, and a center hole for the piston rod to pass through is provided in the middle of the mounting groove, and a plurality of second flow holes are provided around the center hole in the mounting groove, and a piston spring is provided in the mounting groove, and the piston spring is sleeved on the piston rod, and the two ends of the piston spring are respectively connected to the pilot valve sleeve and the end of the piston rod.

[0009] In some embodiments, the pilot valve core is provided with a plurality of third flow holes around the piston rod, a sealing ring is fixed to the end surface of the pilot valve core close to the pilot valve sleeve, and the sealing ring is fitted with the small diameter end of the pilot valve sleeve to form a second sealing surface.

[0010] In some embodiments, a pilot spring is disposed between the pilot valve sleeve and the pilot valve core, and two ends of the pilot spring are respectively connected to the pilot valve sleeve and the pilot valve core.

[0011] In some embodiments, the main valve sleeve assembly also includes a main valve core and an end cover, the end cover is fixed to one end of the main valve sleeve away from the electromagnet assembly, the main valve core is gap assembled between the end cover and the piston sleeve, a flow hole is opened through the middle of the end cover, and a side guide hole is opened on the side wall of the main valve sleeve, and the side guide hole is located at the mating surface of the main valve core and the end cover, and a main spring is arranged between the piston sleeve and the main valve core.

[0012] In some embodiments, a gasket is provided between the end cover and the main valve sleeve, a special-shaped gasket is sleeved on the piston sleeve, and one end of the main spring rests on the special-shaped gasket.

[0013] In some embodiments, the electromagnet assembly includes a pole shoe body, a shell and a magnetic core shaft, the shell is assembled on the coil assembly through a clamping ring, the pole shoe body is fixedly assembled in the shell, the main valve sleeve is assembled in the pole shoe body at one end away from the coil assembly, the magnetic core shaft is coaxially arranged in the pole shoe body, the magnetic core shaft moves close to or away from the pilot valve core, a guide bearing is fixedly arranged in the pole shoe body, the guide bearing is sleeved on the magnetic core shaft, the magnetic core shaft is sleeved with a magnetic core, the magnetic core gap is assembled in the pole shoe body, a magnetic core seat is fixed in the pole shoe body, a magnetic core seat bearing is arranged on the magnetic core seat, the magnetic core seat bearing is sleeved on the magnetic core shaft, a pole shoe body sealing ring is arranged between the shell and the pole shoe body, a shell sealing ring is sleeved on the shell, and a coil sealing ring is sleeved on the end of the shell close to the coil assembly.

[0014] The beneficial effects of the utility model are:

[0015] The first seal is formed by the end structure of the piston rod and the sealing surface of the piston sleeve, and the second seal is formed by the contact between the pilot valve core and the pilot valve sleeve. The steel ball, conical head or T-head at the end of the piston rod are standard parts. The double-sealed structure makes the pilot valve structure more stable, reduces control parameters, simplifies assembly, reduces processing difficulty, facilitates mass production, and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the internal structure of a ball-type pilot valve for hydraulic regulation of the utility model;

[0017] Figure 2 This is a schematic diagram of the structure of a piston sleeve in a ball-type pilot valve for hydraulic regulation of the utility model;

[0018] Figure 3 This is a schematic diagram of the structure of a pilot valve sleeve in a ball-type pilot valve for hydraulic regulation of the utility model;

[0019] Figure 4 This is a structural schematic diagram of a pilot valve core in a ball-type pilot valve for hydraulic regulation of the utility model;

[0020] Figure 5 This is a structural schematic diagram of a second embodiment of a ball-type pilot valve for hydraulic regulation of the utility model;

[0021] Figure 6 This is a structural schematic diagram of a third embodiment of a ball-type pilot valve for hydraulic regulation of the utility model;

[0022] Figure 7 This is a sealing schematic diagram of a ball-type pilot valve for hydraulic regulation of the utility model;

[0023] Figure 8This is a flow channel display diagram of a ball-type pilot valve for hydraulic regulation of the utility model;

[0024] Fig. 9 This is a structural schematic diagram of a ball-type pilot valve for hydraulic regulation of the utility model;

[0025] In the figure, 1-coil assembly, 2-clamp ring, 3-coil sealing ring, 4-housing, 5-housing sealing ring, 6-pole shoe body sealing ring, 7-pole shoe body, 8-main valve sleeve, 9-gasket, 10-end cover, 11-main valve core, 12-main spring, 13-piston sleeve, 14-steel ball, 15-piston spring, 16-special-shaped gasket, 17-pilot valve sleeve, 18-pilot spring, 19-pilot valve core, 20-core seat , 21-magnetic core seat bearing, 22-magnetic core, 23-magnetic core shaft, 24-guide bearing, 25-electromagnet assembly, 26-main valve sleeve assembly, 27-piston rod, 28-piston chamber, 29-sealing surface, 30-first flow hole, 31-mounting groove, 32-center hole, 33-second flow hole, 34-third flow hole, 35-sealing ring platform, 36-conical head, 37-T-head, 38-side guide hole. DETAILED DESCRIPTION

[0026] The technical solution of the present utility model is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present utility model is not limited to the following.

[0027] Embodiment 1: Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figures 7 to 9As shown, a ball-type pilot valve for hydraulic regulation includes a coil assembly 1, an electromagnet assembly 25 and a main valve sleeve assembly 26. The two ends of the electromagnet assembly 25 are respectively equipped with the coil assembly 1 and the main valve sleeve assembly 26. The main valve sleeve assembly 26 includes a main valve sleeve 8, a piston sleeve 13, a pilot valve sleeve 17 and a pilot valve core 19. The piston sleeve 13 is fixed in the main valve sleeve 8. The outer wall of the piston sleeve 13 fits the inner wall of the main valve sleeve 8 to form a seal. The pilot valve sleeve 17 is fixed to one end of the piston sleeve 13 close to the electromagnet assembly 25. The pilot valve core 19 is gap-assembled in the main valve sleeve 8. The pilot valve core 19 has the freedom to move along the axial direction of the main valve sleeve 8. The pilot valve sleeve 17 is located between the pilot valve core 19 and the piston sleeve 13. The pilot valve core 19 is coaxially fixed with a piston rod 27 at one end close to the pilot valve sleeve 17, and a piston chamber 28 is provided at one end of the piston sleeve 13 close to the pilot valve sleeve 17. A sealing surface 29 is formed on the inner wall of the piston chamber 28. The piston rod 27 moves through the pilot valve sleeve 17, and the piston rod 27 contacts the matching sealing surface 29 to form a first sealing surface. The pilot valve core 19 contacts the pilot valve sleeve 17 to form a second seal. The double sealing structure makes the force of the pilot valve structure more stable; specifically: a steel ball 14 is provided at one end of the piston rod 27 away from the pilot valve core 19, and the sealing surface 29 is an annular step surface. The steel ball 14 blocks the annular step surface to form a first sealing surface. The piston sleeve 13 is in a stepped shape. The side wall of 13 is provided with a plurality of first flow holes 30 along its circumferential direction, the first flow holes 30 are connected to the piston cavity 28, the sealing surface 29 is located between the first flow hole 30 and the steel ball 14, and the first flow hole 30 and the piston cavity 28 are cut off by the movement of the steel ball 14. The pilot valve sleeve 17 is in a stepped shape, and the large diameter end of the pilot valve sleeve 17 is fixedly connected to the large diameter end of the piston sleeve 13. The large diameter end of the pilot valve sleeve 17 is provided with a mounting groove 31, and a central hole 32 for the piston rod 27 to pass through is provided in the middle of the mounting groove 31. A plurality of second flow holes 33 are provided around the central hole 32, and a piston spring 15 is provided in the mounting groove 31, and the piston spring 15 is sleeved on the piston rod 27, the two ends of the piston spring 15 are respectively connected to the pilot valve sleeve 17 and the end of the piston rod 27, the pilot valve core 19 is penetrated around the piston rod 27 to open a plurality of third flow holes 34, the end surface of the pilot valve core 19 close to the pilot valve sleeve 17 is fixed with a sealing ring 35, the sealing ring 35 and the small diameter end of the pilot valve sleeve 17 are fitted to form a second sealing surface, the second flow hole 33 and the third flow hole 34 are staggered along the radial direction of the pilot valve core 19, specifically, the second flow hole 33 is located on the inner side of the third flow hole 34, when the sealing ring 35 and the small diameter end of the pilot valve sleeve 17 are fitted to form the second sealing surface, the conduction between the second flow hole 33 and the third flow hole 34 is cut off to form a seal;The steel ball 14 is supported by the piston spring 15 and installed in the piston sleeve 13. The pilot valve core 19 is installed through the axial clearance between the center hole of the pilot valve sleeve 17 and the inner hole of the main valve sleeve 8. When the pilot valve core 19 moves toward the pilot valve sleeve 17, the sealing ring 35 of the pilot valve core 19 cooperates with the pilot valve sleeve 17 to form a second seal. The steel ball 14 is pushed by the piston rod 27 of the pilot valve core 19 and moves toward the sealing surface of the piston sleeve 13 to form a first seal. When the pilot valve core 19 moves away from the pilot valve sleeve 17, the above movement is reversed. Through the opening and closing states of the first seal and the second seal, the flow rate and pressure can be changed linearly in a controllable manner when the fluid flows. ;

[0028] Embodiment 2: Based on embodiment 1, Figure 5 As shown, the steel ball 14 is replaced with a conical head 36, and a conical head 36 is fixed to the end of the piston rod 27 away from the pilot valve core 19. The sealing surface 29 is a conical surface. The inclined surface of the conical head 36 cooperates with the sealing surface 29 to form a first sealing surface, and the first seal is formed by the conical surface cooperation.

[0029] Embodiment 3: Based on Embodiment 1, Figure 6 As shown, the steel ball 14 is replaced with a T-shaped head 37, and a T-shaped head 37 is fixed to the end of the piston rod 27 away from the pilot valve core 19. The sealing surface 29 is a stepped table surface. The T-shaped head 37 cooperates with the stepped table surface to form a first sealing surface, and a first seal is formed by the cooperation of the T-shaped surface.

[0030] In summary, the end shape of the piston rod 27 is not limited to the above shape, as long as a closed mating surface is formed between the end of the piston rod 27 and the inner wall of the piston sleeve 13 to achieve a sealing effect, and the piston rod 27 is driven to move by the spring element buffering.

[0031] Embodiment 4: Based on Embodiment 1, Figure 1As shown, a pilot spring 18 is arranged between the pilot valve sleeve 17 and the pilot valve core 19, and the two ends of the pilot spring 18 are respectively connected to the pilot valve sleeve 17 and the pilot valve core 19, the main valve sleeve assembly 26 also includes a main valve core 11 and an end cover 10, the end cover 10 is fixed to the end of the main valve sleeve 8 away from the electromagnet assembly 25, the main valve core 11 is gap-assembled between the end cover 10 and the piston sleeve 13, a flow hole is opened through the middle of the end cover 10, a side guide hole 38 is opened on the side wall of the main valve sleeve 8, and the side guide hole 38 is located at the matching surface of the main valve core 11 and the end cover 10, a main spring 12 is arranged between the piston sleeve 13 and the main valve core 11, a gasket 9 is arranged between the end cover 10 and the main valve sleeve 8, and a special-shaped gasket is sleeved on the piston sleeve 13 16, one end of the main spring 12 is against the special-shaped gasket 16, the electromagnet assembly 25 includes a pole shoe body 7, a shell 4 and a magnetic core shaft 23, the shell 4 is assembled on the coil assembly 1 through the clamp ring 3, the pole shoe body 7 is fixedly assembled in the shell 4, the main valve sleeve 8 is assembled at the end of the pole shoe body 7 away from the coil assembly 1, the magnetic core shaft 23 is coaxially arranged in the pole shoe body 7, the magnetic core shaft 23 moves close to or away from the pilot valve core 19, a guide bearing 24 is fixedly arranged in the pole shoe body 7, the guide bearing 24 is sleeved on the magnetic core shaft 23, the magnetic core shaft 23 is sleeved with a magnetic core 22, the magnetic core 22 is gap assembled in the pole shoe body 7, a magnetic core seat 20 is fixed in the pole shoe body 7, a magnetic core seat bearing 21 is arranged on the magnetic core seat 20, and a magnetic core seat bearing 2 1 is mounted on the magnetic core shaft 23, a pole shoe body sealing ring 6 is arranged between the housing 4 and the pole shoe body 7, a housing sealing ring 5 is mounted on the housing 4, and a coil sealing ring 2 is mounted on one end of the housing 4 close to the coil assembly 1; the coil assembly 1 pushes the magnetic core shaft 23 fixed on the magnetic core 22 to move through the magnetic circuit formed between the housing 4, the pole shoe body 7, the magnetic core 22 and the magnetic core seat 20 according to the current input by the external control, and the movement of the magnetic core shaft 23 pushes the pilot valve core 19 to overcome the elastic force of the pilot spring 18 and the pressure formed by the piston sleeve 13 entering the liquid, and move toward the pilot valve sleeve 17. When the gap between the pilot valve core 19 and the pilot valve sleeve 17 is gradually reduced, at the same time, the liquid pressure entering the piston sleeve 13 is in The piston spring 15 in a compressed state and the steel ball 14 in contact therewith are also pushed by the piston rod 27 on the pilot valve core 19, and the distance between the steel ball 14 and the sealing surface 29 of the piston sleeve 13 is reduced, the interception effect is increased, and the liquid flow rate flowing into the piston sleeve 13 is reduced. On the other hand, the main valve core 11 connected through the first flow hole 30 on the piston sleeve 13 has an increased liquid pressure near the end of the piston sleeve 13. The liquid pressure here is superimposed on the spring force of the main spring 12, which exceeds the liquid pressure of the liquid flowing in from the end cover 10 from the outside acting on the main valve core 11. The main valve core 11 moves toward the end cover 10, and the gap between the two is reduced, and the interception effect is increased, resulting in a linear decrease in the liquid flow rate flowing in from the outside, thereby forming a controllable flow pressure regulation mechanism.

Claims

1. A ball-type pilot valve for hydraulic regulation, comprising a coil assembly (1), an electromagnet assembly (25) and a main valve sleeve assembly (26), wherein the coil assembly (1) and the main valve sleeve assembly (26) are respectively mounted at both ends of the electromagnet assembly (25), characterized in that: The main valve sleeve assembly (26) comprises a main valve sleeve (8), a piston sleeve (13), a pilot valve sleeve (17) and a pilot valve core (19); the piston sleeve (13) is fixed in the main valve sleeve (8); the outer wall of the piston sleeve (13) fits the inner wall of the main valve sleeve (8) to form a seal; the pilot valve sleeve (17) is fixed to one end of the piston sleeve (13) close to the electromagnet assembly (25); the pilot valve core (19) is installed in the main valve sleeve (8) with a clearance; the pilot valve core (19) has the freedom to move axially along the main valve sleeve (8); the pilot valve sleeve (17) is movable in the axial direction of the main valve sleeve (8); and the pilot valve sleeve (17) is movable in the axial direction of the main valve sleeve (8). ) is located between the pilot valve core (19) and the piston sleeve (13); a piston rod (27) is coaxially fixed to one end of the pilot valve core (19) close to the pilot valve sleeve (17); a piston chamber (28) is formed at one end of the piston sleeve (13) close to the pilot valve sleeve (17); a sealing surface (29) is formed on the inner wall of the piston chamber (28); the piston rod (27) moves through the pilot valve sleeve (17); the piston rod (27) contacts and cooperates with the sealing surface (29) to form a first sealing surface; the pilot valve core (19) contacts the pilot valve sleeve (17) to form a second seal.

2. A ball-type pilot valve for hydraulic regulation according to claim 1, characterized in that: A steel ball (14) is provided at one end of the piston rod (27) away from the pilot valve core (19); the sealing surface (29) is an annular step surface; the steel ball (14) blocks the annular step surface to form a first sealing surface.

3. A ball-type pilot valve for hydraulic regulation according to claim 1, characterized in that: A conical head (36) is fixed to one end of the piston rod (27) away from the pilot valve core (19); the sealing surface (29) is a conical surface; the inclined surface of the conical head (36) cooperates with the sealing surface (29) to form a first sealing surface.

4. A ball-type pilot valve for hydraulic regulation according to claim 1, characterized in that: A T-shaped head (37) is fixed to one end of the piston rod (27) away from the pilot valve core (19); the sealing surface (29) is a stepped table surface; the T-shaped head (37) cooperates with the stepped table surface to form a first sealing surface.

5. A ball-type pilot valve for hydraulic regulation according to any one of claims 2 to 4, characterized in that: The piston sleeve (13) is in a stepped shape. The side wall of the piston sleeve (13) is provided with a plurality of first flow holes (30) along its circumferential direction. The first flow holes (30) are connected to the piston chamber (28). The sealing surface (29) is located between the first flow holes (30) and the steel ball (14). The pilot valve sleeve (17) is in a stepped shape. The large diameter end of the pilot valve sleeve (17) is fixedly connected to the large diameter end of the piston sleeve (13). A mounting groove (31) is provided, a center hole (32) for the piston rod (27) to pass through is provided in the middle of the mounting groove (31), a plurality of second flow holes (33) are provided around the center hole (32) and penetrated through the mounting groove (31), a piston spring (15) is provided in the mounting groove (31), the piston spring (15) is sleeved on the piston rod (27), and two ends of the piston spring (15) are respectively connected to the pilot valve sleeve (17) and the end of the piston rod (27).

6. A ball-type pilot valve for hydraulic regulation according to claim 5, characterized in that: The pilot valve core (19) is provided with a plurality of third flow holes (34) extending through the pilot valve core (19) around the piston rod (27). A sealing ring platform (35) is fixed to the end surface of the pilot valve core (19) close to the pilot valve sleeve (17). The sealing ring platform (35) is fitted with the small diameter end of the pilot valve sleeve (17) to form a second sealing surface.

7. A ball-type pilot valve for hydraulic regulation according to claim 6, characterized in that: A pilot spring (18) is arranged between the pilot valve sleeve (17) and the pilot valve core (19), and two ends of the pilot spring (18) are respectively connected to the pilot valve sleeve (17) and the pilot valve core (19).

8. A ball-type pilot valve for hydraulic regulation according to claim 1, characterized in that: The main valve sleeve assembly (26) further comprises a main valve core (11) and an end cover (10), wherein the end cover (10) is fixed to one end of the main valve sleeve (8) away from the electromagnet assembly (25), and the main valve core (11) is gap-fitted between the end cover (10) and the piston sleeve (13), a flow hole is provided through the middle of the end cover (10), and a side guide hole (38) is provided on the side wall of the main valve sleeve (8), and the side guide hole (38) is located at the mating surface between the main valve core (11) and the end cover (10), and a main spring (12) is provided between the piston sleeve (13) and the main valve core (11).

9. A ball-type pilot valve for hydraulic regulation according to claim 8, characterized in that: A gasket (9) is provided between the end cover (10) and the main valve sleeve (8), a special-shaped gasket (16) is sleeved on the piston sleeve (13), and one end of the main spring (12) abuts against the special-shaped gasket (16).

10. A ball-type pilot valve for hydraulic regulation according to claim 1, characterized in that: The electromagnet assembly (25) comprises a pole shoe body (7), a housing (4) and a magnetic core shaft (23); the housing (4) is mounted on the coil assembly (1) via a clamping ring (2); the pole shoe body (7) is fixedly mounted in the housing (4); the main valve sleeve (8) is mounted on an end of the pole shoe body (7) away from the coil assembly (1); the magnetic core shaft (23) is coaxially arranged in the pole shoe body (7); the magnetic core shaft (23) moves toward or away from the pilot valve core (19); a guide bearing (24) is fixedly arranged in the pole shoe body (7); the guide bearing (24) is fitted On the magnetic core shaft (23), a magnetic core (22) is sleeved on the magnetic core shaft (23), the magnetic core (22) is gap-mounted in the pole shoe body (7), a magnetic core seat (20) is fixed in the pole shoe body (7), a magnetic core seat bearing (21) is provided on the magnetic core seat (20), the magnetic core seat bearing (21) is sleeved on the magnetic core shaft (23), a pole shoe body sealing ring (6) is provided between the outer shell (4) and the pole shoe body (7), an outer shell sealing ring (5) is sleeved on the outer shell (4), and a coil sealing ring (3) is sleeved on one end of the outer shell (4) close to the coil assembly (1).

Images