High-temperature and high-pressure motor

Abstract

An inner sleeve is arranged in an inner cavity of a motor shell, a motor stator containing a coil winding is arranged in an annular cavity between the motor shell and the inner sleeve, a wire outlet pipe is arranged on the motor shell, and the front end and the rear end of the inner sleeve are detachably connected with a front end cover and a rear end cover of the motor in a sealed mode. A rear bearing is arranged between the rear section of a rotor shaft of the motor rotor and the inner sleeve, and a front bearing is arranged between the front section of the rotor shaft and the front end cover; the motor rotor is arranged in the inner sleeve, so that the motor stator and the motor rotor are separated by the inner sleeve and located in the relatively independent cavities, and a medium pumped by the motor is isolated in the area outside the stator so as to prevent the high-temperature and high-pressure medium from reaching the area where the stator is located.

Description

Technical Field

[0001] This invention relates to motors that operate in high-temperature and high-pressure environments. Background Technology

[0002] Using an electric motor as a power source to drive and transport media can be achieved by either using the motor to drive the pump or by setting pumping blades on the motor shaft. For the solution of directly using a motor with pumping blades, if the medium to be pumped is corrosive, it may cause corrosion to the motor coil. When the medium being transported has high temperature and high pressure characteristics, the anti-corrosion, anti-leakage, and temperature resistance properties of the motor need to be redesigned.

[0003] The document titled "A High-Pressure Shielded Pump" (Document No. CN 223120185 U, hereinafter referred to as Document 1) discloses that the pump body 1 is directly connected to the front end of the motor, and the rotor assembly 13 is rotatably connected inside the second bearing three-piece sleeve 10. The stator isolation sleeve 15 is set on the outer periphery of the rotor assembly 13. By adopting the tight cooperation between the stator isolation sleeve 15 and the rotor assembly 13, the efficient sealing of the medium inside the pump is achieved, effectively preventing the leakage of high-pressure easily vaporized medium inside the pump body, ensuring the stable operation and cooling efficiency of the pump. Document 1 does not specifically describe the shape and fixing scheme of the isolation sleeve 15.

[0004] The title is "Electronic Water Pump" (Document No. CN 118188513 A, hereinafter referred to as Document 2).

[0005] In this design, at the first end of the stator assembly S, the stator injection molding layer S0 extends to the inner circumference of the stator core S1 to form a cover-shaped partition structure S01. The partition structure S01 extends axially through the center to form a central cylinder S011. The stator injection molding layer S0 forms two concentric, spaced-apart retaining rings on the outer circumference of the central cylinder S011: an inner retaining ring S012 and an outer retaining ring S013. Thus, while Reference 2 uses a scheme that fully covers the stator to prevent leakage, this solution addresses the leakage problem at the cost of adding injection molding layers to the stator assembly S from all angles. The problem is that when the pumped medium is at a high temperature, the stability of the injection molding layer at temperatures such as 300°C is difficult to guarantee.

[0006] Titled "An Electronic Water Pump" (Document No. CN 119712564A, hereinafter referred to as Document 3), Document 3 relates to an engine cooling water pump. To prevent coolant leakage, both the stator assembly 4 and the rotor assembly 5 are equipped with isolation sleeves for sealing and waterproofing. This solution not only requires isolation sleeves to be used to seal and waterproof the stator assembly 4 and the rotor assembly 5 respectively, but its applicable water temperature environment is usually below 90° (which is the normal operating temperature of the engine), and it does not involve the issue of pressure resistance. Summary of the Invention

[0007] The purpose of this invention is to provide a high-temperature and high-pressure motor in which the medium pumped by the motor is isolated outside the stator to prevent the high-temperature and high-pressure medium from reaching the stator area.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a high temperature and high pressure motor, wherein an inner sleeve is provided in the inner cavity of the motor housing, the motor stator containing the coil winding is placed in the annular cavity between the motor housing and the inner sleeve, the motor housing has a cable outlet pipe, the front and rear ends of the inner sleeve are detachably sealed to the front and rear end covers of the motor, a rear bearing is provided between the rear section of the rotor shaft of the motor rotor and the inner sleeve, and a front bearing is provided between the front section of the rotor shaft and the front end cover.

[0009] In the above technical solution, the motor rotor is placed inside the inner sleeve, which separates the motor stator and the motor rotor and places them in relatively opposing chambers. This allows high-pressure and high-temperature gas to enter the area where the motor rotor is located, but it cannot reach the area where the motor stator is located. This protects the insulation of the coil windings from damage by high-temperature and high-pressure gas. In addition, the inner sleeve meets the strength requirements for compressive strength. Furthermore, the inner sleeve also serves as the bearing housing for the rear bearing, thus avoiding the conventional solution of using the rear end cover of the motor as the bearing housing in traditional technology. This avoids the problem that it is difficult or even impossible to seal directly between the motor rotor, the rear bearing and the rear end cover of the motor. Attached Figure Description

[0010] Figure 1 A schematic diagram of the structure of this invention;

[0011] Figure 2 This is a schematic diagram of the assembly structure of the motor housing and inner sleeve in this invention;

[0012] Figure 3 This is a schematic diagram of a structure for conveying high-temperature and high-pressure media using the present invention. Detailed Implementation

[0013] Combination Figure 1 , 2 The high-temperature and high-pressure motor shown has an inner sleeve 20 inside the motor housing 10. The motor stator 30, which includes the coil winding 31, is placed in the annular cavity between the motor housing 10 and the inner sleeve 20. The motor housing 10 has a cable outlet pipe 12. The front and rear ends of the inner sleeve 20 are detachably sealed to the front end cover 50 and the rear end cover 11 of the motor. A rear bearing 411 is provided between the rear section of the rotor shaft 41 of the motor rotor 40 and the inner sleeve 20, and a front bearing 412 is provided between the front section of the rotor shaft 41 and the front end cover 50.

[0014] In the above technical solution, the inner sleeve 20 is an independent tubular component, with its front and rear ends extending to the front end cover 50 and rear end cover 11 of the motor, respectively, forming a detachable sealed connection with the latter two. This isolates the motor stator 30 and the motor rotor 40 into two completely independent chambers, ensuring that the respective chambers of the motor stator 30 and the motor rotor 40 are not interconnected. Since the front and rear ends of the rotor shaft 41 need to be equipped with front bearings 412 and rear bearings 411, given the structure and motion characteristics of the front bearings 412, rear bearings 411, and the rotor shaft 41, it is impossible or difficult to install seals to prevent gap-like passages along the axial direction at the bearings. The proposed solution retains the natural passageway with an axial gap at the bearing location, but instead uses a rear bearing 411 between the rear section of the rotor shaft 41 and the inner sleeve 20, and a front bearing 412 between the front section of the rotor shaft 41 and the front end cover 50. This solution ensures normal rotation of the rotor shaft 41 without the risk of damage from high-temperature, high-pressure media entering the motor rotor 40, as the motor rotor 40 is made solely of ferromagnetic material and there is no risk of damage from high-temperature, high-pressure gases to the insulating material. It also avoids the extreme difficulty of sealing the coil leads and the outlet pipe 12 when simply implementing a sealed maintenance system for the stator. The solution provided in this application allows the rotor to operate normally even when inert gas at 300°C and 2.5MPa reaches and fills the area where the motor rotor 40 is located. It should be noted that silicon nitride bearings can be used for the motor bearings, eliminating the need for grease lubrication. Ordinary bearing grease is easily lost under high-temperature, high-pressure environments, leading to bearing damage.

[0015] Combination Figure 3 The front end cover 50 is provided with an impeller cover 60 and a seal is provided between the two. The rotor shaft 41 is located in the impeller chamber 61 formed by the front end cover 50 and the impeller cover 60 and the shaft end is connected to the impeller 70. The impeller cover 60 has a medium inlet 62 and a medium outlet 63.

[0016] Figure 3 In the scheme shown, a pumping unit is set at the front end of the motor front cover 50. When inert gas with a high temperature of 300°C and a pressure of 2.5MPa enters the chamber where the impeller 70 is located through the medium inlet 62 on the impeller cover 60, the inert gas is discharged from the medium outlet 63 during the rotation of the impeller 70. During operation, the high temperature and pressure gas will definitely pass through the gap between the front cover 50, the front bearing 412 and the rotor shaft 41 to reach the inner sleeve 20, but it cannot reach the area where the motor stator 30 is located. The high temperature and high pressure of the gas will not have any adverse effects on the insulation materials such as the coil winding 31.

[0017] Preferred solutions include Figure 1 , 2As shown in Figure 3, the inner sleeve 20 is a stepped tubular shape, and a rear bearing 411 is provided between the rear section of the rotor shaft 41 and the small-diameter cavity of the rear section of the inner sleeve 20. The rotor core 42 is located in the large-diameter cavity of the inner sleeve 20. The shape of the inner sleeve 20 provided by this solution ensures that it can accommodate the rotor core 42 and the rear bearing 411, and facilitates the assembly of the motor rotor 40 in the inner sleeve 20.

[0018] The inner sleeve 20 has an extension tube 21 protruding to the outside of the rear end cover 11 at its rear end. A sealing ring 113 is provided between the extension tube 21 and the rear end cover 11. A nut or nut cap 22 is connected to the threaded section of the outer part of the extension tube 21. This solution solves the connection and assembly between the rear end of the inner sleeve 20 and the rear end cover 11. The sealing ring 113 prevents the high-temperature and high-pressure medium inside the inner sleeve 20 from flowing to the motor stator 30.

[0019] The outer peripheral wall of the extension tube 21 is stepped columnar, and a convex ring is provided on the inner end face of the rear end cover 11. The stepped surface of the extension tube 21 presses against the top surface 114 of the convex ring. A sealing ring 113 is provided in the annular area formed between the convex ring provided on the inner end face of the rear end cover 11 and the stepped surface of the extension tube 21.

[0020] After the inner sleeve 20 is fixed and locked with nut 22, the stepped surface of extension tube 21 presses against the top surface 114 of convex ring. This serves two purposes: first, it compresses and deforms the sealing ring 113 to an appropriate degree to ensure the best sealing state and avoid insufficient or excessive deformation; second, it achieves axial positioning of the inner sleeve 20, which provides a prerequisite for the axial positioning of rotor shaft 41; and third, it ensures the connection and fit between the front end of the inner sleeve 20 and the front end cover 50.

[0021] Specifically, the inner sleeve 20 has an external flange 23 at its front end. The flange 23 is placed in an annular groove on the inner end face of the front cover 50, and a sealing gasket 51 is provided between the two.

[0022] Given that the axial position of the flange 23 is fixed, the gap between the bottom of the annular groove on the inner end face of the rear front cover 50 after the front cover 50 is assembled into the motor housing 10 and the flange 23 meets the design gap. This design gap is the compression constraint condition for the sealing gasket 51 to handle the sealing state.

[0023] Preferably, a nut 22 is connected to the threaded section of the outer segment of the extension pipe 21. The extension pipe 21 is connected to the high-pressure, high-temperature conveying pipeline 80. One end of the high-pressure, high-temperature conveying pipeline 80 is connected to the outlet of the air pump 90, and the other end is connected to the medium inlet 62 on the impeller cover 60. The impeller cover 60 has a medium outlet 63 connected to the inlet of the air pump 90. This solution meets the requirement of conveying 300℃, 2.5MPa high-temperature, high-pressure inert gas in an environmental circuit where the air pump 90 is installed on the high-pressure, high-temperature conveying pipeline 80.

[0024] The motor housing 10 and the rear end cover 11 are connected in one piece or in a detachable manner. Cooling gas inlet and outlet are provided at the front and rear parts of the annular cavity between the motor housing 10 and the inner sleeve 20.

[0025] In the illustrated structure, the motor housing 10 and the rear end cover 11 are an integral structure, with a cooling gas inlet 111 and a cooling gas outlet 112 located on the front wall of the motor housing 10. The motor stator 30 has axially penetrating cooling holes 32. The cooling gas inlet 111, cooling gas outlet 112, and cooling holes 32 form a cooling airflow channel to cool the motor stator 30, further reducing the impact of heat from the area where the motor rotor 40 is located on the motor stator 30. To prevent cooling gas leakage, a sealing element 52 is provided between the external flange at the front end of the motor housing 10 and the front end cover 50, ensuring full utilization of the cooling gas.

Claims

1. A high temperature high voltage electric machine characterized by: The inner sleeve (20) is arranged in the inner cavity of the motor housing (10), the motor stator (30) containing the coil winding (31) is arranged in the annular cavity between the motor housing (10) and the inner sleeve (20), the motor housing (10) is provided with a wire outlet pipe (12), the front end and the rear end of the inner sleeve (20) are detachably and sealingly connected with the front end cover (50) and the rear end cover (11) of the motor, and the rear section of the rotor shaft (41) of the motor rotor (40) is provided with the rear bearing (411) between the inner sleeve (20).

2. The high temperature high voltage electric machine of claim 1, wherein: The front end of the front end cover (50) is provided with an impeller cover (60), and a seal is arranged between the front end cover (50) and the impeller cover (60). The shaft end of the rotor shaft (41) located in the impeller cavity (61) surrounded by the front end cover (50) and the impeller cover (60) is connected with the impeller (70). The impeller cover (60) is provided with a medium inlet (62) and a medium outlet (63).

3. The high temperature high voltage electric machine of claim 1 or 2, wherein: The inner sleeve (20) is a stepped tubular, and the rear section of the rotor shaft (41) is provided with the rear bearing (411) between the small-diameter pipe cavity of the rear section of the inner sleeve (20).

4. The high temperature high voltage electric machine of claim 3, wherein: The rear end of the inner sleeve (20) is provided with an extension pipe (21) protruding to the outside of the rear end cover (11). A sealing ring (113) is arranged between the extension pipe (21) and the rear end cover (11). The outer section of the extension pipe (21) is connected with a nut or a nut cap (22).

5. The high temperature high voltage electric machine of claim 4, wherein: The outer peripheral wall of the extension pipe (21) is a stepped column. A convex ring is arranged on the inner end surface of the rear end cover (11). The stepped surface of the extension pipe (21) is pressed against the top surface (114) of the convex ring. A sealing ring (113) is arranged in the annular area surrounded by the convex ring arranged on the inner end surface of the rear end cover (11) and the stepped surface of the extension pipe (21).

6. The high temperature high voltage electric machine of claim 1, wherein: The front end of the inner sleeve (20) is provided with an external flange (23). The flange (23) is horizontally arranged in the annular groove arranged on the inner side end surface of the front end cover (50), and a sealing gasket (51) is arranged between the flange (23) and the front end cover (50).

7. The high temperature high voltage electric machine of claim 4, wherein: The outer section of the extension pipe (21) is connected with a nut (22). The extension pipe (21) is communicated with a high-pressure and high-temperature conveying pipeline (80). One end of the high-pressure and high-temperature conveying pipeline (80) is connected with the gas outlet end of a gas pump (90), and the other end is connected with the medium inlet (62) of the impeller cover (60). The impeller cover (60) is provided with a medium outlet (63) connected with the gas inlet end of the gas pump (90).

8. The high temperature high voltage electric machine of claim 1, wherein: The motor housing (10) and the rear end cover (11) are in an integrated or detachable connection structure. Cooling gas inlets and outlets are arranged at the front and rear parts of the annular cavity between the motor housing (10) and the inner sleeve (20).

9. The high temperature high voltage electric machine of claim 8, wherein: The motor housing (10) and the rear end cover (11) are in an integrated structure. The cooling gas inlet (111) is arranged on the rear end cover (11), and the cooling gas outlet (112) is arranged on the front section of the shell wall of the motor housing (10). The motor stator (30) is provided with an axially-through cooling hole (32).

10. The high temperature high voltage electric machine of claim 1, wherein: The outer flange at the front end of the motor housing (10) is provided with a sealing member (52) between the outer flange and the front end cover (50).

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