Electric auxiliary supercharger rotor structure with motor arranged outside supporting span of floating ring bearing

Abstract

The invention provides an electric auxiliary supercharger rotor structure with a motor arranged outside the supporting span of a floating ring bearing. The electric auxiliary supercharger rotor structure comprises a turbine impeller, the floating ring bearing, a rotating shaft, a thrust spacer sleeve, a shaft sealing sleeve, a motor magnetic rotor, a compressor impeller and a shaft end nut. The compressor impeller has the beneficial effects that the compressor impeller adopts the impeller with the small length-diameter ratio, and the ratio of the axial length of the impeller to the outer diameter of the impeller is smaller than 0.25 while the performance requirement of a supercharger is met, so that the axial length of a rotor structure is shortened, vibration generated when a rotor runs is restrained, and the reliability of the rotor structure is improved.

Description

Technical Field

[0001] The present invention belongs to the field of power machinery, and particularly relates to an electric-assisted supercharger rotor structure with a motor placed outside the support span of a floating-ring bearing. Background Art

[0002] The power following ability of a power system depends on the dynamic response ability of a diesel engine, and the dynamic response ability of the diesel engine is mainly limited by the response speed of the supercharging system. During the acceleration process of the engine, the fuel injection volume in the cylinder can increase rapidly within milliseconds. However, the intake air volume depends on the increase in the supercharger speed, and the supercharger speed in turn depends on the increase in the exhaust gas energy of the cylinder. That is, there is a strong coupling between the oil and gas during the acceleration process of the power system, making it impossible for the supercharger to quickly increase its speed in a timely manner. To solve the problems of slow response speed and difficult acceleration of the supercharging system, a motor is integrated into a conventional supercharger, and the high response characteristics of the motor are used to make up for the deficiencies of the supercharger, thus generating an electric-assisted supercharger. Due to the introduction of a high-speed motor, the electric-assisted supercharger can increase the supercharger speed and the intake air volume before the exhaust gas energy increases, achieving a certain degree of decoupling between the supercharger and the engine, and significantly improving the acceleration performance of the diesel engine. However, compared with traditional turbocharging, due to the intervention of the motor magnetic rotor, the electric-assisted supercharger has a longer axial length, a significantly increased mass on the shaft, and more diverse unbalanced forces. These unfavorable factors make the design of the rotor system more difficult, and a highly stable electric-assisted supercharger rotor structure needs to be sought. Summary of the Invention

[0003] In view of this, the present invention aims to propose an electric-assisted supercharger rotor structure with a motor placed outside the support span of a floating-ring bearing to solve at least one of the problems existing in the above-mentioned prior art, thereby improving the stability of the electric-assisted supercharger rotor structure.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows: An electric-assisted supercharger rotor structure with a motor placed outside the support span of a floating-ring bearing includes a turbine impeller, a floating-ring bearing, a rotating shaft, a thrust spacer, a shaft seal sleeve, a motor magnetic rotor, a compressor impeller, and an end nut. The compressor impeller and the turbine impeller are respectively installed at both ends of the rotating shaft. An end nut is also provided on one side of the compressor impeller. On the other side of the compressor impeller, the motor magnetic rotor, the shaft seal sleeve, the thrust spacer, and the floating-ring bearing are installed in sequence from left to right. A bearing housing is also provided outside the floating-ring bearing.

[0005] Further, the turbine impeller and the rotating shaft are formed into a turbine rotating shaft by friction welding. The floating ring bearing has a radial clearance fit with both the bearing body and the rotating shaft. The axial direction of the floating ring bearing is limited by a snap ring. The thrust spacer has a radial clearance fit with the rotating shaft and a press fit with the rotating shaft axially. The shaft seal sleeve has a radial clearance fit with the rotating shaft and a press fit with the thrust spacer axially. The motor magnetic rotor has a radial clearance fit with the rotating shaft and a press fit with the shaft seal sleeve axially. The compressor impeller has a radial clearance fit with the rotating shaft and a press fit axially. The axial components are locked by applying corresponding torque through the shaft end nut.

[0006] Further, it also includes a bearing cover, a thrust bearing, a heat shield, a motor stator, a motor housing, and a back plate. A bearing cover is also sleeved outside the shaft seal sleeve. A thrust bearing is also installed on one side of the thrust spacer. A heat shield is also installed between the turbine impeller and the bearing body. A motor stator is also installed outside the motor magnetic rotor. A motor housing is also installed outside the motor stator. A back plate is also provided on one side of the compressor impeller.

[0007] Further, the bearing body and the motor housing are both provided with cooling water chambers. The bearing body is internally provided with a bearing water cooling channel, and the motor housing is internally provided with a water cooling channel for the motor.

[0008] Further, an oil inlet hole is provided at the top of the bearing body, and an oil return hole is provided at the bottom side of the bearing body.

[0009] Further, it also includes a turbine end seal ring and a compressor end seal ring. A turbine end seal ring is arranged between the turbine impeller and the floating ring bearing, and a compressor end seal ring is arranged between the motor magnetic rotor and the floating ring bearing.

[0010] Further, the floating ring bearing adopts an oil injection lubrication method.

[0011] Compared with the prior art, the electro-assisted supercharger rotor structure with the motor placed outside the support span of the floating ring bearing of the present invention has the following advantages: (1) For the electro-assisted supercharger rotor structure with the motor placed outside the support span of the floating ring bearing of the present invention, the compressor impeller of the present invention adopts an impeller with a small length-diameter ratio. While meeting the performance requirements of the supercharger, the ratio of the axial length of the impeller to the outer diameter of the impeller is less than 0.25, which shortens the axial length of the rotor structure, is beneficial to suppressing the vibration during the operation of the rotor, and improves the reliability of the rotor structure.

[0012] (2) For the electro-assisted supercharger rotor structure with the motor placed outside the support span of the floating ring bearing of the present invention, the structural arrangement of the present invention arranges the motor magnetic rotor on the compressor impeller side, far away from the high-temperature turbine (the highest temperature reaches 750 °C) end, avoiding the problem of magnetic force failure during its operation.

[0013] (3) For the electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing in the present invention, the magnetic rotor of the motor is arranged outside the support span of the floating ring bearing, which can balance the mass distribution of the rotor system. Since the mass of the magnetic rotor of the motor and the turbine is relatively large, while the mass of the compressor impeller is relatively small, arranging the magnetic rotor of the motor on the compressor impeller side can make the center of gravity of the rotor structure near the midpoint of the bearing support, which is beneficial to balancing the loads of the two bearings, improving the operating stability of the bearings, and meeting the use requirements in the environment of high rotational speed and strong impact vibration.

[0014] (4) For the electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing in the present invention, two cooling water chambers are provided in the bearing body and the motor housing, which can enhance the forced heat transfer in the motor area and the bearing area, effectively control the working environment temperature of the motor, and improve the operating temperature of the bearings.

[0015] (5) For the electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing in the present invention, seal rings are provided on both the turbine side and the compressor side. The bearings are separated from the turbine and the magnetic rotor of the motor to prevent high-temperature gas from entering the magnetic rotor side of the motor, thereby affecting the heat dissipation of the motor. At the same time, it prevents lubricating oil from entering the motor, bringing about oil agitation loss and reducing the performance of the supercharger.

[0016] (6) For the electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing in the present invention, an oil inlet hole is provided at the top of the bearing body to ensure that the lubricating oil cools the bearing, and an oil return hole is provided at the side bottom to enable the lubricating oil to flow out smoothly. Description of the Drawings

[0017] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 It is a schematic cross-sectional view of the overall structure according to the embodiment of the present invention.

[0018] Description of the Reference Numerals in the Drawings: 1. Axial end nut; 2. Compressor impeller; 3. Magnetic rotor of the motor; 4. Shaft seal sleeve; 5. Thrust spacer sleeve; 6. Rotating shaft; 7. Floating ring bearing; 8. Turbine impeller; 9. Turbine end seal ring; 10. Compressor end seal ring; 11. Bearing cover; 12. Thrust bearing; 13. Heat insulation cover; 14. Bearing body; 15. Stator of the motor; 16. Motor housing; 17. Back plate; 18. Bearing water cooling channel; 19. Water cooling channel of the motor. Detailed Embodiments

[0019] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0021] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0022] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0023] As Figure 1 shown, an electric-assisted supercharger rotor structure with a motor placed outside the support span of a floating-ring bearing includes a turbine impeller 8, a rotating shaft 6, a thrust spacer 5, a shaft seal sleeve 4, a motor magnetic rotor 3, a compressor impeller 2, and a shaft end nut 1. The turbine impeller 8 and the rotating shaft 6 form a turbine rotating shaft through friction welding. The floating-ring bearing 7 has a radial clearance fit with both the bearing body 14 and the rotating shaft 6. The axial direction of the floating-ring bearing 7 is limited by a snap ring. The thrust spacer 5 has a radial clearance fit with the rotating shaft 6 and a press fit in the axial direction. The shaft seal sleeve 4 has a radial clearance fit with the rotating shaft 6 and a press fit with the thrust spacer 5 in the axial direction. The motor magnetic rotor 3 has a radial clearance fit with the rotating shaft 6 and a press fit with the shaft seal sleeve 4 in the axial direction. The compressor impeller 2 has a radial clearance fit with the rotating shaft 6 and a press fit in the axial direction. The axial components are locked by applying a corresponding torque through the shaft end nut 1.

[0024] In a preferred embodiment of the present invention, a bearing retainer 11 is also sleeved outside the shaft seal sleeve 4, a thrust bearing 12 is also installed on one side of the thrust spacer sleeve 5, a heat shield 13 is also installed between the turbine impeller 8 and the bearing housing 14, a motor stator 15 is also installed outside the motor magnetic rotor 3, and a back plate 17 is also provided on one side of the compressor impeller 2.

[0025] In a preferred embodiment of the present invention, the rotor structure also has a dual water-cooling structure. Cooling water cavities are provided in both the bearing housing 14 and the motor housing 16. The bearing water-cooling channel 18 is arranged in the bearing housing 14, mainly to ensure that the bearing housing 14 can work at a maximum temperature of 750 °C under high-temperature conditions, and part of the heat of the lubricating oil is taken away by the cooling water. The water-cooling channel 19 of the motor is arranged in the motor housing 16, and part of the heat of the motor is taken away by the cooling water.

[0026] In a preferred embodiment of the present invention, a vortex end seal ring 9 is arranged between the turbine impeller 8 and the floating ring bearing 7 to prevent the high-temperature gas of the turbine impeller 8 from entering the areas of the bearing housing 14 and the motor magnetic rotor 3, and at the same time reduce the lubricating oil in the bearing housing 14 from entering near the turbine impeller 8. The compressor impeller 2 is arranged adjacent to the motor magnetic rotor 3, and a compressor end seal ring 10 is arranged between the motor magnetic rotor 3 and the floating ring bearing 7 to prevent the lubricating oil in the bearing housing 14 from flowing into the vicinity of the motor magnetic rotor 3.

[0027] During actual use, by tightening the shaft end nut 1 to a corresponding torque, parts such as the turbine impeller 8, the rotating shaft 6, the thrust spacer sleeve 5, the shaft seal sleeve 4, the motor magnetic rotor 3, the compressor impeller 2, and the shaft end nut 1 are pressed tightly. The bearing is lubricated by oil injection. The two floating ring bearings 7 are lubricated through the lubricating oil inlet channel on the bearing housing 14 and flow out through the oil return port. Cooling water cavities are provided in both the bearing housing 14 and the motor housing 16, which can effectively control the working environment temperature of the motor and the bearing; the compressor impeller 2 and the motor magnetic rotor 3 are placed adjacent to each other and seals are arranged between the motor magnetic rotor 3 and the bearing housing 14, and seals are also arranged between the turbine impeller 8 and the bearing housing 14, which can greatly reduce the lubricating oil and gas entering the motor area; an oil return channel is provided at the bottom of the bearing housing 14 to ensure that the lubricating oil can flow out smoothly without accumulating oil in the bearing housing 14.

[0028] Advantages of the present invention: The compressor impeller of the present invention adopts an impeller with a small length-diameter ratio. While meeting the performance requirements of the supercharger, the ratio of the axial length of the impeller to the outer diameter of the impeller is less than 0.25, which shortens the axial length of the rotor structure, is beneficial to suppressing the vibration during the operation of the rotor, and improves the reliability of the rotor structure.

[0029] The structural arrangement of the present invention arranges the motor magnetic rotor on the side of the compressor impeller, far from the high-temperature turbine (the highest temperature reaches 750 °C) end, to avoid the problem of magnetic force failure during its operation.

[0030] In the present invention, the motor magnetic rotor is arranged outside the span of the floating ring bearing support, which can balance the mass distribution of the rotor system. Since the masses of the motor magnetic rotor and the turbine are relatively large, while the mass of the compressor impeller is relatively small, arranging the motor magnetic rotor on the compressor impeller side can make the center of gravity of the rotor structure near the midpoint of the bearing support, which is beneficial to balancing the loads of the two bearings, improving the running stability of the bearings, and meeting the requirements for use in a high-speed and strong-impact vibration environment.

[0031] In the present invention, there are two cooling water chambers provided in the bearing body and the motor housing, which can enhance the forced heat transfer in the motor area and the bearing area, effectively control the working environment temperature of the motor, and improve the running temperature of the bearings.

[0032] In the present invention, seal rings are provided on both the turbine side and the compressor side. The bearing is separated from the turbine and the motor magnetic rotor to prevent high-temperature gas from entering the motor magnetic rotor side, thereby affecting the heat dissipation of the motor. At the same time, it prevents lubricating oil from entering the motor, which causes oil churning loss and reduces the performance of the supercharger.

[0033] In the present invention, an oil inlet hole is provided at the top of the bearing body to ensure that the lubricating oil cools the bearing, and an oil return hole is provided at the side bottom to enable the lubricating oil to flow out smoothly.

[0034] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: It includes a turbine impeller (8), a floating ring bearing (7), a rotating shaft (6), a thrust spacer (5), a shaft seal sleeve (4), an electric motor magnetic rotor (3), a compressor impeller (2), and a shaft end nut (1). The two ends of the rotating shaft (6) are respectively installed with a compressor impeller (2) and a turbine impeller (8). A shaft end nut (1) is also provided on one side of the compressor impeller (2). On the other side of the compressor impeller (2), an electric motor magnetic rotor (3), a shaft seal sleeve (4), a thrust spacer (5), and a floating ring bearing (7) are installed in sequence from left to right. A bearing body (14) is also provided outside the floating ring bearing (7).

2. The rotor structure of an electric auxiliary supercharger with the motor placed outside the support span of the floating ring bearing according to claim 1, wherein: The turbine impeller (8) and the rotating shaft (6) form a turbine rotating shaft (6) through friction welding. There is a radial clearance fit between the floating ring bearing (7) and both the bearing body (14) and the rotating shaft (6). The axial direction of the floating ring bearing (7) is limited by a snap ring. The thrust spacer (5) and the rotating shaft (6) are in a radial clearance fit, and the thrust spacer (5) and the rotating shaft (6) are in a pressing fit axially. The shaft seal sleeve (4) and the rotating shaft (6) are in a radial clearance fit, and the shaft seal sleeve (4) and the thrust spacer (5) are in a pressing fit axially. The electric motor magnetic rotor (3) and the rotating shaft (6) are in a radial clearance fit, and the electric motor magnetic rotor (3) and the shaft seal sleeve (4) are in a pressing fit axially. The compressor impeller (2) and the rotating shaft (6) are in a radial clearance fit, and the compressor impeller (2) is in a pressing fit axially. Axial components are locked by applying corresponding torque through the shaft end nut (1).

3. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: It also includes a bearing cover (11) and a thrust bearing (12). A bearing cover (11) is also sleeved outside the shaft seal sleeve (4), and a thrust bearing (12) is also installed on one side of the thrust spacer (5).

4. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: It also includes a heat shield (16). A heat shield (16) is also installed between the turbine impeller (8) and the bearing body (14).

5. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: It also includes an electric motor stator (15) and an electric motor housing (16). An electric motor stator (15) is also installed outside the electric motor magnetic rotor (3), and an electric motor housing (16) is also installed outside the electric motor stator (15).

6. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: It also includes a back plate (17). A back plate (17) is also provided on one side of the compressor impeller (2).

7. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: Both the bearing body (14) and the electric motor housing (16) are provided with cooling water chambers. A bearing water cooling channel (18) is provided inside the bearing body (14), and a water cooling channel (19) of the electric motor is provided inside the electric motor housing (16).

8. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: An oil inlet hole is provided at the top of the bearing body (14), and an oil return hole is provided at the side bottom of the bearing body (14).

9. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: It also includes a turbine end seal ring (9) and a compressor end seal ring (10). A turbine end seal ring (9) is arranged between the turbine impeller (8) and the floating ring bearing (7), and a compressor end seal ring (10) is arranged between the electric motor magnetic rotor (3) and the floating ring bearing (7).

10. An electric auxiliary supercharger rotor structure with the motor placed outside the support span of the floating ring bearing, characterized in that: The floating ring bearing (7) adopts an oil injection lubrication method.

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