External lubrication self-limiting current brushless starting generator for micro turbojet engine

Abstract

The present invention relates to the technical field of micro turbojet engines, and a self-limiting brushless starting generator with external lubrication for a micro turbojet engine, which comprises a motor housing, a front bearing, the outer ring of the front bearing is supported on the motor front cover and is pressed by a front cover pressing plate, a front bearing installation cavity is formed between the front cover pressing plate and the motor front cover, a first oil passage hole is arranged in the motor front cover, and the front bearing installation cavity is communicated with a first through hole on the motor housing through the first oil passage hole; the outer ring of the rear bearing is supported on the motor rear cover and is pressed by a rear cover pressing plate, a rear bearing installation cavity is formed between the rear cover pressing plate and the motor rear cover, a second oil passage hole is arranged in the motor rear cover, and the rear bearing installation cavity is communicated with a second through hole on the motor housing through the second oil passage hole; at least one heat dissipation through hole is arranged on both the motor front cover and the motor rear cover. The present invention greatly improves the lubrication and heat dissipation effects, has a long service life of the motor, and low use cost.

Description

Technical Field

[0001] The present invention relates to the technical field of micro turbojet engines, and particularly to a starting and generating motor for a micro turbojet engine. Background Art

[0002] Micro turbojet engines are used in aircraft such as small unmanned aerial vehicles, target drones or missiles. During startup, a starting motor installed at the front end of the engine drives the rotor component to rotate to a certain speed, and then the engine injects fuel and ignites to start. After successful startup, the engine rotor component is disengaged from the starting motor. The starting motor does not have a power generation function. According to the needs of the aircraft, the starting motor can be replaced with a starting and generating motor. After successful startup, the rotor component of the micro turbojet engine drives the starting and generating motor to generate electricity, providing a certain amount of electrical power to the aircraft, reducing the battery load, and improving the engine efficiency. Brushless motors have the characteristics of no brush spark, high efficiency, low noise, long life, etc. Most advanced micro turbojet engines use brushless motors as starting and generating motors.

[0003] In the prior art, the same-level brushless starting and generating motors for micro turbojet engines use grease-lubricated bearings, which are difficult to withstand high-speed operating conditions. The bearings are pre-injected with grease when installed in the brushless starting and generating motor. During operation, there is no external lubricating oil source, and the lubrication effect is not good during high-speed operation, resulting in serious heating, which can cause problems such as demagnetization and coil aging, and then lead to the failure of the brushless starting and generating motor. Summary of the Invention

[0004] The purpose of the present invention is to avoid the defects of the prior art and provide an externally lubricated self-limiting current brushless starting and generating motor for a micro turbojet engine.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: an externally lubricated self-limiting current brushless starting and generating motor for a micro turbojet engine, including a motor housing, a motor front cover, a motor rear cover, a motor wire, and a motor stator coil fixed inside the motor housing. Both ends of the motor rotor are placed on the front bearing and the rear bearing to support the rotation of the motor rotor in the middle cavity of the motor stator coil. The front bearing is supported and installed inside the motor front cover, and the rear bearing is supported and installed inside the motor rear cover. The outer ring of the front bearing is supported on the motor front cover and is pressed by a front cover pressing plate. A front bearing installation cavity is formed between the front cover pressing plate and the motor front cover. The motor front cover is provided with a first oil passage hole, and the front bearing installation cavity is connected to a first through hole on the motor housing through the first oil passage hole; the outer ring of the rear bearing is supported on the motor rear cover and is pressed by a rear cover pressing plate. A rear bearing installation cavity is formed between the rear cover pressing plate and the motor rear cover. The motor rear cover is provided with a second oil passage hole, and the rear bearing installation cavity is connected to a second through hole on the motor housing through the second oil passage hole; at least one heat dissipation through hole is provided on both the motor front cover and the motor rear cover;

[0006] The lubricating oil source enters the interior of the motor through the first through-hole and the second through-hole on the motor housing;

[0007] The lubricating oil flowing towards the rear bearing forms an oil mist under the action of the high-speed rotating rear bearing and the high-speed air flow flowing in through the heat dissipation through-holes on the motor rear cover. After the oil mist flows through the cavity between the motor rotor and the motor stator coil, it flows out through the heat dissipation holes on the motor front cover;

[0008] The lubricating oil flowing towards the front bearing forms an oil mist under the action of the high-speed rotating front bearing and the high-speed air flow, and flows out through the heat dissipation holes on the motor front cover.

[0009] Furthermore, a first flow-limiting tube and a second flow-limiting tube are respectively installed in the first oil passage hole and the second oil passage hole. After the lubricating oil quantity is restricted by the first flow-limiting tube and the second flow-limiting tube, it flows through the first oil passage hole and the second oil passage hole and enters the front bearing installation cavity and the rear bearing installation cavity.

[0010] Furthermore, the front cover pressing plate fixes the front bearing to the inner side of the motor front cover through the front cover pressing plate fixing screws, and a sealing ring is installed on the outer circumference of the motor front cover; the front cover pressing plate together with the motor front cover, the sealing ring and the front bearing are press-fitted at the front end of the motor housing; the sealing ring includes a first sealing ring and a second sealing ring. The first sealing ring is arranged on the side close to the first through-hole, and the second sealing ring is arranged at the end of the outer circumference of the motor front cover.

[0011] Furthermore, the motor front cover and the motor rear cover are disc-shaped; 3 - 10 heat dissipation through-holes are evenly distributed in the circumferential direction of the motor front cover and the motor rear cover.

[0012] Furthermore, the rear cover pressing plate fixes the rear bearing to the inner side of the motor rear cover through the rear cover pressing plate fixing screws, and a sealing ring is installed on the outer circumference of the motor rear cover; the rear cover pressing plate together with the motor rear cover, the sealing ring and the rear bearing are press-fitted at the rear end of the motor housing.

[0013] Furthermore, the sealing ring includes a third sealing ring and a fourth sealing ring; the third sealing ring is arranged on the side close to the second through-hole, and the fourth sealing ring is arranged at the end of the outer circumference of the motor rear cover.

[0014] Furthermore, at least one motor wire is led out from the motor stator coil and passes through the hole on the motor rear cover.

[0015] Furthermore, the generator is a three-phase brushless motor, and three motor wires are led out from the motor stator coil.

[0016] Furthermore, both the front bearing and the rear bearing are P4-level front angular contact ceramic bearings., and the motor rotor is a neodymium boron magnet that can withstand high temperatures of 180°.

[0017] Furthermore, at least one layer of Kevlar fiber is wrapped around the outer surface of the motor rotor; and the motor rotor and the motor stator coil are both treated to prevent oil mist.

[0018] The beneficial effects of the present invention are:

[0019] 1. The external lubricating self-limiting brushless starter generator for a micro turbojet engine, when working, the external lubricating oil source enters the motor through the small hole of the motor housing, and enters the bearing cavity after limiting the amount of lubricating oil through the flow limiting tubes of the motor front cover and the motor rear cover, and supplies lubricating oil to the front bearing and the rear bearing. After the lubricating oil flows through the rear bearing, the motor rotor, the motor stator coil, and the front bearing, it flows out from the motor heat dissipation hole. While the two lubricating oils lubricate the front and rear bearings, the high-speed airflow and oil mist take away a large amount of heat generated during high-speed operation through the heat dissipation holes, greatly improving the lubrication and heat dissipation effects.

[0020] 2. The motor rotor is made of high-temperature resistant 180° neodymium boron magnet, and is wrapped with Kevlar fiber. The front and rear bearings are made of P4-grade angular contact high-speed ceramic bearings, which enables long-term use under high-temperature and high-speed conditions, greatly improving the service life of the motor, thereby effectively increasing the speed that the brushless generator can withstand.

[0021] 3. The setting of the flow limiting tube reduces the lubricating oil consumption and the use cost while meeting the lubrication demand.

[0022] 4. The motor rotor and the motor stator coil are both treated to prevent oil mist. After passing through the bearing, the lubricating oil flows through the motor coil and the rotor to form an oil film, which can cool the motor coil and the rotor and extend the service life of the motor.

[0023] The above beneficial effects completely solve the problem of poor lubrication and heat dissipation at high speed in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the present invention;

[0025] Figure 2 It is a left-side structural schematic diagram of the present invention;

[0026] Figure 3 It is a right-side structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0027] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0028] Embodiment 1, as Figure 1 , Figure 2 ,Figure 3 As shown, an externally lubricated self-limiting current brushless generator for a micro turbojet engine includes a motor housing 7, a motor front cover 15, a motor rear cover 1, a motor wire 22, and a motor stator coil 8 fixed inside the motor housing 7. Both ends of the motor rotor 9 are placed on the front bearing 20 and the rear bearing 17 to support the motor rotor 9 to rotate in the middle cavity of the motor stator coil 8. The outer ring of the front bearing 20 is supported in the motor front cover 15 and is pressed by the front cover pressure plate 12. A front bearing installation cavity is formed between the front cover pressure plate 12 and the motor front cover 15. The motor front cover 15 is provided with a first The oil passage hole 19, the front bearing installation cavity is connected with the first through hole 11 on the motor housing 7 through the first oil passage hole 19; the outer ring of the rear bearing 17 is supported on the motor rear cover 1 and is pressed by the rear cover pressure plate 4, and a rear bearing installation cavity is formed between the rear cover pressure plate 4 and the motor rear cover 1, and a second oil passage hole 16 is provided in the motor rear cover 1, and the rear bearing installation cavity is connected with the second through hole 5 on the motor housing 7 through the second oil passage hole 16; three first heat dissipation through holes 23 are provided on the motor front cover 15, and three second heat dissipation through holes 24 are provided on the motor rear cover 1;

[0029] At least one motor wire 12 is led out from the motor stator coil 8 and passes through the hole on the motor rear cover 1. The generator is a three-phase brushless motor, and three motor wires 12 are led out from the motor stator coil.

[0030] The lubricating oil source of the present invention enters the interior of the motor through the first through hole 11 and the second through hole 5 on the motor housing 7;

[0031] The lubricating oil to the rear bearing 17 forms oil mist under the action of the high-speed rotating rear bearing 17 and the high-speed airflow flowing in through the heat dissipation holes on the motor rear cover 1. After the oil mist flows through the cavity between the motor rotor 9 and the motor stator coil 8, it flows out through the heat dissipation holes on the motor front cover 15, which cools the bearing, improves the working environment of the bearing, and increases the service life of the bearing. The lubricating oil to the front bearing 20 forms oil mist under the action of the high-speed rotating front bearing 20 and the high-speed airflow, and flows out through the heat dissipation holes on the motor front cover 15. While the lubricating oil at the two places lubricates the front and rear bearings, the high-speed airflow and the oil mist take away a large amount of heat generated during high-speed operation through the heat dissipation holes, greatly improving the lubrication and heat dissipation effects.

[0032] The first oil circuit hole 19 and the second oil circuit hole 16 are respectively installed with a first flow limiting tube 13 and a second flow limiting tube 3. After the lubricating oil is limited by the first flow limiting tube 13 and the second flow limiting tube 3, it flows through the first oil circuit hole 19 and the second oil circuit hole 16 into the front bearing mounting cavity and the rear bearing mounting cavity.

[0033] The front cover pressing plate 12 fixes the front bearing 20 to the inner side of the motor front cover 15 through the front cover pressing plate fixing screws 21, and a sealing ring is installed on the outer circle of the motor front cover 15; the front cover pressing plate 12 together with the motor front cover 15, the sealing ring and the front bearing 20 are press-fitted at the front end of the motor housing 7; the sealing ring includes a first sealing ring 10 and a second sealing ring 14, the first sealing ring 10 is arranged on the side close to the first through hole 11, and the second sealing ring 14 is arranged at the end of the outer circle of the motor front cover 15.

[0034] The rear cover pressing plate 4 fixes the rear bearing 17 to the inner side of the motor rear cover 1 through the rear cover pressing plate fixing screws 18, and a sealing ring is installed on the outer circle of the motor rear cover 1; the rear cover pressing plate 4 together with the motor rear cover 1, the sealing ring and the rear bearing 17 are press-fitted at the rear end of the motor housing 7; the sealing ring includes a third sealing ring 2 and a fourth sealing ring 6; the third sealing ring 2 is arranged on the side close to the second through hole 5, and the fourth sealing ring 6 is arranged at the end of the outer circle of the motor rear cover 1.

[0035] The motor rotor 9 and the motor stator coil 8 are both treated to prevent oil mist, which is an existing technology. After the lubricating oil passes through the bearing, it flows through the motor coil and the rotor to form an oil film, which can cool the motor coil and the rotor and extend the service life of the motor.

[0036] When the micro turbojet engine starts, the brushless starting generator drives the micro turbojet engine rotor component to rotate synchronously through the coupling. When the micro turbojet engine starts successfully by ignition, the speed of the rotor component increases, driving the brushless starting generator to generate electricity. The brushless starting generator of the micro turbojet engine in the prior art is damaged after generating electricity at a high speed of 100,000 r / min for several minutes, cannot withstand the same speed as the micro turbojet engine, and cannot generate high-power electricity. The motor rotor 9 of the present invention also uses a neodymium boron magnet resistant to 180° high temperature, and at least one layer of Kevlar fiber is used to wrap the motor rotor 9. The front bearing and the rear bearing at both ends of the electronic rotor 9 use P4 grade angular contact high-speed ceramic bearings, which can be used for a long time under high temperature and high speed working conditions, greatly improving the service life of the motor, and thus effectively increasing the speed that the brushless starting generator can withstand; the motor front cover 15 and the motor rear cover 1 are provided with a plurality of heat dissipation through holes, and a large amount of high-speed air flow will flow through the brushless starting generator during the operation of the engine. The high-speed air flow can effectively take away the heat generated by the brushless starting generator through the heat dissipation through holes of the front and rear covers of the brushless starting generator. Further, while the lubricating oil lubricates the front and rear bearings, it also takes away the heat generated during high-speed operation, solving the problems of poor lubrication effect and high-temperature failure in the prior art at high speeds. And after current limiting, the lubricating oil volume reduces the lubricating oil consumption while meeting the lubrication requirements, reducing the use cost.

[0037] It is measured that the brushless generator described in Embodiment 2 of the present invention does not affect the fuel consumption of the engine. The maximum power generation of the motor is 1200W, and the pressure flow of the current-limiting pipe is 70ml / 0.8Mpa / min per minute. It can withstand a high speed of 100000r / min and generate electricity with a high power of 1000W at high speed.

[0038] Embodiment 3: The same as Embodiment 1, except that the motor front cover 15 and the motor rear cover 1 are disc-shaped; 3-10 first heat dissipation through holes 23 and second heat dissipation through holes 24 are evenly distributed in the circumferential direction of the motor front cover 15 and the motor rear cover 1.

[0039] Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An externally lubricated self-limiting brushless starting generator for a micro turbojet engine, comprising a motor housing, a motor front cover, a motor rear cover, motor wires, and a motor stator coil fixed inside the motor housing. Both ends of the motor rotor are placed on a front bearing and a rear bearing to support the rotation of the motor rotor in the middle cavity of the motor stator coil. The front bearing is supported and installed on the inner side of the motor front cover, and the rear bearing is supported and installed on the inner side of the motor rear cover. It is characterized in that, The outer ring of the front bearing is supported on the front cover of the motor and is pressed by a front cover pressing plate. A front bearing installation cavity is formed between the front cover pressing plate and the front cover of the motor. A first oil passage hole is provided in the front cover of the motor. The front bearing installation cavity is communicated with a first through hole on the motor housing through the first oil passage hole. The outer ring of the rear bearing is supported on the rear cover of the motor and is pressed by a rear cover pressing plate. A rear bearing installation cavity is formed between the rear cover pressing plate and the rear cover of the motor. A second oil passage hole is provided in the rear cover of the motor. The rear bearing installation cavity is communicated with a second through hole on the motor housing through the second oil passage hole. At least one heat dissipation through hole is provided on both the front cover of the motor and the rear cover of the motor. The lubricating oil source enters the interior of the motor through the first through hole and the second through hole on the motor housing. The lubricating oil leading to the rear bearing forms an oil mist under the action of the high-speed rotating rear bearing and the high-speed air flow flowing in through the heat dissipation through holes on the rear cover of the motor. After the oil mist flows through the cavity between the motor rotor and the motor stator coil, it flows out through the heat dissipation holes on the front cover of the motor. The lubricating oil flowing to the front bearing forms an oil mist under the action of the high-speed rotating front bearing and the high-speed air flow and flows out through the heat dissipation holes on the front cover of the motor.

2. The externally lubricated self-current-limiting brushless starting generator for a micro turbojet engine according to claim 1, characterized in that, A first flow-limiting pipe and a second flow-limiting pipe are respectively installed in the first oil passage hole and the second oil passage hole. The lubricating oil flows through the first oil passage hole and the second oil passage hole into the front bearing installation cavity and the rear bearing installation cavity after the lubricating oil quantity is restricted by the first flow-limiting pipe and the second flow-limiting pipe.

3. The externally lubricated self-limiting current brushless starting generator for a micro turbojet engine according to claim 1, characterized in that, The front cover pressing plate fixes the front bearing to the inner side of the front cover of the motor through front cover pressing plate fixing screws, and a sealing ring is installed on the outer circle of the front cover of the motor. The front cover pressing plate together with the front cover of the motor, the sealing ring and the front bearing are press-fitted at the front end of the motor housing. The sealing ring includes a first sealing ring and a second sealing ring. The first sealing ring is arranged on the side close to the first through hole, and the second sealing ring is arranged at the end of the outer circle of the front cover of the motor.

4. The externally lubricated self-current-limiting brushless starting generator for a micro turbojet engine according to claim 1, wherein The front cover of the motor and the rear cover of the motor are disc-shaped. 3-10 heat dissipation through holes are evenly distributed in the circumferential direction of the front cover of the motor and the rear cover of the motor.

5. The externally lubricated self-current-limiting brushless starting generator for a micro turbojet engine according to claim 1, wherein, The rear cover pressing plate fixes the rear bearing to the inner side of the rear cover of the motor through rear cover pressing plate fixing screws, and a sealing ring is installed on the outer circle of the rear cover of the motor. The rear cover pressing plate together with the rear cover of the motor, the sealing ring and the rear bearing are press-fitted at the rear end of the motor housing.

6. The externally lubricated self-limiting current brushless starting generator for a micro turbojet engine according to claim 5, characterized in that, The sealing ring includes a third sealing ring and a fourth sealing ring. The third sealing ring is arranged on the side close to the second through hole, and the fourth sealing ring is arranged at the end of the outer circle of the rear cover of the motor.

7. The externally lubricated self-current-limiting brushless starting generator for a micro turbojet engine according to claim 1, wherein, At least one motor wire is led out from the motor stator coil and passes through the hole on the rear cover of the motor.

8. The externally lubricated self-current-limiting brushless starting generator for a micro turbojet engine according to claim 7, characterized in that, The generator is a three-phase brushless motor, and three motor wires are led out from the motor stator coil.

9. The externally lubricated self-limiting current brushless starting generator for a micro turbojet engine according to any one of claims 1-8, characterized in that, Both the front bearing and the rear bearing are P4 grade front angular contact ceramic bearings.

10. The externally lubricated self-limiting current brushless starting generator for a micro turbojet engine according to any one of claims 1-8, characterized in that, The motor rotor is a neodymium boron magnet resistant to high temperature of 180°. At least one layer of Kevlar fiber is wound and wrapped on the outer surface of the motor rotor, and both the motor rotor and the motor stator coil are subjected to anti-oil mist treatment.

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