Connection structure of twin-rotor turboshaft engine with starter motor and output load
By directly connecting the starter motor to the gas turbine rotor, eliminating the gear train, and adopting a cooling and sealing structure, the problems of complex structure and heavy weight of the dual-rotor turboshaft engine are solved, achieving the effects of structural simplification, weight reduction, and noise reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHANGZHOU E&E TURBO POWER
- Filing Date
- 2025-08-22
- Publication Date
- 2026-07-31
AI Technical Summary
In existing dual-rotor turboshaft engines, the starter motor and the gas turbine rotor are connected by a gear system, resulting in a complex structure, heavy weight, and high noise, which are difficult to simplify and reduce.
The starter motor is directly connected to the gas turbine rotor, and direct drive is achieved through a coupling and bearing assembly, eliminating the gear train. Cooling and sealing structures are used to reduce heat and corrosion risks, and lubricating oil is used to reduce wear.
The structure was simplified, weight and noise were reduced, transmission efficiency was improved, radial imbalance force was reduced, and cost was lowered.
Smart Images
Figure CN224579399U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of engine technology, specifically to the connection structure of a dual-rotor turboshaft engine with a starter motor and output load. Background Technology
[0002] A turboshaft engine is a type of aero-engine that converts the internal energy of combustion gases into usable work. Compared to currently immature fuel cells and power batteries with energy densities far lower than aviation fuel, turboshaft engines possess significant advantages and application potential in terms of range and lightweight design. Simultaneously, advancements in electric motor and electronic control technologies have resulted in lower noise levels in the power system and more precise propeller control, effectively improving flight performance. Therefore, the vortex-electric hybrid system, combining traditional gas turbines and emerging electric propulsion systems, has emerged and will be a crucial technology for future low-altitude propulsion.
[0003] A twin-rotor turboshaft engine consists of a power turbine rotor and a gas turbine rotor. A starter motor drives the gas turbine rotor to start, and can also be used for power generation if necessary. The power turbine rotor outputs power to drive the rotor. Early turboshaft engines, due to limitations in motor technology, had relatively low speeds. Therefore, traditional turboshaft engines used a gear system between the gas turbine rotor and the starter / generator to match their speeds; similarly, a gear system was used between the aircraft rotor and the power turbine shaft to match their speeds. Turboshaft engine rotors are characterized by high speed and low torque, while high-speed motors are smaller and lighter than low-speed motors. Directly connecting the motor to the engine rotor would save a significant amount of gears and bearings, simplifying the structure, reducing weight, improving efficiency, and reducing noise. With advancements in motor technology, for twin-rotor turboshaft engines, integrating the starter motor into a single unit presents the challenge of simplifying the structure and reducing weight. Utility Model Content
[0004] This invention provides a connection structure for a dual-rotor turboshaft engine, a starter motor, and an output load. This invention simplifies the structure, reduces costs, and lightens the weight.
[0005] The present invention discloses a connection structure for a dual-rotor turboshaft engine, a starter motor, and an output load, comprising a casing, a gas turbine shaft, a power turbine shaft, a starter motor, a first bearing assembly, a second bearing assembly, a coupling, and a load. The casing has an mounting cavity, and the starter motor is located within the mounting cavity. The starter motor includes a stator and a rotor with an inner hole. The stator is located within the mounting cavity and fixed to the casing, and the rotor engages with the stator. The first bearing assembly engages with the gas turbine shaft, and the second bearing assembly is fixed to the power turbine shaft. The second bearing assembly engages with the inner hole of the rotor. The invention also includes a locking component. The power turbine shaft passes through the gas turbine shaft and extends into the mounting cavity, connecting to one end of the coupling. The other end of the coupling is connected to the load.
[0006] The starter motor also includes a transmission sleeve that cooperates with the rotor. The transmission sleeve is fitted onto the gas turbine shaft and fixed to the gas turbine shaft. The locking component is fixed to the gas turbine shaft, and the transmission sleeve is clamped between the locking component and the first bearing assembly.
[0007] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0008] 1. The starter motor does not need to be placed outside the gearbox to drive the gas turbine rotor through the gear system, which helps to simplify the structure, reduce costs and reduce weight.
[0009] 2. The starter motor is no longer placed outside the gearbox to drive the gas turbine rotor through the gear system. Instead, it is placed centrally on the engine shaft. This way, the torque transmission between the generator and the gas turbine shaft will not generate radial unbalanced force due to gear meshing. Attached Figure Description
[0010] Figure 1 This is a cross-sectional view of the connection structure between the first type of dual-rotor turboshaft engine, the starter motor, and the output load.
[0011] Figure 2 for Figure 1 Enlarged view of part P in the image.
[0012] Figure 3 This is a cross-sectional view of the connection structure between the second type of dual-rotor turboshaft engine, the starter motor, and the output load.
[0013] Figure 4 for Figure 3 Enlarged view of the Q part in the image.
[0014] Casing 1, mounting cavity 1a, lubricating oil inlet channel 1b, cooling air passage 1c, gas turbine shaft 2, power turbine shaft 3, shaft shoulder 3a, starter motor 4, stator 4a, rotor 4b, transmission sleeve 4c, first grate 4d, exhaust passage 4e, extraction passage 4f, spiral passage 4g, first bearing assembly 5, second bearing assembly 6, bushing 6a, second bearing 6b, sealing ring 6c, first lubricating oil guide hole 6d, second lubricating oil guide hole 6d1, support ring 6e, second grate 6e1, bearing seat 6f, third bearing 6g, fourth bearing 6h, spacer 6i, adjusting shim 6j, first retaining ring 6k, second retaining ring 6m, coupling 7, load 8, locking component 9, compressor housing A, centrifugal impeller B. Detailed Implementation
[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0016] First Embodiment
[0017] like Figures 1 to 2 The connection structure of the dual-rotor turboshaft engine, starter motor, and output load in this embodiment includes a casing 1, a gas turbine shaft 2, a power turbine shaft 3, a starter motor 4, a first bearing assembly 5, a second bearing assembly 6, a coupling 7, a load 8, and a locking component 9. The casing 1 is provided with a mounting cavity 1a, and the starter motor 4 is located in the mounting cavity 1a. The starter motor 4 includes a stator 4a and a rotor 4b with an inner hole. The stator 4a is located in the mounting cavity 1a and fixed to the casing 1. The rotor 4b cooperates with the stator 4a. The first bearing assembly 5 cooperates with the gas turbine shaft 2. The first bearing assembly 5 preferably adopts a squirrel cage bearing. The first bearing assembly 5 is fixed to the compressor housing A. For example, the outer ring of the first bearing assembly 5 is fixed to the compressor housing A by screws, and the inner ring of the first bearing assembly 5 is interference-fitted with the gas turbine shaft 2.
[0018] During operation, the stator 4a and rotor 4b of the starter motor 4 inevitably generate heat. To reduce this heat, a cooling air passage 1c is provided on the casing 1, with its output end corresponding to the stator 4a and / or rotor 4b. An exhaust passage 4e is provided on the stator 4a, allowing air to pass through the cooling air passage 1c and flow over the surfaces of the stator 4a and rotor 4b, thus carrying away the heat. After exiting the exhaust passage 4e, the air flows into the compressor housing A and is drawn away by the centrifugal impeller B in the compressor. On the other hand, a spiral channel 4g, an input port, and an output port (not shown in the figure) are provided on the outer casing of the stator 4a. Coolant is introduced into the spiral channel 4g through the input port, flowing along the spiral channel 4g to carry away the heat from the stator 4a's outer casing. The coolant is then output from the output port.
[0019] The second bearing assembly 6 is fixed to the power turbine shaft 3. The second bearing assembly 6 is engaged with the inner hole of the rotor 4b. The power turbine shaft 3 passes through the gas turbine shaft 2 and extends into the mounting cavity 1a, where it is connected to one end of the coupling 7. The other end of the coupling 7 is connected to the load 8. The load 8 can be a generator, a propeller, or other types of load.
[0020] The starter motor 4 also includes a transmission sleeve 4c, which mates with the rotor 4b. In this embodiment, the transmission sleeve 4c and rotor 4b are integrally formed. The transmission sleeve 4c is fitted onto the gas turbine shaft 2 and fixed to it. The transmission sleeve 4c is connected to the gas turbine shaft 2 via a key (e.g., a flat key), or it is milled flat on the gas turbine shaft 2. The gas turbine shaft 2 and the transmission sleeve 4c transmit torque through a flat fit. During startup, the rotor 4b drives the gas turbine shaft 2 to rotate and start the engine. The advantage of using a key or flat fit for torque transmission is that it does not generate additional radial force on the shaft, thus balancing the forces on the shaft.
[0021] The locking component 9 is fixed to the gas turbine shaft 2, and the transmission sleeve 4c is clamped between the locking component 9 and the first bearing assembly 5, thus preventing the transmission sleeve 4c from moving axially along the gas turbine shaft 2. The locking component 9 is preferably a nut, and the locking component 9 is threadedly connected to the gas turbine shaft 2.
[0022] The transmission sleeve 4c is fixed to the rotor 4b as a whole. The second bearing assembly 6 includes a bushing 6a, a second bearing 6b, and a sealing ring 6c. The bushing 6a is fixed to the housing 1. The second bearing 6b is sleeved on the power turbine shaft 3 and cooperates with the bushing 6a. After the sealing ring 6c is fixed to the housing 1, one end of the sealing ring 6c forms an axial position for the second bearing 6b. Preferably, the sealing ring 6c forms an axial position for the outer ring of the second bearing 6b. Since the second bearing 6b is located between the bushing 6a and the sealing ring 6c, the bushing 6a and the sealing ring 6c form a bearing seat for mounting the second bearing 6b.
[0023] Because there is a gap between the gas turbine shaft 2 and the power turbine shaft 3, high-temperature oil and gas inevitably enter the space between the two shafts. The high-temperature oil and gas will flow into the inner hole of the rotor 4b. If no measures are taken, the high-temperature oil and gas will flow into the stator 4a and rotor 4b windings, causing winding corrosion. Therefore, in order to avoid the high-temperature oil and gas from corroding the stator 4a and rotor 4b windings, a first grate 4d is provided on the inner wall of the rotor 4b. The other end of the sealing ring 6c is located in the inner hole of the rotor 4b and cooperates with the first grate 4d. Through the sealing structure formed by the first grate 4d and the sealing ring 6c, the flow of high-temperature oil and gas into the stator 4a and rotor 4b windings is greatly reduced.
[0024] In addition, in order to prevent trace amounts of high-temperature oil and gas from flowing into the stator 4a and rotor 4b windings through the gap between the first grate tooth 4d and the sealing ring 6c as much as possible, in this embodiment, an exhaust duct 4f is provided on the rotor 4b, and an exhaust hole is provided on the casing 1 for the exhaust gas extracted through the exhaust duct 4f to be discharged. One end of the exhaust duct 4f is connected to the inner hole of the rotor 4b. When the rotor 4b rotates, the air inside the exhaust duct 4f moves outward due to centrifugal force, forming a "vacuum". The air inside fills this "vacuum" and continues to move outward due to centrifugal force, thus forming the effect of exhaust.
[0025] Because the power turbine shaft 3 operates at high speed (at least 5000 rpm), it generates heat in the second bearing 6b. The higher the speed, the greater the heat generated by the second bearing 6b, and the more easily it wears down. To reduce the heat generated by the second bearing 6b, in this embodiment, an oil inlet channel 1b is provided on the casing 1, and a first oil guide hole 6d is provided on the bushing 6a. One end of the first oil guide hole 6d communicates with the oil inlet channel 1b, and the other end engages with the second bearing 6b. After receiving lubrication from the oil, the second bearing 6b experiences both temperature reduction and wear reduction.
[0026] Since the power turbine shaft 3 passes through the gas turbine shaft 2, the diameter of the portion of the power turbine shaft 3 supporting the second bearing assembly 6 cannot be too large (a large diameter would prevent the power turbine shaft 3 from passing through the gas turbine shaft 2). Therefore, although a shoulder for axially positioning the second bearing 6b can be provided on the power turbine shaft 3, the size of this shoulder is limited by its passage through the gas turbine shaft 2, thus restricting the contact area between the outer diameter of the shoulder and the second bearing 6b. In this embodiment, the second bearing assembly 6 also includes a support ring 6e. The power turbine shaft 3 has a shoulder 3a. One end of the support ring 6e abuts against the second bearing 6b, and the other end of the support ring 6e abuts against the shoulder 3a. The support ring 6e is located inside the sealing ring 6c, and the support ring 6e has second teeth 6e1 that mate with the inner wall surface of the sealing ring 6c. The support ring 6e mates with the inner ring of the second bearing 6b, and the support ring 6e forms an axial position for the inner ring of the second bearing 6b. The contact area between the support ring 6e and the inner ring of the second bearing 6b is greater than the contact area between the inner ring of the second bearing 6b and the shoulder of the power turbine shaft 2. Therefore, the support ring 6e can make the second bearing 6b bear force evenly.
[0027] In this embodiment, in one scenario, the starter motor 4 drives the gas turbine rotor to start, while the power supply for other electrical equipment on the aircraft is provided by the generator and battery. This allows the starter motor to be made very small in size and weight, and the rotor 4b mounted on the gas turbine shaft 2 is also small in size and mass, resulting in a small load on the first bearing assembly 5 during high-speed rotation. The starter motor 4 also has relatively low power consumption during startup, thus placing a small load on the cooling system.
[0028] Another scenario is that starter motor 4, in addition to its starting function, also generates electricity after starting, supplying power to other electrical equipment on the aircraft. When the power generated by starter motor 4 is insufficient, it is supplemented from the generator (load) and the battery. In this case, the load on the bearings and cooling system increases, but it can still withstand it.
[0029] Second Embodiment
[0030] like Figure 3 and Figure 4The difference between this embodiment and the first embodiment is that: the transmission sleeve 4c and the rotor 4b are connected by a spline, and the transmission sleeve 4c and the rotor 4b are separate molded parts. The second bearing assembly 6 includes a bushing 6a, a second bearing 6b, a bearing seat 6f, a third bearing 6g, and a fourth bearing 6h. The bushing 6a is fixed to the casing 1. The second bearing 6b is sleeved on the power turbine shaft 3 and cooperates with the bushing 6a. The bearing seat 6f has a through hole for the power turbine shaft 3 to pass through. After the bearing seat 6f is fixed to the casing 1, one end of the bearing seat 6f forms an axial position for the second bearing 6b. The inner wall of the rotor 4b is provided with a first grate 4d. The other end of the bearing seat 6f is located in the inner hole of the rotor 4b and cooperates with the first grate 4d. The third bearing 6g and the fourth bearing 6h are located in the inner hole of the rotor 4b and are connected to the bearing seat 6f and the rotor 4b, respectively.
[0031] For engines with higher power generation, the rotor 4b of the starter motor 4 will be larger and heavier. Since the rotor 4b is installed in a cantilever state, the negative impact on the rotation state of the entire gas turbine rotor 2 will be amplified. Therefore, in this embodiment, the rotor 4b is supported by the bearing housing 6f, the third bearing 6g, and the fourth bearing 6h to avoid the above situation.
[0032] After the starter motor 4 completes the start-up, if the power turbine shaft 2 drives the load 8 via the coupling 7, the gearbox and propeller are used. All other electrical equipment on the aircraft is supplied by the starter motor 4. Therefore, in this embodiment, the starter motor 4 is used as a generator after completing the start-up task.
[0033] The second bearing assembly 6 also includes a spacer 6i, an adjusting shim 6j, a first retaining ring 6k, and a second retaining ring 6m. The spacer 6i is fitted onto the bearing housing 6f. One end of the spacer 6i abuts against one end of the third bearing 6g, and the other end of the spacer 6i abuts against one end of the fourth bearing 6h. The adjusting shim 6j abuts against the other end of the third bearing 6g. After the first retaining ring 6k is fixed to the rotor 4b, it forms an axial position for the adjusting shim 6j. After the second retaining ring 6m is fixed to the bearing housing 6f, it abuts against the other end of the fourth bearing 6h.
[0034] The casing 1 is provided with an oil inlet channel 1b, and the bearing seat 6f is provided with a second oil guide hole 6d1. The second oil guide hole 6d1 communicates with the oil inlet channel 1b and also cooperates with the second bearing 6b and the third bearing 6g respectively.
[0035] The second bearing assembly 6 also includes a support ring 6e. The power turbine shaft 3 is provided with a shoulder 3a. One end of the support ring 6e abuts against the second bearing 6b, and the other end of the support ring 6e abuts against the shoulder 3a. The support ring 6e is located inside the bearing housing 6f, and the support ring 6e is provided with a second grate 6e1 that mates with the inner wall surface of the bearing housing 6f.
Claims
1. A connection structure between a dual-rotor turboshaft engine, a starter motor, and an output load, comprising a casing (1), a gas turbine shaft (2), a power turbine shaft (3), a starter motor (4), a first bearing assembly (5), a second bearing assembly (6), a coupling (7), and a load (8), wherein the casing (1) is provided with a mounting cavity (1a), the starter motor (4) is located within the mounting cavity (1a), the starter motor (4) comprises a stator (4a) and a rotor (4b) having an inner hole, the stator (4a) is located within the mounting cavity (1a) and fixed to the casing (1), the rotor (4b) engages with the stator (4a), the first bearing assembly (5) engages with the gas turbine shaft (2), the second bearing assembly (6) is fixed with the power turbine shaft (3), and the second bearing assembly (6) engages with the inner hole of the rotor (4b), characterized in that, It also includes a locking component (9), wherein the power turbine shaft (3) extends through the gas turbine shaft (2) into the mounting cavity (1a) and is connected to one end of the coupling (7), and the other end of the coupling (7) is connected to the load (8); The starter motor (4) also includes a transmission sleeve (4c), which cooperates with the rotor (4b). The transmission sleeve (4c) is sleeved on the gas turbine shaft (2) and fixed to the gas turbine shaft (2). The locking component (9) is fixed to the gas turbine shaft (2), and the transmission sleeve (4c) is clamped between the locking component (9) and the first bearing assembly (5).
2. The dual-rotor turboshaft engine of claim 1, wherein the starter motor and output load are connected to the engine by a shaft. The transmission sleeve (4c) is fixed to the rotor (4b) as a whole. The second bearing assembly (6) includes a bushing (6a), a second bearing (6b), and a sealing ring (6c). The bushing (6a) is fixed to the casing (1). The second bearing (6b) is sleeved on the power turbine shaft (3) and cooperates with the bushing (6a). After the sealing ring (6c) is fixed to the casing (1), one end of the sealing ring (6c) forms an axial position for the second bearing (6b). The inner wall of the rotor (4b) is provided with a first grate tooth (4d). The other end of the sealing ring (6c) is located in the inner hole of the rotor (4b) and cooperates with the first grate tooth (4d).
3. The dual-rotor turboshaft engine of claim 2, wherein the starter motor and output load are connected to the engine by a shaft. The casing (1) is provided with an oil inlet channel (1b), and the bushing (6a) is provided with a first oil guide hole (6d). One end of the first oil guide hole (6d) is connected to the oil inlet channel (1b), and the other end of the first oil guide hole (6d) is engaged with the second bearing (6b).
4. The dual-rotor turboshaft engine of claim 2, wherein the starter motor and output load are connected to the engine by a shaft. The second bearing assembly (6) also includes a support ring (6e). The power turbine shaft (3) is provided with a shoulder (3a). One end of the support ring (6e) abuts against the second bearing (6b), and the other end of the support ring (6e) abuts against the shoulder (3a). The support ring (6e) is located inside the sealing ring (6c). The support ring (6e) is provided with a second grate tooth (6e1) that mates with the inner wall surface of the sealing ring (6c).
5. The dual-rotor turboshaft engine of claim 1, wherein the starter motor and output load are connected to the engine by a shaft. The transmission sleeve (4c) and rotor (4b) are splined together. The second bearing assembly (6) includes a bushing (6a), a second bearing (6b), a bearing housing (6f), a third bearing (6g), and a fourth bearing (6h). The bushing (6a) is fixed to the casing (1). The second bearing (6b) is sleeved on the power turbine shaft (3) and mates with the bushing (6a). The bearing housing (6f) has a through hole for the power turbine shaft (3) to pass through. The bearing housing (6f) and the casing are connected. (1) After fixing, one end of the bearing housing (6f) forms an axial position for the second bearing (6b). The inner wall of the rotor (4b) is provided with a first grate tooth (4d). The other end of the bearing housing (6f) is located in the inner hole of the rotor (4b) and cooperates with the first grate tooth (4d). The third bearing (6g) and the fourth bearing (6h) are located in the inner hole of the rotor (4b). The third bearing (6g) and the fourth bearing (6h) are connected to the bearing housing (6f) and the rotor (4b) respectively.
6. The dual-rotor turboshaft engine of claim 5, wherein the starter motor and output load are connected to the engine by a shaft. The second bearing assembly (6) also includes a spacer (6i), an adjusting shim (6j), a first retaining ring (6k), and a second retaining ring (6m). The spacer (6i) is fitted onto the bearing housing (6f). One end of the spacer (6i) abuts against one end of the third bearing (6g), and the other end of the spacer (6i) abuts against one end of the fourth bearing (6h). The adjusting shim (6j) abuts against the other end of the third bearing (6g). After the first retaining ring (6k) is fixed to the rotor (4b), it forms an axial position for the adjusting shim (6j). After the second retaining ring (6m) is fixed to the bearing housing (6f), it abuts against the other end of the fourth bearing (6h).
7. The dual-rotor turboshaft engine of claim 5, wherein the starter motor and output load are connected to the engine by a shaft. The casing (1) is provided with an oil inlet channel (1b), and the bearing seat (6f) is provided with a second oil guide hole (6d1). The second oil guide hole (6d1) is connected to the oil inlet channel (1b), and the second oil guide hole (6d1) is also engaged with the second bearing (6b) and the third bearing (6g) respectively.
8. The dual-rotor turboshaft engine of claim 5, wherein the starter motor and output load are connected to the engine by a shaft. The second bearing assembly (6) also includes a support ring (6e). The power turbine shaft (3) is provided with a shoulder (3a). One end of the support ring (6e) abuts against the second bearing (6b), and the other end of the support ring (6e) abuts against the shoulder (3a). The support ring (6e) is located inside the bearing housing (6f), and the support ring (6e) is provided with a second tooth (6e1) that mates with the inner wall surface of the bearing housing (6f).
9. The connection structure between the dual-rotor turboshaft engine, the starter motor, and the output load according to any one of claims 1-8, characterized in that, The casing (1) is provided with a cooling air passage (1c), the output end of which corresponds to the stator (4a) and / or the rotor (4b), and the stator (4a) is provided with an exhaust passage (4e).
10. The connection structure between the dual-rotor turboshaft engine, the starter motor, and the output load according to any one of claims 1-8, characterized in that, The rotor (4b) is provided with an air extraction channel (4f), one end of which is connected to the inner hole of the rotor (4b).