Turbine assembly and turbine starting device

Abstract

A turbine assembly and a turbine starting device are used to improve the deformation and damage of the keyway of the turbine rotor. The turbine assembly includes a ring, a turbine rotor and a turbine shaft. The ring is provided with a spline on the axial end face; the turbine rotor is provided with a spline groove on the axial end face, and the turbine shaft passes through the turbine rotor and the ring. The ring is circumferentially fastened to the turbine shaft, and the spline of the ring is inserted into the spline groove of the turbine rotor.

Description

Technical Field

[0001] The present invention relates to a diesel engine starting device, in particular to a turbine assembly and a turbine type starting device. Background Art

[0002] The starter is an integral part of the diesel engine startup process, assisting the engine in transitioning from static to dynamic motion. As a key component of the starter, the turbine serves as its power source, converting the kinetic and potential energy of compressed air into mechanical energy. The turbine profile design and shafting arrangement directly impact the starter's aerodynamic performance and reliability.

[0003] The split rotor-turbine shaft structure involves machining the turbine rotor and turbine shaft separately and then connecting them via a flat key to form the turbine assembly. The turbine rotor experiences heavy circumferential loads in the keyway. Furthermore, the high rotational speed of the turbine rotor generates significant centrifugal forces, which in turn creates heavy radial loads in the keyway. Furthermore, the turbine rotor is made of low-strength aluminum, and deformation and damage to the turbine rotor keyway pose significant challenges to product reliability and safety. Summary of the Invention

[0004] The object of the present invention is to provide a turbine assembly and a turbine starting device for improving the deformation and damage of the keyway of the turbine rotor.

[0005] In the first aspect, the present invention provides a turbine assembly. According to an embodiment of the present invention, the turbine assembly includes a ring, a turbine rotor and a turbine shaft; the ring is provided with a spline on the axial end face; the turbine rotor is provided with a spline groove on the axial end face; the turbine shaft passes through the turbine rotor and the ring; wherein, the ring is circumferentially fastened to the turbine shaft; the spline of the ring is inserted into the spline groove of the turbine rotor.

[0006] In one or more embodiments, the ring is connected to the turbine shaft via a flat key.

[0007] In one or more embodiments, the flat key and the ring are both made of steel.

[0008] In one or more embodiments, the turbine rotor includes an axially protruding hub portion, and the spline groove is located on an axial end surface of the hub portion.

[0009] In one or more embodiments, the turbine shaft is a unitary structure.

[0010] In one or more embodiments, the axial end surface of the spline teeth is a convex arc surface on the radial outside, and the height of the convex arc surface decreases radially outward;

[0011] The axial end surface of the groove portion of the spline groove is a convex arc surface on the radial outer side, and the depth of the convex arc surface decreases radially outward;

[0012] The key teeth are inserted into the groove portion, and the convex arc surface of the key teeth fits the convex arc surface of the groove portion.

[0013] In one or more embodiments, a protrusion is provided on the radial inner side of the axial end surface of the key tooth, and the protrusion protrudes from the axial end surface of the key tooth;

[0014] The axial end surface of the groove portion is provided with a recessed portion on the radial inner side, and the recessed portion is recessed from the axial end surface of the groove portion;

[0015] The protrusion is inserted into the recess.

[0016] In one or more embodiments, the side surface of the spline teeth is a plane perpendicular to the circumferential direction;

[0017] The side surface of the groove portion of the spline groove is a plane perpendicular to the circumferential direction;

[0018] The key teeth are inserted into the groove portion, and the side surfaces of the key teeth are in contact with the side surfaces of the groove portion.

[0019] In one or more embodiments, the edges of the spline teeth are rounded.

[0020] In a second aspect, the present invention provides a turbine starting device. According to an embodiment of the present invention, the turbine starting device includes the turbine assembly described above.

[0021] The embodiments of the present invention have at least the following beneficial effects:

[0022] 1. The rotation of the turbine shaft is transmitted to the turbine rotor through the ring. The number of spline teeth on the ring is large, and the load of the turbine rotor is evenly distributed, which reduces the stress on the spline groove and protects the turbine rotor from damage.

[0023] 2. The ring is located on the axial side of the turbine rotor, so that the spline groove of the turbine rotor deviates from the root of the axial center of the turbine rotor, avoiding the area with the largest radial load, reducing the stress on the spline groove, and protecting the turbine rotor from damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0025] Figure 1 is a cross-sectional view of a turbine assembly;

[0026] Figure 2 is an oblique view of the ring;

[0027] Figure 3 is an oblique view of the turbine rotor;

[0028] Figure 4 It is a cross-sectional view of a turbine starter;

[0029] Reference numerals:

[0030] 1- Turbine assembly;

[0031] 2-rings;

[0032] 3-turbine rotor;

[0033] 4-turbine shaft;

[0034] 5-hole of turbine rotor;

[0035] 6-hole of the ring;

[0036] 7- axial end face of the ring;

[0037] 8-spline;

[0038] 9-key teeth;

[0039] 10- axial end face of the turbine rotor;

[0040] 11-spline groove;

[0041] 12-groove;

[0042] 13- axial end face of the key tooth;

[0043] 14- convex arc surface of the key tooth;

[0044] 15- axial end surface of the groove portion;

[0045] 16- convex arc surface of the groove portion;

[0046] 17- protrusion of the key tooth;

[0047] 18-The concave part of the groove;

[0048] 19- side surface of the key tooth;

[0049] 20- side surface of the groove;

[0050] 21- flat key;

[0051] 22-turbine shaft keyway;

[0052] 23- keyway of the ring;

[0053] 24-hub;

[0054] 25- the root of the turbine rotor;

[0055] 26- turbine starting device;

[0056] 27-turbine guide vanes;

[0057] 28-exhaust side bearing;

[0058] 29-intermediate bearing;

[0059] 30- output side bearing;

[0060] 31- shaft seal;

[0061] 32- retaining ring;

[0062] 33-gasket;

[0063] 34-nut;

[0064] 35-protective retaining ring;

[0065] 36-exhaust hood;

[0066] 37-Turbine housing. DETAILED DESCRIPTION

[0067] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to explain the present invention, not to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, features shown or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to cover such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0068] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0069] Figure 1 The cross-sectional structure of the turbine assembly 1 along the axial section is shown. Figure 2 The structure of the ring 2 is shown in an oblique view. Figure 3 The oblique view of the turbine rotor 3 is shown. Figure 1 As shown, the turbine assembly 1 includes a ring 2, a turbine rotor 3 and a turbine shaft 4. Figure 3 The turbine rotor 3 has a hole 5 at the center. The inner diameter of the hole 5 is substantially the same as the outer diameter of the turbine shaft 4. The turbine shaft 4 passes through the hole 5 of the turbine rotor 3. The turbine rotor 3 is sleeved on the radial outer side of the turbine shaft 4. Figure 2The ring 2 has a hole 6 in the center. The inner diameter of the hole 6 is roughly the same as the outer diameter of the turbine shaft 4. The turbine shaft 4 passes through the hole 6 of the ring 2. The ring 2 is sleeved on the radial outside of the turbine shaft 4 and is circumferentially fastened to the turbine shaft 4. The ring 2 and the turbine shaft 4 do not rotate relative to each other in the circumferential direction. The relevant content of the circumferential fastening connection between the ring 2 and the turbine shaft 4 will be described in detail later.

[0070] Continue to refer to Figure 2 The ring 2 is provided with a spline 8 on the axial end surface 7. The spline 8 includes a plurality of key teeth 9. The key teeth 9 protrude from the axial end surface 7. The plurality of key teeth 9 are evenly distributed circumferentially on the axial end surface 7. In the illustrated embodiment, the spline 8 includes six key teeth 9. The key teeth 9 protrude axially from the axial end surface 7 and extend radially on the axial end surface 7.

[0071] Continue to refer to Figure 3 The turbine rotor 3 is provided with a spline groove 11 on the axial end surface 10. The spline groove 11 includes a plurality of groove portions 12, which are recessed from the axial end surface 10 and are uniformly distributed circumferentially on the axial end surface 10. In the illustrated embodiment, the spline groove 11 includes six groove portions 12, which are recessed axially from the axial end surface 10 and extend radially on the axial end surface 10.

[0072] Continue to refer to Figure 1 The spline 8 of the ring 2 is inserted into the spline groove 11 of the turbine rotor 3, and each key tooth 9 of the spline 8 is inserted into each groove portion 12 of the spline groove 11. The rotation of the turbine shaft 4 is transmitted to the turbine rotor 3 through the ring 2. The spline 8 has a large number of key teeth 9, and the load of the turbine rotor 3 is evenly distributed, reducing the stress on the groove portion 12 of the spline groove 11 and protecting the turbine rotor 3 from damage. In addition, the ring 2 is located on the axial side of the turbine rotor 3, and the spline groove 11 of the turbine rotor 3 deviates from the root of the axial center of the turbine rotor 3, avoiding the area with the largest radial load, reducing the stress on the spline groove 11 and protecting the turbine rotor 3 from damage. In addition, the key teeth 9 of the spline 8 exert force on the groove portion 12 of the spline groove 11 over a large area, reducing the stress on the groove portion 12 of the spline groove 11 and protecting the turbine rotor 3 from damage.

[0073] Continue to refer to Figure 2 The axial end surface 13 of the key tooth 9 is a convex arc surface 14 on the radially outer side. The height of the convex arc surface 14 decreases radially outward. The height of the convex arc surface 14 is the axial distance between the convex arc surface 14 and the axial end surface 7 of the ring 2, that is, the height of the key tooth 9. In the illustrated embodiment, the convex arc surface 14 extends radially from the approximately radial middle position of the key tooth 9 to the radial outermost end of the key tooth 9 and connects with the axial end surface 7 of the ring 2.

[0074] Continue to refer to Figure 3The axial end surface 15 of the groove portion 12 of the spline groove 11 is a convex arc surface 16 on the radially outer side. The depth of the convex arc surface 16 decreases radially outward. The depth of the convex arc surface 16 is the axial distance between the convex arc surface 16 and the axial end surface 10 of the turbine rotor 3, that is, the depth of the groove portion 12. In the illustrated embodiment, the convex arc surface 16 extends radially from approximately the radial middle of the groove portion 12 to the radially outermost end of the groove portion 12 and connects to the axial end surface 10 of the turbine rotor 3.

[0075] Continue to refer to Figure 1 The key tooth 9 is inserted into the groove portion 12, and the force is applied to the groove portion 12 mainly through the radial outer part. The key tooth 9 and the groove portion 12 are joined on the radial outer side by the fit between the convex arc surface 14 and the convex arc surface 16. The shape changes of the convex arc surface 14 and the convex arc surface 16 are continuous and gentle, avoiding local stress concentration when the key tooth 9 applies force to the groove portion 12, reducing the stress borne by the groove portion 12, and protecting the turbine rotor 3 from damage.

[0076] Continue to refer to Figure 1 Since the shape change is continuous and gentle, the convex arc surface 16 has a poor limiting effect on the convex arc surface 14, and the convex arc surface 14 is easy to slip relative to the convex arc surface 16, resulting in the key tooth 9 not being properly inserted into the groove portion 12, and the ring 2 not being properly inserted into the turbine rotor 3. For example, Figure 1 In the process, the ring 2 rotates counterclockwise, and the axis of the ring 2 does not coincide with the axis of the turbine rotor 3, but is deflected counterclockwise by a certain angle. The convex arc surface 14 of the key tooth 9 does not fit the convex arc surface 16 of the groove portion 12, but there is a certain gap, and the key tooth 9 is not inserted into the groove portion 12.

[0077] Continue to refer to Figure 2 The axial end face 13 of the key tooth 9 is provided with a protrusion 17 on the radially inner side. The protrusion 17 protrudes from the axial end face 13 of the key tooth 9. In the illustrated embodiment, the protrusion 17 protrudes axially from the axial end face 13 of the key tooth 9. The protrusion 17 is a portion of an annular ring in the circumferential direction, extending radially from approximately one-third of the radial direction of the key tooth 9 to the radially innermost end of the key tooth 9. The radial inner wall surface of the protrusion 17 forms a part of the inner wall surface of the channel 6.

[0078] Continue to refer to Figure 3 The axial end surface 15 of the groove portion 12 is provided with a recessed portion 18 on the radially inner side. The recessed portion 18 is recessed from the axial end surface 13 of the groove portion 12. In the illustrated embodiment, the recessed portion 18 is recessed axially from the axial end surface 15 of the groove portion 12. The recessed portion 18 extends radially from approximately one-third of the radial direction of the groove portion 12 to the radially innermost end of the groove portion 12, communicating with the channel 5. The recessed portions 18 of each groove portion 12 of the spline groove 11 are circumferentially connected to form a complete annular shape.

[0079] Continue to refer to Figure 1The key tooth 9 is inserted into the groove 12, the protrusion 17 is inserted into the recess 18, and the radial outer wall of the protrusion 17 fits the radial outer wall of the recess 18 to form a fixed limit, so that the key tooth 9 is accurately inserted into the groove 12, ensuring that the convex arc surface 14 of the key tooth 9 fits the convex arc surface 16 of the groove 12, thereby ensuring that the ring 2 is accurately inserted into the turbine rotor 3.

[0080] Continue to refer to Figure 2 , the side surface 19 of the key tooth 9 is a plane and perpendicular to the circumferential direction. Figure 3 The side surface 20 of the groove 12 is flat and perpendicular to the circumferential direction. The key tooth 9 is inserted into the groove 12, and the side surface 19 of the key tooth 9 fits the side surface 20 of the groove 12. The force applied by the key tooth 9 to the groove 12 is tangential to the circumferential direction and has no radial or axial components. It only applies rotational force to the turbine rotor 3, and does not apply radial or axial force to the turbine rotor 3.

[0081] Continue to refer to Figure 2 The key teeth 9 have rounded corners and a gentle shape, which avoids local stress concentration when the key teeth 9 apply force to the groove portion 12, reduces the stress borne by the groove portion 12, and protects the turbine rotor 3 from damage.

[0082] Continue to refer to Figure 1 , the ring 2 is connected to the turbine shaft 4 by a flat key 21. In the embodiment shown in the figure, the ring 2 is connected to the turbine shaft 4 by two flat keys 21 arranged in opposite directions, and correspondingly, the turbine shaft 4 is provided with two keyways 22 in opposite directions. Figure 2 Correspondingly, the ring 2 is provided with two opposing keyways 23, and the two keyways 23 occupy part of the protrusions 17 of the two key teeth 9. In another embodiment, the ring 2 is connected to the turbine shaft 4 by other means. For example, the hole 6 of the ring 2 is provided with an internal spline, and the outer circumferential surface of the turbine shaft 4 is provided with an external spline, and the ring 2 and the turbine shaft 4 are spline-connected.

[0083] Continue to refer to Figure 1 The flat key 21 and the ring 2 are both made of steel, resulting in similar strengths between the flat key 21 and the ring 2. Both are relatively strong, and neither is damaged when the flat key 2 applies force to the keyway 22. The flat key 21 and the ring 2 are exemplarily made of 45# steel. The turbine rotor 3 is exemplarily made of aluminum alloy. The turbine shaft 4 is exemplarily made of 20CrMnTi.

[0084] The split turbine shaft includes multiple shaft segments in the axial direction, and the multiple shaft segments are connected by a connecting structure (such as a threaded structure). When subjected to a large torque, the connecting structure between the shaft segments is easily damaged, which greatly limits the torque output capacity of the turbine starting device.

[0085] Continue to refer to Figure 1The turbine shaft 4 is an integral structure and is continuous in the axial direction. It is also called an integrated turbine shaft. It avoids the axial connection of multiple shaft segments in a split turbine shaft, provides a stronger torque output capability than the split turbine shaft, and can output large torque.

[0086] Continue to refer to Figure 3 The turbine rotor 3 is provided with a hub 24. The hub 24 protrudes axially. The axial end face 10 of the hub 24 is also the axial end face 10 of the turbine rotor 3. The axial protrusion of the hub 24 causes the axial end face 10 to further deviate from the axial center position of the turbine rotor 3. The spline groove 11 is located on the axial end face 10 of the hub 24, further deviating from the axial center position of the turbine rotor 3 and further deviating from the root 25 of the axial center of the turbine rotor 3. This reduces the weakening of the strength of the root 25 of the turbine rotor 3, ensures the ability of the root 25 of the turbine rotor 3 to withstand centrifugal force, protects the root 25 of the turbine rotor 3 from being damaged under high centrifugal force at high speed, and can withstand high speed. In addition, there is no physical structure on the radial outer side of the hub 24, so the centrifugal force generated during rotation is small, the radial load is small, and the stress on the spline groove 11 is reduced, protecting the spline groove 11 from being damaged under high speed, and can withstand high speed.

[0087] Figure 4 FIG. 2 shows a cross-sectional view of the turbine starter 26 in the axial section. Figure 4 As shown, the turbine starter 26 includes the turbine assembly 1 described above.

[0088] exist Figure 4 In the illustrated embodiment, the turbine starter 26 also includes, by way of example, a turbine guide vane 27, a retaining ring 32, a gasket 33, a nut 34, a protective retaining ring 35, an exhaust shroud 36, and a turbine housing 37. The turbine starter 26 utilizes a single-stage axial-flow impulse turbine, comprising a turbine guide vane 27 and a turbine rotor 3. The turbine starter 26 is fed by a central intake, with the turbine guide vane 27 secured to the end face of the turbine housing 37 by three screws. In addition to being axially restrained by the turbine rotor 3, the ring 2 is also axially restrained by an exhaust-side bearing 28, a gasket 33, and a nut 34 on its axial side, ensuring axial fixation of the ring 2.

[0089] Continue to refer to Figure 4The turbine starter 26 also includes an exhaust-side bearing 28 and an intermediate-stage bearing 29. The exhaust-side bearing 28 is axially located on the exhaust side of the turbine rotor 3 and adjacent to the turbine rotor 3, supporting the axial end of the turbine shaft 4. The intermediate-stage bearing 29 is axially located on the output side of the turbine rotor 3 and adjacent to the turbine rotor 3, supporting the axial center of the turbine shaft 4. The exhaust-side bearing 28 and the intermediate-stage bearing 29 support the turbine shaft 4 on both axial sides adjacent to the turbine rotor 3. This provides excellent support rigidity for the portion of the turbine shaft 4 axially between the exhaust-side bearing 28 and the intermediate-stage bearing 29, thereby improving the operational stability of the turbine rotor 3. Exemplarily, the exhaust-side bearing 28 is a high-speed, sealed bearing lubricated with grease, with an interference fit on the turbine shaft 4, located within the bore of the exhaust housing 36 and having a clearance fit therewith. The intermediate-stage bearing 29 is a high-speed, sealed bearing lubricated with grease, with an interference fit on the turbine shaft 4, located within the bore of the turbine guide vane 27 and having a clearance fit therewith.

[0090] Continue to refer to Figure 4 The turbine starter 26 also includes an output-side bearing 30. This bearing is axially located on the output side of the turbine rotor 3 and away from the turbine rotor 3. It supports the turbine shaft 4 near its axial end and is located in the axial transition region between the planetary reduction system (not shown) connected to the output side of the turbine starter 26 and the turbine rotor 3. This further strengthens support for the turbine shaft 4 and prevents eccentricity due to high loads. Exemplarily, the output-side bearing 30 is a high-speed, open-type bearing lubricated with lubricating oil. It has an interference fit with the turbine shaft 4 and is located within the bore of the turbine housing 37, with a clearance fit therewith.

[0091] Continue to refer to Figure 4 The turbine starting device 26 also includes a shaft seal 31, which is axially located on the output side of the intermediate stage bearing 29 and radially located between the turbine shaft 4 and the turbine guide vane 27 to isolate oil and gas and complete the shaft system sealing. The shaft seal 31 is illustratively a lip seal ring.

[0092] Although the present invention is disclosed above with reference to the embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention.

Claims

1. A turbine assembly, characterized in that include: A ring member having a spline provided on an axial end face; The turbine rotor is provided with a spline groove on the axial end surface; as well as a turbine shaft passing through the turbine rotor and the ring; in, The ring is circumferentially and tightly connected to the turbine shaft; The spline of the ring is inserted into the spline groove of the turbine rotor; The axial end surface of the spline tooth is a convex arc surface on the radial outside, and the height of the convex arc surface decreases radially outward. The axial end surface of the groove portion of the spline groove is a convex arc surface on the radial outside, and the depth of the convex arc surface decreases radially outward. The spline tooth is inserted into the groove portion, and the convex arc surface of the spline tooth fits the convex arc surface of the groove portion. The axial end face of the key tooth is provided with a protrusion on the radial inner side, and the protrusion protrudes from the axial end face of the key tooth. The axial end face of the groove is provided with a recess on the radial inner side, and the recess is recessed from the axial end face of the groove. The protrusion is inserted into the recess.

2. The turbine assembly according to claim 1, wherein: The ring is connected to the turbine shaft via a flat key.

3. The turbine assembly according to claim 2, wherein: The flat key and the ring are both made of steel.

4. The turbine assembly according to claim 1, wherein: The turbine rotor includes an axially protruding hub portion, and the spline groove is located on an axial end surface of the hub portion.

5. The turbine assembly according to claim 1, wherein: The turbine shaft is an integral structure.

6. The turbine assembly according to claim 1, wherein: The side surface of the key teeth of the spline is a plane perpendicular to the circumferential direction; The side surface of the groove portion of the spline groove is a plane perpendicular to the circumferential direction; The key teeth are inserted into the groove portion, and the side surfaces of the key teeth are in contact with the side surfaces of the groove portion.

7. The turbine assembly according to claim 1, wherein: The edges of the spline teeth are rounded.

8. A turbine starting device, characterized in that include: A turbine assembly as claimed in any one of claims 1 to 7.

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