Two-piece sun race for driven turbocharger

Abstract

The invention relates to a two-piece sun race for a driven turbocharger. A two-piece sun race is disclosed that fits precisely onto a turbine shaft of a drive turbocharger having a traction drive that transmits torque to and from the turbine shaft. A turbine shaft is attached to the turbine and the compressor and is inserted into a two-piece sun race having a traction surface that cooperates with a traction drive. This allows the manufacture and assembly of the traction drive to be simplified because the two parts of the sun race can be simplified on a one-piece traction cylinder and allows greater flexibility in design and assembly of the drive turbocharger than a one-piece traction cylinder.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 543,620, filed on October 11, 2023, entitled “TWO-PIECE SUN RACE FOR DRIVENTURBOCHARGER,” all of the contents disclosed and taught in that U.S. Provisional Application are incorporated herein by reference and made a part of this application for all purposes. Technical Field

[0003] The present application relates to a two-piece sun ring for a driven turbocharger. Background Art

[0004] A driven turbocharger is an improvement over a normal turbocharger because the power of a driven turbine turbocharger (super turbocharger) does not only come from the exhaust gas turbine, which reduces the turbo lag of the supercharged engine. A driven turbocharger can also direct excess turbine power back to the engine to improve engine efficiency. One type of driven turbocharger utilizes a traction drive connected to the turbine shaft to provide torque to the turbine shaft and to obtain torque from the turbine shaft. Summary of the invention

[0005] Therefore, one embodiment of the present invention may include: a driven turbocharger for an engine system, the driven turbocharger comprising: a turbine shaft; a compressor, the compressor being connected to a first position on the turbine shaft; a turbine, the turbine being connected to a second position on the turbine shaft; a two-piece sun ring mounted on the turbine shaft, the two-piece sun ring comprising: a first sun ring member, the first sun ring member being matched with an axial surface A of the turbine shaft by a precision fit; a second sun ring member, the second sun ring member being matched with an axial surface B of the turbine shaft by a precision fit, wherein the diameter of the axial surface B of the turbine shaft is larger than the diameter of the axial surface A of the turbine shaft, so that the second sun ring member can pass through the axial surface A of the turbine shaft without interference during assembly; a traction drive, the traction drive being in contact with the first ring traction surface and the second ring traction surface of the two-piece sun ring to transfer torque to and from the turbine shaft.

[0006] Therefore, an embodiment of the present invention may also include: a method for assembling a rotating component of a drive-type turbocharger, comprising: forming an axial surface A and an axial surface B on a turbine shaft, wherein the diameter of the axial surface B of the turbine shaft is larger than the diameter of the axial surface A of the turbine shaft; inserting the second sun seat ring component of a two-piece sun seat ring onto the axial surface A of the turbine shaft without interference; fitting the second sun seat ring component of the two-piece sun seat ring to the axial surface B of the turbine shaft by precision fitting; fitting the first sun seat ring component of the two-piece sun seat ring to the axial surface A of the turbine shaft by precision fitting. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A is an isometric view of a driven turbocharger with traction drive.

[0008] Figure 1B is an isometric view of a driven turbocharger with traction drive and two-piece sun ring.

[0009] Figure 2 is a cross-sectional view of a one-piece drag barrel of a driven turbocharger corresponding to the design in US Pat. No. 10,539,159.

[0010] Figure 3 is a cross-sectional view of a two-piece sun ring mounted on the turbine shaft of a drive-type turbocharger.

[0011] Figure 4 An exploded view of the rotating assembly is shown during assembly.

[0012] Figure 5 A cross-sectional view of a rotating assembly with a two-piece sun race on a turbine shaft is shown.

[0013] Fig. 6A A cross-sectional view of an alternative embodiment of a two-piece sun race of a rotating assembly is shown.

[0014] Figure 6B A cross-sectional view of an alternative embodiment of a two-piece sun race of a rotating assembly is shown.

[0015] Figure 7 A cross-sectional view of an alternative embodiment of a rotating assembly is shown in which a sleeve is added between the first sun race component and the second sun race component.

[0016] Figure 8 A cross-sectional view of an alternative embodiment of a two-piece sun race is shown, wherein a first sun race piece and a second sun race piece extend axially to mate with one another. DETAILED DESCRIPTION

[0017] Figure 1Ais an isometric view of a driven turbocharger 101 with a traction drive 103. The driven turbocharger 101 corresponds to the prior art in U.S. Patent 10,539,159. The turbine shaft 105 has a compressor 107 connected to a first position on the turbine shaft 105 and a turbine 109 connected to a second position on the turbine shaft 105. The addition of the traction drive 103 complicates the assembly of the driven turbocharger 101 because the turbine shaft 105 also has traction surfaces, namely, barrel traction surfaces 113, 115, that mate with the traction drive 103. One way to simplify the components and assembly of the driven turbocharger 101 is to have a rotating assembly 117 consisting of the turbine shaft 105, a traction barrel 119, a compressor 107, and a turbine 109, wherein the traction barrel 119 has barrel traction surfaces 113, 115 that mate with the traction drive 103. Separating the components of the rotating assembly 117 allows for the use of different materials, so that the traction barrel 119 can be made of a material optimized for the barrel traction surfaces 113, 115, and a different material can be used to make the turbine shaft 105. Having separate components for the rotating assembly 117 can also simplify the individual components, making them easier and more economical to manufacture, and generally allow for greater design flexibility. The traction drive 103 may have various designs, as taught in U.S. Patent Nos. 8,668,614, entitled “High Torque Traction Drive”, issued on March 11, 2014, 9,670,832, entitled “Thrust Absorbing Planetary Traction Drive Superturbo”, issued on June 6, 2017, 10,107,183, entitled “Eccentric Planetary Traction Drive Super-Turbocharger”, issued on October 23, 2018, and 10,539,159, entitled “Two-Piece Shaft Assembly for Driven Turbocharger”, issued on January 21, 2020. U.S. Patent Nos. 8,668,614, 9,670,832, 10,107,183, and 10,539,159 are all specifically incorporated herein by reference for what they disclose and teach.

[0018] Figure 1B FIG. 1 is an isometric view of a driven turbocharger 100 having a traction drive 102 with a two-piece sun ring 118. The driven turbocharger 100 corresponds to the present invention. Instead of a single piece (such as a Figure 1AThe two-piece sun ring 118 is composed of two parts, namely a first sun ring member 130 and a second sun ring member 132, which are both matched with the turbine shaft 104. Dividing the two-piece sun ring 118 into two separate parts can achieve further flexibility and improve the assembly of the traction drive 102.

[0019] Figure 210,539,159. This is a previous design that has limitations that the new design of the present invention seeks to improve. The one-piece drag sleeve 219 is mounted on the turbine shaft 205 by a press fit at the shaft surface A 221 and the shaft surface B 223. For this previous design, the inner surface 225 of the one-piece drag sleeve 219 has a uniform diameter, and similarly, the diameters of the shaft surface A 221 and the shaft surface B 223 of the turbine shaft 205 are also the same as each other. The inner surface 225 of the one-piece drag sleeve 219 is a precision machined surface along its entire length. Similarly, the shaft surface A 221 and the shaft surface B 223 of the turbine shaft 205 are also precision machined surfaces to ensure that the one-piece drag sleeve 219 is precisely fitted to the turbine shaft 205. When the one-piece drag sleeve 219 is pressed onto the turbine shaft 205, the inner surface 225 of the one-piece drag sleeve 219 slides the entire length of the one-piece drag sleeve 219 with interference on the shaft surface A 221 before pressing onto the shaft surface B 223. During the assembly process of the driven turbocharger 201, this very long press fit on the shaft surface A 221 of the turbine shaft 205 may cause problems, resulting in excessive press fit forces, and may cause wear or other damage to the shaft surface A 221 and / or the inner surface 225 of the one-piece drag sleeve 219. In addition, because the driven turbocharger 201 operates at a very high rotational speed of the turbine shaft 205, it is beneficial that the rotational power of the rotating assembly 217 separates the first barrel traction surface 213 and the second barrel traction surface 215 as much as possible on the one-piece drag sleeve 219, similar to the separation of the shaft surface A 221 and the shaft surface B 223 on the turbine shaft 205. The further the first drum traction surface 213 and the second drum traction surface 215 are separated, the more stable the rotational power of the traction drive 203 and the rotating assembly 217. By making the spacing between the first drum traction surface 213 and the second drum traction surface 215 larger and correspondingly increasing the spacing between the shaft surface A 221 and the shaft surface B 223, the runout of the rotating assembly 217 is improved, thereby simplifying the rotational balance of the rotating assembly 117. However, during the press-fit assembly process of the rotating assembly 217, increasing the spacing between the first drum traction surface 213 and the second drum traction surface 215 and increasing the spacing between the shaft surface A 221 and the shaft surface B 223 requires increasing the length of the single-piece traction drum 219 and increasing the distance that the inner surface 225 of the single-piece traction drum 219 slides on the shaft surface A 211 with interference, thereby increasing the possibility of damage during assembly. In addition, as the length of the single-piece traction drum 219 increases, the difficulty and cost of machining the precise diameter of the inner surface 225 of the single-piece traction drum 219 also increases.

[0020] In order to avoid the one-piece traction barrel 219 being press-fitted too long and too hard on the turbine shaft 205, it is beneficial to increase the diameter of the shaft surface B 223 and the corresponding mating portion of the inner surface 225 of the one-piece traction barrel 219. This will greatly shorten the press-fit distance on the shaft surface A 221, but requires the inner surface 225 of the one-piece traction barrel 219 to have two different inner diameters along its length, which increases the difficulty and cost of manufacturing the component. It is extremely important that all mating surfaces of the one-piece traction barrel 219, including the inner surface 225 and the first barrel traction surface 213 and the second barrel traction surface 215, are concentric and parallel, otherwise unbalanced rotation of the rotating assembly 217 will occur. The introduction of additional precision machined surfaces on the inner surface 225 of the one-piece traction barrel 219 complicates the manufacture of the component and reduces the tolerance accuracy.

[0021] Figure 3 3 is a cross-sectional view of a two-piece sun ring 318 mounted on a turbine shaft 304 of a driven turbocharger 300. This updated design of the present invention makes the design and assembly of the rotating assembly 316 more flexible. The two-piece sun ring 318 is composed of a first sun ring member 330 and a second sun ring member 332. The first sun ring member 330 has a first ring traction surface 312 formed on the outside thereof, and has a first inner surface 334 that is matched with the shaft surface A 320 of the turbine shaft 304 by a precision fit. The second sun ring member 332 has a second ring traction surface 314 formed on the outside thereof, and has a second inner surface 336 that is matched with the shaft surface B 322 of the turbine shaft 304 by a precision fit. The precision fit of the first sun ring member 330 and the second sun ring member 332 on the turbine shaft 304 may be a press fit, a slide fit, or a transition fit. The diameter of the shaft surface B 322 of the turbine shaft 304 is greater than the diameter of the shaft surface A 320 of the turbine shaft 304, and accordingly, the diameter of the second inner surface 336 of the second sun ring member 332 is greater than the diameter of the first inner surface 334 of the first sun ring member 330. This allows the second sun ring member 332 to pass through the shaft surface A 320 on the turbine shaft 304 without interference before the second sun ring member 332 is precision-fitted onto the shaft surface B 322 of the turbine shaft 304 during assembly. This eliminates Figure 2, thereby eliminating the excessively long press fit required by the previous design described in . As shown, the first sun seat member 330 and the second sun seat member 332 can be separate and not in contact, or they can be adjacent to each other with mating surfaces therebetween, as described in the alternative embodiments in the figures below. In addition, each component of the two-piece sun seat 318, namely the first sun seat member 330 and the second sun seat member 332, respectively, has only a single precision machined inner diameter, a first inner surface 334 and a second inner surface 336. This simplifies the manufacture of the first sun seat member 330 and the second sun seat member 332, and allows for tighter tolerances on the precision machined surfaces. The precision machined surfaces of the first inner surface 334 and the second inner surface 336 can also be only the width required for precision fit with shaft surface A 320 and shaft surface B 322, respectively, rather than as shown in the alternative embodiments in the figures below. Figure 2 318 has a precision machined surface the entire length of the two-piece sun race 318 as in the previous designs in FIG. The traction drive 302 contacts the first race traction surface 312 and the second race traction surface 314 of the two-piece sun race 318 and transfers torque to and from the two-piece sun race 318 and the turbine shaft 304. In addition, the first race traction surface 312 and the second race traction surface 314 can be shaped as shown so that the thrust on the turbine shaft 304 is absorbed by the traction drive 302, as taught by U.S. Patent 9,670,832, entitled “Thrust Absorbing Planetary Traction Drive Superturbo” issued on June 6, 2017, which is specifically incorporated herein by reference in its entirety for its disclosure and teachings. As shown, the first race traction surface 312 on the first sun race piece 330 can be tilted inwardly away from the compressor 306, which allows the following assembly process to be achieved: after the planet rollers 350 of the traction drive 302 of the drive-type turbocharger 300 are arranged around the turbine shaft 304 during the assembly process of the traction drive 302, the first sun race piece 330 is installed on the turbine shaft 304. This makes the assembly process of the traction drive 302 simpler and easier.

[0022] Figure 4An exploded view of the rotating assembly 416 during assembly is shown. Shaft surface A 420 and shaft surface B 422 are formed on the turbine shaft 404, and the diameter of shaft surface B 422 is larger than the diameter of shaft surface A 420. As a first step, the second sun ring member 432 is inserted through and through the shaft surface A 420 of the turbine shaft 404 without interference. Since the inner diameter of the second inner surface 436 of the second sun ring member 432 is larger than the diameter of the shaft surface A 420 of the turbine shaft 404, the second sun ring member 432 will not contact the turbine shaft 404 without interference before reaching the shaft surface B 422. The second sun ring member 432 is precision-fitted to the turbine shaft 404, wherein the second inner surface 436 is precision-fitted with the shaft surface B 422. With Figure 2 Unlike the previous design shown, the second inner surface 436 has only a short distance of precision fit on the shaft surface B 422 because it does not interfere with the smaller diameter of the shaft surface A 420. An optional intermediate step after the first step is to remove the second inner surface 436 from the shaft surface B 422 before continuing. Figure 3 The traction drive 302 in the assembly is assembled around the turbine shaft 404. Once the second sun race piece 432 is precision-fitted onto the turbine shaft 404, the second assembly step is to insert the first sun race piece 430 onto the turbine shaft 404 and precision-fit onto the shaft surface A 420 of the turbine shaft 404. The first inner surface 434 of the first sun race piece 430 is mated with the shaft surface A 420 in this precision fit. The precision-machined first inner surface A 434 can be made only long enough to precisely fit onto the shaft surface A 420, thereby avoiding Figure 2 The previous design in FIG. 400 interferes excessively with sliding on the shaft surface A 420. In addition, as shown, a shoulder 421 can be formed on the turbine shaft 404 to axially position the first sun race member 430 on the turbine shaft 404. A second shoulder 423 can also be formed on the turbine shaft 404 to also axially position the second sun race member 432 on the turbine shaft 404.

[0023] Figure 5A cross-sectional view of a rotating assembly 516 with a two-piece sun race 518 on a turbine shaft 504 is shown. An optional throw ring 540 is shown on the two-piece sun race 518, located on the outer edge of the two-piece sun race 518, adjacent to the first race traction surface 512 and the second race traction surface 514. These throw rings 540 can help remove traction fluid from the rotating assembly 516 once the traction fluid leaves the first race traction surface 512 and the second race traction surface 514. The traction fluid is used in the traction drive 502 to increase the torque capacity of the traction drive 502, as well as for lubrication, cooling, and preventing damage to the traction drive 502. However, the traction fluid should not travel along the turbine shaft 504 to the compressor 506 or turbine 508, as it needs to remain controlled. The throw ring 540 helps remove the traction fluid from the rotating assembly 516 before it reaches the compressor shaft seal 542 and the turbine shaft seal 544.

[0024] Fig. 6A A cross-sectional view of an alternative embodiment of a two-piece sun race 618 of a rotating assembly 616 is shown. In this embodiment, both the first race traction surface 612 and the second race traction surface 614 are formed on a first sun race piece 630. The second sun race piece 632 is precision fit to the turbine shaft 604 and also mates with the first sun race piece 630. The first sun race piece 630 is also precision fit to the turbine shaft 604.

[0025] Figure 6B A cross-sectional view of an alternative embodiment of a two-piece sun race 618 of a rotating assembly 616 is shown. In this embodiment, both the first race traction surface 612 and the second race traction surface 614 are formed on a second sun race piece 632. The first sun race piece 630 is precision fit to the turbine shaft 604 and also mates with the second sun race piece 632. The second sun race piece 632 is also precision fit to the turbine shaft 604.

[0026] Figure 7A cross-sectional view of an alternative embodiment of the rotating assembly 716 is shown, in which a sleeve 742 is added between the first sun ring piece 730 and the second sun ring piece 732. The addition of the sleeve 742 will increase the stiffness of the rotating assembly 716 because it will have an effect similar to increasing the diameter of the turbine shaft 704. The sleeve 742 can optimize this stiffness with different thicknesses and sizes to adjust and tune the rotational dynamics of the rotating assembly 716. Increasing the stiffness of the rotating assembly 716 may be useful for applications using large, high-mass and high-inertia turbines 708 and / or compressors 706. The ability to increase the effective stiffness of the turbine shaft 704 by adding a sleeve 742 between the first sun ring piece 730 and the second sun ring piece 732 without changing the size of the turbine shaft 704 is an additional benefit of the two-piece sun ring 718.

[0027] Figure 8 A cross-sectional view of an alternative embodiment of a two-piece sun ring 818 is shown, wherein a first sun ring piece 830 and a second sun ring piece 832 are axially extended to mate with each other. Figure 7 The addition of sleeve 742 to increase the stiffness of rotating assembly 816 can have a similar effect to that of increasing the stiffness of rotating assembly 816 without changing the size of turbine shaft 804 or increasing the diameter of turbine shaft 804. Likewise, the different thicknesses and geometries of the axial extensions of first sun ring member 830 and second sun ring member 832 can be used to tune, adjust, and optimize the rotational dynamics of rotating assembly 816. Mate the first sun ring member 830 and second sun ring member 832 of two-piece sun ring 818 by axially extending the first sun ring member 830 and second sun ring member 832 to increase the effective stiffness of turbine shaft 804 is an alternative way to achieve the desired stiffness of rotating assembly 816 without changing the size of turbine shaft 804.

[0028] The above description of the present invention is presented for the purpose of illustration and description. It is not intended to be exhaustive or limit the present invention to the precise form disclosed, and other modifications and variations are possible in light of the above teachings. The embodiments are selected and described in order to best explain the principles of the present invention and its practical application, so that other technical personnel in the field can best utilize the present invention in various embodiments and various modifications suitable for the intended specific use. It is intended that the attached claims be interpreted as including other alternative embodiments of the present invention unless limited by the prior art.

Claims

1. A driven turbocharger for an engine system, comprising: Turbine shaft; a compressor connected to a first location on the turbine shaft; a turbine connected to the turbine shaft at a second location; A two-piece sun seat mounted on the turbine shaft, the two-piece sun seat comprising: a first sun seat ring member, the first sun seat ring member being matched with the shaft surface A of the turbine shaft by precision matching; a second sun race member, the second sun race member being matched with the shaft surface B of the turbine shaft by precision matching, wherein the diameter of the shaft surface B of the turbine shaft is larger than the diameter of the shaft surface A of the turbine shaft, so that the second sun race member passes through the shaft surface A of the turbine shaft without interference during assembly; A traction drive contacts the first race traction surface and the second race traction surface of the two-piece sun race to transfer torque to and from the turbine shaft.

2. The drive-type turbocharger according to claim 1, wherein: The first race traction surface is formed on the first sun race member and the second race traction surface is formed on the second sun race member.

3. The driven turbocharger according to claim 1, wherein: The first race traction surface and the second race traction surface are formed on the first sun race member.

4. The driven turbocharger according to claim 1, wherein: The first race traction surface and the second race traction surface are formed on the second sun race member.

5. The driven turbocharger according to claim 1, wherein: The first race traction surface and the second race traction surface are shaped such that thrust forces on the turbine shaft are absorbed by the traction drive.

6. The driven turbocharger of claim 1 further comprising a throw ring formed adjacent to the first race traction surface.

7. The driven turbocharger of claim 1 further comprising a throw ring formed adjacent to the second race traction surface.

8. The driven turbocharger of claim 1 further comprising a shoulder formed on said turbine shaft, said shoulder axially locating said first sun race member on said turbine shaft.

9. The driven turbocharger of claim 1 further comprising a second shoulder formed on said turbine shaft, said second shoulder axially locating said second sun race member on said turbine shaft.

10. The driven turbocharger according to claim 2, wherein: The first race traction surface on the first sun race member is angled inwardly away from the compressor.

11. The driven turbocharger of claim 1 further comprising a sleeve located between the first sun race member and the second sun race member, the sleeve increasing the effective stiffness of the turbine shaft.

12. A method of assembling a rotating assembly of a driven turbocharger, comprising: forming a shaft surface A and a shaft surface B on the turbine shaft, wherein the diameter of the shaft surface B of the turbine shaft is larger than the diameter of the shaft surface A of the turbine shaft; Inserting the second sun race piece of the two-piece sun race on the shaft surface A of the turbine shaft without interference; Fitting the second sun race piece of the two-piece sun race to the shaft surface B of the turbine shaft by precision fitting; The first sun race piece of the two-piece sun race is fitted to the shaft surface A of the turbine shaft by precision fitting.

13. The method according to claim 12, further comprising: forming a first race traction surface on said first sun race member; forming a second race traction surface on said second sun race member; A traction drive is mated to the first race traction surface and the second race traction surface.

14. The method according to claim 12, further comprising: forming a first race traction surface and a second race traction surface on said first sun race member; A traction drive is mated to the first race traction surface and the second race traction surface.

15. The method according to claim 12, further comprising: forming a first race traction surface and a second race traction surface on the second sun race member; A traction drive is mated to the first race traction surface and the second race traction surface.

16. The method according to claim 13, wherein: The first race traction surface and the second race traction surface are shaped such that thrust forces on the turbine shaft are absorbed by the traction drive.

17. The method according to claim 13, further comprising: A throw loop is formed adjacent the first race traction surface.

18. The method according to claim 13, further comprising: A throw loop is formed adjacent the second race traction surface.

19. The method according to claim 14, wherein: The first race traction surface and the second race traction surface are shaped such that thrust forces on the turbine shaft are absorbed by the traction drive.

20. The method of claim 14, further comprising: A throw loop is formed adjacent the first race traction surface.

21. The method of claim 14, further comprising: A throw loop is formed adjacent the second race traction surface.

22. The method according to claim 15, wherein: The first race traction surface and the second race traction surface are shaped such that thrust forces on the turbine shaft are absorbed by the traction drive.

23. The method of claim 15, further comprising: A throw loop is formed adjacent the first race traction surface.

24. The method of claim 15, further comprising: A throw loop is formed adjacent the second race traction surface.

25. The method of claim 12 further comprising forming a shoulder on said turbine shaft, said shoulder locating said first sun ring member.

26. The method of claim 12 further comprising forming a second shoulder on said turbine shaft, said second shoulder locating said second sun ring member.

27. The method of claim 13, wherein: After the planetary rollers of the traction drive of the drive turbocharger have been arranged around the turbine shaft during assembly of the traction drive, the first sun race component is mounted on the turbine shaft.

28. The method of claim 12, further comprising mating the first sun ring member and the second sun ring member of the two-piece sun ring by axially extending the first sun ring member and the second sun ring member to increase the effective stiffness of the turbine shaft.

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