A bearing structure for a turbocharger

Abstract

This utility model discloses a bearing structure for a turbocharger, belonging to the field of mechanical engineering technology, and specifically relating to a bearing system used to support the high-speed rotating spindle in a turbocharger. This utility model aims to solve the shortcomings of existing technologies, such as the large wear and high transmission resistance of floating ring bearings during start-up and shutdown, and the complex, costly, and unreliable structures of custom ball bearings developed to meet the high-speed requirements of turbochargers. This utility model uses a conventional ball bearing structure, and through the setting of an inner spacer ring, an outer spacer ring, spacers, and a reasonable oil circuit design, achieves the goals of reducing transmission losses, improving performance, reducing costs, and improving reliability. This utility model provides various specific embodiments to adapt to the needs of different turbocharger models.

Description

Technical Field

[0001] This utility model relates to the field of mechanical engineering technology, specifically to a bearing structure for a turbocharger. Background Technology

[0002] In turbochargers, the main shaft needs to withstand extremely high speeds. Traditional floating ring bearings (oil film bearings) suffer from significant bearing wear during startup and shutdown, and their transmission resistance is much greater than that of ball bearings and magnetic bearings, becoming a bottleneck restricting the improvement of turbocharger performance. Although floating ring bearings are widely used in engineering applications, their inherent defects limit the efficient operation of turbochargers.

[0003] To address the challenges of high-speed operation, some manufacturers have developed ball bearings specifically for turbochargers. For example, Chinese patent application CN 103477099 A discloses a bearing unit for a turbocharger, comprising a bearing housing extending in the axial direction and a bearing box disposed within the bearing housing. An oil film-containing gap is created between the outer circumference of the bearing box and the bearing housing, and the bearing housing has a supply hole configured to supply the oil film. A key feature of this patent is that the bearing box includes a rolling bearing, the outer ring of which is rotatably supported within the oil film. While this patent proposes a solution for improving bearing performance using rolling bearings and an oil film, its structure is relatively complex and requires high precision in controlling the oil film.

[0004] These custom ball bearings often have complex structures and high manufacturing costs. They also require specific development for each different turbocharger model, resulting in excessively high overall technical costs. In addition, each new custom bearing comes with new technical risks and relatively poor reliability.

[0005] Therefore, it is necessary to provide a new bearing structure that can meet the high speed requirements of turbochargers, reduce transmission losses, reduce manufacturing costs, and improve reliability. Utility Model Content

[0006] The purpose of this utility model is to provide a bearing structure for turbochargers that can replace existing floating ring bearings, significantly reducing transmission losses. Compared with the complex custom ball bearings in the prior art, this structure has the advantages of simple structure, low cost, high reliability, ease of manufacturing, and compatibility with various turbocharger models.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A bearing structure for a turbocharger, comprising:

[0009] spindle;

[0010] At least two ball bearings are fixed to the spindle;

[0011] Spacer rings, wherein the spacer rings are disposed between or outside the ball bearings;

[0012] Bearing housing for accommodating the ball bearing, spacer ring, and spacer element;

[0013] And the supply and return channels for lubricating oil and cooling oil;

[0014] It also includes a spacer, which is located outside the ball bearing and / or spacer ring and is installed inside the bearing housing;

[0015] The spacer ring includes an inner spacer ring and an outer spacer ring. The inner spacer ring is disposed between the two inner rings of the two ball bearings, and the outer spacer ring is located between the two outer rings of the ball bearings.

[0016] As a further improvement to the above technical solution:

[0017] The spacer is provided with an oil inlet for supplying lubricating oil, which is aligned with the oil inlet of the ball bearing.

[0018] The spacer is provided with a cooling oil inlet hole for supplying cooling oil, which is aligned with the outer side of the ball bearing or the area between two ball bearings.

[0019] An oil return hole is provided below the spacer, and the oil return hole is located on the outer ring of the two ball bearings offset from each other.

[0020] The outer wall of the spacer is provided with a groove, and an elastic element is embedded in the groove. The elastic element is used to adjust the stiffness between the spacer and the bearing seat.

[0021] The spacer consists of two independent parts, each corresponding to a different ball bearing, and a spring is provided between the two spacers to provide preload for their relative positions.

[0022] The spacer and the outer spacer ring are fixed at an angle by a pin.

[0023] The bearing housing has cover plates on both sides, which are used to fix the outer ring of the ball bearing and / or the spacer.

[0024] The inner spacer ring and / or outer spacer ring are designed with a thin-walled structure in the part close to the bearing, while the part away from the bearing is thickened.

[0025] Compared with the prior art, the beneficial effects of this utility model are:

[0026] 1. Reduce transmission losses: Replacing floating ring bearings with ball bearings greatly reduces transmission resistance and improves the performance and efficiency of the turbocharger.

[0027] 2. Reduced costs: By using ball bearings with conventional structures and employing easily machinable spacer rings, spacers, and other matching parts, the overall manufacturing cost of the bearing system is significantly reduced.

[0028] 3. Adjustable rotor dynamic characteristics: By adjusting the elastic element, the stiffness of the bearing system can be controlled to meet the rotor dynamic requirements under different working conditions. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model.

[0030] Figure 2 This is a structural schematic diagram of Embodiment 2 of the present invention.

[0031] Figure 3 This is a structural schematic diagram of Embodiment 3 of the present invention.

[0032] Figure 4 The diagrams are schematic diagrams of embodiments 1 and 3 of this utility model.

[0033] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0034] Figure 6 This is a schematic diagram of a partial structure.

[0035] In the diagram: 1. Bearing; 2. Bearing; 3. Spindle; 4. Inner spacer ring; 5. Outer spacer ring; 6. Lubricating oil inlet; 7. Cooling oil inlet; 8. Oil return hole; 9. Spacer; 91. Spacer; 92. Spacer; 10. Spring; 11. Bearing housing; 12. Pin. Detailed Implementation

[0036] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention. Example

[0037] This embodiment provides a bearing structure for a turbocharger, the core of which is a conventional ball bearing, and through reasonable structural design and oil circuit configuration, high performance and low cost are achieved.

[0038] like Figure 1 ,4 As shown, the bearing structure includes:

[0039] The main shaft 3 (not fully shown in the figure) is connected to impellers (not fully shown in the figure) at both ends.

[0040] Two conventional ball bearings, denoted as bearing 1 and bearing 2, are mounted on the shaft.

[0041] An inner spacer ring 4 is provided between bearing 1 and bearing 2 to ensure the distance between the inner rings of the two bearings.

[0042] An outer spacer 5 is provided outside bearings 1 and 2 and the inner spacer 4. The outer spacer 5 ensures the distance between the outer rings of the two bearings.

[0043] A spacer is provided outside the outer spacer ring 5 and the ball bearing, and the spacer is installed in the bearing housing 11.

[0044] The bearing housing 11 (not fully shown in the figure) is used to house the above-mentioned components and is connected to the turbocharger body.

[0045] In this structure, a rotor auxiliary component 1, a bearing 1, an inner spacer ring 4, a bearing 2, and a rotor auxiliary component 2 are provided between the two impellers of the main shaft 3. It should be emphasized that bearings 1 and 2 are conventional bearings, not the complex custom bearings mentioned in the background section, and their cost is far lower than that of custom bearings. The inner rings of bearings 1 and 2 are fixed to the main shaft 3, while the outer rings are fixed to or positioned by spacers or similar components.

[0046] Oil circuit design:

[0047] Two lubricating oil inlets 6 are provided above the spacer, which are aligned with the oil inlets of bearing 1 and bearing 2, respectively. In addition, three cooling oil inlets 7 are provided, which are aligned with the outer side of bearing 1, the outer side of bearing 2, and between the two bearings (located on the outer side of the inner spacer ring 4).

[0048] Detailed description:

[0049] If the oil inlet of the ball bearing has an annular groove, the oil inlet 6 on the spacer only needs to be aligned with this annular groove. If the oil inlet on the bearing does not have an annular groove, then the corresponding position of the oil inlet 6 on the inner wall of the spacer must have an annular groove to ensure that the lubricating oil can effectively enter the bearing. In the figure of this embodiment, the bearing has an annular groove, and an annular groove is also added to the inner wall of the spacer to provide a more flexible fit.

[0050] Three oil return holes 8 are provided below the spacer, respectively aligned with the outer side of bearing 1, the outer side of bearing 2, and between the two bearings (located on the outer side of the inner spacer ring 4), offset from the outer rings of the two ball bearings. Because the oil inlet hole of the bearing outer ring does not have an annular groove, an annular groove must be made on the spacer to ensure that oil can enter. This annular groove is connected to the oil inlet hole of the bearing outer ring, but the oil return path does not interfere with (is connected to) this annular groove.

[0051] An oil inlet hole is provided above the outer spacer ring 5, which is aligned with the oil inlet hole on the spacer located between the two bearings (here, the cooling oil inlet hole 7). An oil return hole 8 is provided below the outer spacer ring 5, which is aligned with the oil return hole 8 on the spacer located between the two bearings (here, the cooling oil return hole 8).

[0052] The bearing housing 11 is provided with oil inlet and return holes 8 corresponding to the spacer element, as well as oil inlet and return holes 8 corresponding to the outer spacer ring 5. In locations away from the bearing system, the oil passages on the bearing housing 11 can be appropriately combined; for example, two lubricating oil inlets 6 can be merged into one, so that only one interface is needed when connecting the oil pump. Similarly, multiple cooling oil inlets 7 and return holes 8 can also be combined in locations away from the bearing system. Example

[0053] This embodiment is a further improvement on embodiment 1, mainly addressing the situation where the change in the diameter of spindle 3 necessitates the use of different types of bearings.

[0054] like Figure 2 , 5 As shown, the main difference between this embodiment and Embodiment 1 is:

[0055] Due to the change in the diameter of spindle 3, different types of ball bearings are required, resulting in different outer diameters for bearings 1 and 2. To accommodate this difference in outer diameter, the spacer needs adjustment. Considering the difficulty of machining the stepped inner hole, this embodiment divides the spacer into two independent parts (spacer 91 and spacer 92), corresponding to bearings 1 and 2 respectively. To ensure the relative position between the two spacers, a spring 10 can be placed between them to provide thrust preload.

[0056] Furthermore, the axial dimension of this embodiment is larger than that of Embodiment 1, thus more cooling oil passages are provided between the two bearings.

[0057] The specific structure is as follows:

[0058] The spindle 3 is equipped with bearings 1 and 2, which have different outer diameters.

[0059] An outer spacer ring 5 is provided between bearing 1 and bearing 2.

[0060] A spacer 91 is provided on the outside of the bearing 1 and is installed in the bearing housing 11.

[0061] A spacer 92 is provided on the outside of the bearing 2 and is installed in the bearing housing 11.

[0062] Spacer 1 and spacer 2 are connected by spring 10, which is installed on the outside of outer spacer ring 5 and provides thrust preload to the spacer.

[0063] Oil circuit design:

[0064] There is a lubricating oil inlet 6 above the spacer 1, aligned with the oil inlet of the bearing 1. In addition, there are two cooling oil inlets 7, aligned with the left and right sides of the bearing 1 respectively.

[0065] There is a lubricating oil inlet 6 above the spacer 2, aligned with the oil inlet of the bearing 2. In addition, there are two cooling oil inlets 7, aligned with the left and right sides of the bearing 2 respectively.

[0066] Detailed description:

[0067] Similarly, if there is an annular groove at the bearing oil inlet, the oil inlet of the spacer only needs to be aligned; otherwise, the inner wall of the spacer needs to have an annular groove.

[0068] There are two oil return holes 8 below the spacer 1, which are aligned with the left and right sides of the bearing 1, respectively.

[0069] There are two oil return holes 8 below the spacer 2, which are aligned with the left and right sides of the bearing 2, respectively.

[0070] An oil inlet is provided above the outer spacer ring 5, which is aligned with the (middle) oil inlet located between the two spacers. Three oil return holes 8 are provided below the outer spacer ring 5, with the middle oil return hole 8 aligned with the oil inlet of the outer spacer ring 5, and the two oil return holes 8 on both sides close to the bearing 1 and the bearing 2.

[0071] The bearing housing 11 is provided with oil inlet holes and oil return holes 8 corresponding to spacers 1, 2 and the outer spacer ring 5. Similarly, these oil passages can be combined at a location far from the bearing system. Example

[0072] This embodiment is another improvement on embodiment 1, mainly reflected in the structural design of bearing housing 11 and the optimization of the angle positioning method.

[0073] like Figure 3 , 4As shown, compared to Embodiment 1, the left cover plate is integrated into the bearing housing 11 in this embodiment. This means that the angular positioning of the left spacer (if present) can only be performed on the right side. If the spacer is split into two as in Embodiment 2, the angular positioning of the left spacer will become difficult, possibly requiring the machining of a difficult-to-machine groove on the bearing housing 11, and the space between the left end face of the spacer and the groove of the elastic element is very small, making it difficult to arrange the positioning groove.

[0074] The specific structure is as follows:

[0075] Two conventional ball bearings, denoted as bearing 1 and bearing 2, are installed on the spindle 3.

[0076] An inner spacer ring 4 is provided between bearing 1 and bearing 2.

[0077] An outer spacer 5 is provided outside the bearing 1, the inner spacer 4, and the bearing 2.

[0078] A spacer is provided outside the outer spacer ring 5 and the ball bearing, and the spacer is installed in the bearing housing 11.

[0079] Oil circuit design:

[0080] Two lubricating oil inlets 6 are provided above the spacer, aligned with the oil inlets of the bearings. In addition, two cooling oil inlets 7 are provided, aligned with the right side of bearing 2 and between the two bearings, respectively.

[0081] Detailed description:

[0082] Similarly, the fit of the annular groove will be explained.

[0083] Two oil return holes 8 are provided below the spacer, which are respectively aligned with the right side of bearing 2 and between the two bearings.

[0084] An oil inlet hole is provided above the outer spacer ring 5, which is aligned with the oil inlet hole on the spacer located between the two bearings. An oil return hole 8 is provided below the outer spacer ring 5, which is aligned with the oil return hole 8 on the spacer located between the two bearings.

[0085] The bearing housing 11 is provided with an oil inlet and an oil return hole 8 corresponding to the spacer. On the left side of the bearing housing 11, a step is provided, which abuts against the left side of the bearing 1 and the left side of the spacer. The oil inlet and oil return hole 8 are located on the left side of the step (i.e., outside the bearing housing 11). The oil passages on the bearing housing 11 can also be merged at a location away from the bearing system.

[0086] Angle positioning:

[0087] As mentioned above, since the left cover plate is integrated into the bearing housing 11, it may be difficult to position the angle of the left side of the spacer.

[0088] Various possible improvements

[0089] The following are some further improvements and technical features based on the above embodiments, which can be used alone or in combination to enhance the technical effect and protection scope of this application.

[0090] 1. Improved angle positioning:

[0091] like Figure 6 As shown, to ensure that the angular position between the outer spacer ring 5 and the spacer 9 does not rotate excessively, causing the oil inlet and return holes 8 to misalign, a hole can be made on the side of the outer spacer ring 5, and another hole can be made on the side of the spacer 9. A pin 12 is installed in the hole on the side of the spacer 9. The pin 12 is inserted into the hole on the side of the outer spacer ring 5, but does not protrude from the inner wall of the outer spacer ring 5. The hole on the outer spacer ring 5 is larger than the hole on the spacer 9 to ensure that no additional load is generated between the two parts by the pin 12. The pin 12 can be a regular cylindrical pin or a flexible cylindrical pin.

[0092] 2. Another method for angular positioning of spacers:

[0093] At one end of the spacer (e.g.) Figure 5 As shown, notches are set at corresponding positions on the bearing housing 11. A component, such as a flexible cylindrical pin, is embedded in these notches to ensure that the oil inlet and oil return holes 8 are not misaligned due to excessive angular misalignment between the spacer and the bearing housing 11.

[0094] If two notches are provided at one end of the spacer, and these two notches are distributed at 180°, then when it is necessary to adjust the angle of the spacer, a specific wrench can be used to rotate the spacer with the help of these two notches. In this case, only one notch is needed on the bearing housing 11 for positioning.

[0095] 3. Improvements in the machining of inner spacer ring 4 and outer spacer ring 5:

[0096] Due to bearing installation size limitations, the thickness of the portion of the inner spacer that contacts the bearing cannot be too large. If the inner spacer is designed with this thickness along its entire length, it will become a thin-walled component, making machining difficult. Instead, the portion of the inner spacer that contacts the bearing can be designed as thin-walled according to the bearing installation size requirements, while the portion of the inner spacer further away from the bearing is thicker. In this way, the inner spacer is no longer a thin-walled component overall; only a small portion near the bearing is thin, significantly reducing machining difficulty.

[0097] The outer spacer 5 is treated similarly to the inner spacer: the part of the outer spacer 5 that contacts the bearing is designed to be thin-walled according to the bearing installation dimensions, while the part of the outer spacer 5 that is away from the bearing is thickened, which greatly reduces the processing difficulty.

[0098] In this application, a relatively large amount of oil is required for cooling, but a very small amount is required for lubrication. Therefore, the oil paths for lubrication and cooling are separated. The lubricating oil enters through a small hole in the outer ring of the bearing, and the amount is very small. The cooling oil enters by bypassing the outer ring of the bearing, flowing along the side of the bearing. In this way, the heat generated by bearing friction is conducted to the periphery and ultimately carried away by the cooling oil. This means that the cooling oil path cannot enter the bearing itself, but it also cannot be too far away. The return oil for both lubrication and cooling can share a single oil path.

[0099] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A bearing structure for a turbocharger, comprising: spindle; At least two ball bearings are fixed to the spindle; Spacer rings, wherein the spacer rings are disposed between or outside the ball bearings; Bearing housing for accommodating the ball bearing, spacer ring, and spacer element; And the supply and return channels for lubricating oil and cooling oil; The feature is that the spacer is located outside the ball bearing and / or spacer ring, and is installed inside the bearing housing; The spacer ring includes an inner spacer ring and an outer spacer ring. The inner spacer ring is disposed between the two inner rings of the two ball bearings, and the outer spacer ring is located between the two outer rings of the ball bearings.

2. The bearing structure according to claim 1, characterized in that: The spacer is provided with an oil inlet for supplying lubricating oil, which is aligned with the oil inlet of the ball bearing.

3. The bearing structure according to claim 2, characterized in that, The spacer is provided with a cooling oil inlet hole for supplying cooling oil, which is aligned with the outer side of the ball bearing or the area between two ball bearings.

4. The bearing structure according to claim 3, characterized in that, An oil return hole is provided below the spacer, and the oil return hole is located on the outer ring of the two ball bearings offset from each other.

5. The bearing structure according to claim 1, characterized in that, The outer wall of the spacer is provided with a groove, and an elastic element is embedded in the groove. The elastic element is used to adjust the stiffness between the spacer and the bearing seat.

6. The bearing structure according to claim 1, characterized in that, The spacer consists of two independent parts, each corresponding to a different ball bearing, and a spring is provided between the two spacers to provide preload for their relative positions.

7. The bearing structure according to claim 1, characterized in that, The spacer and the outer spacer ring are fixed at an angle by a pin.

8. The bearing structure according to claim 1, characterized in that, The bearing housing has cover plates on both sides, which are used to fix the outer ring of the ball bearing and / or the spacer.

9. The bearing structure according to claim 1, characterized in that, The inner spacer ring and / or outer spacer ring are designed with a thin-walled structure in the part close to the bearing, while the part away from the bearing is thickened.

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