DE102024126233B3 - Turbocharger for a motor vehicle with mechanical decoupling - Google Patents

Abstract

The invention relates to a turbocharger for a motor vehicle with mechanical decoupling, comprising a bearing bush, wherein the bearing bush defines a receiving space with an inner wall. The turbocharger comprises a bearing, wherein the bearing is arranged in the receiving space. The turbocharger comprises a damper element, wherein the damper element is arranged between the inner wall of the bearing bush and the bearing for supporting the bearing on the inner wall of the bearing bush in the receiving space, wherein the damper element comprises a wire mesh or is formed by a wire mesh.

Description

The present invention relates to a turbocharger for a motor vehicle with mechanical decoupling.

The challenge with existing turbocharger technology lies in managing the vibrations generated by turbocharger operation. These vibrations can negatively impact turbocharger bearings, causing not only noise but also increased wear and reduced bearing life. Traditional solutions have proven to be either too cumbersome or technically insufficient to effectively dampen the complex vibration patterns generated during turbocharger operation.

Advances in turbocharger technology play a crucial role in the ride quality of vehicles. The reduction of vibration-induced stress through innovative bearing decoupling not only contributes to the longevity of the turbocharger, but also has a direct impact on vehicle acoustics and engine vibration behavior. Low-vibration operating conditions ensure harmonious power delivery and reduce disruptive noise in the passenger compartment, which significantly contributes to the overall perception of ride comfort and luxury.

The EP 3 990 787 B1 discloses a compressor for a building air conditioning system. A compressor shaft is supported by a foil bearing that includes a wire mesh damper.

The DE 10 2020 134 311 A1 discloses a turbocharger whose rolling bearing is damped and supported in the axial direction by a wire mesh ring.

The EP 3 990 787 B1 reveals a compressor with a low-backlash angular contact ball bearing.

The DE 10 2020 134 311 A1 reveals a turbocharger with axial damper and displacement limitation.

The DE 10 2016 212 552 A1 discloses an electric motor driven air wheel compressor with vibration dampened and compact bearings.

The DE 10 2014 200 743 A1 discloses an exhaust gas turbocharger with damping rings made of metal mesh.

The US 2015/0267740 A1 discloses a turbocharger with a journal bearing designed as a semi-floating ring with hydrodynamic fluid film solid joint tilting pads and compliant dampers.

The present patent application aims to improve both the concept and the practical implementation of this innovative vibration protection mechanism for turbocharger bearings compared to the state of the art and thus to lay the foundation for further developments in this technologically highly relevant field.

For this purpose, the invention provides a turbocharger for a motor vehicle with mechanical decoupling according to claim 1. Advantageous embodiments can be found in the subclaims and the description.

The invention relates to a turbocharger for a motor vehicle with mechanical decoupling, comprising a bearing bush, wherein the bearing bush defines a receiving space with an inner wall, a bearing of the turbocharger, wherein the bearing is arranged in the receiving space, a damper element of the turbocharger, wherein the damper element is arranged between the inner wall of the bearing bush and the bearing for supporting the bearing on the inner wall of the bearing bush in the receiving space, wherein the damper element comprises a wire mesh or is formed by a wire mesh.

The receiving space can be radially defined by the inner wall. The receiving space has a cylindrical volume, particularly a round one. The cross-section through the receiving space can be round.

In an advantageous development, the receiving space, viewed from the front, i.e. in plan view, comprises a rear wall with a passage for a shaft. The receiving space comprises a first end region and a second end region, wherein the first end region is arranged opposite the second end region. The second end region comprises the rear wall with the passage for the shaft. The first end region comprises an opening through which the receiving space is accessible. The damper element can be inserted into the receiving space via the opening. Holding means for fastening the damper element or for closing the opening and thus the receiving space can be arranged at the first end region.

In an advantageous development, the bearing is designed as a ball bearing, rolling bearing, angular contact ball bearing, or needle bearing. In a further advantageous development, the angular contact ball bearing can be preloaded.

Angular contact ball bearings are special types of roller or ball bearings that can accommodate axial and radial loads in a specific direction. They are designed so that the raceways in the inner and outer rings are arranged at a specific angle to each other, giving them the ability to accommodate both radial loads and axial loads acting in one direction.

The inclination of the raceways allows an axial load component to be created and absorbed when the angular contact ball bearing is subjected to radial loads. This can be used in some applications to compensate for axial forces or to create a preload in the angular contact ball bearing arrangement to improve clearance and thus the accuracy and stability of the bearing arrangement.

Angular contact ball bearings require preloading for various technical reasons to ensure optimal performance. Preloading is a method by which a constant load can be applied to the angular contact ball bearing before it is subjected to operating load. This can be particularly important, especially in precision applications such as those found in the automotive industry.

Firstly, the preload prevents excessive play from occurring in the angular contact ball bearing. Play, i.e., the free movement between the bearing components of the angular contact ball bearing, can lead to unwanted vibrations, noise, and imprecise running. Low-play bearing behavior of the angular contact ball bearing is essential, especially in applications where high precision is required.

Secondly, the preload of the angular contact ball bearing increases the rigidity of the entire bearing system. A stiffer angular contact ball bearing can accommodate higher loads, reacts less to external forces, and exhibits more stable behavior. This is particularly important in applications where the angular contact ball bearing is subjected to high loads or shock forces.

Through the targeted preload of the angular contact ball bearing, the balls within the angular contact ball bearing are pressed more evenly between the raceways of the inner and outer rings of the angular contact ball bearing, which optimizes load distribution and thus ensures more even wear. This can extend the service life of the angular contact ball bearing.

Furthermore, the preload helps minimize the formation of micromovements between the rolling elements and the raceways. These micromovements can lead to accelerated fatigue and thus premature failure of angular contact ball bearings exposed to high speeds.

The wire mesh can be designed as a ring-shaped wire mesh. The production of a ring-shaped wire mesh may require the use of special industrial machines designed for wire knitting.

In a first step, the wire material is selected that meets the strength, flexibility, and corrosion resistance requirements for its intended use. The wire can then be unwound from a spool and fed into the knitting machine. The machine can knit in a continuous, circular motion to produce a long, tubular wire mesh. This mesh is then cut and formed into rings, with the ends joined to form a closed circle by welding, soldering, or another joining technique. Finally, the ring-shaped wire mesh can undergo various post-treatments to achieve the desired material properties.

In a further advantageous development, a radially extending oil inlet channel is provided in the inner wall of the receiving space, wherein the oil inlet channel can be fully or at least partially open in the direction of the damper element in order to supply the damper element and/or the bearing with oil. Radial means that, looking into the receiving space, the oil inlet channel extends in the inner wall of the receiving space and fully or at least partially around the receiving space. The oil inlet channel can extend radially in and around the inner wall at an angle of up to 90 degrees, up to 180 degrees, up to 270 degrees, or up to 360 degrees.

In an advantageous further development, the angular contact ball bearing can be preloaded by oil pressure. The oil pressure can be supplied via the oil inlet channel. This method can also be referred to as hydraulic or hydrodynamic preload. It can utilize the force of pressurized oil to exert a uniform and adjustable preload on the angular contact ball bearing. The advantage of this technology lies in its flexibility and precision, as it allows a preload force to be applied to the angular contact ball bearing. to be controlled dynamically and precisely, which can be advantageous when operating conditions change.

For example, if the angular contact ball bearing heats up due to frictional heat during operation, the preload can be adjusted to ensure consistently high accuracy and bearing performance. In addition, the hydraulic preload of the angular contact ball bearing via oil pressure offers the advantage of effective heat dissipation. The oil itself can act as a cooling medium for the angular contact ball bearing. The angular contact ball bearing can be preloaded even when the engine is not running, particularly during the start-up process. In particular, the angular contact ball bearing can be preloaded during a cold start of the vehicle. This can prevent high bearing stress or bearing damage due to insufficient lubrication in the first one to two seconds of the start-up process. This can be particularly important for cold starts in cold conditions when the oil is still viscous.

The damper element can be formed in one piece or in multiple pieces. The damper element can be cylindrical. The cylinder can comprise a first end region and a second end region. The first end region is opposite the second end region.

In a further development according to the invention, the damper element comprises an outer encapsulation and an inner encapsulation, wherein the wire mesh is arranged between the outer encapsulation and the inner encapsulation.

In an advantageous development, the outer encapsulation comprises spaced-apart oil inlet holes around its circumference, and the inner encapsulation comprises spaced-apart oil outlet holes around its circumference. The oil inlet holes are arranged axially centrally in the outer encapsulation, i.e., between the first end region and the second end region. The oil outlet holes are arranged axially at the edge of the inner encapsulation. In this case, a first row of oil outlet holes can be arranged closer to the first end region than to the second end region, and/or a second row of oil outlet holes can be arranged closer to the second end region than to the first end region.

The oil inlet holes penetrate the outer encapsulation radially. The oil outlet holes penetrate the inner encapsulation radially. The oil outlet holes and/or the oil inlet holes can be formed as bores or elongated holes in the outer encapsulation of the damper element and/or in the inner encapsulation of the damper element.

The bearing can include two lubrication grooves running radially around the bearing, through which oil can be channeled around the bearing. The oil drain holes of the damper element can overlap with the two lubrication grooves running around the bearing. This allows the lubrication grooves to be supplied with oil via the damper element. The ball bearing can include additional bores to supply the ball bearing with oil. Alternatively or additionally, the oil can enter the ball bearing via lateral bearing caps on the ball bearing.

This allows the bearing to be lubricated and pressurized with oil, thus preloading it. The oil from the damper element's oil drain holes can be drained through an oil drain channel in the turbocharger's bearing bushing after supplying the bearing with oil. This allows oil to flow through the bearing bushing's receiving chamber. The oil flow through the receiving chamber can be between 0.5 and 2 liters per minute.

In a further advantageous development, the oil inlet holes are completely or at least partially covered by the radially extending oil inlet channel. In other words, the oil inlet channel lies completely or partially over the oil inlet holes. This means that oil can be supplied to the oil inlet holes of the damper element via the radially extending oil inlet channel. This allows oil to be forced through the damper element via the oil inlet channel. The wire mesh can be designed as a filter for filtering the oil.

This allows the damper element to achieve a sufficient, particularly constant, oil flow to supply the bearing with oil.

In a further development according to the invention, the outer encapsulation and the inner encapsulation are fluidically sealed from one another. The sealing can be achieved by means of at least two O-rings between the inner encapsulation and the outer encapsulation with respect to an external space. External space means with respect to the environment. Fluidically sealed means sealed against the escape of oil into the external space. Oil creeping may still be possible and is considered to be sealed. A gap can remain between the outer encapsulation and the inner encapsulation, which gap can be closed by the at least two O-rings. The first O-ring can be located at the first end region between the outer encapsulation and the inner encapsulation and The second O-ring can be located at the second end area between the outer encapsulation and the inner encapsulation. The gap can mechanically decouple the outer encapsulation of the damper element from the inner encapsulation of the damper element, since there is no direct contact between the outer encapsulation and the inner encapsulation. The outer encapsulation is thus supported relative to the inner encapsulation via the at least two O-rings and the wire mesh.

In an advantageous further development, the wire mesh comprises steel wire or consists of steel wire.

In a further advantageous development, the bearing is axially supported in the receiving space via a spring assembly. The receiving space can be closed by a cover cap. The spring assembly can be arranged on the side of the receiving space adjacent to the cover cap, i.e., on the rear wall. The spring assembly can be circular with a free inner diameter. The free inner diameter can be used for the passage of a shaft through the spring assembly.

In an advantageous embodiment, the wire mesh has a mesh size of 10µm to 100µm. The filtering effect of the wire mesh can be varied by adjusting the mesh size.

• 1 einen Turbolader für ein Kraftfahrzeug mit mechanischer Entkoppelung; und
• 2 ein Dämpferelement für einen Turbolader für ein Kraftfahrzeug mit mechanischer Entkoppelung; und
• 3 einen Turbolader für ein Kraftfahrzeug mit mechanischer Entkoppelung.

The invention is described below purely by way of example with reference to the drawings. In the drawings:

• 1 a turbocharger for a motor vehicle with mechanical decoupling; and
• 2 a damper element for a turbocharger for a motor vehicle with mechanical decoupling; and
• 3 a turbocharger for a motor vehicle with mechanical decoupling.

1 shows a turbocharger 100 for a motor vehicle with mechanical decoupling. The turbocharger 100 comprises a bearing bush 110, wherein the bearing bush 110 defines a receiving space 112 with an inner wall 111. A bearing 120 of the turbocharger 100, wherein the bearing 120 is arranged in the receiving space 112. A damper element 130 of the turbocharger 100, wherein the damper element 130 is arranged between the inner wall 111 of the bearing bush 110 and the bearing 120 for supporting the bearing 120 on the inner wall 111 of the bearing bush 110 in the receiving space 112. The damper element 130 comprises a wire mesh 131 or is formed by a wire mesh 131. A spring assembly 140 is additionally arranged in the bearing bush, whereby the bearing 120 is preloaded. The oil is guided into and out of the damper element 130 via an oil inlet channel 113 and an oil outlet channel 114.

In addition to the oil inlet channel 113, the bearing bush includes an oil outlet channel 114 through which oil can be drained. The bearing 120 includes two lubrication grooves 121 extending radially around the bearing 120, through which oil can be guided around the bearing 120. The bearing 120 can thus be supplied with oil.

The damper element 130 comprises an outer encapsulation 132 and an inner encapsulation 133, with a wire mesh 131 arranged between the outer encapsulation 132 and the inner encapsulation 133. The outer encapsulation 132 comprises spaced-apart oil inlet holes 134 on its circumference, and the inner encapsulation 133 comprises spaced-apart oil outlet holes 135 on its circumference, with the oil inlet holes 134 being arranged axially centrally in the outer encapsulation 132 and the oil outlet holes 135 being arranged axially at the edge of the inner encapsulation 133.

The outer encapsulation 132 and the inner encapsulation 133 are fluidically sealed from each other. The seal is provided by at least two O-rings 136 between the inner encapsulation 133 and the outer encapsulation 132 relative to the outside space.

2 shows a damper element 130. The damper element 130 comprises an outer encapsulation 132 and an inner encapsulation 133, wherein a wire mesh 131 is arranged between the outer encapsulation 132 and the inner encapsulation 133. The outer encapsulation 132 comprises oil inlet holes 134 spaced apart from one another on its circumference, and the inner encapsulation 133 comprises oil outlet holes 135 spaced apart from one another on its circumference, wherein the oil inlet holes 134 are arranged axially centrally in the outer encapsulation 132 and wherein the oil outlet holes 135 are arranged axially at the edge of the inner encapsulation 133.

The outer encapsulation 132 and the inner encapsulation 133 are fluidically sealed from each other. The seal is provided by at least two O-rings 136 between the inner encapsulation 133 and the outer encapsulation 132 relative to the outside space.

A gap may remain between the outer encapsulation 132 and the inner encapsulation 133, but this gap is closed by at least two O-rings 136. The gap decouples the outer encapsulation 132 from the inner encapsulation. 133 mechanically, since there is no direct contact between the outer encapsulation 132 and the inner encapsulation 133.

3 shows a turbocharger 100 for a motor vehicle with mechanical decoupling. The turbocharger 100 comprises two damper elements 130 which are inserted into two bearing bushings 110 of the turbocharger 100.

The invention is not limited to the described embodiments. Within the scope of the invention, all described and/or illustrated features can be combined with one another in any way, unless otherwise stated.

Reference symbol

100

Turbocharger

110

bearing bush

111

inner wall

112

recording room

113

Oil inlet channel

114

Oil drain channel

120

warehouse

121

Lubrication groove

130

Damper element

131

Wire mesh

132

External encapsulation

133

Internal encapsulation

134

Oil inlet holes

135

Oil drain holes

136

O-ring

140

spring package

Claims (8)

Turbocharger (100) for a motor vehicle with mechanical decoupling, comprising a bearing bush (110), wherein the bearing bush (110) defines a receiving space (112) with an inner wall (111), a bearing (120) of the turbocharger (100), wherein the bearing (120) is arranged in the receiving space (112), a damper element (130) of the turbocharger (100), wherein the damper element (130) is arranged between the inner wall (111) of the bearing bush (110) and the bearing (120) for supporting the bearing (120) on the inner wall (111) of the bearing bush (110) in the receiving space (112), wherein the damper element (130) comprises a wire mesh (131) or is formed by a wire mesh (131), characterized in that the damper element (130) has an outer encapsulation (132) and an inner encapsulation (133), wherein the wire mesh (131) is arranged between the outer encapsulation (132) and the inner encapsulation (133), wherein the outer encapsulation (132) and the inner encapsulation (133) are fluidically sealed against one another. Turbocharger (100) for a motor vehicle with mechanical decoupling according to Claim 1 , characterized in that the bearing (120) is designed as a ball bearing, rolling bearing, angular contact ball bearing or needle bearing. Turbocharger (100) for a motor vehicle with mechanical decoupling according to one of the preceding claims, characterized in that a radially extending oil channel (113) is provided in the inner wall (111) of the receiving space (112), wherein the oil channel (113) is at least partially open in the direction of the damper element (130) in order to thereby supply the damper element (130) and/or the bearing (120) with oil. Turbocharger (100) for a motor vehicle with mechanical decoupling according to one of the preceding claims, characterized in that the outer encapsulation (132) comprises oil inlet holes (134) spaced apart from one another on its circumference and the inner encapsulation (133) comprises oil outlet holes (135) spaced apart from one another on its circumference, wherein the oil inlet holes (134) are arranged axially centrally in the outer encapsulation (132) and wherein the oil outlet holes (135) are arranged axially at the edge of the inner encapsulation (133). Turbocharger (100) for a motor vehicle with mechanical decoupling according to Claim 4 , characterized in that the oil inlet holes (134) are completely or at least partially covered by the radially extending oil channel (113). Turbocharger (100) for a motor vehicle with mechanical decoupling according to one of the preceding claims, characterized in that the wire mesh (131) comprises or consists of steel wire. Turbocharger (100) for a motor vehicle with mechanical decoupling according to one of the preceding claims, characterized in that the bearing (120) is axially mounted in the receiving space (112) via a spring assembly (140). Turbocharger (100) for a motor vehicle with mechanical decoupling according to one of the preceding claims, characterized in that the wire mesh (131) has a mesh size of 10µm to 100µm.

Images