Throttle device with additional shaft bearing seals

Abstract

Throttle device (1) for regulating a fluid flow, comprising the throttle device (1) a throttle shaft (3); a housing (5); a fluid channel (7); a shaft bearing (9) for supporting the throttle shaft (3) on the housing (5); characterized in that an elastic seal (11) is integrated between the fluid channel (7) and the shaft bearing (9); wherein the elastic seal (11) is designed to seal the shaft bearing (9) fluid-tight against the fluid channel (7) wherein the throttle device (1) further comprises: a protective ring (15); wherein the protective ring (15) is arranged between the elastic seal (11) and the shaft bearing (9); wherein the protective ring (15) is positively connected to the throttle shaft (3), wherein the protective ring (15) is made of a thermoplastic; wherein the protective ring (15) exhibits high resistance to fuel.

Description

State of the art

[0001] Throttle devices can include a throttle valve and a corresponding mechanism for adjusting the throttle valve's opening angle. When a throttle device is installed, for example, in an intake manifold, the amount of fluid flowing through the intake manifold can be regulated.

[0002] Particularly in the automotive industry, throttle devices can be installed in an air duct leading to an internal combustion engine. By changing the opening angle of the throttle valve, the flow cross-section and thus the amount of air supplied to the internal combustion engine can be regulated.

[0003] The opening angle of the throttle valve can be adjusted, for example, by means of an electric motor via a gearbox and a throttle shaft. The throttle shaft can be mounted on a housing of the throttle device. Such shafts are known, for example, from DE 199 09 922 A1 and DE 297 09 248 U1. Throttle devices are also known, for example, from DE 101 38 931 A1 and DE 10 2010 028 982 A1.

[0004] A gap between the throttle shaft and the housing allows fluids, such as condensed water or fuel, to enter the housing and damage the gearbox and its associated electronics. Seals in the throttle shaft bearing are not sufficient to prevent these fluids from entering. Furthermore, relatively high pressures and vacuums can occur in the fluid channel, placing stress on the throttle device's bearings and gearbox.

[0005] A flow control valve is known from DE 10 2008 013 105 A1. A seal is arranged between a flow channel and a shaft bearing.

[0006] Another flow control valve is known from JP 2010 - 185 575 A. The valve is mounted in the flow channel.

[0007] Another flow control valve is known from US 3 096 070 A.

[0008] From DE 10 2006 053 716 A1 a rolling bearing unit and a gas control valve arrangement with a rolling bearing unit are known.

[0009] A throttling device is known from DE 10 2010 028 982 A1.

[0010] A shaft seal is known from DE 297 09 248 U1. Disclosure of the invention

[0011] Therefore, there may be a need for an improved throttle device, a motor vehicle with a corresponding throttle device, and a manufacturing process for a corresponding throttle device, which, with a mechanically stable design of the throttle device, make it possible to ensure protection against the effects of forces and against fluids penetrating the housing.

[0012] This need can be met by the subject matter of the present invention according to the independent claims. Advantageous embodiments of the present invention are described in the dependent claims.

[0013] The following section discusses in detail the features, details and possible advantages of a device according to embodiments of the invention.

[0014] According to the first aspect of the invention, a throttle device for regulating a fluid flow is presented. The throttle device comprises a throttle shaft, a housing, and a fluid channel. Furthermore, the throttle device includes a shaft bearing for supporting the throttle shaft on the housing. An elastic seal is integrated into the throttle shaft or the housing between the fluid channel and the shaft bearing. The elastic seal is designed to provide a fluid-tight seal between the shaft bearing and the fluid channel.

[0015] In other words, the idea of ​​the present invention is based on providing a seal against fluid media outside the shaft bearing, and in particular upstream of the shaft bearing with respect to the fluid channel. In this way, the shaft bearing can be protected from pressure pulses, i.e., from high pressures and negative pressures. Thus, the shaft bearing and the gearbox located behind the shaft bearing in the housing are protected from unwanted force influences and from ingress of media, such as gases and, in particular, liquids. Since the elastic seal is located outside the shaft bearing and upstream of it with respect to the fluid channel, the dead volume between the throttle shaft and the housing, in which, for example, liquid could accumulate, is reduced.

[0016] A further advantage of the invention lies in the fact that decoupling the seal from the shaft bearing allows for a simpler design of the throttle device. Furthermore, by providing an elastic seal between the fluid channel and the shaft bearing, additional seals within the shaft bearing can be omitted. This avoids the need to shorten the shaft bearing, particularly the needle length of a needle bearing. Consequently, a reduction in the mechanical strength of the shaft bearing is also avoided.

[0017] Another advantage is that by arranging the seal in front of the shaft bearing or between the shaft bearing and the fluid channel, sufficient sealing is already ensured before the shaft bearing, so that cheaper and less resistant materials can be used in the shaft bearing.

[0018] The throttle device can be used, for example, in a motor vehicle. The fluid channel can be located on or within an intake manifold that supplies air to an internal combustion engine. The internal combustion engine can be a gasoline or diesel engine. Furthermore, a turbocharger can be fitted to the internal combustion engine.

[0019] The fluid channel can be the part of the throttle device that is positioned directly in an intake manifold and in which the throttle valve is located. In particular, the fluid channel 7 can represent the point in the throttle device where unwanted substances, such as condensed fuel, can enter the throttle device from the intake manifold.

[0020] By changing the opening angle of the throttle valve in the fluid channel, the flow cross-section in the intake manifold can be varied. In this way, the amount of air supplied to the combustion engine can be adjusted. For this purpose, the throttle device can be controlled, for example, by an electrically actuated control unit. An electric motor and a gearbox can be housed in a single unit, connected to the throttle valve by a throttle shaft. The throttle shaft is mounted on a shaft bearing in the housing. Condensation, such as water or fuel, can form in the intake manifold and thus also in the fluid channel within it. This condensate could penetrate from the fluid channel through a gap between the throttle shaft and the housing, reaching the shaft bearing and even the gearbox.Furthermore, relatively high pressures of up to 3.5 bar can occur in the fluid channel, especially if a turbocharger is installed, and negative pressures of up to 0.6 bar can occur in a gasoline engine. These lead to stress on the shaft bearing.

[0021] The throttle device according to the invention has an elastic seal integrated into the throttle shaft, which exerts a radial pressure force against the housing. Alternatively, the elastic seal can be integrated into the housing and exert a radial pressure force on the shaft. In particular, the elastic seal can be designed as a pressure-supported seal. In this way, the space between the throttle shaft and the housing is radially sealed against fluid flow upstream of the shaft bearing. Furthermore, the material of the elastic seal can absorb and dampen pressure pulses from the fluid channel.

[0022] The elastic seal is preferably integrated into the throttle shaft. This means that the throttle shaft at least partially accommodates the elastic seal. For example, a groove can be provided in the throttle shaft in which the elastic seal is positioned. Alternatively, the elastic seal can be integrated into a groove in the housing.

[0023] The elastic seal can, for example, be made of an elastic material and be dimensioned to fill the gap between the throttle shaft and the housing. The elastic seal can be, for instance, a closed, circumferential seal with a C-shaped cross-section. The material of the elastic seal can be selected to be resistant to corrosion and aggressive media such as fuel.

[0024] According to a further embodiment of the invention, the elastic seal is designed as a pressure-supported seal. The throttle shaft has a circumferential groove between the fluid channel and the shaft bearing. The elastic seal is arranged in this circumferential groove. The pressure-supported seal can be designed to convert or redirect a force acting on it in a first direction into a force acting in a second direction. This second direction can be approximately perpendicular to the first. For example, if a force acts on the pressure-supported seal parallel to the throttle shaft, the seal is pressed against the housing in a radial direction relative to the throttle shaft.

[0025] According to a further embodiment of the invention, the elastic seal is designed as a closed sealing ring. For example, the seal can be designed as a pressure-supported O-ring.

[0026] According to a further embodiment of the invention, the elastic seal comprises an elastomer. This elastic seal exhibits high resistance to fuel. In particular, the elastic seal can be especially resistant to gasoline and / or diesel. The elastomer contained in the elastic seal can, for example, be a polymer that almost returns to its original shape after being released. High resistance to fuel can mean that the physical and mechanical properties of the elastic seal are not altered by contact with fuel and that the service life of the elastic seal is not shortened by contact with fuel. In particular, the elastic seal can comprise a peroxide-crosslinked material. Furthermore, the elastic seal can contain antioxidants, fluorosilicones, polyurethanes, and / or fluoroelastomers with a fluorine content of over 60%.

[0027] According to the invention, the throttle device has a protective ring arranged between the elastic seal and the shaft bearing. The protective ring is positively connected to the throttle shaft. The protective ring can be circumferential and closed. It can be designed to be fixed to the throttle shaft and pressed against a bearing shoulder by pressure or spring force. The outer diameter of the protective ring can be larger than the outer diameter of the throttle shaft and / or larger than the outer diameter of the elastic seal.

[0028] Thanks to the positive-locking connection of the protective ring to the throttle shaft, the protective ring can be designed to run completely around the shaft. In contrast, conventional protective rings are not positively connected to the throttle shaft and therefore must have an opening, for example, a C-shape, and thus cannot guarantee optimal sealing.

[0029] In addition to providing a flexible seal, the protective ring can ensure radial and axial sealing of the shaft bearing and the gearbox behind it. Furthermore, the protective ring can also absorb unwanted forces such as pressure pulsations. The elastic seal integrated into the throttle shaft can handle the generation of any axial pressure force on the protective ring.

[0030] According to a further embodiment of the invention, the protective ring is injection-molded onto the throttle shaft. The protective ring is arranged on the throttle shaft such that it is pressed against a shoulder of the shaft bearing. The protective ring can, for example, be injection-molded into a second groove. Furthermore, the protective ring can be pressed against the shoulder of the shaft bearing, for example, by a spring or by the elastic seal. In this way, additional sealing in the axial direction of the throttle shaft is ensured.

[0031] According to the invention, the protective ring comprises a thermoplastic. This protective ring exhibits high resistance to fuels such as diesel or gasoline. The thermoplastic can be, for example, a polyamide, a polycarbonate, a polymethyl methacrylate, or a polyvinyl chloride, or a mixture of these materials. It is particularly advantageous to select the material of the protective ring such that optimal sliding properties between the protective ring and the shoulder of the shaft bearing are ensured.

[0032] According to a further embodiment of the invention, the shaft bearing is designed as a rolling bearing, in particular as a needle bearing.

[0033] According to a second aspect of the invention, a motor vehicle is presented. The motor vehicle comprises an internal combustion engine, an intake manifold, and a throttle device as described above. The intake manifold is designed to supply a quantity of air to the internal combustion engine. The throttle device, and in particular the fluid channel of the throttle device, is arranged in the intake manifold and is designed to regulate the quantity of air supplied to the internal combustion engine.

[0034] According to a third aspect of the invention, a method for manufacturing a throttle device described above is presented. The method comprises the following steps: providing a groove on a throttle shaft between a fluid channel and a shaft bearing, and arranging an elastic seal in the groove such that the shaft bearing is sealed fluid-tight against the fluid channel.

[0035] Further features and advantages of the present invention will become apparent to the person skilled in the art from the following description of exemplary embodiments, which, however, are not to be interpreted as limiting the invention, with reference to the accompanying drawings. Fig. Figure 1 schematically shows a cross-section of a throttling device according to an embodiment of the invention. Fig. Figure 2 shows an enlarged section of Fig. 1 at the location of the elastic seal

[0036] All figures are merely schematic representations of the devices or their components according to exemplary embodiments of the invention. In particular, distances and size relationships are not shown to scale in the figures. Corresponding elements in the various figures are provided with the same reference numbers.

[0037] In Fig. Figure 1 shows a cross-section through a throttle device 1 of a motor vehicle. The throttle device 1 is, for example, arranged in an intake manifold 35 of the motor vehicle. The throttle device 1 has a throttle valve 23, which is attached to a throttle shaft 3 by means of fastening elements 25, such as screws. A Fig. An electric motor (not shown) can adjust the throttle valve 23 via the throttle shaft 3 using a transmission (also not shown). By changing the opening angle of the throttle valve 23 in the intake pipe 35 or in the fluid channel 7, the flow cross-section of the fluid channel 7 is changed. Thus, the amount of air supplied to an internal combustion engine can be regulated by means of the throttle device 1.

[0038] The fluid channel 7 is the part of the throttle device 1 located in the intake pipe 35. The fluid channel 7 can, for example, have an O-shaped housing for the throttle valve 23. The throttle valve 23 is located in or on the fluid channel 7. The fluid channel 7 represents the point in the throttle device 1 where unwanted substances, such as condensed fuel, can enter the throttle device 1 from the intake pipe 35.

[0039] The electric motor and the corresponding gearbox are located in a housing 5. A shaft bearing 9 for supporting the throttle shaft 3 is also provided on the housing 5. The throttle shaft 3 extends through a channel in the housing into the fluid channel 7. In the illustrated embodiment, the shaft bearing 9 is designed as a needle bearing. The channel has a recess with a shoulder 19 facing the fluid channel 7. Furthermore, a first bearing seal 31 is provided on one side of the shaft bearing 9 and a second bearing seal 33 is provided on the opposite side of the shaft bearing 9.In conventional throttle devices, despite the first bearing seal 31 and the second bearing seal 33, fluids such as condensed water or fuel can penetrate through a gap 29 between the housing 5 and the throttle shaft 3 to the shaft bearing 9 and possibly even into a gearbox compartment 21, in which a gearbox and an electric motor may be located.

[0040] To protect the shaft bearing 9 and the gearbox compartment 21 located behind it from undesirable force influences such as pressure pulses and from fluids, an elastic pressure-supported seal 11 is integrated into the throttle shaft 3 between the fluid channel 7 and the shaft bearing 9. The elastic seal 11 has a C-shaped cross-section and is arranged in a first annular circumferential groove 13 of the throttle shaft 3. The elastic seal 11 is positioned upstream of the shaft bearing 9 with respect to the fluid channel 7 and is decoupled from the needle bearing. This reduces dead volume in which fluid can accumulate and allows for a simplified design of the shaft bearing 9 with adequate mechanical stability.

[0041] Furthermore, a closed protective ring 15 is provided between the elastic seal 11 and the shaft bearing 9. The protective ring 15 can be positively molded onto the throttle shaft 3 in a second groove 17. In this configuration, the protective ring 15 projects beyond the dimensions of the throttle shaft 3 and additionally shields the shaft bearing 9 from forces such as pressure pulsations and ingress of fluids. The elastic seal 11 can be pressure-supported and transmit forces acting upon it in such a way that the protective ring 15 is pressed against the shoulder 19 of the shaft bearing 9. Alternatively, the protective ring 15 can be pressed against the shoulder 19 of the shaft bearing 9 by means of a spring 27. The generation of the axial compressive force can also be performed by the upstream elastic seal 11 integrated into the throttle shaft 3.

[0042] In Fig. 2 is an enlarged section of Fig.Figure 1 shows pressure forces on the elastic seal 11 represented by arrows.

[0043] Finally, it should be noted that expressions such as "featuring" or similar terms are not intended to preclude the possibility of further elements or steps being provided. Furthermore, it should be noted that "a" or "an" does not preclude a plurality. Moreover, the features described in connection with the various embodiments can be combined in any way. It should also be noted that the reference numerals in the claims are not to be interpreted as limiting the scope of the claims.

Claims

[1] Throttle device (1) for regulating a fluid flow, comprising the throttle device (1) a throttle shaft (3); a housing (5); a fluid channel (7); a shaft bearing (9) for supporting the throttle shaft (3) on the housing (5); characterized by , that an elastic seal (11) is integrated between the fluid channel (7) and the shaft bearing (9); wherein the elastic seal (11) is designed to seal the shaft bearing (9) fluid-tight against the fluid channel (7) wherein the throttle device (1) further comprises: a protective ring (15); wherein the protective ring (15) is arranged between the elastic seal (11) and the shaft bearing (9); wherein the protective ring (15) is positively connected to the throttle shaft (3), wherein the protective ring (15) is made of a thermoplastic; wherein the protective ring (15) exhibits high resistance to fuel. [2] Throttle device (1) according to claim 1, wherein the elastic seal (11) is integrated into the throttle shaft (3) or into the housing (5). [3] Throttle device (1) according to one of claims 1 and 2, wherein the elastic seal is designed as a pressure-supported seal; wherein the throttle shaft (3) has a circumferential groove (13) between the fluid channel (7) and the shaft bearing (9); wherein the elastic seal (11) is arranged in the circumferential groove (13). [4] Throttle device (1) according to one of claims 1 to 3, wherein the elastic seal (11) is designed as a closed sealing ring. [5] Throttle device (1) according to any one of claims 1 to 4, wherein the elastic seal (11) comprises an elastomer; wherein the elastic seal (11) exhibits high resistance to fuel. [6] Throttle device (1) according to one of the preceding claims, wherein the protective ring (15) is injection-molded onto the throttle shaft (3); and wherein the protective ring (15) is arranged on the throttle shaft (3) such that the protective ring (15) is pressed against a shoulder (19) of the shaft bearing (9). [7] Throttle device (1) according to one of the preceding claims, wherein the shaft bearing (9) is designed as a rolling bearing. [8] motor vehicle, the motor vehicle an internal combustion engine; an intake pipe (35) for supplying a quantity of air to the internal combustion engine; a throttle device (1) according to one of the preceding claims; wherein the throttle device (1) is arranged in the intake pipe (35) and is designed to regulate the amount of air supplied to the internal combustion engine.

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