Priority is claimed to German Patent Application No. DE. 10 2011 102 076.8, filed on May 19, 2011, the entire disclosure of which is hereby incorporated by reference herein.
An embodiment of the invention relates to a hydraulic mount, comprising a support bearing and a seat, which are supported on each other by a spring element that is shaped essentially like a truncated cone and made of elastomeric material, and it also relates to an expansion chamber and a compensation chamber that are each filled with damping fluid and physically separated from each other by a partition in the axial direction, and that in a manner that allows the passage of liquid—are connected by a first damper for damping axially introduced vibrations.
A hydraulic mount is generally known, for example, from German laid-open document DE 100 37 954 A1. In the prior-art hydraulic mount, the support bearing is configured as a first inner supporting element that is surrounded by an outer second supporting element situated at a radial distance, whereby the first and the second supporting elements are connected by a first spring element and by a second spring element. The first spring element and the second spring element delimit at least two chambers that are filled with damping fluid, that are arranged perpendicular to the axis of the hydraulic mount extending in the axial direction, that are arranged essentially opposite from each other in the radial direction, and that—in a manner that allows the passage of liquid—are connected to each other by a second damping opening. Consequently, the prior-art hydraulic mount comprises two dampers, whereby one damper corresponds to that of a conventional hydraulic mount in which, for damping purposes in the axially extending main direction of action, damping fluid is transferred from the expansion chamber through the first damper into the compensation chamber and back again. In order to damp vibrations that are introduced into the hydraulic mount in the radial direction, perpendicular to the main direction of action, the second damper is physically arranged axially adjacent to the first damper, whereby the spring element that is shaped like a truncated cone separates the two dampers from each other on their sides facing each other axially. The prior-art hydraulic mount has large dimensions in the axial direction, which is why it requires a correspondingly large installation space and, due to this design, a relatively large amount of material is needed to manufacture the prior-art hydraulic mount.
In an embodiment, the present invention provides a hydraulic mount including a support bearing and a seat. At least a first and a second partial spring element are each formed from an elastomeric material and connected to each other via an intermediate ring. The spring elements support the support bearing and the seat on each other and have essentially a truncated cone-like shape. An expansion chamber and a compensation chamber are each filled with a first damping fluid. The chambers are physically separated from each other, in an axial direction, by a partition and are connected to each other, in a manner that allows passage of liquid, by a first damper configured to dampen vibrations introduced in the axial direction. A second damper is disposed in the expansion chamber and configured to dampen vibrations introduced in a radial direction. The intermediate ring and the second damper transition from one to the other.
The present invention will be described even greater detail below based on the exemplary, schematic figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:
Reference numerals not shown in latter Figures can be gleaned by reference to earlier figures denoting like or similar parts.
In an embodiment, the invention, compared to the prior-art hydraulic mount, provides a hydraulic mount that has multi-axial damping capacity while having a compact design, especially in the axial direction. It should be possible to manufacture the hydraulic mount inexpensively with a small amount of material.
In an embodiment, the invention provides that the spring element comprises at least two partial spring elements that are connected to each other by an intermediate ring, whereby a second damper is arranged in the expansion chamber in order to damp vibrations introduced in the radial direction, and whereby the intermediate ring and the second damper are configured so as to make a transition from one to the other.
With such an embodiment design, it is advantageous if the hydraulic mount according to an embodiment of the invention, in terms of its dimensions and consequently in terms of the installation space needed, practically does not differ from conventional hydraulic mounts that effectuate damping exclusively in the main axial direction of action.
In the hydraulic mount according to an embodiment of the invention, the second damper is integrated into the expansion chamber. In spite of the compact dimensions, especially in the axial direction, the hydraulic mount has multi-axial damping capacity. The first damper damps vibrations introduced into the hydraulic mount in the main direction of action extending in the axial direction, whereby this damping is effectuated in that, when vibrations are introduced axially into the hydraulic mount, the damping fluid is transferred from the expansion chamber through the first damper and through the partition into the compensation chamber and back again.
In contrast, if vibrations are introduced into the hydraulic mount in the radial direction, the second damper is operational. The second damper preferably comprises two or four expansion chambers that form one or two pairs of chambers. To the extent that damping fluid is displaced out of one chamber of a pair of chambers, the other chamber takes up the displaced damping fluid. As a result, the second damper is highly damping efficient.
The second damper is preferably filled with damping fluid and is closed off so as to be fluid-tight with respect to the expansion chamber during the proper use of the hydraulic mount. The two dampers are thus separated from each other in terms of their function.
Pressure compensation is possible in the case of a high internal pressure in the hydraulic mount, that is to say, an abrupt deviation. Due to this valve function, damage to the hydraulic mount by an impermissibly high internal pressure is avoided.
According to a first embodiment, the intermediate ring can have a holding means that is arranged on its inner circumferential side in the expansion chamber and that is connected to the second damper. Due to such an embodiment, a structurally simple attachment of the second damper in the expansion chamber is possible. Already with conventional hydraulic mounts, which only allow damping of vibrations introduced axially in the main direction of action, the use of intermediate rings that divide the spring element into two partial spring elements is known so that, if necessary, the properties of use of the hydraulic mount can be better adapted to the individual application case. These intermediate rings, however, have no other function than to separate the two partial spring elements from each other in order to achieve the desired spring properties.
The holding means can be configured as a holding claw that is positively or non-positively connected to the second damper. Here, it is advantageous that, like a modular system consisting of several second dampers, the suitable one can be selected and attached in the expansion chamber of the hydraulic mount by means of the holding claw.
According to another embodiment, it can be provided for the intermediate ring and the second damper to be configured so as to make a transition from one to the other as a single piece. Here, it is advantageous that a holding means and a separately produced second damper, as described above, are not needed. The second damper forms an integral part of the intermediate ring. As a result, the hydraulic mount has an especially simple structure with very few parts, and the risk of incorrect assembly is kept to a minimum.
The second damper can comprise a channel part and a closure part, whereby the channel part and the closure part delimit at least one damping channel for damping radially introduced vibrations. In the flow direction, the damping channel can open up on both sides into an expansion chamber that is situated in the second damper and that is filled with the damping fluid, whereby, in order to damp radially introduced vibrations, the damping fluid present in the damping channel is moved back and forth. As a result, greater damping efficiency is achieved.
The damping channel can be configured so as to be helical and bi-level in the axial direction. Here, it is advantageous for the damping channel to be especially long, as a result of which a large mass of damping fluid is contained in the damping channel, and low-frequency high-amplitude vibrations can be damped especially effectively by the large mass of damping fluid that moves back and forth.
According to another embodiment, it can be provided for the second damper to comprise two damping channels that are separated from each other so as to be fluid-tight and that are arranged adjacent to each other in the axial direction. As a result, the second damper has four expansion chambers. With such an embodiment, it is advantageous that each of the damping channels can connect two fluid chambers that are radially opposite from each other, whereby the fluid chambers of the one channel are arranged offset, for example, by 90° relative to the fluid chambers of the other channel. Consequently, it is possible to damp vibrations introduced into the hydraulic mount in different directions, for instance, vibrations introduced into the hydraulic mount radially in the driving direction as well as vibrations introduced into the hydraulic mount radially perpendicular thereto.
The support bearing can be configured so as to be essentially T-shaped as seen in the lengthwise section of the hydraulic mount. The support bearing can comprise an attachment means that is arranged in the center. Such an attachment means can be in the form of, for example, a threaded bolt that projects over the essentially disk-shaped top of the support bearing.
According to another embodiment, the attachment means can be in form of a threaded blind hole that is delimited by the disk-shaped top of the support bearing and by the axial projection.
The axial projection of the support bearing is moveable in the radial direction relative to the second damper and, as a result, it activates the second damper when radial vibrations are introduced into the hydraulic mount. When the axial projection of the support bearing makes a radial movement relative to the second damper, the damping fluid inside the chambers is moved back and forth via the damping channel(s) of the second damper. This damps the vibrations introduced in the radial direction.
The support bearing can comprise a catch extending axially in the direction of the expansion chamber, whereby the support bearing and the catch together have an axial extension that corresponds essentially to the axial extension of the second damper. Due to such an embodiment, the second damper can be activated especially accurately. The axial projection of the support bearing and the catch are each made of a tough-hard material, for example, a metallic material.
With an eye towards achieving the simplest and most cost-effective production of the hydraulic mount possible, it can be provided that the support bearing and the catch are configured so as to make a transition from one to the other as a single piece.
In contrast to this, it is also possible for the catch to be manufactured separately and to be preferably connected coaxially to the support bearing. As a result, different catches can be combined with different support bearings and different spring elements in order to allow the best possible adaptation of the properties of use of the hydraulic mount to each individual application case.
For some application cases, it is advantageous for the hydraulic mount to also have an absorption function in addition to the damping in the axial and radial directions.
For this purpose, it can be provided for an absorption channel to be arranged in the expansion chamber. The absorption channel is dimensioned in such a way that, in order to absorb idling vibrations of an internal combustion engine, the damping fluid situated inside the absorption channel moves in the axial direction back and forth out of the expansion chamber so as to be phase-shifted, preferably in the opposite phase. For this purpose, the absorption channel is connected to the expansion chamber in a manner that allows the passage of liquid.
The absorption channel can be delimited at east partially by the closure part of the second damper. This greatly simplifies the production of the absorption channel.
The absorption channel can be surrounded radially on the outside by the channel part of the second damper. Owing to the integration of the absorption channel into the second damper, the hydraulic mount has a simple structure with very few parts and can be manufactured very cost-effectively. Therefore, there is no need for separate parts to provide an absorption function,
In the embodiments shown here, the partition 7 has a nozzle cage 25 with an upper nozzle disk 26 and a lower nozzle disk 27, whereby, in the area of their outer circumference, the two nozzle disks 26, 27 delimit a channel 28 for damping low-frequency high-amplitude vibrations. In the embodiments shown here, the first damper 9 is part of the partition 7.
Between the two nozzle disks 26, 27, there is an isolating membrane 29 that is made of an elastomeric material, that is exposed to damping fluid from the expansion chamber 4 and from the compensation chamber 5, and that is arranged so as to be elastically resilient between the nozzle disks 26, 27. The isolating membrane 29 has the task of isolating low-amplitude high-frequency vibrations. Such vibrations are generated, for example, by the gas forces and the mass forces of the engine.
In addition to their damping capacity in the axial direction 8, the hydraulic mounts have a damping capacity in at least one radial direction 12. This damping capacity in the radial direction 12 is achieved by the second damper 11, whereby the second damper 11 is arranged in the expansion chamber 4 and is attached to the intermediate ring 10.
In an embodiment, the dimensions of the hydraulic mount as well as the required installation space practically do not differ from hydraulic mounts with or without an intermediate ring by means of which only damping in the axial direction 8 can be achieved. Therefore, the hydraulic mount according to an embodiment of the invention has compact dimensions and a structure with very few parts, as a result of which it can be manufactured inexpensively.
In order to damp vibrations introduced in the radial direction 12, the support bearing 1 moves relative to the second damper 11 in the radial direction, thereby bringing about a back-and-forth movement of the damping fluid 13 in the damping channels 18, 19 of the second damper 11.
In each of the embodiments shown, the second damper 11 is closed off so as to be fluid-tight with respect to the expansion chamber 4 and to the damping fluid 6 located in it during proper use in normal operations.
In the X--direction, vibration is damped by the second damper 11, while in the Y-direction, vibration is damped by the chambers 36.1 and 23.1 with 36.2 and 23.2.
Number | Date | Country | Kind |
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10 2011 102 076.8 | May 2011 | DE | national |