GB2080922A

GB2080922A - Damped mounting assembly

Info

Publication number: GB2080922A
Application number: GB8121192A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-07-15
Filing date: 1981-07-09
Publication date: 1982-02-10
Also published as: JPS5740141A; DE3026766A1

Abstract

A damped mounting assembly comprises an oscillatorily excitable member (1) mounted on a rigid mounting (2) by resilient means (5), e.g. rubber to be screened against sound conducted through solids relative to the mounting, the member (1) being supported, in addition to the resilient means (5), at least in the principal plane of oscillation and relative to the rigid mounting (2) by an absorption support body (3) of high oscillation loss factor, e.g. of hard foamed plastics material. An adjustment screw (4) acting on the body (3) allows precise location of member (1) relative to mounting (2). <IMAGE>

Description

SPECIFICATION Damped mounting assembly The present invention relates to a damped mounting assembly.

For the purpose of noise and oscillation damping, oscillatable members, for example noise-producing sub-assemblies, are mounted by means of rubber elements to be screened against the transmission of sound conducted through solids. The unsteady suspension that inevitably results, for example of a drive system in a housing, ts in many cases not tolerable.

There is accordingly a need for an assembly in which the oscillatorily excitable member is -%ccurately positioned while retaining the damping effect and without oscillations being transmitted to the mounting.

According to the present invention there is provided a damped mounting assembly comprising rigid mounting means, an oscillatorily excitable member mounted on the mounting means by resilient means inhibiting transmission of sound therebetween, and at least one oscillation absorbing support element of high oscillation loss factor additionally supporting the member relative to the mounting means at least in the principal plane of oscillation of the member.

Through the use of a support element or elements of high loss factor, which can consist of a porous material, for example hard foam plastics material, it is possible to position and locate a sub assembly, for example mounted in rubber, or an entire oscillatorily excitable appliance in a fully determined position while retaining the damping effect.

In most cases, it is preferably to provide the support by means of support elements in the direction of all three spatial axes in order to ensure that the oscillatorily excited member in fact remains exactly at the desired location.

To achieve this exact positioning in simple manner, the support elements may be adjustable in their position relative to the mounting means. It is in that case particularly advantageous if the support elements are pressable against the mounting means with an adjustable bias. The adjustability of the support elements can be effected through setscrews which are firmly connected with the support elements and are conducted in threaded bores of the rigid mounting means, so that the support elements are adjustable in their position and so that the bias by which the elements press against the member is adjustable. This adjustable bias is particularly advantageous when a particularly exact positioning of the oscillatorily excited member is required. As a result, the pressing force can be adapted to the mass and the frequency of the oscillatorily excited member.Of course, the choice of the material for the support elements depends on the particular application, on the mass and on the frequency of the oscillation. In choosing the material for the support elements, these factors should therefore be taken into consideration. In that case, attention is to be paid not only to the resistance capabilities of the support elements, but also to its size, which is to be adapted to the respective member.

Embodiments of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a schematic cross-section of a mounting assembly according to a first embodiment of the invention, Fig. 2 is a schematic cross-section of a mounting assembly according to a second embodiment of the invention, and Fig. 3 is a schematic cross-section of a mounting assembly according to a third embodiment of the invention.

Referring now to the drawings, there is shown in Fig. 1 a damped mounting assembly comprising a flange 1 of a gear which is excited into oscillation and which mounted relative to a housing 2 to be considered as rigid. A rubber body 5, which is retained in a bush 8 and with which the gear flange 1 is connected through a threaded sleeve 9 vulcanised into the rubber body 5 and projecting therefrom, serves as bearing. The sleeve 9 is connected by means of a screw 10 with the flange 1 of the gear, and the bush 8, with which the rubber body 5 is also connected through vulcanising, is fastened to the housing 2 by means of screws 1 1. The rubber body 5 permits a largely shock-free bearing of the gear relative to the housing 2, but does not prevent the gear from executing oscillations relative to the housing 2.

An absorption body 3, which is displaceably guided in the sleeve 9 and pressed against the bottom 12 of the bush 8 by means of a screw 4, serves to suppress these oscillations, i.e. to position the gear in a certain position relative to the housing 2. The screw 4 is guided in the interior of the sleeve 9 and has the form of a grub screw, so that it is adjustable from the upper end of the bore 1 3. As the sleeve 9 is rigidly connected to the flange 1 of the gear, the gear is on the one hand resiliently mounted relative to the housing 2 by the rubber body 5 and on the other hand so supported by the support body 3 that the gear is located in a certain position.The support body 3, which has a high loss factor in respect of the transmission of oscillations, thus serves as abutment which absorbs the oscillations of the gear to such an extent that almost no oscillations are transmitted to the housing 2.

In the embodiment according to Fig. 2, a gear flange 1 is suspended through a conventional metal oscillatory body 6 on the housing 2, which comprises a threaded bore 13 for the reception of the setscrew 4, by which the support body 3 is retained and is pressable with bias against the flange 1. The body 3 is adjustably inserted directly between the housing 2 and flange 1 of the gear in order to position the gear in the housing.

In the embodiment according to Fig. 3, the gear flange 1 is connected to the housing 2 by means of a rubber body 7, which is vulcanised to the housing 2 on the one hand and to the gear flange 1 on the other hand. In order to keep the gear almost free of oscillation and in a certain position relative to the housing, a support body 3 is adjustably pressable against the flange 1 by means of a setscrew 4 guided in the housing 2.

In all described embodiments, the support body 3 has a high loss factor so that it enables a positive connection between the oscillatorily excited gear and the housing 2, but absorbs the oscillations, which are noticeable at the gear by virtue of the resilient bearing, to such an extent that the gear can be positioned virtually free of oscillation and thereby in a predetermined position relative to the housing 2 without noticeable oscillations being transmitted to the housing.

The described support of an oscillating member held in resilient bearings can be advantageously applied wherever a sub-assembly or an entire appliance must be suspended insulated against sound conducted through solids and additionally must be exactly located in its position for the purpose of noise or oscillation damping.

Claims

1. A damped mounting assembly comprising rigid mounting means, an oscillatorily excitable member mounted on the mounting means by resilient means inhibiting transmission of sound therebetween, and at least one oscillation absorbing support element of high oscillation loss factor additionaily supporting the member relative to the mounting means at least in the principal plane of oscillation of the member.

2. An assembly as claimed in dlaim 1, wherein the or each support element supports the member relative to the mounting means in all three spatial axes.

3. An assembly as claimed in either claim 1 or claim 2, wherein the or each support element adjustable in position relative to the mounting means.

4. An assembly as claimed in any one of th preceding claims, comprising means causing the or each support element to be pressed against the mounting means with a selectable bias.

5. An assembly as claimed in any one of the preceding claims, wherein the or each support element comprises a porous material.

6. An assembly as claimed in claim 5, wherein the porous material is a hard foam plastics material.

7. A damped mounting assembly substantially as hereinbefore described with reference to any one of the accompanying drawings.