GB2402457A

GB2402457A - A hydraulically damped mounting device

Info

Publication number: GB2402457A
Application number: GB0409487A
Authority: GB
Inventors: Michael Paul Rooke; Peter Michael Trewhell Fursdon
Original assignee: Avon Vibration Management Systems Ltd
Current assignee: Avon Vibration Management Systems Ltd
Priority date: 2003-06-03
Filing date: 2004-04-28
Publication date: 2004-12-08
Anticipated expiration: 2024-04-28
Also published as: GB2402457B; DE102004026592A1; GB0409487D0; GB0312726D0

Abstract

A hydraulically damped mounting device has a first anchor part 101 in the form of a boss and a second anchor part 104 in the form of a cup. The boss and cup 101, 104 are connected by a resilient wall 106 which bounds a working chamber 111 for hydraulic fluid, the working chamber being connected to a compensation chamber 114 by a passageway 112 in a partition 109. A pin 122 is fixed to the cup and extends through a bore 121 in the boss, the bore being lined with resilient material 123 such that there is a space between the resilient material 123 and the pin 122. Larger vibrations cause the pin 122 to strike the resilient material 123, so that material resists further movement of the pin 122, and hence snubbing out relative movement of the boss and cup 101, 104. It is also possible for the bore to lie in the cup and the pin to be attached to the boss and/or for the bore to have fluid filled chambers therein.

Description

HYDRAULICALLY DAMPED MOUNTING DEVICE

The present invention relates to a hydraulically damped mounting device. Such a device usually has a pair of chambers for hydraulic fluid, connected by suitable passageway, and damping is achieved due to the flow of fluid through that passageway.

EP-A-0115417 and EP-A-0172700 discussed two different types of hydraulically damped mounting devices for damping vibration between two parts of a piece of machinery, e.g. a car engine and a chassis. EP-A0115417 disclosed various "cup and boss'' type of mounting devices, in which a "boss", forming one anchor part to which one of the pieces of machinery was connected, was itself connected via a deformable (normally resilient) wall to the mouth of a "cup", which was attached to the other piece of machinery and formed another anchor part.

The cup and the resilient wall then defined a working chamber for hydraulic fluid, which was connected to a compensation chamber by a passageway (usually elongate) which provided the damping orifice. The compensation chamber was separated from the working chamber by a rigid partition, and a flexible diaphragm was in direct contact with the liquid and, together with the partition formed a gas pocket.

In EP-A-0172700 the mounting devices disclosed were of the "bush" type. In this type of mounting device, the anchor part for one part of the vibrating machinery is in the form of a hollow sleeve with the other anchor part in the form of a rod or tube extending approximately centrally and coaxially of the sleeve. In EP-A-0172700 the tubular anchor part was connected to the sleeve by resilient walls, which defined one of the chambers in the sleeve. The chamber was connected via a passageway to a second chamber bounded at least in part by a bellows wall which was effectively freely deformable so that it could compensate for fluid movement through the passageway without itself resisting that fluid movement.

In the hydraulically damped mounting devices disclosed in the specifications discussed above, there was a single passageway. It is also known, from other IS hydraulically damped mounting devices, to provide a plurality of independent passageways linking the chambers for hydraulic fluid.

Fig. 1 of the accompanying drawings shows one example of a ''cup and boss" type of mounting device, and has been disclosed in our UK patent application No. 2282430. The mounting device is for damping vibration between two parts of a structure(not shown), and has a boss 1 connected via a fixing bolt 2 to one of the parts of the structure, and the other part of the structure is connected to a generally U-shaped cup 4. A resilient spring 5 of e.g. rubber interconnects the boss 1 and the cup 4. A partition 7 is also attached to the cup 4 adjacent the spring 5, and extends across the mouth of the cup 4. Thus, a working chamber 8 is defined within the mount, bounded by the resilient spring 5 and the partition 7.

The interior of the partition 7 defines a convoluted passageway 9 which is connected to the working chamber 8 via an opening lo and is also connected via an opening 11 to a compensation chamber 12. Thus, when the boss 1 vibrates relative to the cup 4 (in the vertical direction in Fig. 1), the volume of the working chamber 8 will change, and hydraulic fluid in that working chamber 8 will be forced through the passageway 9 into, or out of, the compensation chamber 12. This fluid movement causes damping. The volume of the compensation chamber 12 needs to change in response to such fluid movement, and therefore the compensation chamber 12 is bounded by a flexible wall 13.

The above structure is generally similar to that described in EP-A0115417, and the manner of operation is similar. In EP-A-0115417, the partition supported a diaphragm which acted as a boundary between fluid in the working chamber and a gas pocket. In the arrangement shown as Fig. 1, there is an annular diaphragm 50 which is convoluted. That diaphragm 50 is held on the partition 7 by an upper snubber plate 22, that snubber plate 22 is held in pace by a ring 40, which is clamped to the partition 7 and to the cup 4, by a clamping ring 41. The resilient spring 5 is also connected to the ring 40. The upper snubber plate 22 has openings 21 which permits fluid in the working chamber 8 to contact the diaphragm 50.

In the arrangement shown in Fig. 1, the passageway 9 is in the form of a spiral, and the internal dimensions S of that spiral are uniform.

In some situations, it is desirable to limit the degree of movement of the boss relative to the cup in a hydraulically damped mounting device of the type illustrated in Fig. 1. In particular, in normal operation, the resilient wall formed by e.g. the spring 5 in Fig.1. will be sufficiently strong to resist the forces that will be applied to it due to movement of e.g. the engine relative the chassis. If, however, the vehicle is involved in a crash or in some extreme driving conditions, very large forces can be applied to the mounting device due to movement of the engine relative the chassis, and it is desirable to provide additional restraint on the movement of the boss relative to the cup to present excessive movement of the invention. It is known to provide straps which extend partially or wholly around the mount which are sufficiently inelastic to resist excessive movement of the boss relative to the cup. Examples of such strap arrangements are disclosed in GB-A-2364363 and GB- A-2376282.

The present invention is also concerned with limiting the movement of the boss relative to the cup, but adopts a different approach. The inventor of the present invention has had the idea of providing a rigid pin which extends from the cup into a bore in the boss, which bore is greater than the size of the pin. Then, as the boss moved, its movement will be limited by the pin.

The degree of movement is then determined by the size of the bore, relative to the smaller size of the pin.

However, with such an arrangement, there would be direct contact between the pin and the bore, and that is undesirable. Therefore, the inventors also propose that the bore contains at least one deformable pad, which acts as a snubber between the wall of the bore and the pin.

The pad or pads could be mounted on the pin or on the wall of the bore, as appropriate. The pad or pads may be resilient, or may involve fluid or gas pockets.

Furthermore, it was realised that an alternative to the above achieving a similar effect, is to mount the pin rigidly on the boss, and have the pin be received in a bore in the cup, again with that bore having one or more deformable, preferably resilient pads.

All of these possibilities are therefore encompassed by the present invention, so at its most general, the present invention proposes that a rigid pin extends between the boss and the cup being fixed to one of them, and being received in the bore in the other, which bore also contains at least one deformable, preferably resilient pad.

Thus, the present invention may provide a hydraulically damped mounting device comprising: first and second anchor parts connected by a first deformable wall; a working chamber at least partially bounded by the first deformable wall; a compensation chamber for hydraulic fluid, the lo compensation chamber being bound by a second deformable wall; a passageway for the hydraulic fluid, interconnecting the working and compensation chambers; wherein the first anchor part is a cup containing the compensation chamber, the cup having an open mouth, and the second anchor part is a boss aligned with the mouth of the cup and connected thereto by the first deformable wall, and wherein a rigid pin extends between the boss and the cup, the pin being fixed to one of the boss and the cup and being received in a bore in the other of the boss and the cup, the bore also containing at least one deformable pad.

The degree of freedom of movement of the boss relative to the pin and hence to the cup, is determined by the size of the bore relative to the size of the pin and the size of the deformable pad or pads. The bore must be larger than the pin, to allow some movement of the boss relative to the cup, to allow the hydraulically damped mounting device to operate as such. However, the amount of movement possible, is determined by the space between the wall of the bore and the pin, and also by the deformable pads in the bore. At its simplest, the deformable pad may be a resilient rubber lining on the wall of the bore, which the pin will strike as it move in any direction. A similar effect may be achieved by providing a rubber flange on the pin, which will strike the wall of the bore as the pin moves relative to the bore.

= It would also be possible, and possibly advantageous, for the pad or pads to contact the pin when the mounting device is in its rest (loaded) position.

There would then be no gap between the pin and the pad(s), and the deformability of the pad(s) would then have an immediate effect on the degree of movement of the pin. Of course, the deformability of the pad(s) means that movement of the pin would still occur and that movement would cause movement of hydraulic fluid between the working and compensation chambers. Such contact between the pad(s) and the pin may be needed to control small amplitude vibrations.

If the bore has a rubber lining, the hole defined within that lining in which the pin is received may be symmetric, but preferable, has different dimensions in different directions, to give different limitations on the movement of the pin in those different directions.

For example, the degree of movement of the pin in a direction which moves the boss towards or away from the base of the cup (hereinafter the ''vertical" direction) may be less than the degree of movement possible perpendicular thereto (the ''transverse" direction).

Similarly, if a flange is provided on the pin, that phalange need not be symmetric. This effect may alternatively be achieved by making either or both of the bore and the pin non-symmetric, but such arrangements may be more difficult to manufacture.

In a further development of the invention, the space between the pin and the wall of the bore contains at least one fluid-filled chamber as an alternative to or addition to at least one resilient pad. Then, the pin may interact with the or each fluid-filled chambers to cause fluid movement for example, if two interconnected fluid- filled chambers are provided, the action by the pin striking the wall of one of the chambers cause fluid to move from that chamber to the other chamber, or from that chamber to a compensation chamber, thereby providing a fluid damping effect on the movement of the pin relative to the wall of the bore.

Thus, for example, two resilient pads of e.g. rubber may be provided within the bore to limit movement of the pin in the vertical direction, and two fluid-filled chambers bound by deformable walls be provided in the transverse directions which are contacted by the pin to cause fluid movement when the pin moves laterally in the I bore. Further resilient pads may then be provided in the fluid chambers if necessary, to prevent excessive collapse of the fluid chambers.

Preferably, the pin is approximately straight and extends transversely between the cup and the boss, and to achieve this, the mouth of the cup may need to be higher, relative to the boss than the arrangement shown in Fig. - 1. It would, of course, be possible to provide a pin of a different shape, or for the pin to extend transversely but be fixed to the cup by a bracket extending from the mouth of the cup.

Normally, as in e.g. the arrangement of Fig. 1, a partition may divide the working chamber from the compensation chamber and the passageway connecting the working and the compensation chamber then be in the I partition. The partition may have on it a diaphragm separating fluid in the working chamber from a gas pocket, to provide an air-spring effect as in e.g. EP-A- 0115417 discussed previously.

Embodiments of the present invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Fig.1. is a sectional view through a hydraulically damped mounting device disclosed in GB-A-2282430 and has already been discussed; Fig.2. is a sectional view through a hydraulically damped mounting device being a first embodiment of the invention; Fig.3. is a perspective view of the mounting device of Fig.2; Fig.4. is a sectional view through the mounting device of Fig.2; Fig.5. is a hydraulically mounting device being a second embodiment of the present invention; Fig. 6. is a sectional view through the mounting device if Fig. 5, and; Fig. 7. is a hydraulically damped device being a third embodiment of the present invention.

The first embodiment of the invention, illustrated in Fig.2. will now be described. For the sake of convenience, the word vertical" will be used to define the direction which is vertical in the figure and is the normal direction of vibration of the mount. Vibrations in the perpendicular direction, but in the plane of the paper, will be described as the ' transverse" direction.

However, it should be noted that the hydraulically damped mounting device may have any orientation in use.

Referring now to Fig.2,the hydraulically damped mounting device is for damping vibration between two parts of a structure (not shown) and has a boss 101 connected by a fixing bolt 102 to the one of the parts of the structure. The other part of the structure is connected to a cup 104. In this embodiment, the cup 104 has a box-like shape, with a open mouth 105. The shape of the cup 104 is more clearly seen in the perspective view of Fig. 3. Note also that Fig.2. shows the rest position of the mounting device when under load.

A resilient spring 106 of e.g. rubber extends from lo the boss 101 towards the cup, and is bonded thereto. A rigid ring 107 is formed in the resilient spring 106 to give it strength where the forces from the boss 101 are applied to the cup 104. A partition 109 extends across the interior of the cup 104, resting on a ledge 110.

Thus, a working chamber 111 is defined within the mounting device, bounded by the resilient spring 106 and the partition 109. The interior of the partition 109 defines a convoluted passageway 112 which is connected to the working chamber 111 via an opening 113 and is also connected via an opening (not shown in Fig. 2) to a compensation chamber 114. The passageway 112 may be in the form of a 'flattened" spiral as in GB 2325720 A. The compensation chamber 114 is bounded by a deformable wall 115. Thus, when the boss 101 vibrates relative to the cup 104 in the vertical direction, the volume of the working chamber 111 will change, and fluid in that working 111 will pass through the passageway 112 to the compensation chamber 114 or vice versa. This fluid movement causing damping.

The partition 109 also supports an annular diaphragm 116 which acts as a boundary between fluid in the working chamber 111, and a gas pocket 117. As can be seen from Fig. 2. the partition 109 has three layers 118, 119, 120, and the gas pocket 117 is formed between the upper and middle layers 118, 119, the passageway 112 is formed primarily in the lower part 120 of the partition 109, but there needs to be a fluid connection through the middle and upper parts of the partition 109 to the opening 113.

The structure of the hydraulically device Fig.2.

described above is generally similar to that of Fig.1, and operates in a similar way. As can be seen, however, the cup 104 is of a different shape, and extends much higher in the vertical direction. The reason for this is that there is a further connection between the boss 10 and the cup 104 which does not exist in Fig. 1. In particular, the boss 101 is in the form of a hollow sleeve, so that a bore 121 is defined in the boss 101, extending therethrough. A rigid pin 122 is positioned in that bore, which extends out of the bore 121 through the wall of the cup 104 near its mouth, and is fixed to the cup 104 as illustrated in Fig.3. Thus, the pin 122 cannot move relative to the cup 104, and thus when the boss 101 moves relative to the cup 104, it also moves relative to the pin 122.

The bore has a lining of rubber material 123, which does not extend all the way to the pin, but in the rest (loaded) position of the mount, is such that a space 124 is defined around the pin. Thus, for limited movement of the boss 101 relative to the cup 104, the pin remains clear of the rubber material 123. However, increase movement of the boss 101 relative to the cup 104 will cause the pin to strike the rubber material 123, some point around the hole 124, and the resilience of the rubber material 123 Will then resist further movement of the pin. The rubber material 123 then acts as a snubber'' resisting further movement of the boss 101 relative to the cup 104.

It would also be possible for the rubber material 123 to be replaced by a unit comprising a sleeve of e.g. plastic or metal material, with an inner liner of a suitably hard rubber. Such an arrangement may be advantageous in enhancing durability.

Thus, consider vibrations of the boss 101 relative to the cup 104 in the vertical direction. At first, the pin 122 is clear of the rubber material 123, and therefore the pin 122 and the rubber material 123 have no effect on the movement of the boss. The movement in the vertical direction thus deforms the resilient wall 106, and hence varies the size of the working chamber, forcing hydraulic fluid through the passageway 111 to or from the compensation chamber 114. At the same time, the diaphragm 116 will move to compress or expand the gas in the air pocket 117. This effect will be the same as in the arrangement of Fig.1. for movement of the boss 101 relative to the cup 104.

However, if the size of the vibrations of the boss 101 relative to the cup 104 are greater than a predetermined amount, the pin 122 will strike the rubber material 123 and the rubber material 123 will then resist further movement of the pin, and hence the boss 101. Of course, at first, such movement continues due to compression of the rubber material 123, but the resistance to that movement will progressively increase until the movement of the boss 101 is snubbed out. Thus, excessive movement of the boss 101 relative to the cup 104 is prevented without there being a sudden jolt. Such an arrangement can thus prevent excessive forces being applied to the mount in e.g. a crash or some extreme driving conditions, without compromising the performance of the mount under normal conditions.

Consider now transverse vibrations. The mount of Fig.1. has little resistance to such vibrations, since there will only be compression of some parts of the spring 5, and indeed parts of that spring 5 might be put under tension, rather than compression, which is undesirable. In the hydraulically damped mounting device of Fig.2, transverse movement of the boss 101 relative to the cup 104 will initially be similar, until the pin 122 strikes the rubber material 123. At that point, further movement of the pin is resisted, thereby preventing parts of the spring 106 being put under tension which could destroy them mount.

It can be seen from the embodiment of Fig. 2. that the hole 124 is not circular, but is oval, so that the degree of movement of the pin 122, and hence the boss 101 relative to the cup 104, is different in the vertical and transverse directions, before that movement is affected by the rubber material 123.

The sectional view of Fig.4. shows how the pin 122 extends wholly through the boss 101 and the walls of the cup 104. Fig. 4. also shows in more detail the structure of the cup itself. In particular, the cup has a rigid base 130, side walls 131, 132, which receive the pin 122, and flanges 133, 134 which clamp the partition 109 to the base 130, and also connect the base 130 to the walls 131, 132. The result is that the pin 122, the partition 109, and the base 130 are rigidly fixed together.

In the embodiment of Figs 2 to 4, the connection between the pin 122 and the boss 101 is of rubber material 123. In the second embodiment, illustrated in Fig.5, there is fluid damping between the pin and the boss. The second embodiment of Fig.5. will therefore now be described in detail. Note that the parts which correspond to the embodiment of Figs 2 to 4 will be indicated by the same reference numerals.

In the embodiment of Fig.5, the configuration of the spring 106, the working and compensation chambers 111, 114, the passageway 112 etc. are all the same as in the embodiment of Fig. 2. and will not be described in detail again. The difference lies within the boss 101.

In particular, the rubber material within the bore 121 comprises upper and lower rubber pads 140, 141, interconnected by deformable walls 142, 143 which bound chambers 144, 145 which are filled with hydraulic fluid.

A duct 146 interconnects those chambers 144, 145. As a result of these components, the space 147 between the pin IS 122 and the rubber material insider the bore 121 is generally in the shape of a four-pointed star.

Consider now vertical movement of the boss 101 relative to the cup 104. At first, the pin 122 moves in the space 147, and thus the behaviour of the mount is exactly the same as in the arrangement of Fig.1.or Fig.2.

However, movement greater than a pre-determined amount will cause the pin 122 to strike one or other of the pads 140, 141, to limit the movement of the pin 122, and hence of the boss 101. As in the arrangement of Fig.2, the pads 140, 141 will compress as the pin 122 is forced against them, providing a spring effect to resist further movement of the boss 101. Thus, the effect for vertical movement is similar to the embodiment of Fig. 2.

However, now consider transverse vibrations. At first, the pin will be clear of the walls 142, 143 and will move freely. However, when the pin strikes e.g. the wall 142 due to movement of the boss 101 towards the right in Fig. 5, that wall 142 will deform, compressing chamber 144 and forcing liquid from that chamber through duct 146 to chamber 145. Such fluid movement through a lo narrow duct will cause damping. The effect is similar if the boss 101 moves to the left in Fig. 5, with the pin 122 striking the wall 143 and causing fluid movement through the duct 146 from the chamber 145 to the chamber 114.

Note also in this embodiment the rubber material forming the pads 140, 141 and the walls 142, 143 is not bonded directly to the wall of the bore 121, but instead there is a sleeve 148 of e.g. plastic material, the outside of which conforms to the bore 121, and the inside of which is shaped to define the duct 146, as well as to support the rubber material of pads 140,141 and walls 142 and 143. The advantage of the use of such a sleeve 148 is that it may be push-fitted into the bore 121 after the fluid chambers 144, 145 have been defined therein and sealed.

The sectional view of Fig. 6. shows that the pads 140, 141 do not extend the full length of the bore 121, which is necessary in order for suitable end-walls to be provided to seal the chambers 144, 145 in a direction perpendicular to the plane of the paper in Fig. 5. Those walls are not visible in Fig. 6.

A third embodiment of the invention is illustrated in Fig.7. The embodiment of Fig. 7. is similar to that of Fig. 5. and the same reference numerals are used. The only l difference between the embodiment of Fig.7. and that of Fig. 5. is that the chambers 144, 145 each contain rubber snubbers 150, 151 which limit compression of the chambers 144, 145. Thus, if the boss 101 moves to the left in Fig.7, its initial movement is unimpeded. Then, it strikes the wall 142, compressing the chamber 144 and forcing hydraulic fluid through the duct 146 to the chamber 145. However, further movement of the boss 101 to the left will cause the wall 142 to strike the snubber 150, limiting the amount of movement of the pin 122 1 relative to the bore 121. A similar effect occurs with the wall 123 and the snubber 151 if the boss moves to the! right in Fig.7.

In all the embodiments described above, the pin 122 is fixed to the cup 104, and is received in a bore 121 in the boss 101. However, as previously mentioned, it is possible for the present invention to be achieved by a pin which is fixed to the boss, and which extends into a bore in the wall of the cup 104. That bore may then be partially filled with rubber material, as in the arrangement of Fig.2, or contain chambers of hydraulic fluid as in the embodiment of Figs. 5 and 7. Thus, in such arrangements, the features within the bore in the wall in the cup may be identical to those in the bore in the embodiments that described above. The effects of such arrangements in limiting movement of the boss relative to the cup are then the same. -

Claims

Claims: 1. A hydraulically damped mounting device comprising: first and

second anchor parts connected by a first deformable wall; a working chamber at least partially bounded by the first deformable wall; a compensation chamber for hydraulic fluid, the compensation chamber being bound by a second deformable - wall; a passageway for the hydraulic fluid, interconnecting the working and compensation chambers; wherein the first anchor part is a cup containing the compensation chamber, the cup having an open mouth, and the second anchor part is a boss aligned with the cup and connected thereto by the first deformable wall, and wherein a rigid pin extends between the boss and the cup, the pin being fixed to one of the boss and the cup and being received in a bore in the other of the boss and the cup, the bore also containing at least one deformable pad.
2. A hydraulically damped mounting device according to claim 1, wherein the deformable pad is a resilient rubber lining on the wall of the bore. Al
3. A hydraulically damped mounting device according to claim 2, wherein the lining has a hole therein into which the pin is received.
4. A hydraulically damped mounting device according to claim 3, wherein the hole has different dimensions in different directions.
5. A hydraulically damped mounting device according to - claim 1, wherein the deformable pad is a rubber flange on the pin.
6. A hydraulically damped mounting device according to any one of the preceding claims, wherein the space between the pin and the wall of the bore contains at least one fluid-filled chamber.
7. A hydraulically damped mounting device comprising: first and second anchor parts connected by a first deformable wall; a working chamber at least partially bounded by the first deformable wall; a compensation chamber for hydraulic fluid, the compensation chamber being bound by a second deformable wall; a passageway for the hydraulic fluid, interconnecting the working and compensation chambers; ?l wherein the first anchor part is a cup containing the compensation chamber, the cup having an open mouth, and the second anchor part is a boss aligned with the cup and connected thereto by the first deformable wall, and wherein a rigid pin extends between the boss and the cup, the pin being fixed to one of the boss and the cup and being received in a bore in the other of the boss and the cup, the bore containing at least one fluid filled chamber.
8. A hydraulically damped mounting device according to claim 6 or claim 7 having two fluid filled chambers, the chambers being interconnected by a duct for fluid movement therebetween.
9. A hydraulically damped mounting device according to - any one of the preceding claims, wherein a partition divides the working chamber from the compensation chamber.
10. A hydraulically damped mounting device according to claim 9, wherein the passageway is in the partition.
11. A hydraulically damped mounting device according to claim 9 and claim 10, wherein there is a diaphragm separating fluid in the working chamber from a gas pocket in the partition.
12. A hydraulically damped mounting device substantially as herein described with reference to and as illustrated in Figs. 1 to 9, or Figs. 5 and 6, or Fig. 7 of the accompanying drawings.

12. A hydraulically damped mounting device substantially as herein described with reference to and as illustrated in Figs. 1 to 4, or Figs. 5 and 6, or Fig. 7 of the accompanying drawings. in'

Amendments to the claims have been filed as follows: Claims: 1. A hydraulically damped mounting device comprising: first and second anchor parts connected by a first deformable wall; a working chamber at least partially bounded by the first deformable wall; a compensation chamber for hydraulic fluid, the compensation chamber being bound by a second deformable wall; a passageway for the hydraulic fluid, interconnecting the working and compensation chambers; wherein the first anchor part is a cup containing the compensation chamber, the cup having an open mouth, and the second anchor part is a-boss aligned with the cup and connected thereto by the first deformable wall, and wherein a rigid pin extends between the boss and the cup, the pin being fixed to one of the boss and the cup and being received in a bore in the other of the boss and the cup, the bore also containing at least one deformable pad.

2. A hydraulically damped mounting device according to claim 1, wherein the deformable pad is a resilient rubber lining on the wall of the bore. as

3. A hydraulically damped mounting device according to claim 2, wherein the lining has a hole therein into which the pin is received.

4. A hydraulically damped mounting device according to claim 3, wherein the hole has different dimensions in different directions.

5. A hydraulically damped mounting device according to claim 1, wherein the deformable pad is a rubber flange on the pin.

6. A hydraulically damped mounting device according to any one of the preceding claims, wherein there is a space between the pin and the wall of the bore and the space contains at least one fluid-filled chamber.

A hydraulically damped mounting device comprising: first and second anchor parts connected by a first deformable wall; a working chamber at least partially bounded by the first deformable wall; a compensation chamber for hydraulic fluid, the compensation chamber being bound by a second deformable wall; a passageway for the hydraulic fluid, interconnecting the working and compensation chambers; wherein the first anchor part is a cup containing the compensation chamber, the cup having an open mouth, and the second anchor part is a boss aligned with the cup and connected thereto by the first deformable wall, and wherein a rigid pin extends between the boss and the cup, the pin being fixed to one of the boss and the cup and being received in a bore in the other of the boss and the cup, the bore containing at least one fluid filled chamber.

8. A hydraulically damped mounting device according to claim 6 or claim 7 having two fluid filled chambers, the chambers being interconnected by a duct for fluid movement therebetween.

9. A hydraulically damped mounting device according to any one of the preceding claims, wherein a partition divides the working chamber from the compensation chamber.

10. A hydraulically damped mounting device according to claim 9, wherein the passageway is in the partition.

11. A hydraulically damped mounting device according to claim 9 and claim 10, wherein there is a diaphragm separating fluid in the working chamber from a gas pocket in the partition. s