WO2018091271A1

WO2018091271A1 - Electric household appliance, and vibration damper therefor

Info

Publication number: WO2018091271A1
Application number: PCT/EP2017/078006
Authority: WO
Inventors: Daniel Micko
Original assignee: BSH Hausgeräte GmbH
Priority date: 2016-11-21
Filing date: 2017-11-02
Publication date: 2018-05-24
Also published as: DE102016222842A1

Abstract

A vibration damper for an electric household appliance comprises an elastic damper member (16) and two contact members (14, 15) which are force-locked to each other via the damper member (16, 30) and are harder than the damper member (16, 30). At least a first of the contact members (15) has a plurality of projections (21) which make depressions (23) in a surface (18) of the damper member (16).

Description

Electric household appliance and vibration damper for it

The present invention relates to a household electrical appliance, and more particularly to a vibration damper which in such apparatus is incorporated in a transmission path between a source of vibration, e.g. an electric motor, and a vibratable element can be provided by the vibratable element such as a wall of a device housing. Such a vibratable element, if not properly damped, can provide a greater contribution to the operating noise of the device than the airborne sound emitted directly from the vibration source.

As an effective element of such a vibration damper, a damper body made of an elastically deformable material may be provided, which is arranged between two contact bodies, one on the side of the vibration source and one on the side of the oscillatory element. By deforming under the pressure of the former abutment body driven by the oscillation source, such a vibration damper can transmit its movement with reduced amplitude to the abutment body remote from the oscillation source.

The more easily the damper body is deformable, the lower is the oscillation amplitude transmitted to the remote system body for a given frequency of oscillation. In order to make the damper body easily deformable, it is known to realize it in the form of a base plate with projections distributed thereon, wherein the projections touch one of the contact body Thus, for example, DE 10 2009 027 881 A1 and GB 2506654 each show a damper body in which a Base plate surrounds an electric motor and are compressed from the base plate to the outside protruding projections in contact with a plant body.

The smaller the number and the cross-sectional area of the projections, the smaller the restoring force that these projections can oppose to a displacement of the contact body. Nevertheless, by reducing the number or cross-sectional area of the projections, the damping can not be arbitrarily improved because the smaller the number of projections, the stronger becomes each one of them flattened, and thereby the cross-section of each individual projection grows again.

An object of the present invention is to provide a vibration damper for a household electric appliance with improved effect.

The object is achieved by having in a vibration damper with an elastic damper body and two contact bodies, which are frictionally connected via the damper body and harder than the damper body, at least a first of the contact body has a plurality of projections through which in a surface of the damper body Depressions are pressed.

While in the conventional vibration damper, the projections of the damper body are flattened by the pressure of the contact body and thereby greatly increases the contact surface between damping and body with increasing deformation of the projections, the projections of the contact body in the vibration damper according to the invention a pressure of the damper body not or at most to a lesser extent after, but press yourself into the damper body. In this case, the deformation of the damper body is not limited to the immediate contact surface between damping and contact body, and the contact surface between the damping and contact body can be kept smaller for a given pressure force than in the conventional case that the damper body has the projections. The smaller contact surface in turn causes an improved mobility of the contact body relative to the damper body and thus improved damping. Height, cross-sectional shape and distance of the projections should be adapted to the elasticity of the damper body so that between two of the projections depressed, adjacent recesses, the surface of the damper body extends without contact with the contact body. In a section through two adjacent projections, the width of a surface of the damper body, on which touch the damper body and the contact body, should be greater than the width of a extending between the projections, without contact with the surface of the damper body extending surface. Preferably, the projections are arranged periodically. This facilitates an optimization of dimensions and distances of the projections and the elasticity of the damper body with regard to an optimal damping result. The projections are distributed in at least one, preferably in two spatial directions, ie there is at least one translational operation, and preferably two translation operations in different directions, which map one of the projections onto another. The projections may be elongated in a common preferred direction to facilitate mating of damping and abutment body along the preferred direction.

The surface of the damper body, on which the projections are distributed, may be prismatic or cylindrical; the preferred direction may then be parallel to an axis of the surface.

The first abutment body may have a surface which engages around the steamer body on at least part of its circumference and from which the protuberances protrude from radially inward.

According to a first preferred embodiment, the vibration damper comprises a carrier plate and a plurality of arms which protrude from the edge thereof in the plane of the carrier plate and in each case form a first damper body.

On the support plate, a vibration source such as an electric motor may be mounted.

The second body can be held here in a recess of the damper body; In particular, the damper body may have the shape of a pipe or hollow cylinder, in the outer side of which press in the projections of the first contact body, and in the cavity of the second contact body is inserted. According to a second preferred embodiment, the first abutment body has a flat surface on which the projections are distributed, and is deflectably connected to a base in a direction perpendicular to the surface. Thus, the damper body can be placed on the base without necessarily coming into contact with the projections; This contact can be made only by moving the first contact body. This facilitates the attachment of the damper body; In addition, a scratching of the damper body can be avoided by the projections.

The base may have an internal cavity which provides space at least for the damper body, preferably also for the second body and possibly a vibration source connected to the second body. The surface of the first contact body may then be part of a wall of the cavity.

Preferably, the cavity has an open side, and the first abutment body is a resilient tongue that extends along a sidewall of the cavity and has a free end facing the open side. This free end may carry a locking projection that narrows the open side of the cavity to secure the damper body in the cavity. By pivoting the tongue aside, both the engagement of the projections in the damper body and the narrowing of the open side by the locking projection can cancel, so that the damper body and possibly associated with him components can be removed from the cavity.

The invention further relates to an electrical household appliance, in particular a household refrigerator, with a device housing and an electric motor, which is fixed in the device housing via at least one vibration damper as described above.

Such a vibration damper is more effective, the higher the frequency of the vibration to be damped. The deeper the frequencies that are to be damped, the more yielding the vibration damper must be. A material with spring constant 0 would allow any deflection of the vibration source side abutment body, without in turn one resulting from the deflection force on the other To transmit plant body, and would thus dampen a vibration of the first body perfectly. On the other hand, such a material would yield indefinitely even under the weight of the vibration source and would not be able to prevent direct contact of the contact body and thus a not damped by the damper body vibration transmission.

Further features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying figures. Show it:

1 shows a fan for a household refrigeration appliance with vibration dampers according to a first embodiment of the invention in a perspective view.

FIG. 2 shows a vibration damper of the ventilator from FIG. 1; FIG.

3 is an enlarged detail of FIG. 2

4 shows various cross-sectional shapes of protrusions;

Fig. 5 is a section along the plane V-V of Fig. 2;

6 shows an alternative section along the plane V-V;

7 is an exploded view of a vibration damper according to a second embodiment of the invention; and

8 shows a section through the fan of FIG. 7. FIG.

Fig. 1 shows a section of a no-frost refrigerator. A fan 1 comprises a rotatable about an axis 2 fan 3 with a base plate 4 and of the base plate 4 in the direction of the axis 2 projecting air blades 5. A hub of the fan 3 forms the rotor of the fan 3 driving electric motor 6; the stator of the electric motor is mounted on a support plate 7. Several arms 8 are radially from the support plate 7 with respect to the axis 2. Vibration damper 9 connect the Arms 8 with a wall 10 of a device housing of the refrigerator. The components of the vibration dampers 9 are shown in Fig. 1 in an exploded view.

The fan 1 is housed in a distribution chamber 1 1 of the device housing, extending from the not shown in Fig. 1 channels to storage compartments of the refrigerator. The distribution chamber 1 1 is separated from an evaporator chamber by an intermediate wall 12, which is shown transparent in Fig. 1 in order to fully show the underlying fan 1 can. The fan wheel 3 overlaps with an opening 13 of the intermediate wall 12, so that 3 cold air is sucked in the axial direction from the evaporator chamber by rotation of the fan wheel, is ejected in the radial direction in the distribution chamber 1 1 and flows from there via the channels to the storage compartments ,

The remote from the base plate ends of the arms 8 and protruding from the wall 10 pins each form rigid contact body 14, 15 of the vibration damper 9, between which an elastically resilient damper body 16, typically made of rubber, is held. The damper body 16 holds the abutment bodies 14, 15 at a distance from each other, so that they can swing against each other about a rest position, without touching each other. The damper body 16 is here a hollow cylinder, in the inner cavity 17 of the pin-shaped contact body 14 is inserted and held frictionally. The other abutment body 15 at the end of the arm 8 has the shape of a claw which engages an outer surface 18 of the damper body 16 to more than half of its circumference. In the example shown, the claw extends over about three quarters of the circumference; It could also be replaced by a surrounding the damper body 16 on its entire circumference ring.

On an inner side 19 of the claw, projections 21 are formed at uniform intervals radially inward into the cavity 20 which is encompassed by the claw. In the illustration of Figure 1, these projections 21 are elongated rib-shaped in the axial direction. but they can also have the shape of nubs, pyramids or the like, whose extent in the axial direction is the same as in the circumferential direction of the inner side 19th FIG. 2 shows an enlarged plan view of one of the vibration dampers 9 of FIG. 1. The projections 21 are shown here with a cross section in the form of a triangle, wherein a point 22 of the triangle facing away from the inner side 19 forms a depression 23 in the surface 18 of FIG Damper body 16 depresses. As can be seen in the again enlarged view of Figure 3, the surface 18 is in each case in a narrow region 24 on both sides of the tip 22 on the projection 21; between the adjacent regions 24 of two tips 22, a region 25 of the surface 18 extends without contact with the inside 19. The width of this region 25 is a multiple of the width of the adjacent region 24th

How large the areas 24, 25 and the ratio of their widths are in the individual case, depending on the cross section and height of the projections 21 are different. Various possible cross-sectional shapes are shown in FIG. 4; Thus, the tip 22 may be rounded as shown in Fig. 4a, to avoid too deep cutting into the damper body 16 and to achieve a reasonably uniform pressure distribution across the width of the region 24 in which damper body 16 and projection 21 contact each other.

A cross-section of the protrusions 21 having mutually parallel flanks 26 as shown in FIG. 4b may be selected to make the width of the region 24 substantially independent of the contact pressure and the resulting depth of the recess 23.

Fig. 5 shows an axial section through the vibration damper 9 along the plane V-V of Fig. 2. The rib-shaped projections 21 extend continuously in the axial direction from one side of the arm 8 to the other.

In the variant of FIG. 6, the rib-shaped projections 21 are each replaced by a plurality of successive projections 27 in the axial direction. The longitudinal sectional shapes of the projections 27 may be triangular or rectangular with more or less rounded tips according to the cross-sectional shapes shown in Figs. 3 and 4; in the case shown here, they are triangular sawtooth-shaped, to facilitate pushing the arm 8 on the damper body 16, but to make it difficult to peel off. To ensure that the arms 8 or the base plate 4 can not come in direct vibration transmitting contact with the wall 10, the damper body may be provided on a wall 10 facing end face with a circumferential ridge 28 whose diameter is greater than that of the cavity 20th In the same way as the projections 21 and 27 reduce the contact surface between the contact body 15 and the damper body 16 and thus facilitate a deflection of the fan 1 relative to the damper body 16, projections on the pin-shaped contact body 14 may be formed to a deflection of the Damper body 16 relative to the contact body 14 to facilitate. These projections may extend axially along the pin-shaped abutment body 14, but it may also be circumferential ribs around the abutment body 14, which contribute in addition to a tighter fit of the damper body 16 on the abutment body 14.

Fig. 7 shows a fan assembly for a refrigerator according to a second embodiment of the invention. It comprises a per se known fan 29, two damper body 30 and a fan housing 31, which is provided for unbuffered installation in a household refrigerator, in particular on a wall opening of the evaporator chamber of a no-frost refrigerator. The fan 29 is of a per se known type, with a flat parallelepiped-shaped frame 32, in which extends between the two main square surfaces, a cylindrical passage 33, mounted in the passage 33 fan 34 and housed in the hub 35 of the impeller 34 electric motor , The damper bodies 30 made of a rubber-elastic material each extend in a C-shaped manner over a vertical side 36 of the frame 32 and in each case a part of horizontal sides 37, 38.

The fan housing 31, which is provided to receive the fan 29 with the damper bodies 30 mounted thereon, is a plastic molded part in the form of a one-sided, preferably top, open box. At two adjacent to the open side 39 narrow sides 40 of the fan housing 31, a tongue 41 is cut free, so that a free end of the tongues 41 adjacent to the open side 39. The tongues 41 each form a first contact body 48 of the vibration damper according to the invention. On an inner surface 42 of the tongues 41 are projections 43, here in pyramidal shape, in two spatial directions, here in a matrix arrangement of rows and columns, distributed. Corresponding projections may be provided on an open side 39 opposite bottom side 44 of the fan housing 31. At the free end of the tongues 41 each projecting into the open side 39 locking projection 45 is formed. Fig. 8 shows the fan housing 31 with inserted fan 29 in a schematic section. The fan 29 rests on the projections 43 of the bottom side 44, wherein the tips of the projections are pressed into the damper body 30. On the left narrow side 40, the tongue 41 is in a rest position in which press their projections 43 recesses 46 in the damper body 30. The frame 32 forms a second contact body 49, which supports the damper body 30 against the pressure of the projections 43. The locking projection 45 of the right tongue 41 extends over the fan 29.

On the right narrow side 40, the tongue 41 is shown in an elastically deflected position, in which the projections 43 have no contact with the opposite damper body 30 and the locking projection 45 does not overlap with the fan 29. At rest, both tongues 41 are in the rest position, in which the fan is secured by the locking projections 45 in the fan housing 31. When both tongues 41 are in the deflected position, the locking projections 45 clear a path on which the fan 29 can be pulled out of the fan housing 31.

The tops of the locking projections 45 can, as indicated in FIG. 8 by a dashed outline on the left-hand tongue 41, be provided with an insertion bevel 47, so that the fan 29 can push the tongues 41 aside when pushed into the fan housing 31.

It is obvious that the vibration dampers described above as examples in connection with fans or their motors as vibration sources are also applicable for reducing the noise emission in any other types of vibration sources. In refrigerators come as such other sources of vibration in particular flaps or valves for air distribution from the evaporator chamber different storage compartments or for controlling the flow of refrigerant and a refrigerant flow driving compressor into consideration.

reference numeral

1 fan

2 axis

3 fan wheel

4 base plate

5 air scoops

6 electric motor

7 carrier plate

8 arm

9 vibration dampers

10 wall

1 1 distribution chamber

12 intermediate wall

13 opening

14 plant body

15 plant body

16 damper body

17 cavity

18 surface

19 inside

20 cavity

21 lead

22 tip

23 deepening

24 area

25 area

26 flank

27 advantage

28 footbridge

29 fans

30 damper body

31 fan housing

32 frames 33 passage

34 fan wheel

35 hub

36 vertical side

37 horizontal side

38 horizontal side

39 open side

40 narrow side

41 tongue

42 inner surface

43 lead

44 bottom side

45 locking projection

46 deepening

47 insertion bevel

48 plant body

49 system bodies

Claims

Vibration damper for a household electrical appliance with an elastic damper body (16, 30) and two contact bodies (14, 15, 48, 49) which are frictionally connected via the damper body (16, 30) and harder than the damper body (16, 30) characterized in that at least a first of the abutment bodies (15, 48) has a plurality of projections (21, 27, 43) through which recesses (23, 46) are formed in a surface (18) of the steamer body (16, 30). are pressed.

Vibration damper according to claim 1, characterized in that the surface (18) of the damper body (16, 30) in a region (25) between two adjacent recesses (23) without contact with the first bearing body (15, 48).

Vibration damper according to claim 1 or 2, characterized in that in a section through two adjacent projections (21), the width of a portion (24) of the surface (18) of the damper body (16) on which the damper body (16) and the Contact body (14) is greater than the width of a portion (25) of the surface (18) extending between the projections (21) without contact with the first bearing body (15, 48).

Vibration damper according to one of the preceding claims, characterized in that the projections (21, 27, 43) are arranged periodically.

Vibration damper according to one of the preceding claims, characterized in that the projections (27, 43) are distributed in two spatial directions.

Vibration damper according to one of the preceding claims, characterized in that the projections (21, 27) are elongated in a common preferred direction.

7. Vibration damper according to one of the preceding claims, characterized in that the surface (18) of the damper body (16) is prismatic or cylindrical.

8. Vibration damper according to one of the preceding claims, characterized in that the first bearing body (15) has a surface (19) which surrounds the damper body (16) on at least part of its circumference and that the projections (21) from the surface ( 19) project radially inwards. 9. Vibration damper according to claim 8, with a support plate (7) and a plurality of arms (8) which protrude in the plane of the support plate (7) from the edge and each form a first contact body (15).

10. Vibration damper according to one of the preceding claims, characterized in that the second contact body (14) in a recess (17) of the

Damper body (16) is held.

1 1. Vibration damper according to one of claims 1 to 6, characterized in that the first contact body (48) has a flat surface (42) on which the projections (43) are distributed and the first contact body (48) in a housing

(31) is arranged to be deflectable in a direction perpendicular to the surface (42).

12. Vibration damper according to claim 1 1, characterized in that the housing (31) has an inner cavity and the surface (42) of the first

Abutment body (48) is part of a wall of the cavity.

13. Vibration damper according to claim 12, characterized in that the cavity has an open side (39) that the first contact body (48) is a resilient tongue (41) extending along a side wall (40) of the cavity and one of open end (39) facing free end, and that the free end of the open side (39) narrowing locking projection (45) carries. An electric household appliance, comprising a device housing and a vibration source selected from an electric motor (6), a valve or a flap, which is fixed in the device housing via at least one vibration damper (9) according to one of the preceding claims.