CN221237111U - Improved viscous damper - Google Patents

Abstract

An improved viscous damper (1) comprising a cup-shaped element (2) and a cover (3) rigidly connected to each other to define a space (4), and a rotary element (5) accommodated in the space (4) together with a viscous medium, the cup-shaped element (2) defining at least one hole (7), the at least one hole (7) being configured to insert the viscous medium into the space (4) during assembly of the damper (1), the hole (7) in use accommodating a pin (8), the pin (8) being accommodated in the hole (7) with a predefined radial pretension.

Description

Improved viscous damper

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the priority of Italian/European Patent Application No. 102022000020292 filed on October 3, 2022, the entire disclosure of which is incorporated herein by reference.

Technical Field

The utility model relates to a damper, in particular to a viscous damper (viscous damper) used for motor vehicles.

The utility model is preferably, but not exclusively, applied to damping the vibration of the crankshaft of an internal combustion engine. The application will be mentioned below by way of example.

Background technique

In the motor industry, the amplitude of the torsional vibrations of the drive shaft is usually reduced by using dampers which are distinguished by their operating principle, ie by the way in which they are used to damp the vibrations.

Torsional vibration friction dampers have been widely used in the past in motor vehicle engines; generally speaking, the dampers consist of a flywheel driven in rotation by a drive shaft via a friction coupling; due to its high moment of inertia, the flywheel tends to exhibit a constant rotation speed, thereby damping any torsional vibrations of the drive shaft by friction.

For motor vehicle applications with higher specific power, dampers are employed that use elastic materials or viscoelastic fluids as damping means, operating on a principle similar to that cited above. In the case of viscoelastic fluid dampers, the coupling between the drive shaft and the flywheel is obtained by inserting a viscous medium, typically a silicone fluid.

The fluid is inserted into a space housing the rotating element/flywheel and delimited by a cup-shaped portion and a disk rigidly connected to the cup-shaped portion.

In the cup-shaped portion, a hole is usually provided which allows the introduction of a viscous medium into the space housing the rotating element/flywheel, once the disc is rigidly connected to said cup-shaped portion.

The hole is usually closed by a plug element, as described, for example, in patents JP2007177851, JP2007177852 or WO96/27748A1.

However, the above-mentioned closures are not effective in sealing, also in view of the variations in operating temperatures to which the damper is subjected.

Therefore, it is necessary to provide a viscous type damper which has high sealing performance so as to prevent the viscous medium from flowing out.

The object of the present invention is to meet the above-mentioned needs in an optimized and inexpensive manner.

Utility Model Content

The above objects are achieved by a viscous damper 1, which rotates about an axis A and comprises a cup-shaped element 2 and a cover 3 rigidly connected to each other to define a space 4; the damper 1 comprises a rotating element 5 accommodated in the space 4 together with a viscous medium, the cup-shaped element 2 defining at least one hole 7, at least one hole 7 being configured to insert the viscous medium into the space 4 during assembly of the damper 1; the hole 7 accommodates a pin 8 in use, the pin 8 is accommodated in the hole 7 with a predefined radial preload, the pin 8 is a chamfered pin,

Therein, the rotary element 5 defines a seat 9 at the at least one hole 7 , the seat 9 being annular around the A axis and radially coinciding with the axis of the at least one hole 7 .

In particular, the pin 8 is made of aluminium or steel.

Advantageously, the cup-shaped element 2 and/or the cover 3 are made of aluminium or steel.

In particular, the viscous medium is silicone oil.

Preferably, the rotating element 5 is accommodated relative to the cup-shaped element 2 and/or the cover 3 by means of sliding support means.

In particular, the sliding support device comprises at least one bushing 6 .

In detail, the cup-shaped element 2 comprises an outer cylindrical portion 2a, a radial portion 2b and an inner cylindrical portion 2c, at least one hole 7 being provided on the radial portion 2b.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the present invention, preferred embodiments are described below by way of non-limiting examples and with reference to the accompanying drawings, in which:

· FIG1 is a radial cross-sectional view of a viscous damper according to the utility model;

FIG. 2 is an enlarged view of a portion of the viscous damper of FIG. 1 .

Detailed ways

FIG. 1 shows a viscous damper 1 according to the present invention, which mainly comprises an annular cup-shaped element 2 rotating around an A-axis.

The cup-shaped element 2 is advantageously mounted on a rotating hub (not shown) which is driven in rotation about the axis A by the shaft of the internal combustion engine.

Specifically, the cup-shaped member 2 mainly includes an outer cylindrical portion 2a, a radial portion 2b cantilevered radially from one end of the outer cylindrical portion 2a relative to the A axis, and an inner cylindrical portion 2c connected to the radial wall 2b at one end thereof.

Advantageously, the outer cylindrical portion 2a comprises a cylindrical wall coaxial with the A axis, the radial portion 2b comprises a wall extending perpendicularly to the outer cylindrical portion 2a, and the inner cylindrical portion 2c is connected at one end to the same side of the outer cylindrical portion 2a and is shaped to allow it to be fixed to the above-mentioned hub.

Preferably, the cup-shaped element 2 is made of a metallic material, such as aluminum or steel.

The damper 1 further comprises a cover 3 carried by the cup-shaped element 2 and configured to define a space 4 together with the outer cylindrical portion 2 a , the radial portion 2 b and the inner cylindrical portion 2 c of the cup-shaped element 2 .

In particular, the cover 3 is rigidly connected (for example fixed by welding) to the outer cylindrical portion 2a and the inner cylindrical portion 2c on the opposite side of the radial portion 2b. Thus, the space 4 is axially delimited by the radial portion 2b and the cover 3 along the A axis, while it is radially delimited between the outer cylindrical portion 2a and the inner cylindrical portion 2c relative to the A axis.

Thus, according to the above, the cover 3 has an annular shape and is advantageously a flat element, such as an annular disk.

As known per se, the dimensions of the space 4 are suitable for housing a rotating element 5, advantageously of annular shape and configured to rotate about an axis A. Preferably, the rotating element 5 is made of a metallic material, such as aluminium or steel.

Advantageously, the rotating element 5 is supported relative to the cup-shaped element 2 by means of a sliding support. Advantageously, the sliding support comprises a bushing 6, such as an L-shaped bushing. In particular, the bushing 6 is interposed between the rotating element 5 and the inner cylindrical portion 2c; more preferably, it is L-shaped, and they are respectively located between the rotating element 5, the inner cylindrical portion 2c and the cover 3, and between the rotating element 5, the inner cylindrical portion 2c and the radial portion 2b.

In addition to the rotating element 5, the space 4 is configured to accommodate a viscous medium, such as, for example, a silicone fluid. In order to insert the viscous medium, the cup-shaped element 2 defines a hole or several through holes 7, which are configured to allow the space 4 to communicate with the outside. In the illustrated embodiment, the above-mentioned hole 7 is arranged in the radial wall 2b. Obviously, there can be several holes 7, as shown, for example, in FIG. 1, which is only for illustrative purposes.

Near the orifice 7 , in particular at its axis, the rotary element 5 may additionally define a seat 9 configured to facilitate the insertion of fluid inside the space 4 , avoiding overpressure during fluid injection and acting as a “reservoir” during damper operation.

Advantageously, seat 9 has an annular shape coaxial with axis A and radially coincident with the axis of hole 7 .

The viscous damper further comprises a pin 8, which is configured to be received inside the hole 7 as a seal so as to isolate the space 4 from the external fluid. In particular, the pin 8 is received inside the hole 7 with radial preload.

In more detail, the axial dimension of the pin 8 is smaller than the thickness of the wall and the cup-shaped element 2 .

Advantageously, the pin 8 is chamfered so that it can be chamfered at the outside of the wall of the cup-shaped element 2 relative to the space 4 .

In particular, the pin 8 has a substantially cylindrical shape, and chamfers are provided at the axial ends.Preferably, the pin 8 is made of a metallic material, such as aluminum or steel.

The operation of the above described viscous damper embodiment is as follows.

In a standard operating procedure, the cup-shaped element 2 is driven by the hub to which it is connected. The rotation of the cup-shaped element 2 causes the viscous medium to rotate, which, due to the viscosity of the viscous medium, drives the rotating element 5 to rotate with an angle delay. The friction generated due to the deflection resistance between the rotating element 5 and the cup-shaped element 2 suppresses the vibration of the hub 2, which is known per se.

The damper 1 is assembled as follows. The rotating element 5 is inserted in the cup-shaped element 2 of the insertion slide; the rotating element is closed by a cover 3 welded to the cup-shaped element. When the cup-shaped element 2 is turned over, the space 4 is filled with a viscous medium through at least one hole 7; then, the pin 8 is pushed in and chamfered to completely seal the hole 7.

It can be seen from the above that the advantages of the viscous damper according to the utility model are obvious.

A good seal and simple assembly are ensured by compression of the pin inserted into the hole.

Likewise, the fact that the pin is chamfered increases the sealing of the damper, since the chamfered material ensures the seal between the pin 8 and the hole 7 .

Finally, it is obvious that modifications and variations may be made to the viscous damper according to the invention without departing from the scope of protection defined in the claims.

Obviously, the constituent elements of the damper, the shape of the rotating element and the nature of the viscous medium may vary.

Similarly, the number of pins and holes can be increased, made of different materials and have different shapes. In particular, they can be calibrated for different preload forces.

Claims (7)

1. A viscous damper (1) rotatable about an axis (a) and comprising a cup-shaped element (2) and a cover (3) rigidly connected to each other to define a space (4), characterized in that the viscous damper (1) comprises a rotatable element (5) accommodated in the space (4) together with a viscous medium, the cup-shaped element (2) defining at least one hole (7), the at least one hole (7) being configured to insert the viscous medium into the space (4) during assembly of the viscous damper (1), the at least one hole (7) accommodating, in use, a pin (8), the pin (8) being accommodated in the at least one hole (7) with a predefined radial pre-tension, the pin (8) being a chamfer-treated pin,

Wherein the rotary element (5) defines a seat (9) at the at least one hole (7), the seat (9) being annular about the axis (a) and radially coinciding with the axis of the at least one hole (7).

2. Viscous damper according to claim 1, characterized in that the pin (8) is made of aluminium or steel.

3. Viscous damper according to claim 1, characterized in that the cup-shaped element (2) and/or the cover (3) are made of aluminium or steel.

4. A viscous damper according to any one of claims 1-3, characterized in that the viscous medium is silicone oil.

5. A viscous damper according to any one of claims 1-3, characterized in that the rotary element (5) is accommodated relative to the cup-shaped element (2) and/or the cover (3) by sliding support means.

6. Viscous damper according to claim 5, characterized in that the sliding support means comprise at least one bushing (6).

7. A viscous damper according to any one of claims 1-3, characterized in that the cup-shaped element (2) comprises an outer cylindrical portion (2 a), a radial portion (2 b) and an inner cylindrical portion (2 c), the at least one hole (7) being formed on the radial portion (2 b).