KR101961075B1

KR101961075B1 - Shaft device formed of fiber plastic composite material

Info

Publication number: KR101961075B1
Application number: KR1020187007573A
Authority: KR
Inventors: 헬무트 쉬르만; 바르바라 회링
Original assignee: 호리바 유럽 게엠바하
Priority date: 2015-09-21
Filing date: 2016-09-19
Publication date: 2019-03-21
Also published as: DE102015115913A1; EP3353439A1; CN108026979A; KR20180044930A; WO2017050684A1; CN108026979B

Abstract

The shaft device comprises an inner shaft portion 1 formed of a fiber plastic composite material,

An outer shaft portion (2) formed of a fiberglass composite material surrounding said inner shaft portion (1), and an outer shaft portion

(3) formed between the inner shaft part (1) and the outer shaft part (2) at a part of the joint (3) in which the layer (4) formed of thermoplastic urethane do. The damping characteristics of the shaft device are determined according to the TPU layer.

Description

Shaft device formed of fiber plastic composite material

The present invention relates to a shaft device for torque transmission. In particular, shaft devices can be used in test benches.

The shaft device serves to transmit the torque and can be used, for example, in a test bench for transmitting torque flow between a load on one side or a driving part on the other side and a test object (for example, a combustion motor or brake) on the other side.
According to DE 10 2011 112 708 A1, it is known that the shaft body and the connecting flange use a shaft connection part composed of a fiber plastic composite (FPC).
The use of fiber plastic composites for torque transmission can reduce the mass momentum of inertia, which can have a positive impact on the overall system dynamics. However, the shaft connection formed of a fibrous plastic composite has insufficient damping for many applications. To increase damping in many cases, additional damping elements, such as vibration absorbers or rubber clutches, must be incorporated into the shaft train to reach the desired damping.
WO 2011/042486 A1 discloses a shaft device having internal and external shaft portions and a joint formed therebetween. The inner and outer shaft portions are connected to each other by a soluble layer made of thermoplastic polyurethane (TPU).
DE 102 25 796 A1 discloses a similar shaft device.

DE 10 2011 112 708 A1 WO 2011/042486 A1 DE 102 25 796 A1

It is an object of the present invention to provide a shaft device which is at least partly formed of a fibrous plastic composite material and to use it to obtain improved damping.

According to the invention, this object is solved by a shaft device having the features of claim 1. Preferred embodiments are described in the dependent claims. Such a shaft device can be advantageously used particularly in a test bench device.

The shaft device includes an inner shaft portion formed of a fiberglass composite material, an outer shaft portion formed of a fibrous plastic composite surrounding the inner shaft portion over the overlap region, and a joint formed within the overlap region between the inner shaft portion and the inner shaft portion Wherein the joint is at least partially provided with a layer formed of thermoplastic urethane (TPU).

Thus, the inner shaft portion and the outer shaft portion overlap in the overlapping region over a predetermined length, thereby forming a joint therebetween. The joint may be cylindrical and at least partially filled with TPU. The damping characteristics of the overall system can be adjusted by adjusting the shape of the joint and filling with the TPU.

Thermoplastic urethanes belong to the thermoplastic elastomer group (also known as elastoplasts). These are plastic materials that exhibit similar behavior to classical elastomers at room temperature but undergo plastic deformation under heat and cause thermoplastic behavior. Thus, TPU is a urethane-based thermoplastic elastomer.

In particular, the dimensions of the joint, such as the height or width of the joint, and a predefined damping characteristic can be obtained depending on the axial length of the TPU layer as well as the properties of the TPU material.

The fibrous plastic composite enables the shaft device to have a very low weight. The TPU has a high shear strength as compared to a general elastomer and is particularly suitable as a damping layer. Further, by using the TPU, the overlap region in which the joint length, that is, the TPU layer is formed, can be reduced.

The outer shaft portion may be formed as a hollow shaft such that the inner shaft portion may be readily disposed or placed into the hollow region.

Likewise, the inner shaft portion can be formed as a hollow shaft, on the one hand, to reduce weight and on the other hand to easily manufacture the inner shaft portion from the FPC.

The fibrous plastic composite may be, for example, a fiber reinforced plastic or a fiber composite plastic. These are materials consisting of reinforcing fibers and plastic matrices. The matrix surrounds the fibers bound to the matrix by adhesive or cohesive forces. By using the fiber material, the fibrous plastic composite obtains the elastic behavior along the direction.

Suitable fibers are inorganic reinforcing fibers such as glass fibers or organic reinforcing fibers such as, in particular, aramid fibers, carbon fibers, polyester fibers and the like. Since the FPC material is known, further explanation may be omitted here.

Carbon fiber reinforced plastic (CRP) was found to be particularly suitable for shaft devices, which are described in detail below.

The joint surface between the thermoplastic urethane layer and each associated shaft portion may at least partially comprise a layer formed of an adhesive. It has been found that linking fibrous plastic composites, especially CRP, with the TPU layer is problematic. By using an adhesive, the TPU layer can be permanently and reliably connected to the FPC material of the shaft portion. Accordingly, it is preferable that the TPU layer is at least partially adhered to the FPC shaft portion by an adhesive.

The inner shaft portion and the outer shaft portion may form a longitudinal interference fit assembly. This means that the outer diameter of the inner shaft portion is slightly larger than the inner diameter of the outer shaft portion before assembling them. Where the excess of the inner shaft portion may be only a few thousandths of a millimeter or a few hundredths of a millimeter. The inner shaft portion and the outer shaft portion are axially coupled to each other by longitudinal urging, and the TPU layer disposed therebetween is press-fitted therebetween. By this process, a stable assembly of the inner shaft portion, the TPU layer and the outer shaft portion can be obtained.

The two coupling principles discussed above, namely the adhesion of the TPU layer on the one hand and the longitudinal interference fit on the other hand, can be combined with one another to reach a certain stability.

As an alternative to longitudinal constraining assemblies, it is also possible to consider a lateral retention fitting assembly, which may also be combined with bonding the TPU layer.

According to a variant, it is possible to provide several pairs of inner shaft portions and inner shaft portions which are formed by outer shaft portions connected by thermoplastic urethane layers, wherein the pairs are arranged coaxially with respect to each other, The torque being transmitted by the pair. Thus, in the mechanical cascade connection, several pairs of inner shaft portions and outer shaft portions are provided to transmit the torque to be transmitted. The joint between the inner shaft portion and the outer shaft portion is provided with a TPU layer, respectively. Here, some of the shaft portions may be connected to the other two shaft portions overlapping each other in the overlap region. In this way, the inner shaft portion can be connected to the two outer shaft portions and vice versa.

According to an embodiment, two inner shaft portions are provided which are interconnected by a common outer shaft portion, and a TPU layer is provided at the joint between each inner shaft portion and the outer shaft portion. Thus, even if a very compact design is used, a larger (total) overlap region in which a larger amount of TPU or TPU layer is formed can be obtained. In this way, a wide range of damping values can be achieved according to the design, since the damping characteristics are determined substantially only by the TPU layer.

By distributing the TPU layer to a plurality of pairs of shaft portions, it is possible to form respective overlap regions so as to have a short axial length. This manufacturing simplifies the engagement of the shaft portion in particular.

The shaft connection described above can be advantageously used in a test bench device for testing a test object. The test bench device may include a load or drive, such as a dynamometer or an eddy current brake, which may be coupled to the test object in the coupling section. The test object may be, for example, a motor, a brake or an overall drive train. On the one hand, in the torque flow between the load or drive and on the other hand the coupling section, a shaft connection may be provided which may comprise the shaft device described above. In particular, the shaft device may comprise a shaft portion formed of an FPC and may comprise a TPU layer disposed therebetween.

Thus, by dimensioning and designing the TPU layer, the damping behavior of the shaft connection can be adjusted to a range suitable for the requirements of the test bench.

These and other advantages and features of the present invention are described in detail below based on embodiments using the accompanying drawings.

According to the present invention, improved damping can be obtained by using and providing a shaft device that is at least partially formed of a fibrous plastic composite material.

1 is a cross-sectional view of a shaft device according to a first embodiment.
2 is a sectional view of the shaft device according to the second embodiment.

1 shows a cross-sectional view of a cross section of a shaft device with an inner shaft portion 1 and an outer shaft portion 2.

The inner shaft portion 1 and the outer shaft portion 2 are made of a fibrous plastic composite material (FPC). In particular, carbon fiber reinforced plastic (CRP) has proved to be suitable here.

The outer shaft portion 2 is formed of a hollow shaft so that the inner shaft portion 1, which is also formed of a hollow shaft, is formed in a predetermined region,

).

Between the inner shaft portion 1 and the outer shaft portion 2 is formed a joint 3 provided with a layer 4 formed of thermoplastic urethane (TPU). The TPU layer 4 extends over the entire length of the joint 3,

Lt; RTI ID = 0.0 > 1 < / RTI > Likewise, it is also possible that only a portion of the joint 3 is filled with the TPU layer 4 or that the multiple TPU layers are axially offset relative to each other.

The joint 3 and thus the TPU layer 4 are formed of hollow cylinders in the example shown.

Fig. 2 shows another embodiment in which elements similar or identical to those of Fig. 1 are denoted by the same reference numerals.

The shaft device shown in Fig. 2 includes two inner shaft portions, with the inner shaft portion 1 on the left side and the inner shaft portion 1 'on the right side of the figure. The two inner shaft portions 1, 1 'are connected to the common outer shaft portion 2 on each TPU layer 4, 4'. Also in this case, the shaft portions 1, 1 ', 2 are formed of an FPC material such as CRP.

Between each pair of shaft portions 1 and 1 ', two joints - as in the embodiment of FIG. 1 - are formed, as shown in FIG. 2 (for the joint shown on the left in the drawing) 3 '(for the joint shown on the right of the figure).

Depending on the design of such a shaft device, the desired damping characteristics can be achieved by sizing the TPU layer 4 or 4 '.

Due to the high shear strength of the TPU, the joint length between the inner shaft portion 1 and the outer shaft portion 2,

May be formed as short as particularly apparent in Fig.

The series connection of the two TPU layers 4, 4 'shown in Fig. 2 can also be repeated so that the force is transmitted by several TPU elements or TPU layers.

In the TPU layers 4, 4 '

Can be kept short, the degree of freedom of design can be obtained. Further, when the shaft portion is in the long overlap region (

), The coupling process during manufacture of the shaft device can be simplified.

It has been found that TPU and CRP are difficult to combine with each other. It may therefore be advantageous to form an adhesive connection on the joint surface between each shaft portion (inner shaft portion 1, 1 ', outer shaft portion 2) to be connected to each TPU layer 4.

In addition to the adhesive connection, in the second manufacturing step, further pressure can be achieved by the longitudinal interference fit assembly. In this case, it may be advantageous that the inner shaft portion 1 is somewhat larger than the inner diameter of the outer shaft portion 2 so that the respective pressing forces can be generated. As an alternative to the longitudinal retaining assembly, a lateral retaining assembly is also possible.

By providing a TPU layer, an increase in damping and a change in the dynamic characteristics of the overall system can be achieved. In particular, the overall damping characteristics and torsional stiffness of the system can be intentionally adjusted.

Claims

An inner shaft portion (1) formed of a fiber plastic composite material;
Overlap area (

An outer shaft portion (2) formed of a fiberglass composite material surrounding said inner shaft portion (1);
The overlap region (

(3) formed between said inner shaft part (1) and said outer shaft part (2)
The joint (3) is provided at least partially with a layer (4) formed of thermoplastic urethane (TPU)
The layer 4 formed of thermoplastic urethane comprises a joining surface with respect to the inner shaft part 1 on one side and an outer shaft part 2 on the other side,
Wherein the inner shaft portion (1) and the outer shaft portion (2) form longitudinal longitudinal interference fit assemblies and / or transverse interference fit assemblies.

The method according to claim 1,
Wherein the outer shaft portion (2) is formed of a hollow shaft.

The method according to claim 1,
Wherein the inner shaft portion (1) is formed as a hollow shaft.

4. The method according to any one of claims 1 to 3,
The fiber plastic composite material is selected from the group of carbon fiber reinforced plastic (CRP), glass fiber composite material, inorganic fiber composite material, ceramic fiber composite material, aramid fiber composite material, plastic fiber composite material, natural fiber composite material.

4. The method according to any one of claims 1 to 3,
Wherein the engagement surface between the shaft portions (1, 2) associated with the layer (4) formed of thermoplastic urethane at least partially comprises a layer formed of an adhesive.

4. The method according to any one of claims 1 to 3,
There are provided a plurality of pairs each having an inner shaft portion 1 and an outer shaft portion 2 connected to the inner shaft portion 1 through a thermoplastic urethane layer 4;
The pairs being coaxially disposed with respect to each other;
Wherein the torque transmitted by the shaft device is transmitted by the pair.

4. The method according to any one of claims 1 to 3,
Two inner shaft portions (1, 1 ') connected to each other by a common outer shaft portion (2) are provided;
Wherein the joints (3, 3 ') between each inner shaft part (1, 1') and the outer shaft part (2) are provided with layers (4, 4 ') formed of thermoplastic urethane.

A test bench device for testing a test object,
A load or a driver;
A coupling section to which the test object can be coupled;
And a shaft connection provided on the one hand to the torque flow between the load or drive and on the other hand the coupling section,
Wherein the shaft connection comprises a shaft device according to any one of claims 1 to 3.

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