DE8711633U1 - Torque transmission coupling - Google Patents

Description

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PATENT ATTORNEYS DiF£,',«Ifrü,'K. WiE&iacgr;pKpf tf, DfPL ₁ -P ¹ HYS. Dr, KiFlNCKE

Dipl^InGi R A-WEiCKMANN,- Dipl.-Ghem, B, Hüber Drying. H. LiSKA, Dipl.-Phys. Dr. J,

8ÖÖ0 MUNICH 86 P.O. BOX 860 820 MOHLSTRASSE &ugr;

TELEi=ON (OgD) 98 03 52 B TO Se TELEX 522621

Fahrzeugteile GmbH ft Co.KG telegramm patentweiocmann Munich Ketschendorfer Straße 38 - 48
D-8630 Ceburg

Torque transmission clutch (with internal priority from G 86 27 248)

The innovation relates to a torque transmission coupling with a flexible shaft, both ends of which are connected in a rotationally fixed manner to connecting pieces, wherein at least one of the ends is formed by an end piece with a non-circular cross-section, which is inserted into a complementary driving opening of the connecting piece.

Torque transmission couplings of this type, for example in motor vehicles, are used to transmit torque between two components, for example an engine block and a gear unit of a seat adjustment. The flexibility of the shaft results in a simplified assembly and the possibility of relative movement of the connected components relative to each other. The shaft can be mounted in a casing that does not follow the shaft rotation. The coupling of the shaft to the components is usually carried out via a plug-in coupling, which is connected by an end piece with a non-circular cross-section, in particular a square end piece, the shaft and

a complementary drive opening for the respective connecting piece. The flexible shaft consists of used spring wire or the like in order to ensure the required mechanical strength. Accordingly, the respective end piece is also made of metal. In order to avoid the high manufacturing costs that arise when the end piece is fitted precisely into the drive opening, the connecting piece is made with a smaller dimension in relation to the

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1Ö so that there is a corresponding clearance between the end piece and the drive opening. The disadvantage of this, however, is that due to this clearance, when the flexible shaft rotates, alternating loads can occur with corresponding noise development and increased wear, namely when different contact surfaces of the end piece alternately strike the corresponding counter surfaces of the drive opening. This is particularly the case when the flexible shaft is connected to the connecting piece

is bent so that corresponding tilting moments act on the |

end piece rotating in the drive opening.

The purpose of the innovation is to ensure smoother running of a torque » transmission coupling of the type mentioned above.

This task is solved by coating at least the end piece of the shaft, preferably the entire shaft, with plastic.

The plastic coating of the end piece allows for a reduction in the assembly play , especially because the flexibility of the plastic allows for a slight oversize of the end piece including the plastic layer. Furthermore, the plastic layer dampens the play-related impacts of the end piece in the drive opening and reduces the noise accordingly. When using a sleeve surrounding the shaft, the plastic coating ensures

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Coating of the shaft for a smooth, low-friction run of the shaft in the casing.

Polyacetal is particularly preferred as a material for plastic coating, as this material is characterized by high wear resistance and low friction coefficient. This material is also easy to process, especially in the powder coating process.

Polyacetal type PA 11 or PA 12 has proven to be particularly favorable.

The running of the shaft within the casing is further improved by coating the inside of the casing with plastic, preferably polyacetal.

It has been found that during operation, especially when starting, the end piece can hit the bottom of the drive opening. Such impacts due to the corresponding axial movement of the end piece within the drive opening also occur when a corresponding functional part connected to a drive motor via the torque transmission coupling reaches a stop position. To dampen these impacts and thus improve smooth running, it is suggested to attach a damper plug to the end piece, which can be made of rubber or other elastic plastic, for example.

It is particularly preferred that the damper plug be formed as a single piece with the coating of the end piece or shaft. Alternatively, the damper plug made of rubber can also be vulcanized onto the end piece at the front.

&iacgr; The invention is explained using the drawings and a preferred embodiment.

Here you can see a shaft 5 12 guided in a casing 10, the left end of which is shown in the figure and is inserted into a hole 14 of a component 16 not shown in detail. The other end can be connected in the same way to another component, for example an engine block. The shaft 12 consists of

10 direct spring wire and has a circular cross-section, as indicated by dashed lines in the figure. The shaft 12 merges into an end piece 18 with a square cross-section. This end piece 18 is inserted into a complementarily shaped drive opening 20 of the connecting piece 14.

15. The cover 10 is attached to the component 16 as shown by

symbolized by two broken lines 22* A rotation i of the shaft 12 within the casing therefore results in a rotation of the connecting piece 14*

I 20 The shaft 10, including its end piece 18, is covered with a plastic layer 24 made of polyacetal of type PA 11 or PA 12. Likewise, the inside of the casing 10 can be covered with a plastic layer 26

I must be made of appropriate material.

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The plastic layers 24, 26 ensure low-friction, smooth shaft movement. The plastic-coated end piece

&rgr; 18 has at most a small amount of play within the j drive opening 20. Any slight impact movements

&bull; 30 between end piece 18 and driving opening 20 are dampened by the plastic layer 24.

I To dampen impacts of the end piece 18 against the I bottom 28 of the drive opening 20 (direction of movement A in the j 35 figure), a damper plug is provided on the front side of the end piece 18

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made of shock-absorbing material. Particularly simple i manufacture as well as a simple, mechanically stable connection of plug 30 and shaft 10 is achieved by one-piece ·'

Formation of the plastic layer 24 with the plug 30. So- |

far a circumferential coating of end piece and shaft is not i

If necessary, the damper plug can also be attached to the front of the uncoated end piece in a manner not shown. If the damper plug is made of rubber, it is vulcanized onto the end piece for the sake of simplicity.

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Claims (7)

Patent attorneys Dipl.-Ing. H;. ^e*i'skma°nn;*Dipl.-Phys. Dr. K. Fincke Dipl.-Ing. RA. "^Ei ckm ann, Dipl.-Chem. B. Huber Dr.-Ing. H. Liska, Dipl.-Phys. Dr. J. Prechtel PREWI ⁸⁰⁰ ° ^{mOnchen S6} PO BOX 860 820 2 7. AUJJ· 1987 MÖHLSTRASSE TELEPHONE (0 89) 910352 TELEX 522621 £S &Ggr;O S &bgr; TELEGRAM PATENTWUCKMANN MÖNCHEN Vehicle Parts GmbH & Co.KG
Ketschendorfer Strasse 38 - 48 D--3630 Coburg Torque transfer sk up &rgr; 1 un g (with internal priority from G 86 27 248) Protection claims 1. Torque transmission coupling with a flexible shaft (12), both ends of which are connected to connecting pieces in a rotationally fixed manner, with at least one of the ends being formed by an end piece (18) with a non-circular cross-section, which is inserted into a complementary driving opening (20) of the connecting piece (14), characterized in that at least the end piece (13) of the shaft (12), preferably the entire shaft (12), is coated with plastic. 2. Torque transmission coupling according to claim 1, characterized in that the plastic is formed with polyacetal. 3. Torque transmission coupling according to claim 2, characterized in that the plastic is made of polyamide of type PA 11 or PA 12. I I I I -2- 4. Torque transmission coupling according to one of the preceding claims with a sleeve (10) surrounding the shaft (12),
characterized in that the inside of the cover (10) is coated with plastic, preferably with polyacetal. 5. Torque transmission coupling according to one of the preceding claims or the preamble of claim 1, characterized by a damper plug (30) attached to the front side of the end piece (18). 6. Torque transmission coupling according to claim 5, characterized in that the damper plug (30) is formed integrally with the coating (plastic layer (24)) of the end piece (18). 7. Torque transmission coupling according to claim 5, characterized in that the rubber-formed air plug is vulcanized onto the front side of the end piece. &igr;« &igr;&igr; t &igr; Ii