D e s c r i p t i o n

BEARING ARRANGEMENT FOR A BICYCLE

The invention relates to a bearing arrangement for a foot pedal of a bicycle, which has a shaft element which is arranged in a housing by means of a bearing, wherein the bearing is sealed against the environment by at least one sealing device.

A bearing arrangement according to this design is known from DE 90 14 394 Ul. Here, the foot pedal of a bicycle and specifically the shaft element of it is borne by two annular contact ball bearings. To seal the inner of the bearings against the environment a ring-shaped sealing element with a sealing lip is arranged in the axial end region of the bearing arrangement wherein the sealing element is connected with the housing and wherein the sealing lip contacts a surface of the shaft element.

DE 40 24 426 Al seals a bearing arrangement of the above design concept by employing a felt ring. The felt ring is connected with a part which is fixed to the housing and rubs against a radial seat of the shaft element.

Similar solutions are know from DE 697 21 955 Tl, CH 312 492, DE 198 56 626 Al and WO 99/04988 to seal a bearing arrangement for a foot pedal of a bicycle.

It has been found that the ability of existing sealing arrangements to seal the inner of the bearings against influences of the environment and also to keep the lubricant inside the space of the bearings could be better.

Therefore, it is an o b j e c t of the invention to improve a bearing arrangement according to the above mentioned design concept to achieve better sealing abilities. So, the lifetime of the bearing arrangement should be enlarged.

The s o l u t i o n according to the invention is characterized in that the sealing device of the bearing arrangement has a seal carrier which is arranged directly or indirectly on the shaft element, wherein at least one sealing ring with at least one sealing lip is connected to the seal carrier and wherein at least one sealing lip is in contact with the face side of the housing.

According to a preferred embodiment of the invention the contact area of the face side which is contacted by the sealing lip is flat.

An alternative embodiment of the invention is characterized in that the face side of the housing has a ring groove in which the sealing lip is partially axially inserted.

So, it is to be understood that the face side is any side region of the housing which perpendicular is orientated or directed into the axial direction of the bearing arrangement. Also the face side in the meaning of the invention can be a recess (groove) machined in the side region of the housing.

It is to be understood that the housing consists of all parts which are connected during ordinary use of the bearing arrangement, e. g. side rings or washers which are connected to the carrier element of the housing which bears the bearing and which is connected with a frame part of the bicycle.

The solution according to the concept where the ring groove is employed in which the sealing lip is partially axially inserted has preferably a design in which the ring groove has a rectangular cross section. The sealing lip can contact a first face of the ring groove which has a perpendicular oriented in axial direction of the bearing arrangement. Alternatively, the sealing Hp can contact a second face of the ring groove which has a perpendicular oriented in radial direction of the bearing arrangement. Also a combination is possible, i. e. the sealing ring can have at least two sealing lips which contact the first face of the ring groove and the second face of the ring groove.

Preferably, the bearing has two bearing elements arranged in axial distance. Here, the bearing elements can be ball bearings or roller bearings. Preferably annular contact ball bearings are employed.

A preferred embodiment has a design where at least one of the raceways of the bearings is made from a sheet metal part which is inserted onto the shaft element and/or into the housing.

It is beneficial if the housing consists at least partially, preferably completely, of plastic material.

Another solution is characterized in that the shaft element and/or the housing has at least one raceway for a ball or rolling element which is machined directly into the material of the shaft element and/or the housing. In an alternative solution the shaft element and/or the housing has at least one seat on which a raceway is arranged.

Furthermore, a raceway carrier can be arranged on the shaft element which carries a raceway for a ball or rolling element. The raceway carrier can consist of plastic material.

To further improve the sealing ability one of the raceways and/or the raceway carrier can be sealed by means of an O-ring.

Finally, the shaft element can have a tubular shape.

By the proposed design of a bearing arrangement an improved sealing effect of the bearing arrangement can be achieved. Furthermore, the weight of the arrangement can be minimized by using plastic elements instead of metal elements.

The drawings show preferred embodiments of the invention. The figures show:

Fig. 1 a radial cross section of a bearing arrangement for a foot pedal of a bicycle according to a first design,

Fig. 2 a radial cross section of such a bearing arrangement according to a second design and

Fig. 3 the left region of the housing with the sealing device according to fig. 1 in enlarged depiction.

Fig. 1 shows a bearing arrangement 1 by which a foot pedal 2 of a bicycle is borne. The foot pedal 2 has or is in the middle region a shaft element 3 which is kept in its position relatively to a housing 4 by means of a bearing 5. The bearing 5 consists of two bearing elements 5' and 5", which both are annular contact ball bearings. The housing 4 is a substantial sleeve-like element which is made from plastic material, e. g. from thermoplastic material.

To protect the bearing 5 against influences of the environment and to make sure that lubricant remains inside the space of the bearing 5 sealing devices 6 are located in both axial end regions of the housing 4.

Each sealing device 6 has a ring-shaped seal carrier 7 which is connected with the shaft 3 and rotates during use of the bearing arrangement 1. At the radial end of the seal carrier 7 a sealing ring 8 is fixed. It can be that the sealing ring 8 is connected to the seal carrier 7 by a vulcanisation process. By vulcanizing the seal carrier can partly or completely be covered with the material of the sealing ring 8. The sealing ring 8 is made of a typical sealing material, e. g. rubber, while the seal carrier 7 is preferably made of metal. The sealing ring 8 has at least one, preferably two sealing

As can be seen from fig. 1 and fig. 3 the housing 4 has a ring groove 12 at its face sides 10. The groove 12 has a substantial rectangular form in cross section with a first face 13 and a second face 14. The face 13 has a perpendicular directed in axial direction A of the bearing arrangement 1. The face 14 has a perpendicular directed in radial direction R.

As can be further seen the housing 4 has two seats 20 and 21 for receiving raceways 15 and 16 for the balls 19 of the bearing elements 5', 5". Correspondingly, the shaft element 2 is machine (turned) in that way that a seat 23 is formed for receiving a raceway 18. So, the seats 21 and 23 of the housing 4 and the shaft elements 2 together with the raceways 16 and 18 and the balls 19 form the bearing element 5".

To form the bearing element 5' a raceway carrier 24 with ring-shaped geometry (preferably made from plastic material) and with a seat 22 is pressed on the shaft element 2 in the depicted position, which receives the raceway 17. The bearing element 5' is consequently established by the raceway carrier 24, the seats 20 and 22, the raceways 15 and 17 and the balls 19.

AU raceways 15, 16, 17, 18 are made of sheet metal.

To ensure a tight seal effect an O-ring 25 is located between the raceway carrier 24 and the shaft element 3.

The embodiment according to fig. 2 has a different design insofar as the face sides 10 of the housing 4 have no groove 12 but have a flat contact area 11. This area 11 is contacted by the sealing lip 9 of the sealing ring 8.

To axially fix the different components of the bearing arrangement 1 well known methods can be used. A specific design is depicted in fig. 1 and 2.

In fig. 1 the right seal carrier 7 is pressed on a cylindrical seat 26 of the shaft element 3 until it axially contacts a shoulder 27. The raceways 15, 16, 17, 18 are arranged as explained above. The same applies for the raceway carrier 24 and the O-ring 25. To axially fix the whole arrangement the left seal carrier 7 is axially shifted into the depicted position. To fix part 7 in this position snapping elements 28 are supplied in the seal carrier 7 as well as on the shaft element 3 correspondingly.

The solution according to fig. 2 uses interlocking means 29 (spring-like elements) to axially secure the single elements to create the depicted formation of components. Here the shaft element 3 has a substantial cylindrical outer circumference.

List of reference signs

1 Bearing arrangement

2 Foot pedal

3 Shaft element 4 Housing

5 Bearing

5' Bearing element

5" Bearing element

6 Sealing device 7 Seal carrier

8 Sealing ring

9 Sealing lip 9' Sealing lip 9" Sealing lip 10 Face side of the housing

11 Contact area

12 Ring groove

13 First face of the ring groove

14 Second face of the ring groove 15 Raceway

16 Raceway

17 Raceway

18 Raceway

19 Ball / rolling element 20 Seat

1 Seat 2 Seat 3 Seat 4 Raceway carrier

25 O-ring

26 Seat

27 Shoulder

28 Snapping element

29 Interlocking means

A Axial direction

R Radial direction