DE102022200155B3 - Arrangement with a bottom bracket gear for a bicycle or pedelec - Google Patents

Abstract

An arrangement with a bottom bracket gear (2) arranged in a housing (1) for a bicycle or pedelec (3) is proposed, wherein at least one oil sump (5) for oil supply is assigned to a bottom area (4) of the housing (1), whereby at least one oil collection area (6) separate from the oil sump (5) is provided for temporarily receiving a predetermined quantity of oil, with oil being drawn from the oil sump (5) during operation into the oil collection area ( 6) can be pumped to temporarily lower the oil level (7) in the oil sump (5). A bicycle or pedelec (3) with the arrangement is also proposed.

Description

The present invention relates to an arrangement with a bottom bracket gear arranged in a housing for a bicycle or pedelec. Furthermore, the invention relates to a bicycle or pedelec with the arrangement.

Bottom bracket gears for conventional bicycles or e-bikes or pedelecs are operated with grease lubrication or oil lubrication. Here, in particular, an oil sump lubrication is used, in which the oil sump with the oil for the oil supply is assigned to a bottom area of the housing. The oil sump lubrication preferably uses low-viscosity, smooth-running oil for encapsulated gear designs in order to keep the drag torque losses as low as possible. At the same time, however, targeted cooling and lubrication is also necessary for tribological areas of the transmission that are located radially on the inside and are difficult to access, so that a sufficient oil level in the oil sump is required. This results in the problem between, on the one hand, sufficient filling quantity for adequate lubrication and cooling of the components and, on the other hand, the resulting drag losses due to the components immersed in the oil.

From the pamphlet DE 10 2020 207 252 A1 a transmission for motor vehicles is known in which a compensating tank is provided which is designed to collect oil from the interior, the compensating tank being fluidically connected to the oil sump via at least one return. Oil is pumped from the oil sump into the expansion tank via submerged transmission components.

The pamphlet DE 10 2005 005 154 A1 also discloses a vehicle with a transmission in which, in addition to an oil sump, a transmission oil reservoir is provided in the transmission housing and is connected to the oil sump via a fluid path. If the vehicle is not in operation, oil can be pumped through the transmission components into the transmission oil reservoir when towing, for example, in order to lower the transmission oil level.

From the pamphlet DE 10 2009 009 648 A1 a transmission with an oil pan for a motor vehicle is also known, in which the oil pan is arranged pivotably in the housing and has a plurality of holes for lowering the oil level.

Furthermore, from the pamphlet DE 10 2017 005 825 A1 a bicycle power unit is known in which a case is provided with an oil pan at the bottom portion to receive oil from a sprocket.

The pamphlet CN 2 12 500 785 U discloses a bicycle with an automatic grease leveling mechanism for a mid-engine transmission.

Finally, from the pamphlet DE 10 2020 102 986 A1 a pedal generator with planetary gears is known, in which a lubricant supply is provided. A planetary gear carrier of the planetary gear has an oil guiding device for guiding oil in order to guide the oil to the planetary gears. The Ölleitvorrichtung is formed by several ribs.

The present invention is based on the object of proposing an arrangement and a bicycle or pedelec with the arrangement in which adequate lubrication and cooling of the bottom bracket gear is provided with the lowest possible drag torque losses.

This object is achieved according to the invention by the features of patent claims 1 and 12, respectively. Advantageous and claimed developments result from the dependent claims and the description as well as the drawings.

Accordingly, an arrangement is proposed with a bottom bracket housing arranged in a housing for a bicycle or pedelec, wherein at least one oil sump for supplying oil is assigned to a bottom area of the housing. In order to achieve an adequate oil supply with the lowest possible drag losses, it is provided that at least one oil collection area, separate from the oil sump, is provided for temporarily collecting a predetermined amount of oil, with oil from the oil sump via rotating components or the like immersed in the oil in the oil sump during of operation can be conveyed into the oil collection area to temporarily lower the oil level in the oil sump.

With the proposed arrangement, a drag torque-reducing oil supply is realized in the bottom bracket gear of a bicycle or pedelec by lowering the oil level by transferring the oil from the oil sump into the oil collection area or into the oil bunker as an oil equalization space. Due to the constant circulation of the oil in the oil collection area and the associated direct oil wetting of the enlarged inner wall of the transmission housing around which the flow occurs, efficient cooling of the oil and thus also of the components cooled by the oil is achieved in a particularly advantageous manner.

It is preferably provided within the scope of the invention that the oil collection area is arranged essentially above the central axis of the bottom bracket gear in the housing. In this way the oil can flow back into the oil sump from the oil collection area independently but with a delay due to gravity. The oil level is temporarily lowered due to the delayed return flow of the oil into the oil sump.

In order to be able to set a desired oil level in the oil sump for a predetermined period of time, it is necessary to control an amount of oil flowing out of the oil collection area. A particularly structurally simple solution for this can be realized in that the oil collection area has at least one throttle element or the like as an oil outlet for reducing the amount of oil flowing out, so that the amount of oil flowing into the oil collection area is greater than the amount of oil flowing out of the oil collection area.

In order to filter the oil in a particularly simple manner and thus increase the wear and tear and the service life of the bottom bracket gearbox, it is provided that at least one clamping magnet is provided in the oil collecting area. In order to be particularly effective, the clamping magnet can preferably be arranged in a lower flow-calmed area of the oil collecting area.

Within the scope of the present invention, the oil collection area can be designed as a separate push-in component, for example made of plastic or the like. However, it is also conceivable for the oil collection area to be designed in a quasi-integral manner with the housing, for example by providing a housing recess or the like in the interior of the housing for the oil collection area.

Depending on the design and type of the bottom bracket gear, different components can be used to convey the oil into the oil collection area in the proposed arrangement. In the case of a bicycle without an additional electric drive, for example, at least one brake ring or the like of a shift actuator system for actuating shifting elements of the bottom bracket gear mechanism to set different gear ratios can be provided as a rotating component for pumping the oil into the oil collecting area, with the oil collecting area being located approximately radially on the outside in relation to the brake ring is arranged in the housing.

In order to increase the pumping capacity of the oil from the oil sump into the oil collection area, it can be provided within the scope of the invention that the brake ring has several transport pockets or the like along the outer circumference for receiving the oil when it is immersed in the oil sump. It is particularly structurally simple and cost-effective if the existing toothing is redesigned for this purpose, so that the teeth of the toothing are designed as a kind of conveying pockets.

To optimize the oil supply in the bottom bracket gearbox, the oil collecting area is arranged in the housing such that the oil outlet of the oil collecting area is assigned to a shift drum of the shift actuator of the bottom bracket gearbox for oil supply, for example.

If, for example, the proposed arrangement is used for a pedelec with an additional electric drive, it can be provided that a primary drive or the like for transmitting a drive torque, for example, arranged axially parallel to the bottom bracket gear, can be used as a rotating component for conveying the oil from the oil sump into the oil collection area Machine is provided on an output of the bottom bracket gear. The primary drive can, for example, be connected in such a way that it rotates constantly, as a result of which the oil can be pumped continuously from the oil sump to the oil collection area. The oil can be conveyed from the oil sump to the oil collection area by the rotating primary drive.

It is possible, for example, for ribbing and/or indentations or the like to be provided to increase the surface area in the oil collection area. B. the electric machine can be discharged particularly efficiently from the oil. In the case of an application for e-bikes and pedelecs, the oil collection area integrated into the housing is preferably introduced directly next to the stator of the electric machine, which is pressed into the housing bore without play, so that the electric machine is cooled particularly advantageously via a short heat conduction path to the oil collection area.

In order to further improve the efficiency of the oil production via the primary drive, for example as a chain or belt drive or spur gear drive, it can be provided that an oil inlet of the oil collection area is assigned, for example, an oil baffle or the like for the direction-controlled supply of the oil, the oil baffle supporting the primary drive at least partially surrounded. The oil baffle is preferably designed as a 1-part inflatable plastic part or as a multi-part plastic injection-moulded part with a main body and a clipped-in or welded-on cover.

The arrangement position of the primary drive with the oil baffle can accordingly in the housing can be selected in order to achieve an optimal oil supply. For example, if a rotor shaft of the electric machine can be connected or is connected to the output of the bottom bracket gearbox via at least one planetary gear set as a reduction gear set and the primary drive, the primary drive with the oil pan can be arranged between the electric machine and the planetary gear set, viewed axially, so that not only the bottom bracket gearbox but also the electrical machine and the planetary gear set are sufficiently supplied with oil.

If the components in tribological contact are lubricated and cooled by preferably filling them with low-viscosity low-viscosity oil, the two chambers of the multi-stage bottom bracket gearbox and the reduction gear set of the electric motor are preferably designed in such a way that they can be opened via the passage for the chain, belt or spur drive pinion of the Primary drive are connected to each other and thus form a common oil budget. In this special case, the sealing between the oil and the outside area takes place via a radial shaft seal or a sealed ball or roller bearing, which are arranged axially between the primary and a secondary drive for driving a wheel of the bicycle or pedelec. It is also conceivable to place the stator and the rotor of the electric motor directly in this open oil chamber, whereby the windings of the stator, where the heat loss occurs and thus the hotspot of the electric motor, are wetted directly with the oil-air mixture and cooled very efficiently. Furthermore, it is possible to delimit the reduction gear set, including the primary drive, from the stator and rotor of the electric motor before oil can enter the electric motor by means of a wall that is sealed off from the rotor shaft. As a result, the electrical machine can be operated in the dry room with reduced drag torque losses by avoiding oil shearing in the air gap.

A further aspect of the present invention relates to a bicycle or pedelec with the arrangement described above, resulting in the advantages already described and other advantages.

The present invention is explained in more detail below with reference to the drawings.

• 1 eine schematische geschnittene Ansicht einer ersten Ausführungsvariante einer erfindungsgemäßen Anordnung mit über Bremsringe als rotierende Bauteile zur Förderung des Öls in einen Ölsammelbereich zur Ölversorgung des Tretlagergetriebes;
• 2 eine schematische geschnittene Seitenansicht der ersten Ausführungsvariante der Anordnung mit einem als separates Einschiebeteil ausgebildeten Ölsammelbereich;
• 3 eine schematische geschnittene Seitenansicht der ersten Ausführungsvariante der Anordnung mit einer Gehäuseausnehmung als Ölsammelbereich;
• 4 eine schematische geschnittene Seitenansicht einer zweiten Ausführungsvariante mit einem Primärtrieb als rotierendes Bauteil zur Förderung des Öls in den Sammelbereich zur Ölversorgung in dem Gehäuse;
• 5 eine schematische geschnittene Ansicht einer ersten Anordnungsmöglichkeit des Primärtriebes mit einer Ölfangschale gemäß 4; und
• 6 eine schematische geschnittene Ansicht einer zweiten Anordnungsmöglichkeit des Primärtriebes mit der Ölfangschale gemäß 4.

Show it:

• 1 a schematic sectional view of a first embodiment of an arrangement according to the invention with brake rings as rotating components for promoting the oil in an oil collection area for oil supply of the bottom bracket gear;
• 2 a schematic sectional side view of the first embodiment variant of the arrangement with an oil collection area designed as a separate insertion part;
• 3 a schematic sectional side view of the first embodiment of the arrangement with a housing recess as an oil collecting area;
• 4 a schematic sectional side view of a second embodiment variant with a primary drive as a rotating component for promoting the oil in the collection area for oil supply in the housing;
• 5 a schematic sectional view of a first possible arrangement of the primary drive with an oil drip tray according to 4 ; and
• 6 a schematic sectional view of a second arrangement possibility of the primary drive with the oil drip tray according to 4 .

In the 1 until 6 Various views and design variants of an arrangement according to the invention with a bottom bracket gear 2 arranged in a housing 1 for a bicycle or pedelec 3 for oil supply are shown merely as examples, with the bottom bracket gear 2 being connected to the drive wheel of the bicycle or pedelec 3 via a secondary drive 22. A chain or belt drive is provided as the secondary drive 22 , for example.

In the proposed arrangement, a bottom area 4 of the housing 1 is assigned an oil sump 5 for oil supply. In order to realize an efficient oil supply, it is provided that at least one oil collection area 6, which is separate from the oil sump 5, is provided for temporarily collecting a predetermined quantity of oil, with oil from the oil sump 5 being pumped during operation into the Oil collection area 6 for temporarily lowering the oil level 7 in the oil sump 5 can be conveyed.

Irrespective of the respective embodiment variants, it is provided that the oil collection area 6 is arranged essentially above a center axis 8 of the bottom bracket gear 2 in the housing 1 . The oil collecting area 6 has a throttle element 20 as an oil outlet for reducing the amount of oil flowing out, so that the amount of oil flowing into the oil collecting area 6 is greater than the amount of oil flowing out of the oil collecting area 6 . For example, a clamping magnet 9 is provided for oil filtering in the oil collection area 6 . The clamping magnet 9 is below provided in the area of the oil outlet in the oil collection area or container 6 .

In 1 a first variant is shown, in which at least one brake ring 10 of a shift actuator system for actuating shifting elements of the bottom bracket gearbox 2 for shifting different gear ratios is provided as a rotating component for conveying the oil into the oil collecting area 6, with the oil collecting area 6 in relation to the brake ring 10 being approximately is arranged radially on the outside of the housing 1.

According to 2 is provided in the arrangement that the oil collection area 6 is designed as a separate push-in component, for example made of plastic or the like. Thus, the oil collection portion 6 can be slid into the housing 1 as a unit. To improve the delivery of the oil from the oil sump 5 into the oil collection area 6 to reduce the oil level 7, delivery pockets 11 are provided on the circumference of the brake ring 10 for receiving the oil when it is immersed in the oil sump 5 in the manner of a bucket wheel delivery. The normal oil level and the oil level lowered by the oil extraction 7 are in 2 also implied. In addition, the oil level 23 in the oil collection area 6 is shown.

In 3 For example, the oil collection area 6 is designed as a housing recess in the interior of the housing 1 . as well as in 2 the oil outlet of the oil collection area 6 is arranged radially above the shift drum 12 of the bottom bracket gear 2, so that the oil escaping from the oil collection area 6 can be used to lubricate the shift drum 12. The housing recess for forming the oil collection area 6 can be directly embedded in the housing 1, for example by a cast pocket or machining, and the throttled discharge of the oil can be designed as a bore or a milled or cast groove.

In the 4 until 6 a second embodiment variant of the arrangement according to the invention is shown, in which a primary drive 13 is provided as a rotating component for conveying the oil from the oil sump 5 into the oil collection area 6 for transmitting a drive torque of an electric machine 14 arranged axially parallel to the bottom bracket gearbox 2 to an output 15 of the bottom bracket gearbox 2 is. For this purpose, a rotor shaft 21 of the electric machine 14 is connected or can be connected via a planetary gear set 17 as a reduction gear set and the primary drive 13 to the output 15 of the bottom bracket gearbox 2, with the primary drive 13 being arranged with an oil baffle 16 viewed axially between the electric machine 14 and the planetary gear set 17 is.

It is provided that an oil inlet of the oil collection area 6 is assigned the oil guide shell 16 for the direction-guided supply of the oil, the oil guide shell 16 surrounding the primary drive 13 at least in sections. For example, a belt or chain drive, spur drive or the like can be used as the primary drive 13 . The oil is conveyed from the oil sump 5 via the oil baffle 16 into the inlet of the oil collection area 6 by the rotating components of the primary drive 13 . The oil collection area 6 has the chipping magnet 9 for removing metallic chips from the oil. The oil outlet of the oil collection area 6, which is provided with the throttle element 20, for example, is assigned to a shift drum 19 of the shift actuator system of the planetary gear set 17 as a reduction gear set for the electric machine 14, so that the shift drum 19 is also supplied with oil. The shift drum 19 and then the shift drum 12 underneath it of the shift actuator system of the bottom bracket gear 2 are first supplied with oil from the oil collection area 6 before the oil returns to the oil sump 5 . means arrows are in 4 the oil flow in the housing 1 and the direction of rotation of the rotating components are indicated.

In 5 a schematic sectional view of the pedelec 3 is shown with the second embodiment variant of the arrangement according to the invention, in which a first possible arrangement of the primary drive 13 is shown. Here it is provided that the planetary gear set 17 as a reduction gear set for the electric machine 14 is arranged on a side of the primary drive 13 facing away from the electric machine 14, viewed axially, so that the planetary gear set 17 is arranged between the primary drive 13 and a pedal crank 18 of the pedelec 3, viewed axially .

In 6 the second embodiment variant of the arrangement according to the invention is shown, in which a second possible arrangement of the primary drive 13 is shown. It is provided here that the planetary gear set 17 is arranged on the side of the primary drive 13 facing away from the pedal crank 18 . Both in the first and in the second possibility of arranging the primary drive 13 , the primary drive 13 is arranged between the planetary gear set 17 and the electric machine 14 when viewed axially.

Reference List

1

Housing

2

bottom bracket gear

3

bicycle or pedelec

4

bottom area of the housing

5

oil sump

6

oil collection area

7

oil level

8th

Center axis of the bottom bracket gear

9

chip magnet

10

Brake ring of the shift actuator of the bottom bracket gear

11

Delivery pockets on the brake ring

12

Shift drum of the shift actuator of the bottom bracket gearbox

13

primary drive

14

electric machine

15

downforce

16

oil baffle

17

Planetary gear set as a reduction gear set

18

crank

19

Shift drum of the shift actuator of the planetary gear set

20

throttle element

21

Rotor shaft of the electric machine

22

secondary operation

23

Oil level in the oil collection area

Claims (12)

Arrangement with a bottom bracket gear (2) arranged in a housing (1) for a bicycle or pedelec (3), wherein at least one oil sump (5) for oil supply is assigned to a bottom area (4) of the housing (1), at least one of the oil sump (5) a separate oil collection area (6) is provided for temporarily receiving a predetermined amount of oil, oil from the oil sump (5) being poured into the oil collection area (6) temporarily during operation via rotating components immersed in the oil in the oil sump (5). lowering of the oil level (7) in the oil sump (5) and wherein the oil collection area (6) is arranged in the housing (1) in such a way that the oil outlet of the oil collection area (6) of a shift drum (12) of a shift actuator system for actuating shift elements of the Bottom bracket gear (2) is assigned or that the oil outlet of the oil collecting area (6) of a shift drum (19) is assigned to a shift actuator of a planetary gear set (17) for an electric machine (16). is. arrangement according to claim 1 , characterized in that the oil collection area (6) is arranged essentially above the central axis (8) of the bottom bracket gear (2) in the housing (1). arrangement according to claim 1 or 2 , characterized in that the oil collecting area (6) has a throttle element (20) as an oil outlet for reducing the amount of oil flowing out of the oil collecting area (6), so that the amount of oil flowing into the oil collecting area (6) is greater than the amount of oil flowing out of the oil collecting area (6 ) is. Arrangement according to one of the preceding claims, characterized in that the oil collection area (6) is designed as a separate push-in component. Arrangement according to one of Claims 1 until 3 , characterized in that the oil collection area (6) is designed as a housing recess in the interior of the housing (1). Arrangement according to one of the preceding claims, characterized in that at least one brake ring (10) of a switching actuator system for actuating switching elements of the bottom bracket gear (2) is provided as a rotating component for conveying the oil into the oil collecting area (6), the oil collecting area (6) relative to the brake ring (10) is arranged approximately radially on the outside in the housing (1). arrangement according to claim 6 , characterized in that the brake ring (10) has a plurality of delivery pockets (11) along the outer circumference for receiving the oil when it is immersed in the oil sump (5). Arrangement according to one of the preceding claims, characterized in that a primary drive (13) for transmitting a drive torque of an electric machine (14) arranged axially parallel to the bottom bracket gear (2) to an output ( 15) of the bottom bracket gear (2) is provided. arrangement according to claim 8 , characterized in that an oil inlet of the oil collection area (6) is associated with an oil baffle (16) for directional supply of the oil, the oil baffle (16) surrounding the primary drive (13) at least in sections. arrangement according to claim 8 or 9 , characterized in that a rotor shaft (21) of the electrical machine (14) can be connected or is connected to the output (15) of the bottom bracket gear (2) via at least one planetary gear set (17) and the primary drive (13), the primary drive (13 ) is arranged with the oil baffle (16) seen axially between the electric machine (14) and the planetary gear set (17). Arrangement according to one of the preceding claims, characterized in that the oil-collecting area (6) has ribbing and/or incorporated depressions to increase the surface area. Bicycle or pedelec (3) with an arrangement according to one of the preceding claims.

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