DE102019220043A1 - Bottom bracket transmission with an arrangement for actuating a brake shift element - Google Patents

Abstract

A planetary gear set type bottom bracket transmission is proposed for a bicycle or a pedelec, with an arrangement for actuating at least one brake shift element (B1, B2, B3, B4), with at least one rotatably mounted shift drum (1) in operative connection with at least one as a brake shift element (B1 , B2, B3, B4) executed brake pawl (3, 4, 5, 6) for locking and releasing an associated brake ring (7, 8, 9, 10), the brake ring (7, 8, 9, 10) with a assigned transmission component for shifting a gear stage (G1 to G16) with a predetermined radial play (25, 29) is non-rotatably connected. Furthermore, a bicycle or pedelec with a bottom bracket gear is proposed.

Description

The present invention relates to a planetary gear set type bottom bracket transmission for a bicycle or a pedelec with an arrangement for actuating a brake switching element. The invention also relates to a bicycle or pedelec with the bottom bracket gear.

For example from the publication DE 10 2018 208 381 A1 an arrangement for actuating at least one switching element of a bottom bracket transmission is known, in which brake switching elements are actuated. The actuation or actuation of the brake shift element takes place via a shift sleeve which is arranged coaxially to a central axis of rotation of the bottom bracket gear. In the event of a rotary movement of the switching sleeve, an associated brake switching element is actuated by actuating a pawl arranged radially outside the switching sleeve and movably mounted in the housing and equipped with a locking cam. The pawl engages through openings made in the shift sleeve in a driving toothing of a transmission component and can thereby block it.

In the known arrangement, the braking force, when actuated using a pawl, acts asymmetrically on one side on the blocked or fixed transmission component. This load must be absorbed by its storage. Because of the low circumferential speeds and the high proportions of mixed friction, a simple and inexpensive plain bearing is unsuitable for the radial loads that occur. As a result, a structurally complex and expensive roller bearing is necessary.

The present invention is based on the object of proposing a bottom bracket transmission as well as a bicycle or pedelec with the bottom bracket gear, which realize an inexpensive and structurally simple storage and guidance of the transmission components.

This object is achieved according to the invention by the features of patent claim 1 and 11, respectively, with advantageous and claimed developments resulting from the subclaims and the description as well as the drawings.

Thus, a planetary gear set type bottom bracket transmission for a bicycle or a pedelec with an arrangement for actuating at least one brake switching element is proposed. In order to realize a particularly inexpensive and structurally simple mounting of the transmission components, it is provided that at least one rotatably mounted shift drum is in operative connection with at least one brake pawl designed as a brake shift element for locking and releasing an assigned brake ring, the brake ring with an assigned transmission component for shifting a Gear stage is rotatably connected to a predetermined radial play.

In this way, a bottom bracket gear is proposed in which the gear component to be fixed or to be locked is guided or stored within a gear bore of the housing of the bottom bracket gear by means of a form-fittingly coupled separate brake ring with radial play, so that the force emanating from the brake pawl does not affect the or to be locked transmission component to be released, but can be diverted directly into the bottom bracket gearbox via the brake ring.

The fact that the brake ring can execute a corresponding radial movement due to its radial play without changing the radial position of the transmission component, a radial displacement of the other transmission components is also prevented in the locked state of the associated transmission component. Accordingly, the transmission components are arranged coaxially to one another even in the locked state. As a result, in the case of the bottom bracket transmission for mounting the transmission components, it is possible to use advantageously inexpensive and structurally simple plain bearings. In addition, radial load-dependent bearing losses are largely avoided, which significantly increases the transmission efficiency. Even in the open state, that is to say in the released state, the corresponding brake ring can be guided and driven by the coupled transmission component in the bore of the housing without load and without dragging torques. Any tolerances, especially on transmission components under load, which cause them to rotate eccentrically, are absorbed by the radial play between the brake ring and the coupled transmission component.

In the present invention it is provided that the brake ring and the assigned gear component are arranged in the housing bore and connected to the predetermined radial play in a rotationally fixed manner via driving teeth. The driving teeth can be formed by various types of form-fitting design. The housing bore can, for example, be provided with a pressed-in sleeve or the like to optimize wear. The brake ring provided advantageously provides acoustic decoupling from the transmission component, as a result of which the switching noises are significantly reduced.

It is also possible that the housing bore for receiving the brake ring and the assigned transmission component is arranged eccentrically to a central transmission axis of rotation. When the brake pawl is operated, the associated brake ring is rotated by the torque acting on it, depending on the radial play, around the contact point of the brake ring tooth and brake ring ratchet system until it rests in the housing bore at an angle of approx. 90 ° to the contact point. This means that, depending on the tolerance, the brake ring is arranged, for example, radially between 0.1 mm and 0.2 mm, that is, by an average of 0.15 mm, approximately eccentrically to the central axis of rotation of the transmission. If this eccentricity is appropriately reserved for the housing bore, the unscrewing of the brake ring is effectively prevented when the brake pawl is actuated and the eccentric positioning is canceled and thus aligned exactly coaxially with the brake switching element closed or the brake pawl actuated.

As part of a next development, it can be provided that the brake pawl is preferably designed as a rocker arm. However, it is also conceivable that a rocker arm or the like is used as a brake pawl instead of a rocker arm. Regardless of the particular design, the lever or levers can preferably be arranged in a groove-shaped recess or the like in the housing of the bottom bracket transmission.

In order to realize an assembly-friendly and structurally simple actuation or actuation chain between the shift drum of the brake pawl and the brake ring to be locked and the gear component of the bottom bracket gear connected to it, for example, the brake pawl for locking and releasing the brake ring and thus also the assigned gear component with a first rocker arm of a locking toothing or the like of the brake ring are assigned, while the brake pawl for actuation with a second rocker arm is assigned to a cam track arranged along the circumference of the shift drum as a shift gate. The cam track on the outer circumference of the shift drum can be implemented by mountains and valleys or similar areas arranged one behind the other, so that the brake pawl is pivoted around the pivot axis when changing between mountain and valley on the cam track, so that the first rocker arm of the brake pawl into the locking teeth of the associated brake ring engages or releases it. It is also possible that other contours are used, which realize the functionality described above for locking and releasing the brake ring.

In order to provide a particularly space-saving and easy-to-assemble arrangement of the brake pawl and the shift drum in the housing of the bottom bracket gear, the invention provides that a pivot axis of the brake pawl and a rotation axis of the shift drum are each arranged axially parallel to the central transmission axis of rotation.

If several brake shift elements are provided in the proposed bottom bracket transmission, which are to be actuated via a common shift drum, a next development of the invention can provide that several brake pawls for locking and releasing a respective associated brake ring are assigned to a common bearing pin as a common pivot axis. For example, the axis-parallel pivot axis of the bearing pin can be arranged spatially offset to the axis of rotation of the shift drum in the housing of the bottom bracket gear to enable a particularly space-saving arrangement in space and at the same time to enable the function or actuation of the assigned brake shift element in a structurally simple manner.

For example, in the context of the invention, the locking of the brake ring and thus the associated transmission component in the proposed bottom bracket transmission can be effected by the brake pawl, for example through a pressure load or a tensile load on the associated brake ring. For example, the end of the first rocker arm to implement a pressure brake pawl can be placed on a flank of the locking teeth of the brake ring. In this embodiment, no special structural shape of the end of the first rocker arm is advantageously required, since when the brake pawl is inserted, the end of the first rocker arm rests against the corresponding flank of the locking toothing of the brake ring and locks the brake ring through a pressure load.

It is also conceivable that the end of the first rocker arm to implement a pull-brake pawl is designed, for example, hook-shaped or the like in order to engage behind a flank of the locking toothing of the brake ring and thereby to lock the brake ring, which is effected by a tensile load. In order to achieve an improved mode of operation when actuating the proposed bottom bracket transmission, it is provided that the brake pawl of the arrangement is designed to be spring-loaded. Depending on the version, whether a normally closed or a normally open version is to be implemented, the spring force is transferred accordingly to the brake pawl. In a normally closed design, the pawl tip or the end of the first rocker arm is the The brake pawl is pressed or pulled into the locking teeth of the brake ring to be locked by the spring force. In a normally open version, the pawl tip or the end of the first rocker arm of the brake pawl is pressed or pulled out of the locking teeth of the brake ring by the spring force in order to cancel the locking effect on the brake ring.

As part of a next embodiment of the invention, the application of the spring force for the brake pawl can be implemented by a spring-loaded pressure piece or the like, which is mounted, for example, in a corresponding recess in the housing in such a way that one end of the spring-loaded pressure piece acts on the first rocker arm of the brake pawl . Another embodiment of the invention can provide that the spring force is implemented by a compression, tension, leg spring or the like.

In order to further improve the manufacturing costs and the mode of operation of the proposed bottom bracket transmission, the shift drum can be implemented by providing multiple cam tracks or shifting gates arranged axially one behind the other for actuating multiple brake pawls. This makes it possible, for example, to actuate or switch a bottom bracket transmission with four brake shift elements and four freewheel clutches for realizing, for example, 16 gear stages with the arrangement, since the freewheel clutches are also actuated indirectly by actuating the brake pawls.

In order to prevent over-rotation of the shift drum, it can be provided that a stop provided on the shift drum, for example, axially, radially or the like is implemented so that a shift movement from the first gear step directly into the highest gear and vice versa is prevented with the shift drum.

Another aspect of the present invention is the stress on a bicycle or a pedelec with the above-described bottom bracket transmission, which results in the above-described and other advantages.

The present invention is further explained below with reference to the drawings.

• 1 ein schematischer Getriebeschnitt eines erfindungsgemäßen Tretlagergetriebes eines Fahrrades oder Pedelecs mit einer Anordnung zum Betätigen zumindest eines Bremsschaltelements;
• 2 ein Getriebeschnitt durch das Tretlagergetriebe mit einer beispielhaften Bremsklinke zum Sperren und Freigeben eines zugeordneten Bremsringes mit einer Mitnahmeverzahnung zu einem Hohlrad als Getriebebauteil;
• 3 ein schematischer Getriebeschnitt durch das Tretlagergetriebe mit einer weiteren beispielhaften Bremsklinke zum Sperren und Freigeben eines zugeordneten Bremsringes mit einer Mitnahmeverzahnung zu einem Sonnenrad als Getriebebauteil;
• 4 eine schematische Prinzipdarstellung des Tretlagergetriebes mit den durch eine Schaltwalze zu betätigenden Bremsschaltelementen; und
• 5 ein Schaltschema der Bremsschaltelemente und der Freilaufkupplungen des Tretlagergetriebes gemäß 4.

Show it:

• 1 a schematic gear section of a bottom bracket gear according to the invention of a bicycle or pedelec with an arrangement for actuating at least one brake switching element;
• 2 a gear section through the bottom bracket gear with an exemplary brake pawl for locking and releasing an associated brake ring with driving teeth to a ring gear as a gear component;
• 3 a schematic gear section through the bottom bracket gear with another exemplary brake pawl for locking and releasing an associated brake ring with driving teeth to a sun gear as a gear component;
• 4th a schematic representation of the principle of the bottom bracket transmission with the brake shift elements to be actuated by a shift drum; and
• 5 a circuit diagram of the brake switching elements and the overrunning clutches of the bottom bracket gear according to 4th .

In the 1 to 4th are different views of a bottom bracket transmission according to the invention in planetary gear set design for a bicycle or pedelec with an arrangement for actuating at least one brake switching element B1 , B2 , B3 , B4 shown as an example. 5 shows a circuit diagram for the brake switching elements B1 , B2 , B3 , B4 and overrunning clutches F1 , F2 , F3 , F4 of the bottom bracket gear, which is only designed as an example as a 16-speed gearbox. Under a brake switching element B1 , B2 , B3 , B4 is generally understood to be an actuatable brake that has a transmission component in the closed state with a housing 32 of the bottom bracket transmission connects. In the context of the invention it is provided that the brake switching elements B1 , B2 , B3 , B4 as brake pawls 3 , 4th , 5 , 6th are executed.

It is a bottom bracket transmission in planetary gear set design, so with several, preferably four planetary gear sets RS1 , RS2 , RS3 , RS4 for a bicycle or pedelec with an arrangement for actuating at least one brake switching element B1 , B2 , B3 , B4 suggested.

In order to provide a structurally simple and inexpensive mounting and guidance in the proposed bottom bracket transmission, there is at least one rotatably mounted shift drum 1 in operative connection with at least one as a brake switching element B1 , B2 , B3 , B4 executed brake pawl 3 , 4th , 5 , 6th for locking and releasing an assigned brake ring 7th , 8th , 9 , 10 , where the respective brake ring 7th , 8th , 9 , 10 with an assigned transmission component for shifting a gear G1 to G16 is rotatably connected with a predetermined radial play.

Like, for example 1 As can be seen, the bottom bracket transmission includes a first brake pawl 3 , a second brake pawl 4th , a third brake pawl 5 , a fourth brake pawl 6th to lock and Release of the respectively assigned brake ring 7th , 8th , 9 , 10 which are each connected non-rotatably to an assigned gear component, but with predetermined radial play. As the example of the bottom bracket transmission in addition to the overrunning clutches F1 , F2 , F3 , F4 four brake switching elements B1 , B2 , B3 , B4 includes, which are operated accordingly, are therefore four brake pawls 3 , 4th , 5 , 6th required, the quasi the brake switching elements B1 , B2 , B3 , B4 form and the correspondingly assigned brake ring 7th , 8th , 9 , 10 lock or release to the respective gear G1 to G16 to realize.

The four brake pawls 3 , 4th , 5 , 6th for locking and releasing the respectively assigned brake ring 7th , 8th , 9 , 10 are a common bearing pin 11 as a common swivel axis 12th assigned. The common swivel axis 12th the brake pawls 3 , 4th , 5 , 6th and an axis of rotation 13th the shift drum 1 are each axially parallel to a central gear rotation axis 2 arranged.

As in particular from the 2 and 3 can be seen are the common pivot axis 12th the brake pawls 3 , 4th , 5 , 6th and the axis of rotation 13th the shift drum 1 Spatially offset from one another in order to realize a space-saving and assembly-friendly arrangement in the proposed bottom bracket transmission.

The brake pawls 3 , 4th , 5 , 6th are each designed as a rocker arm, with a first rocker arm 14th , 15th a locking toothing 20th , 21 of the respective brake ring 7th , 8th , 9 , 10 is assigned to lock and unlock and wherein a second rocker arm 18th , 19th one along the circumference of the shift drum 1 arranged cam track 16 , 17th is assigned as a shift gate. With the brake pawls shown as an example 3 , 4th , 5 , 6th pressure brake pawls are shown in which the locking is effected by a pressure load. This is done in such a way that the end of the first rocker arm 14th , 15th on one flank of the locking teeth 20th , 21 of the assigned brake ring 7th , 8th , 9 , 10 is applied to in this way the rotary movement of the brake ring 7th , 8th , 9 , 10 and to block or block the respectively assigned transmission component.

2 shows an example of a gear section through the bottom bracket gear and the bearing pin 11 in a plane of the second brake pawl 4th and the associated brake ring 8th the second brake pawl 4th . The brake ring 8th and the ring gear assigned as a transmission component 22nd are coaxial with one another in a housing bore 23 arranged and via a driving gear 24 with a predetermined radial play 25th non-rotatably connected. In the representation according to 2 is the open state of the second brake pawl 4th shown as there is one end of the first rocker arm 14th the second brake pawl 4th not in the locking teeth 20th of the brake ring 8th is located. This is because there is one end of the second rocker arm 18th on a mountain of the assigned curved path 16 the shift drum 1 so that the first rocker arm 14th the second brake pawl 4th against a spring-loaded pressure piece 26th is pressed so that the locking teeth 20th the assigned brake ring 8th and the ring gear connected to it in a rotationally fixed manner 22nd releases.

In 3 is another gear section through the bottom bracket gear in the area of the first brake shift element B1 or the first brake pawl 3 and the associated brake ring 7th as well as the sun gear 27 executed transmission component, which rotatably with the brake ring 7th is connected, shown. The brake ring 7th the first brake pawl 3 is with the sun gear 27 also coaxially to each other in the housing bore 23 arranged and via a driving gear 28 with a predetermined radial play 29 non-rotatably connected. In 3 is the locked state of the brake ring 7th and the sun gear 27 through that into the ratchet teeth 21 engaging first brake pawl 3 shown. One end of the first rocker arm 15th the first brake pawl 3 lies on one flank of the locking teeth 21 of the brake ring 7th on while one end of the second rocker arm 19th at a valley of the assigned curved path 17th the shift drum 1 is present. Through the spring-loaded pressure piece 30th becomes the first rocker arm 15th the first brake pawl 3 into the locking teeth 21 pressed so that the rotational movement of the brake ring 7th and the sun gear 27 Is blocked. The braking force is effective in the locked state 31 in advantageously in the housing 32 derived and therefore does not affect the transmission components. The braking torque 33 acts on the brake ring 7th , as in 3 indicated.

When pressing the first brake pawl 3 becomes the assigned brake ring 7th rotated by the torque acting on it depending on the radial play around the support point of the brake ring tooth and brake ring ratchet system until it is in the housing bore 23 at an angle of 90 ° to the point of support, the angle in 3 is indicated.

In 4th is a schematic representation of the bottom bracket transmission with four planetary gear sets RS1 , RS2 , RS3 , RS4 shown only as an example. For realizing the 16 gear steps G1 to G16 are the planetary gear sets RS1 , RS2 , RS3 , RS4 four brake switching elements B1 , B2 , B3 , B4 as well as four overrunning clutches F1 , F2 , F3 , F4 assigned. The transmission structure, known per se, is not described further, since it is apparent to a person skilled in the art.

The corresponding circuit diagram of the in 4th bottom bracket gear shown is in 5 shown. In the circuit diagram shown in accordance with 5 means a dash next to the brake switching elements B1 , B2 , B3 , B4 an open state, that is, a release of the assigned transmission component, while a point in the shift pattern indicates the closed state of the brake shifting elements B1 , B2 , B3 , B4 corresponds to. With the overrunning clutches F1 , F2 , F3 , F4 means a line in the shift pattern for realizing the respective gear step G1 to G16 the overtaking drive state, while a point in the shift pattern for realizing the corresponding gear step G1 to G16 realized the lock state.

The switching logic or the switching pattern of the bottom bracket gear is in the respective cam tracks 16 , 17th as brake switching elements B1 , B2 , B3 , B4 executed brake pawls 3 , 4th , 5 , 6th deposited. This means that it is also possible to deliberately omit the individual gears G1 to G16 in order to be able to display larger or smaller gear steps with the same bottom bracket gear for different target groups. With the brake pawls provided 3 , 4th , 5 , 6th as brake switching elements B1 , B2 , B3 , B4 the overrunning clutches are also indirectly used F1 , F2 , F3 , F4 actuated.

From the shift pattern are for each gear step G1 to G16 the operating states for realizing this gear step G1 to G16 for the brake pawls 3 , 4th , 5 , 6th specified. For example, to implement the first gear stage G1, all of the brake pawls are used 3 , 4th , 5 , 6th Approved. For example, in the second gear stage G2, the first brake pawl is 3 closed while the other three pawls 4th , 5 , 6th are released. This actuation is carried out by the assigned cam tracks or shifting gates 16 , 17th realized by the shift drum 1 cam tracks arranged axially one behind the other 16 , 17th to operate the brake pawls 3 , 4th , 5 , 6th having.

A perceptible delimitation and positioning of the individual gears G1 to G16 during the rotary movement of the shift drum 1 For the driver to realize, it is provided that the shift drum 1 a spring-loaded detent 34 assigned. The detent 34 of the individual gear steps G1 to G16 can be radial or axial on the shift drum 1 be provided. For example, this locking 34 via one in a bore in the housing 32 the bottom bracket gear guided and spring-loaded ball can be realized, as in 1 indicated.

In the case of the bottom bracket transmission proposed according to the invention, there is also a bearing on both sides within the housing 32 the bottom bracket gear of the shift drum 1 and the bearing pin 11 to accommodate the brake pawls 3 , 4th , 5 , 6th advantageously possible, whereby the tolerance chain can be minimized.

List of reference symbols

1

Shift drum

2

Gear rotation axis

3

first brake pawl

4th

second brake pawl

5

third brake pawl

6th

fourth brake pawl

7th

Brake ring of the first brake pawl

8th

Brake ring of the second brake pawl

9

Brake ring of the third brake pawl

10

Brake ring of the fourth brake pawl

11

Bearing pin

12th

Pivot axis of the bearing pin or the brake pawl

13th

Axis of rotation of the shift drum

14th

first rocker arm of the second brake pawl

15th

first rocker arm of the first brake pawl

16

Cam track or shift gate for the second brake pawl

17th

Cam track or shift gate for the first brake pawl

18th

second rocker arm of the second brake pawl

19th

second rocker arm of the first brake pawl

20th

Locking teeth of the brake ring of the second brake pawl

21

Locking teeth of the brake ring of the first brake pawl

22nd

Ring gear

23

Housing bore

24

Driving teeth between the brake ring and the ring gear

25th

Radial play

26th

Pressure piece of the second brake pawl

27

Sun gear

28

Driving teeth between brake ring and sun gear

29

Radial play

30th

Pressure piece of the first brake pawl

31

Braking force

32

casing

33

Braking torque

34

spring-loaded detent

RS1

Planetary gear set

RS2

Planetary gear set

RS3

Planetary gear set

RS4

Planetary gear set

B1

first brake switching element

B2

second brake switching element

B3

third brake switching element

B4

fourth brake switching element

G1 to G16

Gear step

F1

first one-way clutch

F2

second overrunning clutch

F3

third overrunning clutch

F4

fourth one-way clutch

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102018208381 A1 [0002]

Claims (11)

Planetary gear set design for a bicycle or pedelec, with an arrangement for actuating at least one brake shift element (B1, B2, B3, B4), characterized in that at least one rotatably mounted shift drum (1) is in operative connection with at least one brake shift element (B1, B2, B3, B4) executed brake pawl (3, 4, 5, 6) for locking and releasing an assigned brake ring (7, 8, 9, 10), the brake ring (7, 8, 9, 10) with an assigned Gear component for shifting a gear stage (G1 to G16) is rotatably connected with a predetermined radial play (25, 29). Bottom bracket gear after Claim 1 , characterized in that the brake ring (7, 8, 9, 10) and the assigned gear component are arranged coaxially to one another in a housing bore (23) and are connected to the radial play (25, 29) in a rotationally fixed manner via driving teeth (24, 28) . Bottom bracket gear after Claim 1 or 2 , characterized in that the brake pawl (3, 4, 5, 6) is designed as a rocker arm, a first rocker arm (14, 15) of a locking toothing (20, 21) of the brake ring (7, 8, 9, 10) for locking and release is assigned and wherein a second rocker arm (18, 19) is assigned to a cam track (16, 17) arranged along the circumference of the shift drum (1) as a shift gate. Bottom bracket transmission according to one of the preceding claims, characterized in that a pivot axis (12) of the brake pawl (3, 4, 5, 6) and a rotation axis (13) of the shift drum (1) are each arranged axially parallel to a central gear rotation axis (2). Bottom bracket transmission according to one of the preceding claims, characterized in that several brake pawls (3, 4, 5, 6) for locking and releasing a respective associated brake ring (7, 8, 9, 10) a bearing pin (11) as a common pivot axis (12) assigned. Bottom bracket gear according to one of the Claims 3 to 5 , characterized in that one end of the first rocker arm (14, 15) for realizing a pressure brake pawl (3, 4, 5, 6) on a flank of the locking teeth (20, 21) of the brake ring (7, 8, 9, 10 ) can be applied. Bottom bracket gear according to one of the Claims 3 to 5 , characterized in that one end of the first rocker arm (14, 15) for realizing a pull-brake pawl is approximately hook-shaped in order to engage behind a flank of the locking teeth (20, 21) of the brake ring (7, 8, 9, 10). Bottom bracket transmission according to one of the preceding claims, characterized in that the brake pawl (3, 4, 5, 6) is spring-loaded. Bottom bracket transmission according to one of the preceding claims, characterized in that the shift drum (1) has several cam tracks (16, 17) arranged axially one behind the other for actuating several brake pawls (3, 4, 5, 6). Bottom bracket transmission according to one of the preceding claims, characterized in that the shift drum (1) and the at least one brake pawl (3, 4, 5, 6) with the associated brake ring (7, 8, 9, 10) in a housing (32) of the Bottom bracket gear are stored. Bicycle or pedelec with a bottom bracket gear according to one of the preceding claims.

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