CN112178068A

CN112178068A - Synchronization unit for a manual transmission

Info

Publication number: CN112178068A
Application number: CN202010633398.8A
Authority: CN
Inventors: 沃尔夫冈·福尔克; 安德列亚斯·登普夫勒; 尤尔根·宾德尔; 维尔纳·菲尔古特; 帕特里克·费舍尔
Original assignee: Hoerbiger Antriebstechnik Holding GmbH
Current assignee: Hoerbiger Antriebstechnik Holding GmbH
Priority date: 2019-07-04
Filing date: 2020-07-02
Publication date: 2021-01-05
Also published as: DE102019118135A1

Abstract

The invention relates to a synchronization unit (10) for a manual transmission, comprising a hub (12) which is connected to a transmission shaft in a rotationally fixed and axially fixed manner and is rotatable about a central axis (14). Furthermore, a sliding sleeve (16) which is slidable along the center axis (14) relative to the hub (12) and is coupled to the hub (12) in a rotationally fixed manner, and at least one carrier plate (42) for pre-synchronization are provided. The carrier plate (42) is at least partially disposed in an axial groove (44) radially inward of the sliding sleeve (16).

Description

Synchronization unit for a manual transmission

Technical Field

The invention relates to a synchronization unit for a manual transmission, comprising: a hub which is connected to the transmission shaft in a rotationally fixed and axially fixed manner and which is rotatable about a central axis; a sliding sleeve slidably and non-rotatably coupled to the hub along a central axis; and at least one pallet for pre-synchronization.

Background

Such synchronization units are known from the prior art.

The so-called presynchronization takes place here at the beginning of the shifting operation. In this case, at least one carrier plate is pressed against the synchronizer ring by sliding of the sliding sleeve, so that the friction cone of the synchronizer ring is in frictional contact with a corresponding friction cone on the clutch body. The synchronizer ring is thereby usually twisted into its locking position.

Synchronization units of the type mentioned at the outset are subject to constant cost pressure, so that it is generally sought to build them simply and inexpensively.

However, the simplification of the synchronization unit structure encounters a limitation that vibrations within the synchronization unit should be avoided. This is particularly relevant when the rotational speed is very high. Vibration of components within the synchronization unit leads on the one hand to undesired noise generation and on the other hand to undesired damage of components of the synchronization unit.

A further object of the development of synchronization units is generally the small installation space requirement, i.e. the compact construction of the synchronization unit.

Disclosure of Invention

Against this background, the object of the invention is: an improved synchronization unit is provided. The synchronization unit should in particular be simple and inexpensive to construct, avoid undesirable vibrations and have a small installation space requirement.

This object is achieved by a synchronization unit of the type mentioned at the outset in which the carrier plate is arranged at least partially in an axial groove radially inside the sliding sleeve. Thus, unlike the known synchronizing units, the so-called pallet cavity (drucktopf) is dispensed with in the hub beam (Nabensteg). I.e. the clearance of the hub beam for accommodating the pallet cavity is eliminated. The synchronization unit according to the invention therefore has only a small installation space requirement which does not exceed the installation space requirement of a synchronization unit which is designed without the possibility of presynchronization. This applies in particular to the radial installation space requirement with respect to the rotational axis of the synchronization unit. The omission of the gap in the hub beam also improves the mechanical stability of the hub beam. In this way undesired vibrations in the synchronization unit are avoided. Furthermore, the axial grooves in the sliding sleeve are easy to manufacture with standard machines and equipment, so that the synchronization unit thus equipped can be produced simply and at low cost.

The synchronization unit preferably comprises three pallets which are evenly distributed over the circumference, i.e. with an angular separation of 120 °. All three pallets are preferably designed identically. Thus, the pallet is a common piece.

According to one embodiment, the carrier has a centering projection on at least one side pointing in the circumferential direction in the installation position, which centering projection engages in a centering recess provided in a wall of the axial groove pointing in the circumferential direction in the neutral position of the synchronization unit. In this case, a centering recess is preferably provided in both walls of the axial groove which point in the circumferential direction, and a centering projection is provided on the carrier plate, corresponding thereto, on both sides which point in the circumferential direction. The term centering pocket is to be understood here in a broad sense. The centering indentation is designed, for example, as an opening, window or recess. By centering the pallet, undesired movements of the pallet relative to the sliding sleeve are avoided, thus undesired vibrations and noise are avoided. Furthermore, the centering of the pallet causes the pallet to occupy the preset position in the neutral position of the synchronizing unit. Thereby avoiding or at least reducing undesired drag torques within the synchronization unit. The centering arrangement on the circumferentially directed side of the pallet also makes the centrifugal force generated by the rotation of the synchronizing unit have no influence on the centering. This is particularly effective in comparison with known pallets that are centered via radially outwardly directed sides in the mounted position. Thus, the centering is achieved substantially independently of the centrifugal force.

According to a preferred embodiment, the centering projection is configured to be elastic relative to the rest of the carrier, so that the carrier can be pushed out of its neutral position when the centering projection is elastically compressed. Furthermore, this function can be supported and/or ensured by the integral elastic structure of the carrier in the circumferential direction.

According to a preferred variant, the centering projection or projections are formed integrally with the carrier. In other words, the pallet is one-piece.

The centering indentation can be configured as a section of a detent groove extending in the circumferential direction. The latching recess extends transversely to an axial recess in which the carrier plate is accommodated. The latching recess cuts at least one circumferentially directed wall of the axial recess. In the case of a centering recess deep in both sides in the axial groove, the axial groove and the latching groove form a cross when viewed in the radial direction. The radially outwardly directed groove base of the detent recess can extend circumferentially or tangentially. This is not important for the function of centering the deep recess.

The support plate preferably rests radially on the outside against the groove bottom of the axial groove. In other words, the carrier is supported radially on the outside on the groove base of the axial groove. In this way the influence of centrifugal forces on the function of the pallet is reduced.

According to one variant, the carrier plate has a U-shaped cross section, as seen in the axial direction, wherein the base of the U-shaped cross section is arranged radially outside in the installed position and the legs of the U-shaped cross section project radially inward from the base. In this respect, a centering projection is preferably provided in each leg. The base of the U-shaped cross section rests on the groove base of the axial groove and thus ensures the support of the pallet. Such pallets are lightweight and easy to manufacture.

The synchronizing unit may comprise at least one synchronizing ring, wherein the carrier is coupled with the synchronizing ring in the axial direction. By means of such a coupling, the relative movement of the synchronizer ring with respect to the sliding sleeve is limited, so that undesired vibrations of the synchronizer ring can also be prevented. Furthermore, this connection can be used to actively reset the synchronizer ring into its ventilation position by means of the carrier plate.

The synchronization unit can also be of double-acting design and comprise two synchronization rings which are arranged at opposite ends of the synchronization unit. The two synchronizer rings are then connected in the axial direction by means of a carrier plate. In this case, too, undesirable vibrations of the synchronizing ring are avoided by the coupling with the carrier. The two synchronizer rings are reset to the ventilation position.

In this case, the segments of the carrier can engage in radial receptacles on the synchronizer ring for coupling in the axial direction. The radial receptacle can be designed as an undercut (Hinterschnitt) which acts in the axial direction. By means of the receptacle, the synchronizer ring can be reliably held in its ventilation position in the non-actuated state of the synchronization unit. This reduces the drag torque on the one hand and prevents a relative movement of the synchronizer ring with respect to the remaining components of the synchronization unit on the other hand. This reduces unwanted vibrations and noise within the synchronization unit.

The radial receptacle is advantageously formed between a synchronizing ring connection (synchroringbund) which projects substantially radially outward from the friction cone section of the synchronizing ring and the tooth segments of the synchronizing ring, in particular the synchronizing ring connection is segmented in the circumferential direction. For coupling in the axial direction, a section of the carrier plate engages between the synchronizing ring joint and the adjacent tooth segment. Such a coupling is reliable in its mode of action and is simple and inexpensive to manufacture.

For example, the synchronizer ring joint may be manufactured by axially pushing a portion of a friction cone section of the synchronizer ring. Therefore, no additional structural elements are required to manufacture the synchronizer ring joint.

In one embodiment, the carrier plate bears radially on the inside against the synchronizer ring, in particular against a friction cone section of the synchronizer ring. In this way, the synchronizing ring is centered within the synchronizing unit by means of the carrier. The support plate rests on its radial outer side on the groove bottom of the axial groove. This prevents relative movement of the synchronizer ring in the radial direction with respect to the remaining components of the synchronization unit and avoids undesirable vibrations and undesirable noise. In one variant, the carrier is pretensioned in the radial direction, so that the carrier centers the synchronizer ring with a certain pretension.

The pallet may comprise an L-shaped support foot having a radial leg and a tangential leg, wherein at least a section of the radial leg and the tangential leg axially reverse the synch ring joint and the tangential leg tangentially bears against the synch ring. The contact between the supporting foot and the synchronizing ring comprises a surface contact consisting of tangential legs. In this way, the synchronizer ring can be reliably centered. Furthermore, a secure return of the synchronizer ring into the ventilation position can be achieved by means of the support foot.

In one variant, the carrier plate for coupling with the synchronizer ring has two L-shaped support feet, wherein the tangential legs project in opposite directions from the respective radial leg. In this variant, the carrier plate rests against the synchronizing ring via two surfaces which are each formed on the tangential leg. A particularly reliable centering and/or resetting of the synchronization ring is obtained.

In the case of a pallet coupled with two synchronizer rings, the pallet may be configured in an H-shape when viewed from a radial direction. In this case, a total of four tangential legs of the four support feet project from the base body of the carrier plate and thus form H-shaped legs.

The synchronizer ring is preferably supported on the hub radially on the outside, in particular on a section of the hub which overlaps the synchronizer ring in the axial direction and in the radial direction. Such a section can also be referred to as a bridge (Steg) or a joint (Bund) and is not circumferential in particular. Alternatively, such a section can be designed as an axially projecting tongue plate. Such a bearing of the synchronizer ring is also referred to as Renault-Indexerung. In a preferred embodiment, the section of the hub on which the synchronizer ring is supported is located on the periphery of the hub outside the position where the carrier plate is located. This results in a precise and reliable mounting of the synchronizer ring. Thereby avoiding undesired vibrations of the synchronizing ring. Likewise, only a small drag torque occurs in such a bearing in the ventilated state of the synchronization unit.

In one embodiment, the carrier plate has a circumferentially continuous recess for receiving the hub section, starting from its radially inner end in the mounting position. In this way, the carrier plate also serves for centering relative to the hub. This applies in particular to synchronizer rings and sliding sleeves.

The carrier plate is advantageously configured as a stamped and bent part made of sheet material. The stamped and bent parts made of sheet material can be produced simply and inexpensively. This applies in particular to a large number of pieces. At the same time, such a component can be provided with a certain elasticity. Furthermore, the predetermined tolerances can be easily complied with in the stamped and bent part.

Furthermore, the carrier may also be one-piece. In the case of pallets which are stamped and bent parts made of sheet material, the stamped and bent parts are thus produced by forming from a single sheet blank. In this case, the pallet can also be referred to as a flat spring pallet (blattfederdrucksn) or a profiled spring (Formfedern).

The centering projections are then preferably designed as outwardly bent sheet tongues.

Drawings

The invention is explained below with the aid of different embodiments shown in the drawings. In the drawings:

fig. 1 shows an exploded view of a synchronization unit according to the invention;

FIG. 2 shows a cross-sectional view of the synchronization unit of FIG. 1 in a radial plane;

fig. 3 shows a perspective view of a detail III of the synchronization unit shown in fig. 2;

fig. 4 shows a sectional view corresponding to fig. 2 of a detail IV of the synchronization unit shown in fig. 2;

fig. 5 shows a sectional view corresponding to fig. 2 of a detail V of the synchronization unit shown in fig. 2;

FIG. 6 shows a perspective view of the sliding sleeve and three pallets of the synchronization unit of FIG. 1 arranged therein;

FIG. 7 shows a detail VII of the view shown in FIG. 6;

FIG. 8 shows a perspective view of the pallet of the synchronizing unit shown in FIG. 1;

FIG. 9 shows a top view of the pallet shown in FIG. 8;

FIG. 10 shows the pallet of FIGS. 8 and 9 in an installed position;

FIG. 11 shows a perspective view of two synchronizing rings of the synchronizing unit shown in FIG. 1, which are coupled by three pallets;

FIG. 12 shows a perspective view of an alternative embodiment of a synchronization unit according to the present invention;

FIG. 13 shows a perspective view of the pallet of the synchronizing unit shown in FIG. 12;

fig. 14 shows a top view of the pallet shown in fig. 13.

Detailed Description

Fig. 1 shows a synchronization unit 10 for a manual transmission of a motor vehicle.

The synchronization unit comprises a hub 12, which is connected to the transmission shaft in a rotationally fixed and axially fixed manner and is rotatable about a central axis 14.

Furthermore, a sliding sleeve 16 is provided, which is coupled in a known manner to the hub 12 via an external toothing 18 provided on the hub 12 and an internal toothing 20 provided on the sliding sleeve 16 cooperating therewith.

Due to this coupling, the sliding sleeve 16 is connected to the hub 12 in a rotationally fixed manner, but at the same time is slidable along the central axis 14 relative to the hub 12.

In the embodiment shown, the synchronization unit 10 is designed as a two-sided synchronization unit 10. The hub 12 can therefore be coupled to the first clutch member 22 or the second clutch member 24 in a rotationally fixed manner, depending on the actuating direction of the sliding sleeve 16.

In order to be able to effect such a coupling only when the rotational speed of the hub 12 corresponds to the rotational speed of the respective coupling-required

clutch bodies

22, 24, the first clutch body 22 is provided with a first synchronizer ring 26 and the second clutch body 24 is provided with a second synchronizer ring 28.

In this case, the first synchronizing ring 26 comprises, in a known manner, a friction cone section 30 which can interact with a corresponding friction cone section 32 on the associated first clutch body 22 to achieve rotational speed synchronization. Furthermore, the first synchronizing ring 26 is equipped with a total of three toothed segments 34, which serve as locking teeth. The sliding movement of the sliding sleeve 16 in the direction of the first clutch body 22 can therefore be blocked by means of the toothed segment 34 until the rotational speed of the first clutch body 22 is synchronized with the rotational speed of the hub 12.

In the same manner, the second synchronizing ring 28 includes a friction cone section 36 that can cooperate with a friction cone section 38 provided on the second clutch body 24 to synchronize the rotational speeds of the hub 12 and the second clutch body 24. Furthermore, the synchronizer ring 28 also has a total of three toothed segments 40, which serve as locking teeth and block the sliding movement of the sliding sleeve 16 in the direction of the second clutch body 24, as long as the hub 12 and the second clutch body 24 do not rotate at the same rotational speed.

It goes without saying that the synchronization unit 10 can alternatively be configured to act on only one side. Correspondingly, only one single clutch body and one single synchronizer ring are present.

In the example shown, the synchronization unit 10 has three pallets 42, which are used for what is known as pre-synchronization.

All the support plates 42 are constructed as stamped and bent parts made of sheet metal and are designed in one piece (see in particular fig. 8 and 9).

Furthermore, the carrier plates 42 are constructed as a common piece, i.e. all carrier plates 42 are shaped identically.

In the synchronization unit 10, the carrier plates 42 are each at least partially accommodated in a correspondingly configured radially inner axial groove 44 of the sliding sleeve 16, see fig. 4.

In this case, the support plates 42 each rest radially on the outside against a groove base 46 of the axial groove 44, see fig. 7.

In the neutral position of the synchronization unit 10, i.e. in the non-shifted state, the sliding sleeve 16 is centered over the hub 12 and the carrier plate 42 is centered on the sliding sleeve 16.

For this purpose, each support plate 42 has a centering

projection

48a, 48b on its two sides pointing in the circumferential direction, respectively, see fig. 8 and 9.

In the neutral position, the centering projections 48a of the three pallets 42 engage into the arranged centering deep portions 50a, respectively, and the centering projections 48b engage into the correspondingly arranged centering deep portions 50 b.

Here, the centering recessed

portions

50a, 50b (see fig. 7) are provided on the

walls

52a, 52b of the axial grooves 44 arranged to the respective retainer plates 42 in the circumferential axial direction.

In the embodiment shown, the centering

indentation

50a, 50b is also configured as a section of a detent groove 54 extending in the circumferential direction.

Each axial groove 44 is cut substantially perpendicularly by the locking groove 54, so that a centering

pocket portion

50a, 50b is obtained in the circumferentially directed

wall

52a, 52b of the axial groove 44.

Furthermore, the synchronizer rings 26, 28 are coupled to one another in the axial direction via a carrier plate 42 (see in particular fig. 11). In other words, each of the shoes 42 is coupled with both synchronizing

rings

26, 28 in the axial direction.

For this purpose, a radial receptacle 56 is provided on each

synchronizer ring

26, 28 for each carrier plate 42.

These receptacles 56 are located between the

toothed segments

34, 40 of the

respective synchronizer ring

26, 28 and the associated synchronizer ring joint 58.

Here, the synchronizer ring joint 58 projects substantially radially outward from the respective associated

friction cone section

30, 36.

In the embodiment shown, the synchronizer ring joint 58 is segmented, that is to say, segments of the synchronizer ring joint 58 are provided only in peripheral regions of the respective

friction cone section

30, 36 in which the carrier plate 42 is also present.

The remaining peripheral regions of the synchronizer rings 26, 28 are designed without synchronizer ring coupling 58.

Such a synchronizer ring joint 58 can be produced, for example, by what is known as axial pressing of a region of the

friction cone section

30, 36 of the

respective synchronizer ring

26, 28. In this case, such a section of the

friction cone sections

30, 36 is plastically deformed under axial loading forces, resulting in a bulge which projects radially outward. This is shown as a segment of the synchronizer ring joint 58.

In other words, the synchronizer ring coupling 58 is an axially acting undercut on the

respective synchronizer ring

26, 28.

The carrier plate 42 engages in this axially acting undercut or in a radial receptacle 56 formed by it on each of the synchronizer rings 26, 28.

For this purpose, a total of four L-shaped

support feet

60a, 60b, 60c, 60d are provided on each carrier plate 42, wherein in the example shown the

support feet

60a, 60b engage in the receptacles 56 on the first synchronizing ring 26 and the

support feet

60c, 60d engage in the receptacles 56 on the second synchronizing ring 28.

Each

support foot

60a, 60b, 60c, 60d here comprises a

radial leg

62a, 62b, 62c, 62d and a

tangential leg

64a, 64b, 64c, 64 d.

Here, the

tangential legs

64a, 64b project in opposite directions from the respective

radial legs

62a, 62 b. The same applies to the tangential legs 64c, 64d projecting in opposite directions from the radial legs 62c, 62b of the arrangement, respectively.

At least one section of the

tangential legs

64a, 64b, 64c, 64d and the correspondingly configured

radial legs

62a, 62b, 62c, 62d, viewed in the axial direction, snaps over the correspondingly configured synchronizing ring joint 58 and thus ensures the coupling of the corresponding carrier plate 42 with the synchronizing rings 26, 28.

In addition, the

tangential legs

64a, 64b, 64c, 64d bear against the associated synchronizer rings 26, 28, specifically against the bottom of the associated receptacle 56. The base of the radial receptacle 56 is here always a section of the

friction cone sections

30, 36 provided.

In this way, the synchronizer rings 26, 28 are centered on the sliding sleeve 16 by means of a carrier plate 42 which bears on its radial outer side against a groove base 44 of a correspondingly provided axial groove 44.

Furthermore, the synchronizer rings 26, 28 are also supported on the hub 12 on the radial outside.

For this purpose, the hub 12 comprises

segments

66a, 66b, which overlap the respectively associated synchronizer rings 26, 28 both in the axial direction and in the radial direction.

In the exemplary embodiment shown, these

portions

66a, 66b are designed as tongues which project axially from the hub 12 and against which the respectively associated synchronizer rings 26, 28 bear radially inwardly.

For this purpose, the

segments

66a, 66b can also engage in correspondingly configured

recesses

67a, 67b on the correspondingly configured synchronizer rings 26, 28.

The carrier plate 42 is additionally supported on the hub 12.

For this purpose, the support plates 42 each have a continuous circumferential recess 68, which starts from a radially inner end of the support plate (see in particular fig. 4).

Centering of the sliding sleeve 16 relative to the hub 12 also occurs.

In order to be able to fulfill all the above-mentioned functions, the support plate 42 is provided with a U-shaped cross section, viewed in the axial direction. In this case, the base 70a of the groove-shaped cross section is arranged radially outward in the installed position and rests on the groove base 46 of the axial groove 44.

Legs

70b, 70c of U-shaped cross-section project radially inwardly from the base 70 a.

At the axial ends of each support plate 42,

support feet

60a, 60b, 60c, 60d emanate from

legs

70b, 70 c.

In the embodiment shown, the base 70a is furthermore designed in two parts. The two parts are connected to each other by

spring webs

72a, 72 b.

Due to this configuration, the support plate 42 is H-shaped when viewed in the radial direction (see in particular fig. 9).

In operation of the synchronization unit 10, the sliding sleeve 16 is moved in a known manner by means of a shift fork, not shown in more detail, in the direction of the

clutch bodies

22, 24 assigned to the gear to be shifted. The support plate 42 is initially located in the neutral position, which means that the centering

projections

48a, 48b engage in the arranged centering

indentation parts

50a, 50 b.

If the operating force of the sliding sleeve 16 exceeds a certain amount, the retainer plate 42 elastically deforms in the circumferential direction so that the centering

protrusions

48a, 48b can be pushed out in the axial direction from the arranged centering recessed

portions

50a, 50 b.

The elasticity required for this is ensured, on the one hand, by the elastic design of the centering

projections

48a, 48b and, on the other hand, by the overall design of the support plate 42 as being elastic in the circumferential direction. The two-piece construction of the base 70a and the

spring tabs

72a, 72b contribute particularly to the latter.

Furthermore, the synchronizer rings 26, 28 can be reset into their respectively assigned ventilation position by means of the carrier plate 42. For this purpose, the supporting

feet

60a, 60b, 60c, 60d are designed such that they are deformed axially outwards in a resilient manner when engaging gear. If the sliding sleeve 16 is returned again into its neutral position, the supporting

feet

60a, 60b, 60c, 60d are elastically deformed back and carry the associated synchronizer rings 26, 28 in the process.

As already mentioned, the carrier plate 42 is designed as a stamped and bent part made of sheet material. Due to their elastic properties, the pallets can also be referred to as leaf spring pallets (blattfederdruckstecke) or form springs (Formfedern).

Fig. 12 to 14 show a second embodiment of the synchronization unit 10. Only the differences from the first embodiment already described are discussed here, and reference is made to the above-described design.

In the synchronization unit of the second embodiment, the carrier plate 42 no longer has supporting feet. This relates in particular to the tangential legs of the support foot.

Thus, the carrier plate 42 also does not rest on the correspondingly assigned friction cone section of the synchronizer rings 26, 28. Thus, the synchronizer ring is also not centered on the sliding sleeve 16 by the carrier 42 and is also not reset by the carrier 42.

Thus, the synchronizer rings 26, 28 are now also designed without radial receptacles for the carrier plates 42.

According to the second embodiment, the carrier plate 42 does not couple the synchronizer rings 26, 28 in the axial direction.

The carrier plate 42 of the second embodiment is still constructed as a one-piece stamped and bent piece made of sheet material. However, their shape is different from that of the pallet 42 of the first embodiment.

In addition to the already mentioned support feet, this also relates to the radially outer side of the support plate 42 in the mounted position, i.e. the base 70a of its U-shaped cross section.

The base is provided with two indentations 74a, 74b which are radially continuous on the base 70a in the mounted position.

The recesses 74a, 74b have a substantially V-shaped cross section, viewed in the radial direction, the tips of the cross sections each being oriented toward the center of the carrier plate 42.

In this way an X-shaped profile of the pallet is obtained when the pallet 42 is viewed in the radial direction.

The principle of action of the synchronization unit 10 according to the second embodiment is similar to that of the first embodiment and is therefore referred to herein. In particular, the operating principle is suitable for centering the carrier plate 42 on the sliding sleeve 16.

Claims

1. Synchronization unit (10) for a gear change transmission, comprising:

a hub (12) which is connected to the transmission shaft in a rotationally fixed and axially fixed manner and which can rotate about a central axis (14),

a sliding sleeve (16) which is slidable along the central axis (14) relative to the hub (12) and is coupled non-rotatably to the hub (12), and

at least one pallet (42) for pre-synchronization,

characterized in that the carrier plate (42) is at least partially arranged in an axial groove (44) radially inside the sliding sleeve (16).

2. Synchronization unit (10) according to claim 1, characterized in that the carrier (42) has a centering projection (48a, 48b) on at least one side directed in the circumferential direction in the mounted position, which centering projection engages into a configured centering indentation (50a, 50b) in a neutral position of the synchronization unit (10), wherein the centering indentation (50a, 50b) is provided in a wall (52a, 52b) of the axial groove (44) directed in the circumferential direction.

3. Synchronization unit (10) according to claim 2, characterized in that the centering deep portion (50a, 50b) is configured as a segment of a circumferentially extending detent groove (54).

4. Synchronization unit (10) according to one of the preceding claims, characterized in that the carrier plate (42) rests radially on the outside against a groove bottom (46) of the axial groove (44).

5. Synchronization unit (10) according to one of the preceding claims, characterized in that the carrier plate (42) has a U-shaped cross section, viewed in the axial direction, wherein a base (70a) of the U-shaped cross section is arranged radially outside in the mounted position and legs (70b, 70c) of the U-shaped cross section project radially inwards from the base.

6. Synchronization unit (10) according to one of the preceding claims, characterized in that at least one synchronization ring (26, 28) is provided and the carrier plate (42) is coupled with the synchronization ring (26, 28) in axial direction.

7. Synchronization unit (10) according to claim 6, characterized in that the segments of the carrier plate (42) engage into radial receptacles (56) on the synchronization rings (26, 28) for coupling in the axial direction.

8. Synchronization unit (10) according to claim 7, characterized in that the radial receptacle (56) is configured between a synchronization ring connection (58) which projects substantially radially outward from a friction cone section (30, 36) of the synchronization ring (26, 28) and a tooth section (34, 40) of the synchronization ring (26, 28), in particular the synchronization ring connection (58) is segmented in the circumferential direction.

9. Synchronization unit (10) according to one of claims 6 to 8, characterized in that the carrier (42) bears radially on the inside against the synchronization ring (26, 28), in particular against a friction cone section (30, 36) of the synchronization ring (26, 28).

10. Synchronization unit (10) according to claims 8 and 9, characterized in that the carrier plate (42) comprises an L-shaped support foot (60a, 60b, 60c, 60d) with a radial leg (62a, 62b, 62c, 62d) and a tangential leg (64a, 64b, 64c, 64d), wherein at least a section of the radial leg (62a, 62b, 62c, 62d) and the tangential leg (64a, 64b, 64c, 64d) axially back-engage the synchronization ring joint (58) and the tangential leg (64a, 64b, 64c, 64d) tangentially bears against the synchronization ring (26, 28).

11. Synchronization unit (10) according to claim 10, characterized in that the carrier plate (42) has two L-shaped supporting feet (60a, 60b, 60c, 60d) for coupling with the synchronization rings (26, 28), wherein the tangential legs (64a, 64b, 64c, 64d) project in opposite directions from the respective radial legs (62a, 62b, 62c, 62 d).

12. Synchronization unit (10) according to one of claims 6 to 11, characterized in that the synchronization ring (26, 28) is supported on the hub (12) radially outside, in particular the synchronization ring (26, 28) is supported on a section (66a, 66b) of the hub (12) overlapping the synchronization ring (26, 28) in the axial and radial direction.

13. Synchronization unit (10) according to one of the preceding claims, characterized in that the carrier plate (42) has, in the mounted position, a circumferentially continuous recess (68) for receiving a hub section, starting from its radially inner end.

14. Synchronization unit (10) according to one of the preceding claims, characterized in that the carrier plate (42) is configured as a stamped bent piece made of sheet material.

15. Synchronization unit (10) according to any one of the preceding claims, characterized in that the carrier plate (42) is one-piece.