Multiple-cone synchronizer, component description

N26.60-2295-79

Shown: Multiple-cone synchronizer on NSG 370

2 Main shaft

3 Countershaft

8 3rd/4th gear multiple-cone synchronizer

7 1st/2nd gear multiple-cone synchronizer

Location

The 1st/2nd gear multiple-cone synchronizer is located on the main shaft. The 3rd/4th gear multiple-cone synchronizer is located on the countershaft in model 906 and on the main shaft in model 639.

Task

High-performance synchronization is required to provide high torque transfer and allow frequent shifting while reducing the shift forces that need to be applied. The task of multiple cone synchronization is to bring the idler gears of gears 1, 2, 3 and 4 into sync with the associated shaft by means of dynamic friction in order to permit flawless and silent shifting.

Multiple cone synchronization in gears 1, 2, 3 and 4 meets these requirements and therefore offers the following advantages during shifting compared with single-cone synchronization:

 Faster synchronization

 Greater shift comfort

 Lower shift forces

N26.60-2297-82

Design of double-cone synchronizer shown on 1st gear in the NSG 370

2 Main shaft

9 1st gear idler gear

10 2nd gear idler gear

33 Cone ring

34 Friction ring

35 Synchronizer ring

36 Sliding sleeve

37 Synchronizer body

39 Needle roller bearing

40 Thrust piece

N26.60-2298-82

Design of triple-cone synchronizer shown on 2nd gear in the NSG 400

2 Main shaft

9 1st gear idler gear

10 2nd gear idler gear

33 Cone ring

34 Friction ring

35 Synchronizer ring

36 Sliding sleeve

37 Synchronizer body

39 Needle roller bearing

40 Thrust piece

41 Friction lining

 Double-cone synchronization is used in the transmission variants TSG 360 and NSG 370 for gears 1, 3 and 4, and in transmission variant NSG 400 for gears 3 and 4.

Function of double-cone synchronization, general

When the gear is not engaged the sliding sleeve is held on the synchronizer body by the thrust pieces. At the same time the idler gears of the gears run loose on the main shaft.

When shifting, the sliding sleeve is pushed by the shift fork towards the idler gear to be shifted. The 3 thrust pieces are pressed against the synchronizer ring. As a result they move this axially and press it against the beveled friction ring of the idler gear to be shifted.

As long as the sliding sleeve and idler gear to be shifted rotate at different speeds, a friction torque arises which twists the synchronizer ring until the 3 thrust pieces abut the side of its recesses.

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As a result the blocking teeth are now located in front of the shift dogs of the sliding sleeve and block the displacement of the sliding sleeve. By dynamic friction between the friction ring, the synchronizer ring and the idler gear to be shifted the latter is accelerated or braked and thus synchronization is produced between the idler gear to be shifted and the sliding sleeve.

Once synchronization is produced between the idler gear to be shifted and the sliding sleeve, a circumferential force no longer acts on the synchronizer ring. The synchronizer ring can be turned back by the bevels on the sliding sleeve claws. The sliding sleeve is therefore no longer locked and can be pushed over the shift teeth of the idler gear to be shifted. The connection between the main shaft and the idler gear to be shifted is made.

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 A triple-cone synchronizer is used in transmission variant NSG 400 for 1st and 2nd gear in transmission variant TSG 360 for 2nd gear. An additional cone ring between the friction ring and synchronizer ring and a friction lining attached to the friction ring are the decisive components. The friction surfaces of the nested synchronizer rings are additive. This means that the 1st gear and 2nd gear idler gears can be braked or accelerated faster or with less force.

Function of triple cone synchronization, general

When the gear is not engaged the sliding sleeve is held on the synchronizer body by the thrust pieces. The wheels of the gears run loose on the main shaft at the same time.

When shifting, the sliding sleeve is pushed by the shift fork towards the idler gear to be shifted. The 3 thrust pieces are pressed against the synchronizer ring. As a result they move this axially and press it against the beveled friction ring of the idler gear to be shifted.

As long as the sliding sleeve and idler gear to be shifted rotate at different speeds, a friction torque arises which twists the synchronizer ring until the 3 thrust pieces abut the side of its recesses. As a result the blocking teeth are now located in front of the shift dogs of the sliding sleeve and block the displacement of the sliding sleeve.

By dynamic friction between the friction ring, the synchronizer ring and the idler gear to be shifted the latter is accelerated or braked. The idler gear to be shifted and the sliding sleeve are then synchronized.

Once synchronization is produced between the idler gear to be shifted and the sliding sleeve, a circumferential force no longer acts on the synchronizer ring. The synchronizer ring can be turned back by the bevels on the sliding sleeve claws. The sliding sleeve is therefore no longer locked and can be pushed over the shift teeth of the idler gear to be shifted. The connection between the main shaft and the idler gear to be shifted is made.