Single-cone synchronizer, component description

N26.60-2301-79

Shown: 5th/6th gear single-cone synchronizer in the NSG 370 and NSG 400

2 Main shaft

20 Reverse gear single-cone synchronizer

19 5th/6th gear single-cone synchronizer

Location

The 5th/6th gear single-cone synchronizer and the reverse gear single-cone synchronizer are located on the main shaft.

Task

The task of single-cone synchronization consists of bringing the 5th/6th gear idler gears the and reverse gear into sync with the associated shaft by means of dynamic friction in order to permit flawless and silent shifting.

Single cone synchronization offers the following advantages:

 Fast synchronization

 Low shift forces

 Long service life, i.e. low wear and even friction value

N26.60-2299-82

Design of the single-cone synchronizer

2 Main shaft

13 Constant-mesh gear on drive shaft

14 6th gear idler gear

35 Synchronizer ring

36 Sliding sleeve

37 Synchronizer body

39 Needle roller bearing

40 Thrust piece

N26.60-2300-82

Design of the reverse gear single-cone synchronizer

2 Main shaft

15 Reverse gear idler gear

35 Synchronizer ring

36 Sliding sleeve

37 Synchronizer body

39 Needle roller bearing

40 Thrust piece

Function of 5th/6th gear synchronization

When the gear is not engaged the sliding sleeve is held on the synchronizer body by the thrust pieces. The constant-mesh gear rotates fixed with the drive shaft and the 6th gear idler gear rotates loosely with the main shaft.

During shifting, the sliding sleeve is pushed through the 5th/6th gear gearshift arm or 5th/6th gear shift fork in the direction of the 6th gear idler gear or the constant-mesh gear. The 3 thrust pieces are pressed against the synchronizer ring. They then move it axially and press it against the beveled friction ring of the 6th gear idler gear or constant-mesh gear.

As long as the sliding sleeve and the 6th gear idler gear or constant-mesh gear 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.

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By dynamic friction between the friction ring, the synchronizer ring and the 6th gear idler gear or constant-mesh gear, the 6th gear idler gear or constant-mesh gear is accelerated or braked and thus synchronization is produced between the 6th gear idler gear or constant-mesh gear and the sliding sleeve.

Once synchronization is produced between the 6th gear idler gear or constant-mesh gear and the sliding sleeve, there will no longer be any circumferential force acting on the synchronizer ring. The synchronizer ring can be turned back by the bevels on the sliding sleeve claws. The sliding sleeve is then no longer blocked and can be pushed over the shift teeth of the 6th gear idler gear or constant-mesh gear. The connection between the main shaft and the 6th gear idler gear is then established.

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Function of reverse gear synchronization

When reverse gear is not engaged the sliding sleeve is held on the synchronizer body by the thrust pieces. The reverse gear idler gear runs loose on the reverse gear at the same time.

When shifting the sliding sleeve is pushed towards the reverse gear idler gear by the reverse gear shift fork. 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 reverse gear idler gear.

As long as the sliding sleeve and reverse gear idler gear 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 reverse gear idler gear the latter is accelerated or braked and thus synchronization is produced between the reverse gear idler gear and the sliding sleeve.

Once synchronization is produced between the reverse gear idler gear 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 blocked and can be pushed over the shift teeth of the reverse gear idler gear. The connection between the main shaft and the reverse gear idler gear is made.