Synchronizer and method for shifting a gear

Patent metadata

Field	Value
Publication number	US-2016201736-A1
Application number	US-201414914740-A
Country	US
Kind code	A1
Filing date	Aug 28, 2014
Priority date	Sep 2, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

A synchronizer ( 10 ) for a gear transmission has a synchronizer body ( 12 ), which is associated to a transmission shaft, and a first and a second synchronizer ring ( 32, 34, 36, 38 ) which are associated to a first and a second transmission gear ( 28, 30 ). Furthermore, the synchronizer ( 10 ) has a sliding sleeve ( 26 ) and at least one thrust piece ( 18 ) which is shiftably arranged on the synchronizer body ( 12 ) and can exert an axial compressive force on the corresponding synchronizer ring ( 32, 34, 36, 38 ). Furthermore, the synchronizer ( 10 ) includes an elastic actuating element ( 20 ) which is active between the sliding sleeve ( 26 ) and the thrust piece ( 18 ), wherein on the sliding sleeve ( 26 ) a detent recess ( 50 ) for the neutral position as well as a release contour ( 54 ) are provided. The release contour ( 54 ) can cooperate with the actuating element ( 20 ) such that when the sliding sleeve ( 26 ) is shifted for being engaged with one of the transmission gears ( 28, 30 ), the thrust piece ( 18 ) is urged away from the corresponding synchronizer ring ( 32, 34, 36, 38 ). The release contour ( 54 ) has an axial length which is not more than twice the idle stroke of the sliding sleeve ( 26 ) between the neutral position and the position in which the corresponding synchronizer ring ( 32, 34, 36, 38 ) presses against an associated friction surface.

First claim

1 . A synchronizer ( 10 ) for a gear transmission, comprising a synchronizer body ( 12 ) which is associated to a transmission shaft, a first and a second synchronizer ring ( 32 , 34 , 36 , 38 ) which are associated to a first and a second transmission gear ( 28 , 30 ) and during a shifting operation can synchronize the rotational speeds of the synchronizer body ( 12 ) and the corresponding transmission gear ( 28 , 30 ), a sliding sleeve ( 26 ) which is non-rotatably arranged on the synchronizer body ( 12 ) and can be shifted from a neutral position in opposite directions into a first and a second shifting position in order to non-rotatably couple the first and the second transmission gear ( 28 , 30 ) with the synchronizer body ( 12 ), and at least one thrust piece ( 18 ) which is shiftably arranged on the synchronizer body ( 12 ) and during a shifting operating can exert an axial compressive force on the corresponding synchronizer ring ( 32 , 34 , 36 , 38 ), wherein an elastic actuating element ( 20 ) is provided, which is active between the sliding sleeve ( 26 ) and the thrust piece ( 18 ), characterized in that a detent recess ( 50 ) for the neutral position as well as a release contour ( 54 ) are provided on the sliding sleeve ( 26 ), wherein the release contour ( 54 ) can cooperate with the actuating element ( 20 ) such that when the sliding sleeve ( 26 ) is shifted for being engaged with one of the transmission gears ( 28 , 30 ), the thrust piece ( 18 ) is urged away from the corresponding synchronizer ring ( 32 , 34 , 36 , 38 ), and wherein the release contour ( 54 ) has an axial length which is not more than twice the idle stroke of the sliding sleeve ( 26 ) between the neutral position and the position in which the corresponding synchronizer ring ( 32 , 34 , 36 , 38 ) presses against an associated friction surface.

2 . The synchronizer ( 10 ) according to claim 1 , characterized in that the actuating element ( 20 ) is arranged on the thrust piece ( 18 ) via a spring ( 24 ).

3 . The synchronizer ( 10 ) according to claim 2 , characterized in that the actuating element ( 20 ) comprises a ball ( 22 ) which in the neutral position is urged into the detent recess ( 50 ) of the sliding sleeve ( 26 ) by the spring ( 24 ).

4 . The synchronizer ( 10 ) according to claim 1 , characterized in that the release contour ( 54 ) is adjoined by a protrusion ( 52 ) on the side associated to the detent recess ( 50 ) and by a holding portion ( 56 ) on the opposite side, wherein the center of the protrusion ( 52 ) has an axial distance to the center of the detent recess ( 50 ) which is smaller than the axial shifting path of the sliding sleeve 26 that is covered, in order to transmit a torque from the synchronizer body ( 12 ) to one of the transmission gears ( 28 , 30 ).

5 . The synchronizer ( 10 ) according to claim 4 , characterized in that the center of the protrusion ( 52 ) has an axial distance to the center of the detent recess ( 50 ) which is smaller than the axial shifting path of the sliding sleeve ( 26 ) minus the distance covered by the thrust piece ( 18 ) from the neutral position up to the abutment against the corresponding synchronizer ring ( 32 , 36 ).

6 . The synchronizer ( 10 ) according to claim 1 , characterized in that the release contour ( 54 ) includes an angle α to the axial alignment (A) of the synchronizer ( 10 ), which lies between 10° and 40°.

7 . The synchronizer ( 10 ) according to claim 1 , characterized in that each of the first and the second synchronizer ring ( 32 , 34 , 36 , 38 ) is formed cone-shaped.

8 . The synchronizer ( 10 ) according to claim 1 , characterized in that the side of the sliding sleeve ( 26 ) associated to the synchronizer body ( 12 ) is formed mirror-symmetrical with respect to its vertical middle axis.

9 . A method for shifting a gear in a synchronizer ( 10 ) with a synchronizer body ( 12 ) which is associated to a transmission shaft, a first and a second synchronizer ring ( 32 , 34 , 36 , 38 ) which are associated to a first and a second transmission gear ( 28 , 30 ) and during a shifting operation can synchronize the rotational speeds of the synchronizer body ( 12 ) and the corresponding transmission gear ( 28 , 30 ), a sliding sleeve ( 26 ) which is non-rotatably arranged on the synchronizer body ( 12 ) and from a neutral position can be shifted in opposite directions into a first and a second shifting position, in order to non-rotatably couple the first and the second transmission gear ( 28 , 30 ) with the synchronizer body ( 12 ), and at least one thrust piece ( 18 ) which is shiftably arranged on the synchronizer body ( 12 ) and during a shifting operation can exert an axial compressive force on the corresponding synchronizer ring ( 32 , 34 , 36 , 38 ), wherein an elastic actuating element ( 20 ) is provided which is active between the sliding sleeve ( 26 ) and the thrust piece ( 18 ), with the following steps:
a) axially shifting the sliding sleeve ( 26 ) from a neutral position to a shifting position, b) pressing the thrust piece ( 18 ) rotating with the synchronizer body ( 12 ) against the synchronizer ring ( 32 , 34 , 36 , 38 ) associated to the transmission gear ( 28 , 30 ) for pre-synchronization, c) synchronizing the rotational speeds of the synchronizer body ( 12 ), of the corresponding synchronizer ring ( 32 , 34 , 36 , 38 ) and of the transmission gear ( 28 , 30 ), d) further axial shifting of the sliding sleeve ( 26 ) to the shifting position after completed synchronization, e) exerting an axial force pointing away from the corresponding transmission gear ( 28 , 30 ) on the thrust piece ( 18 ), in particular on the actuating element ( 20 ), by the release contour ( 54 ) of the sliding sleeve ( 26 ) during further axial shifting so that the thrust piece ( 18 ) no longer rests or is pressed against the corresponding synchronizer ring ( 32 , 34 , 36 , 38 ), and f) reaching of the shifting position, wherein the actuating element ( 20 ) no longer rests against the release contour ( 54 ).

10 . The method according to claim 9 , characterized in that the exerted axial force is greater than the frictional force between the thrust piece ( 18 ) and the synchronizer body ( 12 ).

11 . The synchronizer ( 10 ) according to claim 7 , characterized in that per transmission gear ( 28 , 30 ) a cone-shaped intermediate ring ( 40 , 42 ) and two cone-shaped synchronizer rings ( 32 , 34 , 36 , 38 ) are provided, between which the intermediate ring ( 40 , 42 ) is arranged.

12 . The synchronizer ( 10 ) according to claim 3 characterized in that the release contour ( 54 ) includes an angle α to the axial alignment (A) of the synchronizer ( 10 ), which lies between 10° and 40° and wherein per transmission gear ( 28 , 30 ) a cone-shaped intermediate ring ( 40 , 42 ) and two cone-shaped synchronizer rings ( 32 , 34 , 36 , 38 ) are provided, between which the intermediate ring ( 40 , 42 ) is arranged.

13 . The synchronizer ( 10 ) according to claim 3 , characterized in that the release contour ( 54 ) is adjoined by a protrusion ( 52 ) on the side associated to the detent recess ( 50 ) and by a holding portion ( 56 ) on the opposite side, wherein the center of the protrusion ( 52 ) has an axial distance to the center of the detent recess ( 50 ) which is smaller than the axial shifting path of the sliding sleeve ( 26 ) that is covered, in order to transmit a torque from the synchronizer body ( 12 ) to one of the transmission gears ( 28 , 30 ).

14 . The synchronizer ( 10 ) according to claim 13 , characterized in that the release contour ( 54 ) includes an ang

Assignees

• Hoerbiger Antriebstechnik Hold

Inventors

• Back Ottmar

Classifications

• F16D23/06 Primary

  and a blocking mechanism preventing the engagement of the main clutch prior to synchronisation · CPC title

• F16H63/30

  Constructional features of the final output mechanisms · CPC title

• F16H2063/3093

  Final output elements, i.e. the final elements to establish gear ratio, e.g. coupling sleeves or other means establishing coupling to shaft · CPC title

• F16D2023/0618

  Details of blocking mechanism comprising a helical spring loaded element, e.g. ball · CPC title

• F16D2023/0631

  Sliding sleeves; Details thereof · CPC title