Self-energizing synchronizer with force limiting

Abstract

A pin-type, double-acting synchronizer mechanism (22) includes friction clutches (24,36 and 26,38), jaw clutches (28,14b,16b), self-energizing ramps, (13f,13g,13h,13i and 29e,29f,29g,29h), and springs (33) to limit the maximum self-energizing or additive force provided by the ramps. The ramps act between a shaft (12) and jaw clutch (28). A shift flange (32) is rotatably fixed to the jaw clutch (28) by splines which allow relative axial movement against the force of the springs (33). The jaw clutch (28) and the shaft (12) include mating splines (29,13) divided into spline portions (29a,29b,29c,29d and 13a,13b,13c,13d,13e) to define the ramps to control limited relative rotation between the jaw clutch (28) and shaft (12), and to provide surface area and structural strength for transmitting full torque to the shaft and gears.

What is claimed is:  
     
       1. A self-energizing synchronizer mechanism for a first gear secured against axial movement on a shaft having an axis about which the gear and shaft rotate relative to each other, the mechanism comprising: 
       first friction and jaw means respectively engagable with friction and jaw means affixed to the first gear for respectively synchronizing and positive connecting the first gear to the shaft in response to a shift force (F o ) axially directed toward the first gear moving a shift means toward the first gear;  
       means connecting the first jaw means for axial movement with the shift means;  
       first and second blocker means operative when engaged for preventing engagement of the jaw means prior to the synchronizing;  
       pre-energizing means for engaging the friction means in response to initial axial movement of the shift means by the shift force (F o ) from a neutral position toward the first gear for engaging the blocker means in response to engagement of the friction means producing an initial synchronizing torque (T o ) and for transmitting the shift force (F o ) to the first friction means via the blocker means to increase the engaging force of the friction means;  
       first self-energizing means including first and second ramp means engagable in response to synchronizing torque (T o ) in one direction for reacting the synchronizing torque between the friction means and the shaft and for producing an axial additive force (F a ) for further increasing the force engaging the first friction means; characterized by:  
       resilient means engaged by the axial additive force ( F   a ) for limiting the axial additive force (F a ). ;  
         means for providing a force path for the shift force  ( F   o )  to the first friction means independent of the resilient means.   
     
     
       2. The synchronizing mechanism of  claim 1 , wherein: 
       the ramp means are interposed between the shaft and one of the friction means; and  
       the resilient means is interposed between one of the ramp means and one of the friction means.  
     
     
       3. The synchronizer mechanism of  claim 1 , wherein: 
       the shift means includes a radially extending flange;  
       the first jaw means including internal spline teeth mating continuously with external spline teeth affixed to the shaft, the internal and external spline teeth having portions thereof removed for defining said first and second ramp means, said ramp means allowing limited relative rotation between the first jaw means and the shaft.  
     
     
       4. The synchronizer mechanism of  claim 3 , including means for securing the flange against rotation relative to the first jaw means and for allowing relative axial movement therebetween; and 
       said resilient means reacts between the flange and first jaw means.  
     
     
       5. The synchronizer mechanism of  claim 4 , wherein: 
       said resilient means includes at least one spring washer.  
     
     
       6. The synchronizer mechanism of  claim 1 , further including a second gear axially spaced from the first gear and secured against axial movement on the shaft for rotation about the shaft axis relative to the shaft and first gear; 
       second friction and jaw means respectively engagable with friction and jaw means affixed to the second gear for respectively synchronizing and positive connecting the second gear to the shaft in response to a shift force (F o ) axially directed toward the second gear moving the shift means toward the second gear;  
       third and fourth blocker means operative when engaged for preventing engagement of the second jaw means prior to the synchronizing;  
       pre-energizer means for engaging the second friction means in response to initial axial movement of the shift means by the shift force (F o ) from the neutral position toward the second gear, for engaging the third and fourth blocker means in response to engagement of the second friction means producing an initial synchronizing torque (T o ), and the initial synchronizing torque for transmitting the shift force (F o ) to the second friction means via the third and fourth blocker means to increase the engaging force of the second friction means; and  
       second self-energizing means including third and fourth ramp means engagable in response to synchronizing torque in one direction for reacting the synchronizing torque between the friction means associated with the second gear and the shaft and for producing an axial additive force (F a ) for further increasing the force engaging the second friction means; characterized by:  
       resilient means engaged by the axial additive force ( F   a ) for limiting the axial additive force (F a ) increasing the force engaging the second friction means. ;  
         means for providing a force path for the shift force  ( F   o )  to the first friction means independent of the resilient means.   
     
     
       7. The synchronizer mechanism of  claim 6 , wherein: 
       the first and second ramp means are interposed between the shaft and the friction means associated with first gear, and the third and fourth ramp means are interposed between the shaft and the friction means associated with the second gear; and  
       the resilient means is interposed between the first ramp means and one of the friction means associated with the first gear, and between the third ramp means and the friction means associated with the second gear.  
     
     
       8. The synchronizer mechanism of  claim 6 , wherein: 
       the shift means includes a radially extending flange; and  
       the first and second jaw means are defined by a rigid annular jaw member having internal spline teeth mating continuously with external spline teeth affixed to the shaft, the internal and external spline teeth having portions thereof removed for defining said first, second, third and fourth ramp means, said ramp means allowing limited relative rotation between the annular jaw member and the shaft.  
     
     
       9. The synchronizer mechanism of  claim 8 , including means for securing the flange against rotation relative to the first jaw means and for allowing relative axial movement therebetween; and 
       said resilient means for transmitting and limiting the value of the additive axial forces between the annular jaw member and the flange.  
     
     
       10. The synchronizer mechanism of  claim 9 , wherein: 
       said resilient means includes at least one spring washer for transmitting the additive force (F a ) to the friction means associated with the first gear and at least one spring washer for transmitting the additive force to the friction means associated with the second gear.  
     
     
       11. A pin-type synchronizer mechanism for the first and second gears mounted for rotation and secured against movement on a shaft having an axis about which the gears and the shaft rotate, the mechanism comprising: 
       gear friction and jaw means affixed to each gear, the friction means engagable with first and second axially spaced apart and axially movable friction means for respectively synchronizing the first and second gears with the shaft, and the jaw means engagable with axially movable first and second jaw means connected for rotation with the shaft;  
       shift means for axially moving the axially movable friction and jaw means into said engagement in response to an axially bi-directional shift force (F o ) applied to the shift means, means connecting the first and second jaw means for axial movement with the shift means;  
       blocker means operative when engaged for preventing engagement of the jaw means prior to the synchronizing;  
       pre-energizer means for engaging either one of the first and second friction means in response to initial axial movement of the shift means by the shift force (F o ) from a neutral position toward one of the gears for engaging the blocker means in response to engagement of the friction means producing an initial synchronizing torque (T o ), and for transmitting the shift force (F o ) to the engaged friction means via the engaged blocker means to increase the engaging force of the engaged friction means;  
       first self-energizing means including first and second ramp means engagable in response to synchronizing torque in one direction for reacting the synchronizing torque between the shaft and friction means associated with first gear and for producing an axial additive force (F a ) for further increasing the force engaging the first friction means;  
       second self-energizing means including third and fourth ramp means engagable in response to synchronizing torque in the one direction for reacting the synchronizing torque between the shaft and the friction means associated with the second gear and for producing an axial additive force for further increasing the force engaging the second friction means; characterized by:  
       resilient means for limiting the axial additive forces (F a ) increasing the force engaging the first and second friction means.  
     
     
       12. The synchronizing mechanism of  claim 11 , wherein: 
       the ramp means are interposed between the shaft and one of the friction means; and  
       the resilient means is interposed between one of the ramp means and one of the friction means.  
     
     
       13. The synchronizer mechanism of  claim 11 , wherein: 
       the shift means includes a radially extending flange;  
       the first jaw means including internal spline teeth mating continuously with external spline teeth affixed to the shaft, the internal and external spline teeth having portions thereof removed for defining said ramp means, said ramp means allowing limited relative rotation between the first and second jaw means and the shaft.  
     
     
       14. The synchronizer mechanism of  claim 13 , including means for securing the flange against rotation relative to the first and second jaw means and for allowing relative axial movement therebetween; and 
       said resilient means reacts between the flange and first jaw means.  
     
     
       15. The synchronizer mechanism of  claim 14 , wherein: 
       said resilient means includes at least two spring washers.  
     
     
       16. The synchronizer mechanism of  claim 11 , wherein: 
       the shift means includes a radially extending flange; and  
       the first and second jaw means are defined by a rigid annular jaw member having internal spline teeth mating continuously with external spline teeth affixed to the shaft, the internal and external spline teeth having portions thereof removed for defining said first, second, third and fourth ramp means, said ramp means allowing limited relative rotation between the annular jaw member and the shaft.  
     
     
       17. The synchronizer mechanism of  claim 16 , including means for securing the flange against rotation relative to the first jaw means and for allowing relative axial movement therebetween; and 
       said resilient means for transmitting and limiting the value of the additive axial forces between the annular jaw member and the flange.  
     
     
       18. The synchronizer mechanism of  claim 17 , wherein: 
       said resilient means includes at least one spring washer for transmitting the additive force (F a ) to the friction means associated with the first gear and at least one spring washer for transmitting the additive force to the friction means associated with the second gear.  
     
     
       19. The synchronizer mechanism of  claim 1 , wherein: 
         the means for providing the force path for the shift force  ( F   o )  independent of the resilient means includes the the first blocker means being rigidly affixed to the shift means.   
     
     
       20. The synchronizer mechanism of  claim 1 , wherein: 
         the pre - energizing means including resilient means for transmitting the shift force  ( F   o )  from the shift means to the first friction means for producing an initial synchronizing torque effective to cause engagement of the blocker means via a path independent of the blocker means, the engaged blocker means then being operative to transmit the shift force  ( F   o )  to the first friction means to increase the engaging force of the friction means; and    
         the self - energizing means including means for transmitting the axial additive force  ( F   a )  to the first friction means via the blocker means to further increase the force engaging on the resilient means and the friction means.   
     
     
       21. The synchronizing mechanism of  claim 20 , wherein: 
         the pre - energizing means includes a plurality of circumferentially spaced apart pre - energizer assemblies.   
     
     
       22. The synchronizing mechanism of  claim 1 , wherein: 
       
         the ramp means are interposed between the shaft and one of the friction means. 
       
     
     
       23. The synchronizer mechanism of  claim 1 , wherein: 
       
         said resilient means includes at least one spring washer. 
       
     
     
       24. The synchronizer mechanism of  claim 1 , wherein: 
       
         the means for transmitting the axial additive force includes means affixed to the shift means for transmitting the axial additive force. 
       
     
     
       25. The synchronizer mechanism of  claim 6 , wherein: 
         the means for providing the force path for the shift force  ( F   o )  independent of the resilient means includes the the third first blocker means being rigidly affixed to the shift means.   
     
     
       26. The synchronizer mechanism of  claim 6 , wherein: 
         the pre - energizing means including the resilient means for transmitting the shift force  ( F   o )  from the shift means to the second friction means for producing an initial synchronizing torque effective to cause engagement of the third and fourth blocker means via a path independent of the third and fourth blocker means, the engaged third and fourth blocker means then being operative to transmit the shift force  ( F   o )  to the second friction means to increase the engaging force of the friction means; and    
         the self - energizing means including means for transmitting the axial additive force  ( F   a )  to the second friction means via the third and fourth blocker means to further increase the force engaging resilient means and the second friction means.   
     
     
       27. The synchronizing mechanism of  claim 25 , wherein: 
         the pre - energizing means includes a plurality of circumferentially spaced apart pre - energizer assemblies.   
     
     
       28. The synchronizer mechanism of  claim 1 , wherein: 
       
         the first and second ramp means are interposed between the shaft and the friction means associated with first gear, and the third and fourth ramp means are interposed between the shaft and the friction means associated with the second gear. 
       
     
     
       29. The synchronizer mechanism of  claim 6 , wherein: 
       
         said resilient means includes at least one spring washer. 
       
     
     
       30. The synchronizer of  claim 6 , wherein: 
       
         the means for transmitting the axial additive force includes means affixed to the shift means for transmitting the axial additive force.