Transmission brake device

Abstract

A transmission brake device includes: a friction plate set configured such that a plurality of rotation-side friction plates; an engaging piston disposed on an axial side of the friction plate set; a clearance adjustment piston disposed on a side of the engaging piston opposite to the friction plate set; a clearance adjustment hydraulic chamber configured to move the clearance adjustment piston; and an engaging hydraulic chamber configured to move the engaging piston; a biasing member disposed between each adjacent pair of the fixed-side friction plates, the biasing member being configured to bias each adjacent pair of the fixed-side friction plates in directions away from each other. The biasing member distributes the clutch clearance in a gap between each adjacent pair of the fixed-side friction plates when a hydraulic pressure is supplied only to the clearance adjustment hydraulic chamber.

The invention claimed is: 
     
       1. A transmission brake device, comprising:
 a friction plate set configured such that a plurality of rotation-side friction plates that are axially movably engaged with a predetermined rotary member, and a plurality of fixed-side friction plates that are axially movably engaged with a transmission case are alternately disposed; 
 an engaging piston disposed on an axial side of the friction plate set; 
 a clearance adjustment piston disposed on a side of the engaging piston opposite to the friction plate set, and configured to move the engaging piston toward the side of the friction plate set so as to adjust a clutch clearance; 
 a clearance adjustment hydraulic chamber configured to move the clearance adjustment piston toward the side of the friction plate set when a hydraulic pressure is supplied to the clearance adjustment hydraulic chamber; 
 an engaging hydraulic chamber configured to move the engaging piston toward the side of the friction plate set when a hydraulic pressure is supplied to the engaging hydraulic chamber, 
 a retaining plate disposed axially on a side of the friction plate set opposite to the engaging piston; and 
 a stopper member fixed to the clearance adjustment piston, and extending toward a side of the retaining plate, wherein 
 the transmission brake device includes a biasing member disposed between each adjacent pair of the fixed-side friction plates, the biasing member being configured to bias each adjacent pair of the fixed-side friction plates in directions away from each other, and 
 the biasing member distributes the clutch clearance in a gap between each adjacent pair of the fixed-side friction plates when a hydraulic pressure is supplied only to the clearance adjustment hydraulic chamber out of the clearance adjustment hydraulic chamber and the engaging hydraulic chamber, 
 the biasing member is circumferentially provided with a plurality of biasing portions for biasing each adjacent pair of the fixed-side friction plates in the directions away from each other, and 
 the engaging piston is provided with a bulging portion bulging toward the side of the friction plate set, 
 the clearance adjustment piston is provided with a bulging portion bulging toward the side of the friction plate set, the bulging portion of the clearance adjustment piston being received in the bulging portion of the engaging piston, 
 the engaging hydraulic chamber is formed by the bulging portion of the engaging piston, and the bulging portion of the clearance adjustment piston received in the bulging portion of the engaging piston, and 
 the stopper member is abutted against the retaining plate when the clearance adjustment piston is moved toward the side of the friction plate set so as to restrict movement of the clearance adjustment piston at a position where the clutch clearance of a predetermined size is formed. 
 
     
     
       2. A transmission brake device, comprising:
 a friction plate set configured such that a plurality of rotation-side friction plates that are axially movably engaged with a predetermined rotary member, and a plurality of fixed-side friction plates that are axially movably engaged with a transmission case are alternately disposed; 
 an engaging piston disposed on an axial side of the friction plate set; 
 a clearance adjustment piston disposed on a side of the engaging piston opposite to the friction plate set, and configured to move the engaging piston toward the side of the friction plate set so as to adjust a clutch clearance; 
 a clearance adjustment hydraulic chamber configured to move the clearance adjustment piston toward the side of the friction plate set when a hydraulic pressure is supplied to the clearance adjustment hydraulic chamber; 
 an engaging hydraulic chamber configured to move the engaging piston toward the side of the friction plate set when a hydraulic pressure is supplied to the engaging hydraulic chamber, 
 a retaining plate disposed axially on a side of the friction plate set opposite to the engaging piston; and 
 a stopper member fixed to the clearance adjustment piston, and extending toward a side of the retaining plate, wherein 
 the transmission brake device includes a biasing member disposed between each adjacent pair of the fixed-side friction plates, the biasing member being configured to bias each adjacent pair of the fixed-side friction plates in directions away from each other, and 
 the biasing member distributes the clutch clearance in a gap between each adjacent pair of the fixed-side friction plates when a hydraulic pressure is supplied only to the clearance adjustment hydraulic chamber out of the clearance adjustment hydraulic chamber and the engaging hydraulic chamber, 
 the engaging piston is provided with a bulging portion bulging toward the side of the friction plate set, 
 the clearance adjustment piston is provided with a bulging portion bulging toward the side of the friction plate set, the bulging portion of the clearance adjustment piston being received in the bulging portion of the engaging piston, 
 the engaging hydraulic chamber is formed by the bulging portion of the engaging piston, and the bulging portion of the clearance adjustment piston received in the bulging portion of the engaging piston, and 
 the stopper member is abutted against the retaining plate when the clearance adjustment piston is moved toward the side of the friction plate set so as to restrict movement of the clearance adjustment piston at a position where the clutch clearance of a predetermined size is formed.