TM-9-2520-234-35 Technical Manual for M109 Transmission XTG-411-2A Download

CHAP 2, SEC II DESCRIPTION AND OPERATION OF PAR 17-18 MAIN TRANSMISSION ASSEMBLY 17. RIGHT AND LEFT BRAKES AND APPLY CAMS a. Components (figs. 377 and 378, — fold-outs 6 and 7) (1) Right and left brakes and apply components are identical except that certain items must be made to right or left configuration. This is true of com- ponents such as cam rings. Operation of brake components is identical for both right and left sides. Because of the close similarity of one side to the other, only the left side components are described. (2) The brake and apply compo- nents include cam stationary ring 28 (fig. 378, fold-out 7), twelve steel balls 27, cam rotating ring 19, hub 15, anchor ring 74 (fig. 377, fold-out 6), nine pins 78, nine springs 77, ten plates 17 (fig. 378, fold-out 7) and ten disks 18. Cam stationary ring 29 is mounted on the transmission rear housing by dowels and bolts 30, Cam ro- tating ring 19 is installed on stationary ring 28 after balls 27 are positioned in inclined pockets of the stationary cam. Matching inclined pockets in the rotating cam also index with the balls. The cavity between the cams is sealed by ring seals 26 and 32. (3) Hub 15 is supported at one end by ball bearing 16 and splined, at the opposite end, to the steer planetary car- rier 2. Brake disks 18 have internal splines which engage external splines on the hub. Brake plates 17 have external splines which engage internal splines in anchor ring 74 (fig. 377, fold-out 6) which is stationary. Pins 78 and springs 77 are installed in holes in anchor ring 74 and retained by retaining rings 73. Reaction plate assembly 66 serves the brake and geared steer clutch jointly. b. Operation (figs. 377 and 378, fold-outs 6 and 7) (1) The brakes are used for two purposes. When applied simultaneously by the mechanical linkage, they serve as ve- hicle service and parking brakes. When the vehicle is steered in first, second and reverse 1 gears, the brakes apply indepen- dently and hydraulically. (2) When applied mechanically, the brake linkage rotates cam ring 19 (fig. 378, fold-out 7) on cam stationary ring 28. The inclined ball pockets in the cams roll on balls 27, causing the rotating cam to move away from the stationary cam and toward brake plates 17 and disks 18. After running clearance is taken up, the plates are compressed against reaction plate assembly 66 (fig. 377, fold-out 6). This locks hub 15 (fig. 378, fold-out 7) to anchor ring 74 (fig. 377, fold-out 6) and slows or stops the rotation of the geared steer planetary carrier 2 (fig. 378, fold- out 7). Thus the transmission output is slowed or stopped. (3) During steer (in first, second and reverse 1), hydraulic pressure is di- rected to the cavity between cam rings 19 and 28. This pressure applies the brake. Note that, during steer, cam ring 19 moves away from cam ring 28 without rotation. 18. BRAKE LINKAGE AND AIR VALVES a. Components (fig. 379, fold-out 8) — (1) The linkage components by which the service and parking bakes are applied include spindle assembly 77, cage assembly 72, right-brake apply shaft 97, left-brake apply shaft 84, right-brake apply cam assembly 83, left-brake apply cam assembly 75, shafts 2 and 65, cam followers 6 and 62, cam follower links 3 and 60, link assemblies 10 and 69, adjust- ing nuts 20 (fig. 378, fold-out 7) and 14 (fig. 380, fold-out 9), ratchets 21 (fig. 378, fold-out 7) and 15 (fig. 380, fold-out 9), springs 22 (fig. 378, fold-out 7) and 16 (fig. 380, fold-out 9) and retainer assem- bly 87 (fig. 379, fold-out 8). (2) Retainer assembly 87, spindle assembly 77 and cage assembly 72 support brake apply shafts 84 and 97 in the trans- mission rear housing. Brake apply cam assemblies 75 and 83 are splined to their respective brake apply shafts. Cam fol- lower links 3 and 60 are pivoted at their upper ends on shafts 2 and 65, installed in the transmission rear housing. Link assem- blies 10 and 69 connect to the lower ends of the cam follower links. The cam fol- lowers 6 and 62 rotate in the cam follower links. The threaded ends of link assem- 18 Change 2