Differentials for Motor Vehicles 



Comparisons which illustrate the merits of various types 

 By Marius C. Krarup 



HP 1 



left pick-up plate 

 Left ratchet 



AXLE SHAFT 

 LEFT FLANGE 



BALL THRUST BEARING 



IHE Bailey is the name of a new 

 differential gear for motor vehicles. 

 It transmits power to both driving- 

 wheels when these can rotate at the 

 same speed, but only to one wheel when 

 the other runs faster. The power 

 is divided at the rate at which 

 the wheels can utilize it for trac- 

 tion if the wheels have the same 

 speed but one is inclined to slip. 

 Traction from 

 one of the 

 wheels is thus 

 sacrificed on all 

 curves, wheth- 

 er the going 

 is good or not, 

 in order to con- 

 centrate power 

 and traction on 

 one of the 

 wheels when 

 traction from 

 the other is lost 

 for lack of fric- 

 tion with the 



road surface from slippery mud or snow. 

 The casing is rotated by a bevel gear or 

 worm drive, as usual. To the casing are 

 secured two heavy pawls, of which one 

 holds the left and the other the right 

 wheelshaft by engaging notched disks fixed 

 upon the ends of the shafts. The pawls 

 are pressed against ball-pivots by coil 

 springs. Their seats in the disks are 

 shaped so as to make the engagement 

 hold in either direction of movement, for 

 backward as well as forward driving; but 

 if one of the disks is forced around by the 

 road contact of its wheel faster than the 

 casing and the pawl are rotated by the 

 power, this movement is permitted by 

 means of a cam plate that lifts the pawl 

 out of its seat. This action seems to be as 

 follows : The pair of cam plates is mounted 

 on a sleeve as a rigid unit that turns 

 around with' the casing, and opposite to 

 each pawl one of the plates has a semi- 

 circular recess that limits sideways turning 

 of the pawl on its ball pivot, while the 

 other plate here has a straight-line contour 

 passing obliquely under the active end of 

 the pawl but coming to a point directly 



DRIVE SHAFT 



DRIVE PINION 



RIGHT PICK-UP PLATE 

 RIGHT'RATCHET 

 AXLE HOUSING 



A differential which concentrates power on one 

 wheel when the other has lost traction on a bad road 



before it This gives the lifting action. 

 When both pawls drive, they stand at 

 right angles transversely, balanced one 

 against the other, but when one of the 

 disks, actuated from 

 the road, begins to 

 push its pawl, the 

 latter begins to turn 

 a little on its 

 pivot, allowing 

 the disk the 

 same small 

 movement,and 

 thereby the 

 relatively im- 

 movable cam 

 plate gets a 

 higher point of 

 support under 

 the pawl, rais- 

 ing it and per- 

 mitting the 

 disk further 

 unhindered 

 rotation. 



LE SHAFT 

 RIGHT FLANGE 

 DIFFERENTIAL HOUSING 

 PAWL 



A compari- 

 son with other differentials illustrates 

 the merits of each. In the ordinary 

 balance gear differential of the type still 

 used in a majority of motor vehicles 

 the four small bevel pinions revolve 

 on the plan of freely balancing the pres- 

 sures on all teeth engaged. The engine 

 power turns the casing which carries with 

 it the two pivot pins on which two of the 

 pinions are mounted. The two wheel- 

 shaft pinions, each in mesh with both of 

 the power-transmitting pinions, can con- 

 form with the turning of the casing by 

 revolving, taking the wheelshafts with 

 them. If one wheelshaft resists as much 

 as the other, one side of the actuating 

 pinions is resisted as much as the other, 

 and these pinions remain balanced and un- 

 moved in relation to their pins. The 

 teeth engaged become mere lugs gripping 

 the wheelshaft pinions and forcing them 

 to follow, by revolving. But, the moment 

 one wheelshaft resists more than the other, 

 from any cause whatsoever, the pressure 

 on the teeth on one side of the actuating 

 pinions becomes greater than that on the 

 other side. These pinions are no longer 



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