| 摘要 |
A power-assisted steering gear has reaction means to provide a "road feel" at the steering wheel. The gear includes a steering spindle comprising a first part 1 and a second part 2. The first part is formed with a rotary valve 3 and the second part 2, which is constructed as a steering worm, is formed with a control bush 5 cooperating with the valve 3 which is connected to the steering worm via a torsion rod 6. The steering worm is operatively connected by way of recirculating balls 14 to a power piston 13 which is axially slidable in a gear casing 12 and meshes with a steering sector 16. The torsion rod 6 is surrounded by a hollow reaction piston 20 which is supported on the two ends 23, 24 of the torsion rod 6. The adjacent ends of the reaction piston 20 and the first steering spindle part 1 are formed with complementary V-shaped recesses 21,22 which upon assembly of the two elements 1 and 20 form, in conjunction with the peripheral surface of the end 23 of rod 6, a peripheral zig-zag channel which serves to guide a row of balls 25. The channel with the balls 25 constitutes centring means for the rotary valve 3, 5. At its end remote from the centring means the reaction piston 20 forms a chamber 30 which accommodates a centring spring 31 and which is connected to a working pressure duct 34, 35. <IMAGE> |
