Power steering device

A power steering device comprising:

• an input shaft operatively connected to steering wheels;
• an output shaft operatively connected to wheels;
• a torsion bar for connecting said input shaft and output shaft to each other therethrough;
• said input shaft and output shaft generating assisting force depending on the amount of rotation thereof when they are rotated relatively to each other while twisting said torsion bar;
• a member arranged so as to be rotated integrally with said output shaft;
• a spring setting section provided at one of said output shaft and member;
• a pair of leaf spring structures arranged in said spring setting section so as to interpose said input shaft therebetween;
• said leaf spring structures each being provided with a spring-side support section;
• said input shaft being formed on an outer peripheral surface thereof with shaft-side support sections;
• said shaft-side support sections of said input shaft each being arranged so as to be opposite to said spring-side support section of each of said leaf springs when said input shaft and output shaft are in a neutral state;
• and
• balls or rollers each interposedly arranged between each of said spring-side support sections and each of said shaft-side support sections opposite to each other;
• said balls or rollers being arranged so as to deflect said leaf spring structures, resulting in being displaced from said spring-side and shaft-side support sections while rolling therebetween when said input shaft and output shaft are rotated relatively to each other;
• said balls or rollers each being arranged so as to roll between each of said leaf spring structures and said input shaft after they are displaced from said support sections;
• said leaf spring structures each being constituted by a first leaf spring and a second leaf spring;
• said first leaf spring of each of said leaf spring structures including said spring-side support section constituted by a V- or U-shaped groove, a pair of rolling surface sections arranged so as to be contiguous to said spring-side support section and outwardly extend from both ends of said spring-side support section, a pair of support leg sections each arranged so as to be contiguous to each of said rolling surface sections and outwardly extend therefrom, and a pair of holding sections each arranged so as to be contiguous to each of said support leg sections and outwardly extend therefrom;
• said holding sections of said first leaf spring being pressedly contacted with press contact surfaces defining said spring setting section;
• said second leaf spring of each of said leaf spring structures being constructed so as to exhibit elastic force for forcing each of said balls or rollers toward said input shaft through a rear surface of said first leaf spring.