| 摘要 |
<p>1,224,406. Variable-speed belt gearing. MASSEY-FERGUSON INDUSTRIES Ltd. 24 Oct., 1969 [29 Oct., 1968], No. 52120/69. Heading F2D. In a V-belt expanding pulley gear, for agricultural machines, having input and output pulleys 12, 18 on parallel motor and driven shafts 14, 16 connected by belts 36, 38 to a variable double countershaft pulley assembly 22 carried in slotted arms 44 of a carrier pivoted at 48, and formed by three flanges 24, 30, 26, the centre one 30 of which is displaceable between the outer two 24, 26 for ratio change by pivotal movement of the pulley assembly 22 about the pivot 48 by an hydraulic ram 50 between limit stops 64, 66 on a screwed adjuster 58, the belt tension is automatically controlled by a toggle linkage belt tensioner 68 which provides increasing linear force on the countershaft pulley assembly 22 along its guide slots 42, upon belt stretch, to provide constant belt tension to maintain power output and improve belt life. As shown, the belt tensioner toggle-linkage is loaded by a spring 104, whilst in Fig. 7 (not shown), the spring is replaced by a constant pressure hydraulic unit (112). In Fig. 8 (not shown), the toggle-linkage is connected to a variable-pressure rotary valve (136) the position of which, controlled by the toggle-linkage, varies the hydraulic pressure in a ram 126 to duplicate the required force on pulley assembly 22 to maintain belt tension.</p> |
