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- Autors
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Semenyuk V.F., Vudvud O. M.
- Issue
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Hoisting and transport equipment, 2019, №2(61)
- Pages
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26-34
- DOI
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10.15276/pidtt.2.61.2019.02
- Abstract
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This research deals with the way of spring-hydraulic brake controlling through hydraulic resistance creating. Substantiated is the controlling hydraulic drive use expediency. With this approach, the brake’s hydraulic drive performs not only the locking function preventing the spring from breaking loose at full stop of the crane, but also power loading one as it creates the braking force totally or partially when engaged together with the spring.
The spring-hydraulic brake’s hydraulic part resistance consists of the resistance at pipeline (on straight sections and local resistances) and this one at hydraulic equipment. A right selection of hydraulic equipment allows the hydraulic resistance value control therefore controlling the spring-hydraulic brake braking force. The hydraulic resistance value is directly related to the hydraulic losses value.
Using the hydraulic resistance value and its change nature investigated is the process of crane braking with a spring-hydraulic shock absorber only at the hydraulic resistance expense. Braking started, the braking force slightly increases up to a value of 10000 N due to the hydraulic valve opening, after that there is a smooth increase in force (equipment reaching the control function operating value) and then up to the braking process end the braking force holds a constant value.
It is established that at the hydraulic resistance and the spring combined action it is possible to significantly reduce the spring stiffness from 7000-9000 N/m to 3000-5000 N/m, that in turn reduces the brake overall dimensions, also allowing the braking force change magnitude and law. This combination reduces dynamic loads in both actuator and metal structure of the braking crane for 30-40% compared to the normally closed drum brake. Elaborated are the recommendations concerning on the choice of spring type and the spring-hydraulic brake’s hydraulic resistance value.
- Keywords
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bridge crane, spring-hydraulic brake, hydraulic resistance, dynamic load
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