Crusher Hammer Technology
Hammer design plays a significant role in crusher efficiency because, in most types of crushers, the hammers do most of the work. Early hammer designs were only concerned with mass and general shape of the hammer. Today the technology of Pennsylvania hammers is highly developed, and we give careful consideration to a great many factors:
Location of the hammer’s center of gravity
The center of gravity determines the focus of impact, which in turn helps to control the amount of impact and the general shape of the shattered particle. The center of gravity must be controlled to utilize the full mass of the hammer against the feed.
Air paths created by hammer rotation
The air paths created by the hammer sweep usually contain a certain amount of fines and other small particles which must be directed away from the hammer shanks and rotor discs; otherwise, premature wear would occur. Pennsylvania hammers are designed so that the resulting air paths are directed toward open areas of the crushing chamber, away from vital parts.
Edge configuration of the hammer head
The edges of each Pennsylvania hammer face are shaped to a special geometry in order to produce maximum hammer life with the lowest amount of friction.
Hammer hardness is the most essential factor in determining hammer life, for while the hammer head must be extremely hard and resistant to wear, the shank must be more ductile in order to absorb shock. To produce this on certain designs, Pennsylvania uses a special method of heat treating that creates a gradually varying hardness between the shank and the tip, without any abrupt changes. However, in cross section, the hardness extends for the full depth instead of merely the surface. Hammer hardness is normally gauged according to the Brinnel method.
As a result of continued improvements, Pennsylvania hammer design plays a major role in producing high efficiency and in reducing maintenance problems. As the company introduces refinements to the hammers, users are provided with the latest designs as part of their normal resupply orders.