moreover, Under conditions of serial and mass production for processing spur wheels are widely used pretty productive heads (cutters), and for wheels with circular tooth — cutting heads.
Head (cutters) work in pairs on special machines such as shaping with a modified design of the cradle. Both heads, identical in size and design, installed at an angle to one another. One golovkoj is handled right and the other left side of the tooth of the wheel. Each of the heads is a team of the milling cutter with a diameter of 150 or 275 mm. Teeth have basically the back relief surface. Sharpening them made on the front «surface. The front corner is approximately 20° and the rear angle on the tops of the AB=12 . Thus the back angle on the sides of 4°.
the disadvantages of milling heads is the impossibility of obtaining a flat base to the hollows of the teeth. This is due to the lack of supply coupled heads along the tooth of the cut wheel. However, due to the relatively small radial depth of the base it has no effect on the strength of the tooth and the quality of the gear milled to a pair of wheels. On the contrary, the profile of the teeth, milled heads, no different from the tooth profile obtained by a pair of planing cutters, which ensures complete interchangeability of the wheels, cut these two methods. In addition, the performance of subreserve-tion is 3-4 times higher compared to zorostrianism.
the Teaching of bevel gears with spiral tooth is made using the break-in bevel hob cutter. In the latter case is run with zero-backlash engagement of the workpiece with the paired wheel.
depending on the design and use of head are divided into several types. For cutting all sizes of bevel gears there are ten sizes of heads with a diameter from 12.7 mm to 457,2 mm. Distinguish the whole head, with inserted cutters and segment. Whole heads are manufactured with nominal diameter from H-> up to 2″ and are applied to the wheel of small module. They have two or four incisors. Head large diameters are used for the wheels of medium size and are made with inserted cutters and with inserted segments having two or three cutter.
depending on the nature of the processing and the direction of rotation of the head are divided into PA’s rough or finished, one-, two — and tripartite and left or right rotation. In turn, the draft is divided into two — and tripartite. Bilateral head consists of outer and inner cutters, staggered. Each of the cutters only handles one side of the profile and the adjacent to it part of the depression. It should be noted that all of the tripartite heads combine the two methods up and running, and bilateral—only by copying. The triangular heads have three types of cutters: the outer, inner and middle. The outer and inner cutters handle the sides between the teeth, and the middle — bottom of the basin.
Finishing heads are mainly used for final processing of the teeth. If the production of small wheels, the finish is also rough ubonratana. In this case, the processing is carried out in multiple passes and lower the cutting data. The finishing heads can be divided into one — and bilateral, right and left rotation. Unilateral have all, or only outer or inner teeth. In addition, the fine head, in contrast to the draft have regulatory wedges, which is achieved by accurate adjustment of the cutters for a certain diameter in the radial direction according to the available one or two unregulated cutters. The performance of the head is significantly superior to the worm bevel cutter.
of Special interest is a finishing bevel gears with circular tooth circular broach, which uses the method of Polubotko gear cutting machines. In this case, for 1 revolution of the circular broach is handled by one cavity of the tooth, and then the process of dividing.
Circular tracking consists of a housing and eight blocks-cutters, secured to the housing by bolts. Each block has two cutter with outer and inner cutting blades. The cutting blades of the cutters located on the end of the body, have the rise per tooth sz = 0,08—0,1 mm. the outer cutters of the same lift by the increase in diameter of the broach and internal — by reducing the. The last two segments have one gauge inner and outer cutter. The dividing rotation of a workpiece after the cutting of each tooth without removal of the broach tool has a single sector free from cutters. Introduction Polubotok processing method enables to improve the performance of finishing gear teeth by up to 5 times and significantly improve the accuracy and quality of gears.