Classification of bevel gears
(1) Straight bevel gears. This is the standard form of a bevel gear, the cross section of which is perpendicular to the busbar of the cone, and the tooth height is in the form of a contraction tooth, that is, from the large end (outer end) of the tooth along the indexing cone busbar to the small end (inner end) of the tooth, The tooth height gradually decreases. Straight bevel gears have the advantages of simple design, manufacture and installation, and easy adjustment; the disadvantages are large running noise and impact; suitable for low speed transmission (<5m/s).
(2) Helical bevel gears. Similar to the tooth surface formation of the cylindrical helical gear, the intersection of the involute helicity of the helical bevel gear with the base conical surface and any conical surface coaxial with the base conical surface is a conical spiral. It is usually used as a design reference to construct a helical bevel gear by using a projection curve on the indexing conical surface of a line at an angle of β with the indexing cone on the tangent plane of the indexing conical surface (ie, the indexing cone spiral). Tooth shape. The tooth height of the helical bevel gear is also in the form of a shrink tooth. When a pair of helical bevel gears mesh, as with helical helical gears, the contact line of the tooth surface is a diagonal curve, and the contact curve first changes from short to long, and then shortens from length to disengagement. Therefore, the helical bevel gear has a smoother transmission and less impact and vibration than the straight bevel gear, and is suitable for medium, high speed and heavy load applications.
(3) Curved bevel gears. The curved teeth are further divided into arc teeth, long outer cycloidal teeth (referred to as cycloidal teeth) and quasi-involute teeth. The pitch of the cycloidal bevel gear adopts the form of contour tooth, the tooth height at each point along the indexing cone busbar is constant, and the tooth height of the spiral bevel gear is still in the form of contraction tooth. The curved bevel gear has the characteristics of stable transmission, low noise and large carrying capacity, and is suitable for various types of mechanical equipment and vehicles (such as automobile differentials) with high speed and heavy load.