【正文】 在解決問題的過程中，我們也學到了很多知識。蝸桿和蝸輪蝸桿蝸輪機構(gòu)主要用作有限空間需較小齒輪的體積的情況。面 節(jié)圓和齒頂之間的表面。基圓與運動方向相切（或與壓力角方向相切）的圓。小小的一段齒距包括了許多的齒形。 參考文獻[1] 吳宗澤主編．《機械設(shè)計》．北京：高等教育出版社，2001（2005重?。?[2] 申永勝編著．《機械原理教程》.第二版．北京：清華大學出版社，2005．12[3] 馬從謙等編著．《漸開線行星齒輪傳動設(shè)計》.北京：機械工業(yè)出版社，1987[4] 江耕華等編著．《機械傳動設(shè)計手冊》：煤炭工業(yè)出版社，1990[5] 張國瑞等編著．《行星傳動技術(shù)》.上海：上海交通大學出版，1989[6] 程居山主編.《礦山機械》.徐州：中國礦業(yè)大學出版社，1998[7] 李昌熙等編著.《采煤機》.北京：煤炭工業(yè)出版社，1996[8] 東北大學《機械零件設(shè)計手冊》編寫組.《機械零件設(shè)計手冊》：冶金工業(yè)出版社，2001[9] 曾正明.《機械工程材料手冊》.北京：機械工業(yè)出版社，2002英語文獻GearsTo transmit Gears are vital factors in machinery ,which are uses to transmit power or motion from one shaft to another .They may be used only motion from one part of a machine to another,or they may be used to change the speed or the torque of one shaft with with relation to of the first mechanism invented using gears wad the fact,a clock is little more than a train of study and research have been made on gears in recent years because of their wide use under exacting have to transmit heavier loads and run at high speeds than ever engineers and the machinists all consider gearing the prime element in nearly all classes of machinery.Super Gears Spur gears will be considered first for several the first place ,they are simplest and the least expensive of gears and they may be used to transmit power between parallel shafts,also,spur gears definitions are usually applicable to other types .It is important go understand the following definitions,since they are important factors in the design of any equipment utilizing gears.Diametric Pitch The number of teeth per inch of pitch cirle diameter .The diameter pitch is usually an integer .A small number for the pitch implies a large tooth spur gears must have the same diameter pitch .The speed ratio is based on the fact that meshing gears may have differentsized pitch circles and hence different number of teeth.Circular Pitch The distance from a point on one tooth to the corresponding point on an adjacent tooth ,measrued along the pitch is a liner dimension and thus bas liner units.Pitch Circle The circle on which the ratio of the gear set is based,when two gears are meshing ,the two pitch circles must be exactly tangent if the gears are to function tangency point is known as the pitch point.Pressure Angle The angle between the line of action and a line perpendicular to the centerlines of the two gears in mesing .Pressure Angles for spur gears are usually or 20 degrees,although other values can be gears must have the same pressure the case of a rack,the teeth have the straight sides inclined at an angle corresponding to the pressure angle.Base Circle A circle tangent to the line of action (or pressure line ) .The base circle is the imaginary circle about which an involutes cure is developed .Most spur gears follow an involutes cure from the base circle to the top of the tootch,this cure can be visualized by observing a point on a taut cord an it is unwound from a cylinder .In a gear ,the cylinder is the best circle.Addendum The radial distance form the pitch circle to the top of the tooth .Dedendum The radial distance from file pitch circle to the root of the tooth.Clearance The difference between the addendum and the addendum.Face Width The width of the tooth measured axially.Face The surface between the pitch circle and the top of the tooth.Flank The surface between the pitch circle and the bottom of the tooth.Helical Gears These gears have their tooth element at an angle or helix to the axis of the are more difficult and expensive to make than spur gears,but are quieter and stronger. They may be used to transmit power between parallel shafts at an angle to each in the same or different planes.Herringbone Gears A herringbone gear is equivalent to a righthand and a lefthand helical gear placed side by of the angle of the tooth,helical gears create considerable side thrust on the shaft. A herringbone gear corrects this thrust by neutralizing it ,allowing the use of a small thrust bearing instead of a large one and perhaps eliminating one a central groove is made round the gear for ease in machining.Bevel Gears Bevel gears are used to connect shafts, which are not parallel to each the shafts are 90 each other, but they may be more or less than 90 two meshing gears may have the same number of teeth for the purpose of changing direction of motion only,or they may have a different number of teeth for the purpose of changing both speed and direction .The faces of the teeth lie on the surface of the frustum of a cone,therefore the teeth elements are not parallel to each other it can be seen that this lack of parallelism creates a machining problem so that two passes with a tool must be tooth elements may be straight or spiral ,so that we have plain anti spiral evel gears.Worm and Worm Gears A wormandwormgear bination is used chiefly where it is desired to obtain a high gear reduction in a limited space,normally the worm drivers the worm gear and is not reversible ,that is to say,the worm gear can not drive the worms can be rotated in either direction,clockwise or counterclockwise.Racks A rack is a gear with an infinite radius,or a gear with its perimeter stretched out into a straight is used to change reciprocating motion to rotary motion or vice lathe