目录
第1章 前言··········································································1
1.1播种机的常识和技术现状·······················································1
1.2播种方式及常见播种类型·······················································3
1.2.1条播·············································································3
1.2.2穴播·············································································4
1.2.3撒播·············································································4
1.2.4精密播种·······································································4
1.2.5联合作业机和免耕播种························································5
1.3播种工作过程和机械构造·······················································5
1.3.1工作过程·······································································5
1.3.2机械构造·······································································6
1.4播种机械的发展趋势·····························································7
第2章 总体设计····································································9
2.1 概述···············································································9
2.2 设计任务········································································10
2.3 设计目的········································································10
2.4 动力方案选择···································································10
2.5 设计题目分析及设计思想·····················································12
2.6 设计主参数及机构类型确定··················································12
2.6.1工作速度······································································12
2.6.2播量的确定···································································13
2.6.3种、肥箱的容积······························································13
2.6.4机架设计······································································14
2.6.5工作幅度······································································14
2.6.6 排种、排肥机构设计·························································14
2.6.7开沟器设计····································································18
2.6.8覆土器设计···································································22
2.6.9镇压轮设计····································································23
2.6.10 地轮设计····································································23
第3章 传动设计及播种技术措施···········································25
3.1传动原理简图和动力传递路线图····································25
3.1.1传动原理简图·································································25
3.1.2动力传动路线图······························································25
3.2传动原理·········································································25
3.3技术措施·········································································26
3.3.1播种均匀性和各行排量一致性措施·········································26
3.3.2降低破种率措施······························································27
3.3.3种肥同播时，肥料的利用率··················································27
第4章 零部件设计·······························································28
4.1种箱及肥箱设计·································································28
4.2开沟器设计及校核······························································29
4.3排种器···········································································31
4.4地轮参数确定···································································32
4.4.1轮子直径和轮辋宽度的确定·················································32
4.4.2轮子滚动阻力计算····························································32
4.5汽油机的选择及链轮设计······················································33
4.5.1汽油机总功率确定····························································33
4.5.2汽油机及减速器的选择······················································34
4.5.3传动比的确定·································································35
4.5.4链轮选择及设计计算·························································36
4.6地轮轴设计······································································41
4.7键的校核·········································································47
4.8销的校核·········································································48
4.9轴承的校核······································································49
第5章 播种机使用·······························································50
5.1播种量调整······································································50
5.2实际操作说明···································································51
5.2.1播种作业前准备······························································51
5.2.2播种机的试播及作业·························································53
5.2.3播种机的保养与保管·························································54
5.2.4播种质量检查·································································54
第6章 毕业设计小结····························································57
参考文献·············································································59
第1章 前言
1.1 播种机的常识和技术现状
以作物种子为播种对象的机械称为种植机械，即播种机械。农业是关系国计民生的基础产业，而播种作业是农业生产过程中六大环节之一，播种机械化是农业机械化过程中最为复杂，也是最为重要的工作。播种机械所面对的播种方式、作物种类、品种变化繁多，这就需要播种机械有较强的适应性并且能满足不同种植要求的工作性能。
播种机一般由机架、牵引或悬挂装置、种子箱、排种器、传动装置、输种管、开沟器、划行器、行走轮和覆土镇压装置等组成。其中影响播种质量的主要是排种装置和开沟器。
1.机械播种的农业技术要求：
1)播量符合要求且准确，排种（排肥）均匀稳定，穴距及每穴粒数均匀。
2)播深符合要求且均匀一致，种子应播在湿土上，用湿土覆盖，无露籽现象，覆土均匀，干早地区播后应同时镇压，以利保墒。
3)播行直，行距一致，地头整齐，不重不漏。
4)尽量采用联合作业。
2.播种机的性能指标：排量稳定性、各行排量一致性、排种均匀性和播种均匀性、穴粒数合格率、粒距合格率、播深稳定性、种子破损率。
3.播种机的分类：
播种机的种类很多，一般可按下列方法进行分类。
1)按播种方式分为撒播机、条播机、穴播机和精密播种机。
2)按适应作物分为谷物播种机、中耕作物播种机及其他作物播种机。
3)按联合作业分为施肥播种机、播种中耕通用机、旋耕播种机、旋耕铺膜播种机。
4)按动力联接方式分为牵引式、悬挂式和半悬挂式。
5)按排种原理分为机械式、气力式和离心式播种机。
公元前1世纪,中国已推广使用耧，这是世界上最早的条播机具，至今仍在北方旱作区广泛应用（如图1—1）。
图1—1三耧车
欧洲第一台播种机于1636年在希腊制成。1830年，俄国人在畜力多铧犁上加装播种装置制成犁播机。英、美等国在1860年以后开始大量生产畜力谷物条播机。20世纪以后相继出现了牵引和悬挂式谷物条播机，以及运用气力排种的播种机。1958年挪威出现第一台离心式播种机，50年代以后逐步发展各种精密播种机（如图1—2）。
图1—2气吸式播种机
中国在20世纪50年代从国外引进谷物条播机、棉花播种机等，60年代先后研制成功悬挂式谷物播种机（如图1-3）、离心式播种机、通用机架播种机和气吸式播种机等多种机型,并研制成功了磨纹式排种器。到70年代,已形成播种中耕通用机和谷物联合播种机两个系列并投入生产。供谷物、中耕作物、牧草、蔬菜用的各种条播机和穴播机都已得到推广使用。与此同时，还研制成功了多种精密播种机。
图1—3 国内常见的谷物播种机
1.2 播种方式及常见播种类型
播种方式应根据作物品种和当地农业技术要求而定，并随农业生产的发展而发展。基本播种方式有：条播、穴播（点播）、撤播、精密播种、及联合作业播种机五种。
与播种方式对应，播种机主要有谷物条播机、玉米穴播机、棉花穴播机、牧草撒播机等。这几种机型的辅助部件基本相同，只是其核心工作部件——排种器有较大差异。
1.2.1条播：
按要求的行距、播深和播量将种子播成条行，称为条播。条播一般不计较种子粒距，只注意一定长度区段内的粒数。条播的作物便于进行中耕除草、追肥、喷药等田间管理工作，故应用广泛。条播根据作物生长习性不同，有窄行条播、宽带条播、宽窄行条播等不同形式。其条播机主要用于谷物、蔬菜、牧草等小粒种子的播种作业。
1.2.2穴播（点播）：
按规定的行距、穴距、播深将种子定点播入土中，称为点播。在地上定点掘穴，将几粒种子成簇的播入种穴，称为穴播。这种播种方法可保证苗株在田间分布合理、间距均匀。较条播节省种子。成簇播种可以提高出苗能力。每穴可播 1粒或多粒种子，分别称单粒精播和多粒穴播。其穴播机主要用于玉米、棉花、甜菜、向日葵、豆类等需要中耕的作物,通常又称中耕作物播种机。
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