汽车恐龙的消亡
汽车恐龙的消亡 ――为什么美国汽车工业行将就木？ 汽车城底特律正在庆祝。一百年以前，福特先生建立起他的事业，美国人同汽车的蜜月开始了。美国汽车市场高速增长，年销售量超过一千六百万辆。十年之内，这个数量将接近两千万辆。因为又会有两千六百万年轻的美国人渴望得到其第一辆汽车。 但是旅程将不会是顺利的：更像坐在福特雷鸟车上而不去听那庞大的V8 发动机发出的讨厌的嘈杂声。 所有迹象表明，在底特律，事情被严重扭曲了。除非有重大变化，汽车工业将破产，而福特汽车，三大汽车公司里最糟糕的一个，将首当其冲。 成也萧何，败也萧何。 坦率地说，问题不断的美国汽车工业，曾经被注销过，又反弹回来。克莱斯勒能进入八十年代应感谢美国联邦政府的担保，同时期，福特也仅仅是逃过了破产的命运。华盛顿支撑美国汽车工业，颁布法令限制日本汽车进口。 即使如此，克莱斯勒在九十年代早期，又差一点上演伤心一幕，直到把它自己卖给了戴姆勒－奔驰。 在1991年，三大汽车公司总亏损额达到七十亿美金。据说，1992年，通用汽车差一点崩溃，有一小时，老板们聚集在一起，盯着传真机，等着信用评级调低的噩耗传来，那样的话，通用汽车就被推下了悬崖。 噩耗没来，通用复活了。 整个九十年代，汽车工业进行的现代化改造，以及限制日本汽车的措施，帮了底特律一把。但汽车工业的救世主却是美国人对SUV，面包车及皮卡的喜好。多年以来，这些硕大的汽车获得巨大的成功，底特律绝大部分利润都来与此。今天，他们占了美国汽车销量的一半。同日本产品竞争。日本产品面临关税。 今天，丰田，日产和本田在美国...
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| Cam Shaft |
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The camshaft is driven by the
crankshaft by one of three methods:
- Gear drive
- Sprockets and timing chain
- Sprockets and timing belt
Camshaft parts. Courtesy of
Ford Motor Corporation.
- Check the camshaft for:
- a plugged oil feed,
- the correct cam lift or
- any broken or severely
worn areas.
- Check each lobe and journal
for:
- scoring,
- scuffing,
- fractured surface,
- pitting,
- and signs of abnormal
wear.
Steel camshaft and roller
followers in good condition.
Badly burned and worn
camshaft bearing bores.
Normal lobe wear is a pattern
slightly off center with a wider wear pattern at the
nose than at the heel. The off-center wear is a
result of the slight taper of the lobe used in
conjunction with the convex shape of the lifter to
rotate the lifter.
Normal wear patterns are
slightly off center on the lobe. Reprinted with the
permission of Ford Motor Company.
- If the wear pattern extends
to the edges of the lobe, the lifter will not
rotate.
- If there is any scoring or
galling, the camshaft will have to be replaced
or reconditioned.
Premature lobe and lifter wear
is generally caused by metal-to-metal contact
between the cam lobe and lifter bottom due to
inadequate lubrication. The nose will be worn from
the cam lobes, and the lifter bottoms will be worn
to a concave shape or may be worn completely away.
This type of failure usually
begins within the first few minutes of operation. It
is the result of insufficient lubrication.
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