Leaderboard


Popular Content

Showing most liked content since 09/23/2017 in Images

  1. 1 point
    saurabhjain

    constant mesh gearbox.jpg

    From the album Gears

    Construction: It is made up of following components: 1. Counter shaft or Lay Shaft: This shaft is in direct contact with the clutch and the main shaft. Keeping in mind according to the gear ratio, the speed of the counter shaft may be less that the speed of the engine. The gear ratio can be defined as the ratio of the teeth of driven gear to the teeth of the driver gear. 2. Main shaft: This shaft operates the speed of the vehicle. The power is made available to the main shaft through the gears from the counter shaft. This is done in accordance with the gear ratio. 3. Dog clutch: Dog clutch is special feature of constant mesh gearbox. It is used for the coupling of any two shafts. This is done by interference. Using a dog clutch, various gears can be locked to the output and input shafts. 4. Gears: The main work of the gears is the transmission of power between the shafts. If the gear ratio is more than one, the main shaft will work at a speed that is slower than the counter shaft, and vice versa. The arrangement of both reverse, as well as forward gears, is present.
  2. 1 point
    saurabhjain

    Jigs and fixtures

    From the album Engineering images 10

    What are Jigs? Jigs are the work holding device which holds, supports and locate the workpiece and guides tools to perform a specific operation. In other words we can say that, jigs are the device which is used for both purposes of holding the workpiece and guiding the tool. It is a tool which is used to control the location and motion of the tool during the operations. Jigs main purpose is to provide repeatability, accuracy and interchangeability in the manufacturing of products. It is used in the unidimensional machining i.e drilling, taping, reaming etc. Jigs are found to be light in weight and have complex designing. In jigs, gauge blocks are not necessary and the cost of jigs is higher. They are the special tools particularly used in drilling, reaming, tapping and boring Operations. Jigs are not fixed to the machine table until a big operation is not required to perform. What are Fixtures? Fixtures are the work holding device which holds, supports and locate the workpiece but not guides the cutting tool to perform a specific operation. In other words the fixtures are only the work holding device that holds, supports and locate the workpiece in desried position to perform any operation. The main purpose of the fixtures is to hold and locate the workpiece during any machining operation in the industries. And to provide repeatability, accuracy and interchangeability in the manufacturing of products. It is used in multidimensional machining i.e. milling, grinding, turning etc. Fixtures are found to be heavy in weight and have less complex designing. In fixtures, gauge blocks may be provided for effective handling and the cost of fixtures is not so high. Fixtures are specific tools used particularly in milling machine, shapers and slotting machine. Fixtures are fixed to the machine table. Difference Between Jigs and Fixtures in Tabular Form: The various difference between jigs and fixtures in the tabular form are given below: S.no Jigs Fixtures 1. It is a work holding device that holds, supports and locates the workpiece and guides the cutting tool for a specific operation. It is a work holding device that holds, supports and locates the workpiece for a specific operation but does not guide the cutting tool 2. jigs are used in unidimensional machining i.e. drilling,reaming, tapping, etc fixtures are used in multidimensional machining i.e. milling,turning,grinding,etc . 3. Jigs are light in weight. Fixtures are rigid and bulky. 4. Gauge blocks are not necessary. Gauge blocks may be provided for effective handling. 5. The jigs are special tools particularly used in drilling, reaming, tapping and boring operation. Fixtures are specific tools used particularly in milling machine, shapers and slotting machine 6. Usually it is not fixed to the machine table. It is fixed to the machine table. 7. Its cost is more. Its cost is less as compared with the jig. 8. Their designing is complex. Their designing is less complex. Summary of Difference Between Jigs and Fixtures Jigs are the device which is used to holds, supports and locate the workpiece and it guides the cutting tool for a specific operation. Fixtures are the device which is used to hold, support and locate the workpiece and they don’t guide the cutting tool. Jigs are used in unidimensional machining whereas fixtures are used in multidimensional machining. In jigs, gauge blocks is not necessary. In fixtures gauge blocks may provided for effective handling. Jigs are light in weight as compared with the fixtures. The cost of jigs is higher when it is compared with the fixtures. The jigs designing is complex where as fixtures designing is less complex. Jigs are not fitted to the machine table but fixtures are fitted.