What is a herringbone gear pump?
What is a herringbone gear pump?
The herringbone gear pump (Figure 3-3) is a modification of the spur gear design. The liquid is pumped in the same manner as in the spur gear pump. However, in the herringbone pump, each set of teeth begins its fluid discharge phase before the preceding set of teeth has completed its discharge phase.
What is the advantage of herringbone gear over helical gear in gear pump?
Their advantage over the helical gears is that the side-thrust of one half is balanced by that of the other half. This means that herringbone gears can be used in torque gearboxes without requiring a substantial thrust bearing.
Why are herringbone gears not used in a transmission?
Herringbone Gear Herringbone gears are typically smaller than the comparable double helical and are ideally suited for high shock and vibration applications. Herringbone gearing is not used very often due to their manufacturing difficulties and high cost.
What is a spur gear pump?
Spur gear pumps use pairs of counter-rotating toothed cylinders to move fluid between low-pressure intakes and high-pressure outlets. Fluid is trapped in pockets formed between gear teeth and the pump body until the rotating gear pairs bring individual elements back into mesh.
How are herringbone gears cut?
An effective cutting process for a herringbone gear typically involves hobbing, milling, and shaping, though these methods depend largely on whether or not a gap is required between the two helixes or if the herringbone is to be continuous. When cutting herringbone teeth, rotary cutters and hobs are typically used.
What is the difference between double helical and herringbone gears?
A herringbone gear has no gap between the helices. A double-helical gear has a gap between the helices. External herringbone or double-helical gears have teeth that project outwards, whereas internal double-helical gears have teeth that project inwards.
What are the disadvantages of helical gears?
Some of the disadvantages of helical gears are they are less efficient then spur gears due to tooth slippage. The diagonal profile of the teeth is what causes the slippage and also leads to axial thrust on the shaft. It is important to choose a bearing that can withstand the axial thrust generated by the gears.
Why do gears have angled teeth?
In spiral bevel gears, the teeth are angled and curved to provide for more gradual tooth engagement and more tooth-to-tooth contact than with a straight bevel gear. This design greatly reduces the vibration and noise produced, especially at high angular velocities (>1,000 rpm).
What is hydraulic gear pump?
A gear pump uses the meshing of gears to pump fluid by displacement. They are one of the most common types of pumps for hydraulic fluid power applications. The gear pump was invented around 1600 by Johannes Kepler. Gear pumps are also widely used in chemical installations to pump high viscosity fluids.
What are the different types of gear pumps?
Generally, gear pumps are of five types:
- External Gear Pump.
- Internal Gear Pump.
- Lobe Pump.
- Ge-rotor Pump ( Generated Rotor Pump )
- Screw Pump.
How are herringbone gears manufactured?
Are helical gears stronger than spur gears?
Helical gears are more durable than spur gears because the load gets distributed across more teeth. Hence, for a given load, the force will be spread out better than with a spur gear, resulting in less wear on individual teeth. Spur gears can be really loud.
What are the advantages of herringbone gears?
Compared with single-helical gears, the herringbone gears have significant advantages of higher load carrying capacity, lager total contact ratio and lower axial force. Therefore, the herringbone planetary gear train (HPGT) is also applied to heavy machinery such as coal cutter, aerospace engine, etc.
What is a double helical gear used for?
The double-helical gear, also referred to as the herringbone gear (Figure 39.8 ), is used for transmitting power between parallel shafts. It was developed to overcome the disadvantage of the high-end thrust that is present with single-helical gears.
What is planetary gear train?
Planetary gear train (PGT) has been widely used in the transmissions of helicopters, automobiles, wind turbine, aircraft engines, etc.
