Internal meshing pump referred to as internal
gear pump, its structure is more compact than the external gear oil pump, the shape size is smaller, the pressure and displacement of the general internal gear oil pump is smaller, often used for small machines with lubricating oil pump.
FIG. 22 shows the structure diagram of gear oil pump. The main components are pump body 2, outer gear 1, inner gear ring 3, crescent shaped spacer, 4 and end cover. The outer gear 1 and inner gear ring 3 meshing with each other, the center of the two gears to maintain an eccentric distance, the two gears can be reciprocal driving wheel, but generally by the inner gear ring as the main driving wheel, it and drive shaft 5 made of one.
When the inner ring 3 turns counterclockwise as shown, it turns the outer gear 1 in the same direction. The working chamber of the pump is separated into two sealing chambers and B by two meshing gears and crescent shaped spacer 4, and the volume change is produced. On the left side of the chamber due to the two gear teeth out of meshing, A volume increase, pressure decrease, suction process, until the teeth to crescent block on the left side of the tip, all volume among the tooth filled with oil, and thus divided into two road, after the teeth turned into crescent every piece of the right side of the tip, mesh teeth began to enter, A volume decreases, and the pressure increases, squeezing the oil into the discharge chamber B.
Figure 22
Because the number of teeth of the two gears is not equal, the speed of the two gears is not equal, and the speed is inversely proportional to the number of teeth of the two gears. The inner gear pump and the outer gear oil pump have similar characteristics, but the location is a little smaller than the outer gear oil pump with the same pitch circle diameter, tooth shape, tooth width and speed.
The position of the crescent block and the rotation direction of the pump determines the direction of suction and oil discharge of the pump, that is, the position change of the crescent block or the rotation direction of the pump can change the direction of suction and oil discharge of the pump. If you need to change the direction of rotation of the pump, and to keep the original direction of suction and oil discharge unchanged, as long as the crescent block in the original position of 180 degrees on the rotation.
FIG. 23 shows the reversible
KCB gear pump structure. The inner ring 2 is the main driving wheel, which is driven by the drive shaft 10. Crescent shaped block 4 and side plate 9 made a rest, driven shaft 3 is fixed on the side plate 9, the outer gear 5 sliding sleeve on the shaft, the side plate also plays a end face sealing role, the central side plate has a small concave hole, there are steel ball 8 and spring 7, so that the side plate is close to the gear end. In addition, on the lateral side of the side plate, there is also a limit pin 6, pin 6 is blocked in the pump end cover 11 half of the mass groove in one end, so that the side plate and the crescent partition plate unchanged. If the pump is reversed, such as turning from the counterclockwise direction in FIG. 22b to the clockwise direction in FIG. 26C, the rotation force of the active inner gear ring will drive the driven outer gear and crescent spacer to revolve around the active shaft, until the pin on the oil pump is blocked by the other end of the semicircular plant on the end cover. At this time, the rotation center O1 of the crescent partition and the outer gear has rotated 180 degrees around the center O of the driving shaft, and keep the direction of suction and oil discharge unchanged.
图23
