Internally meshed gear pump with radial compensation

Abstract

The invention discloses an internally meshed gear pump with radial compensation. The internally meshed gear pump comprises a pump shell, a gear shaft, an inner gear ring, a side pate, a sliding bearing and a radial compensation device, wherein the radial compensation device is arranged in the clearance between the inner gear ring and the gear shaft and comprises a large crescent block, a small crescent block, a seal roller, a limiting pin and a small pin roll. Through self-adaptive compensation of the oil hydraulic difference between an oil storage channel and a gear groove, the small crescent block can radially move in the large crescent block, the radial forces of the small crescent block and the large crescent block along an arc-shaped surface are close to each other and the defect of eccentric abrasion of a crescent block of a traditional compensation device is eliminated; oil liquid in the gear grooves of the inner and outer gears are converged in multiple stage to be output through tenuous oil channels at two end surfaces of the two crescent blocks; instantaneous impact caused when oil liquid with different pressures are converged into a high pressure area is avoided; the flow rate and pressure pulsation is low.

Description

technical field [0001] The invention relates to an internal meshing gear pump, in particular to an internal meshing gear pump with radial compensation under high pressure working condition. Background technique [0002] High-pressure hydraulic systems are widely used in many equipment such as casting machines, injection molding machines and forging machines. At present, with the development of high-end equipment such as military equipment and offshore drilling platforms, further high-pressure hydraulic systems have become an inevitable trend, and the biggest challenge lies in the development of high-quality high-pressure pumps. [0003] Internal gear pumps are widely used in various construction machinery due to their outstanding features such as low noise, small oil trapping, compact structure and good stability. However, they still cannot meet the working requirements of ultra-high pressure hydraulic systems (such as above 35MPa). The main reason is that the internal leak...

AI Technical Summary

Problems solved by technology

For example: (1) Using a single crescent block, the pump body and the crescent block are fixedly connected by a single pin (such as patent 200420021259.6), and the distance between the crescent block and the tooth top is a fixed value. This device has the advantage of simple structure, but after the crescent block is worn The pump leakage rate rises sharply and the service life is short

(2) A single piece of crescent block is adopted, and a pin is inserted inside. The crescent block can rotate around the pin, and its two sides are respectively in contact with the tooth tops of the inner ring gear and the gear shaft, thereby realizing the radial compensation function (such as patent US20100233005 and patent 201210429565.2), this scheme reduces its service life due to severe wear of the crescent block

Under the action of high stress, the wear of the contact position is intensified and the gap between the rest of the crescent block and the top of the tooth is increased, and the internal leakage increases accordingly, which restricts the pressure increase of the pump

[0007] 2) The way of unilateral high-pressure support forms a non-uniform gap between the inner crescent block and the tooth top of the gear, which easily leads to vibration and noise

With the eccentric wear and damage of the crescent block, the gap difference between different positions between the tooth top and the crescent block will increase, and the instability will increase when the pressurized oil passes through the non-uniform gap, which will easily cause the crescent block to vibrate and cause the noise of the pump to increase. High (refer to patent US2008226484), which weakens the advantages of low vibration and low noise of the internal meshing gear pump

[0008] 3) The crescent block and the tooth top of the gear are in contact with few teeth, which is easy to deform under high pressure, and the working reliability of the pump is insufficient

The stress on the two is greatly increased due to the reduction of the stress area, which causes the crescent block in the high pressure area to deform, which easily leads to the failure of radial compensation, which leads to the failure of the hydraulic pump to work normally.

[0009] 4) When entering the high-pressure area through the cogging of the internal gear and the cogging of the external gear, the pressure of the two lines of oil that enters is uneven, which will cause flow and pressure pulsation, which is difficult to meet the requirements of high-precision liquid output

Images