2019年10月31日星期四

Two kinds of gear pump characteristics and performance analysis

Gear pump is characterized by: small size, light weight, simple structure, easy manufacture, low price, reliable work, self-priming performance is better, not sensitive to oil pollution, easy maintenance.

The disadvantage is: large flow and pressure pulsation, noise, displacement and other variables.

Internal gear pump compared with the external gear pump, the main small, small flow pulsation, noise, etc., but the processing difficulties, the use is limited. Here the meshing point of the tooth surface contact line has been playing the role of high-pressure, low pressure chamber, so the gear pump does not need to set a special flow control mechanism.

1, external gear pump flow

Displacement: V = πDhB = 2πm2zB

In fact, the volume between teeth is slightly larger than the size of the teeth, so usually take 3.33, then: V = 6.66zm2B

Flow rate: q = Vnηv = 6.66zm2Bnηv

The above calculation is the average external gear pump flow.

Features:

1) The average flow of the gear pump is proportional to the number of teeth and to the square of the modulus.

2) The flow of gear pump is proportional to tooth width, but the increase of tooth width is limited by the increased hydraulic radial force of gear. Generally, tooth width B = (6 ~ 10) m and small value at high pressure.

3) increasing the speed can increase the pump flow, but by the pump suction performance limits. Gear pump speed is generally 1000 ~ 1500r / min.

4) In addition, in the positive displacement hydraulic pump, the gear pump has the largest flow pulsation.

2, gear pump trapped oil phenomenon and unloading

★ trapped oil hazards of the phenomenon:

So that the pressure in the closed volume increased dramatically, so that the bearing is subject to a large additional load, while generating power loss and liquid heating and other undesirable phenomena; dissolved in the liquid air will precipitate bubbles, resulting cavitation, causing vibration and noise.

★ eliminate the trapped oil phenomenon:

Open the notch on the side plate of the gear pump or on the floating bushing. Asymmetrical, it must be ensured that the suction and pressure chambers can not be brought into direct contact with each other at all times; such gear pumps can not be reversed.

3, gear pump leakage and compensation measures

Gear pump there are three parts of the leak: the gear between the end face and the end cover; tooth top and housing within the hole and gear meshing Department. Among them, the maximum leakage between the gear end face and the end cap accounted for 75 ~ 80% of the total leakage.

4, improve the external gear pump pressure measures

End clearance automatic compensation principle:

The use of special access to the gear pump hydraulic oil pressure chamber led to the outer side of the floating sleeve, the role of a certain shape and size of the area, resulting in hydraulic force, the sleeve pressed to the gear end face, the force must be greater than the gear The effect of the end face acting on the inner side of the sleeve ensures that the sleeve always presses the end face of the gear automatically under various pressures so as to reduce the leakage of the end face of the gear pump so as to increase the pressure.

5, radial imbalance force

★ Hazard:

Large unbalanced radial force can make the shaft bend, tooth top contact with the shell, while accelerating bearing wear and reduce bearing life.

★ measures:

In order to reduce the impact of radial unbalance force, usually take to reduce the pressure port approach.

Reduce the gear teeth, thus reducing the addendum diameter, bearing area decreases.

Appropriate to increase the radial clearance.

6, internal gear pump

Internal gear pump with involute gear pump and cycloid gear pump two.

Cycloid gear pump, also known as the rotor pump, the two gears differ by a tooth.

Cnc Router With CCD


CCD Cnc Router with Visual system with Camera for Sign Board Cutting, Print image edge cutting, Versio.

Introduction:
1) Cnc Router with CCD Vision Router System is among the most versatile CNC machining systems you will find on the market. The T-slot bed makes it very easy to place the sheet stock down for cutting and routing, and even setup custom jigs, fixtures and clamps for parts marking applications.
2) It can produce accurate, repeatable, cost-effective work in considerably less time than it takes to do t he same work by hand. Featuring our state-of-the-art Vision Controller and our graphically advanced Vision software, this machine is perfect for a wide variety of applications including milling, drilling, contouring, and routing.

3) Application for Routing out wood signs, Cutout letters, Control panels, Cutting out sheets of material and 3D signs in sign foam, wood and more!


Cnc Router with CCD camera for decoration Camera
The machine comes with a camera to realize the Vision function.
Cnc Router Machine's spindle High Frequency Powerful spindle
The High quality UTECH R2 series Cnc Router Machine comes standard with 3.5kw high frequency spindle. This precision spindle requires no maintenance. Fully programmable speeds from 6000 to 24000 RPM, more powerful and less noise.
stepper motor Drive Motors
Patent design 1:4 gear reducer install on the driving motor, makes the motor is more powerful, and having a longer time service life.
The stepper motors are installed on all axes to ensure precise positioning of the gantry and the spindle in accordance with a predetermined program at high speed. Stepper motors are well proven high degree of reliability.
The machine is installed 4 pieces of motors.
woodworking cnc router for wood MDF UTECH Patent pressing clamp
The patent design pressing clamp is convenient for the user to assemble and disassemble the material.
plastic cnc cutting machine with CCD camera XYZ ASK Square Guide Rail(German)+Flange slider
HIGH PRECISION LINEAR GUIDE RAIL HIGH RIGIDITY OF [ASK" (German)
Due to the increased stability and rigidity provide high precision movement of the gantryand high-speed drilling spindles in X, Y, Z. achieved high machining accuracy and durability of the machine without loss of accuracy parameters.
KT plate cnc router with visual positioning system Machine handpiece
The spindle is fixed on the high quality aviation aluminum T061/6063 plate, the plate is machined by high precision CNC machining center.
Cnc Router with helical gear XY Helical Rack Gear(Germany)
Unlike gears with straight teeth, oblique engages gradually, not immediately over the entire length. Helical gearing has no zone-pair gearing. In spur gear the load on the teeth is applied instantly. The teeth in helical gears are loaded gradually as you approach them in the area of gear meshing is always at least two pairs of teeth
wood cnc machine TBI High-Precision Ball-screw Transmission (Taiwan)
1. High transmission efficiency.
2. High transmission accuracy, smooth movement, no creep phenomenon. The ball screw drive is basically rolling friction, and the frictional resistance is small. The frictional resistance has almost no relation with the speed of movement.
3. There is no free travel in the reverse direction. After the ball screw and nut are pre-tightened, the axial clearance can be eliminated. In this way, there is no dead zone in the reverse direction, which can improve the axial transmission accuracy and axial stiffness.


plastic cnc router

Cnc Router With Ccd

Cnc Router With Ccd,Cnc Engraving Router With Ccd,3D Cnc Router With Ccd,Cnc Router With Ccd Camera

Shandong U-May CNC Technology Co., Ltd. , https://www.sesamecnc.com

没有评论:

发表评论