CN101985938A - Three-axis composite dry pump with screw and roots rotor - Google Patents

Abstract

The invention relates to a vacuum pump, in particular to a three-axis composite dry pump with screw rods and Roots rotors. It includes a motor, a main shaft and a driven shaft. The main shaft drives the driven shaft through the gear meshing at the shaft end. Two driven shafts are parallel and symmetrically assembled on both sides of the main shaft. The main shaft and the driven shafts on both sides are equipped with screw rotors and Roots rotors, and the screw rotors and Roots rotors on each shaft are separated by partitions. The invention can have a higher pumping speed in a wider pressure range, and is nearly double the pumping speed compared with the two-axis compound dry pump, and has good dynamic balance characteristics, and the reliability and service life are improved. Big improvement.

Description

A three-shaft compound dry pump with screw and Roots rotor

technical field

The invention relates to a vacuum pump, in particular to a three-axis composite dry pump with screw rods and Roots rotors.

Background technique

Existing dry pumps all adopt a two-shaft structure. The rotor shaft, especially the driving shaft, is subjected to asymmetric periodic forces, resulting in large vibration and noise, and low pumping efficiency. Pumping speed, but also increases the consumption of energy.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a three-axis composite dry pump with a screw and a Roots rotor, which solves the problems of high vibration noise and low pumping efficiency. the

The three-axis compound dry pump of the screw and Roots rotor of the present invention includes a motor, a main shaft and a driven shaft. The main shaft is equipped with a driving gear, and the driven gear meshed with the driving gear is assembled on the driven shaft. There are two driving shafts, which are parallel and symmetrically assembled on both sides of the main shaft. The main shaft and the driven shafts on both sides are equipped with screw rotors and Roots rotors. The screw rotors and Roots rotors on each shaft are separated by a partition .

The separator is provided with three shaft holes, an air hole is opened below the shaft hole of the left driven shaft, and an air hole is opened above the shaft hole of the right driven shaft, and the two air holes are symmetrically distributed up and down along the line where the shaft holes are located. .

The Roots rotors are installed vertically on the main shaft and the driven shaft.

The number of leaves of the Roots rotor is two, four, six or eight.

The connecting line between the centers of the main shaft and the two driven shafts on the same cross section is a straight line or a triangle.

The number of stages of the Roots rotor is 1-6.

When the number of stages of the Roots rotor is 2 to 6, the adjacent two stages are separated by partitions.

Compared with the prior art, the remarkable features and beneficial effects of the present invention are: due to the technical scheme of the present application, the most remarkable feature is that the Roots and the screw are combined, so that the three-axis compound dry pump of the screw and the Roots rotor It can have a large pumping speed in a wide pressure range, and the power curve of the compound dry pump can still approximate a horizontal line as the pressure changes. This performance effectively reduces energy consumption.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the schematic diagram of the pumping process of Roots part;

Figure 3 is the cross-sectional profile of the Roots rotor;

Fig. 4 is a structural schematic diagram of a triangular arrangement of the center line of the rotor cross section;

In the figure: 1 motor, 2 driving gear, 3 right driven gear, 4 main shaft, 5 driving screw rotor, 6 right driven screw rotor, 7 partition, 8 right driven shaft, 9 right driven Roots rotor, 10 Intake cavity, 11 Left driven Roots rotor, 12 Left driven shaft, 13 Active Roots rotor, 14 Left driven screw rotor, 15 Exhaust cavity, 16 Left driven gear, 17 Air intake, 18 Exhaust Mouth, 19 bearing end caps, 20 pump bodies, 21 upper bearing blocks, 22 lower bearing blocks, 23 upper bearings, 24 gear chambers, 25 lower bearings.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Example 1. The three-axis composite dry pump of screw and Roots rotor of the present invention, wherein motor 1 is connected with main shaft 4, driving gear 2, left driven gear 16 and right driven gear 3 are respectively assembled on main shaft 4 through key connection, On the left driven shaft 12 and the right driven shaft 8, the three shafts are distributed in parallel. Driven by the three synchronous gears, the three shafts rotate in opposite directions to each other. On the main shaft 4, the left driven shaft 12 and the right driven shaft A screw rotor and a 2-stage eight-lobe Roots rotor are fixed on the shaft 8. The screw rotor and the Roots rotor are respectively fixed on the three shafts through key connections. The main shaft 4, the left driven shaft 12 and the right driven shaft 8 are in the The shaft shoulders at both ends are equipped with bearings, and the upper bearing 23 is fixed on the upper bearing seat 21. There is a cavity gear chamber 24 connected to the top of the upper bearing seat 21, and the shaft shoulders of the three shafts extending to the gear chamber 24 are equipped with bearings, gears, etc. The chamber 24 and the upper bearing seat 21 are integrally cast, and the cavity inside the upper bearing seat 21 is the exhaust chamber 15, which communicates with the exhaust port 18, and the motor 1 is fixed on the gear chamber 24 by bolts. The bearing housing 21 is connected with the pump body 20 through bolts, and the three four-lobe Roots rotors inside the pump body 20 are installed on the main shaft 4, the left driven shaft 12 and the right driven shaft 8 respectively perpendicular to each other. The screw rotor is separated by a partition 7, and the partition 7 is provided with three shaft holes, an air hole is opened below the shaft hole of the left driven shaft 12, an air hole is opened above the shaft hole of the right driven shaft 8, and two air holes It is symmetrically distributed up and down along the straight line where the shaft hole is located. The lower bearing seat 22 is fixed on the pump body 20 by bolts, the cavity inside the lower bearing seat 22 is the air intake chamber 10, and the lower bearing seat 22 at the top of the air intake chamber 10 has an air inlet 17, and the air inlet 17 Connected with the air intake pipeline, the bearing end cover 19 is fixed on the lower bearing seat 22 by bolts.

The screw rotor is synchronously driven and meshed by three gears, the gap between the teeth is very small, but there is no contact, so it can generate a high vacuum and is not easy to wear. Compared with other dry pumps such as scroll pumps and claw pumps, the screw pump has obvious advantages, not only has a higher compression ratio, but also is relatively stable.

There are two schemes for the arrangement of the three axes: one is that the three axes are arranged horizontally, and the other is that the three axes are arranged in a triangle. Since the design of the three shafts requires the meshing of three synchronous gears, in order to prevent the interference of the two air intake and exhaust, and to simplify the structure, it is better to adopt a horizontal arrangement of the three axes, and a triangular arrangement can also be used.

The working process of the present invention is: the power source is provided by the motor 1 . The motor 1 is directly connected to the main shaft 4 to drive the main shaft 4 to rotate. The main shaft 4 is connected with the driving gear 2 through a key, and drives the left driven gear 16 and the right driven gear 3 to rotate. Left driven gear 16 and right driven gear 3 are connected with left driven shaft 12 and right driven shaft 8 respectively, drive two driven shafts to rotate. In this way, the synchronous rotation of the driving screw rotor 5 , the left driven screw rotor 14 , the right driven screw rotor 6 , the driving Roots rotor 13 , the left driven Roots rotor 11 and the right driven Roots rotor 9 is realized. The non-contact engagement between the rotors forms a closed space together with the inner wall of the pump, so as to realize periodic suction and exhaust.

The inner rotors of the pump are separated by a partition 7. The gas discharged from the interaction between the rotor and the rotor, and between the rotor and the inner wall of the pump passes through the air holes in the partition plate 7 , the air intake chamber 10 and the exhaust chamber 15 and is finally discharged through the exhaust port 18 . Under the rotation of the rotors at all levels, the gas transportation process is realized. On the basis of retaining some advantages of Roots pump and screw pump, the three-axis compound dry pump of screw and Roots rotor has more advantages of its three-axis arrangement and the combination of screw and Roots: good dynamic balance performance and stable operation , effective vibration and noise reduction; compact structure, smaller volume at the same pumping speed, effectively reducing costs, lower failure rates, and reduced maintenance costs.

Example 2. Its structure, connection and working process are the same as those in Example 1, except that the main shaft and the driven shafts on both sides are equipped with two-stage eight-lobe Roots rotors.

Example 3. Its working process is the same as that of Embodiment 1, except that the main shaft 4, the left driven shaft 12 and the right driven shaft 8 are arranged in a triangle.

Claims (7)

1. three compound dried pumps with screw rod and roots rotor, comprise motor, main shaft and driven shaft, be equipped with driving gear on the main shaft, the driven gear that is meshed with driving gear is assemblied on the driven shaft, it is characterized in that driven shaft is two, parallel and the symmetrical main shaft both sides that are assemblied in all are equipped with screw rotor and roots rotor on main shaft and the both sides driven shaft, and screw rotor and roots rotor on every axle separate by dividing plate.

2. a kind of three compound dried pumps as claimed in claim 1 with screw rod and roots rotor, it is characterized in that described dividing plate is provided with three axis holes, below the axis hole of left driven shaft, open a pore, open a pore above the axis hole of right driven shaft, two pores are symmetrically distributed up and down along the straight line at axis hole place.

3. a kind of three compound dried pumps with screw rod and roots rotor as claimed in claim 1 is characterized in that described roots rotor is orthogonal to be installed on main shaft and the driven shaft.

4. a kind of three compound dried pumps with screw rod and roots rotor as claimed in claim 1 is characterized in that the described roots rotor number of sheets is two leaves, four leaves, six leaves or eight leaves.

5. a kind of three compound dried pumps with screw rod and roots rotor as claimed in claim 1 is characterized in that the described main shaft and the line of centres of two driven shafts on same cross section are straight line or triangle.

6. a kind of three compound dried pumps with screw rod and roots rotor as claimed in claim 1 is characterized in that described roots rotor progression is 1 grade～6 grades.

7. a kind of three compound dried pumps with screw rod and roots rotor as claimed in claim 6 when it is characterized in that described roots rotor progression is 2 grades～6 grades, separate with dividing plate between the adjacent two-stage.

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