CN201396281Y

CN201396281Y - Multistage three-blade Roots vacuum pump

Info

Publication number: CN201396281Y
Application number: CN200920024057XU
Authority: CN
Inventors: 孙成忠
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-19
Filing date: 2009-03-19
Publication date: 2010-02-03
Anticipated expiration: 2019-03-19

Abstract

The utility model relates to a multistage three-blade Roots vacuum pump which belongs to the field of vacuum pumps. The multilevel three-blade Roots vacuum pump comprises multistage pump bodies, rotors arranged on a driving shaft and a driven shaft are arranged in a pump cavity of each stage of pump body. The utility model is characterized in that each stage of pump body is in an independent integral structure; and each stage of pump body has high pumping speed and high ultimate vacuum. The outer circular arc radius of the direct atmosphere discharge separation wall is identical with the outercircular radius of the pump body. During assembly, the upper middle separation wall and the lower middle separation wall are combined through screws and are installed between two adjacent stages of pump bodies, and the rotors are in a three-blade shaft in the circumferential symmetrical distribution. The utility model overcomes the defect of incapability of direct atmosphere discharge of the existing Roots vacuum pump in the single-stage structure, and has the advantages of high pumping speed, high ultimate vacuum and direct atmosphere discharge.

Description

Multistage three leaf Roots pumps

Technical field

The utility model belongs to field of vacuum, is specifically related to a kind of multistage three leaf Roots pumps.

Background technique

Roots pump generally uses as mechanical booster pump in vacuum equipped, be generally the single step arrangement formula, its rotor shapes is two lobate, this pump is discharging directly into atmosphere separately, must form unit with fore pump during use uses, fore pump is selected the improper vacuum environment that is easy to pollute, and can not realize not having the dry-type working state of oil, so using scope is subjected to bigger restriction.

The model utility content

The purpose of this utility model is to solve the defective that the Roots pump of existing single step arrangement form can not discharging directly into atmosphere, provides that a kind of pumping speed is big, ultimate vacuum is high, the multistage three leaf Roots pumps of discharging directly into atmosphere.

The utility model is achieved through the following technical solutions:

Be a kind of multistage three leaf Roots pumps, comprise the multistage pump housing, be equipped with in the pump chamber of every grade of pump housing and be installed in the master, rotor on the driven shaft, it is characterized in that described each grade pump housing is independently monolithic construction, be provided with the external intermediate bulkheads between every grade of pump housing, described external intermediate bulkheads is by forming being much of intermediate bulkheads and following intermediate bulkheads, the outer arc radius of described external intermediate bulkheads is identical with the outer arc radius of the pump housing, to go up intermediate bulkheads with screw during assembling and following intermediate bulkheads is combined and is installed between the adjacent two-stage pump housing, described rotor is the tri-lobed that circumference is symmetrically distributed.

The end face molded lines of each leaf of small rotor is made up of circular arc AB and cycloid BC; The end face molded lines of relatively large each leaf of rotor is made up of circular arc ab, straight line bc, circular arc cd, straight line de, cycloid ef, circular arc fg.

The ratio of rotor maximum outside diameter and its pitch circle is between 1.2～1.55.

Gap between rotor end-face and the pump housing end face is 0.05～0.8mm.

Each grade pump housing is equipped with flow channel or air-flow path, or is provided with flow channel and air-flow path simultaneously.The both sides of the afterbody pump housing are provided with the aeration mouth that communicates with pump chamber.

The external intermediate bulkheads is a hollow structure, is provided with suction port, inter-stage air-flow path, relief opening.

The mode that rotor can adopt length to shorten step by step also can adopt rotor length to be divided into the mode of two-stage, and promptly the length of second level rotor and other rotors is identical and less than the length of first order rotor.

The utility model has the following advantages compared to existing technology:

Small rotor molded lines of the present utility model is made of circular arc, cycloid, and relatively large rotor is made of multiple circular arc, straight line and cycloid, the rotor engaged good airproof performance; Separate with the external intermediate bulkheads between the pump housings at different levels, form multistage independent pump chamber, this kind structure is than easier processing in built-in next door and assembling; By the aeration hole of the pump housing, the part of the gas after the discharge gas cooling is returned pump chamber again, reduce the temperature of pump chamber effectively, obtain higher compression ratio, realize not having the clean vacuum that oil does not have dirt, and can discharging directly into atmosphere.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is a multi-stage rotor assembly stereogram;

Fig. 3 is the A-A sectional drawing among Fig. 1;

Fig. 4 is an external intermediate bulkheads structural representation;

Fig. 5 is the B-B sectional drawing among Fig. 4;

Fig. 6 is embodiment's 1 rotor end-face molded lines schematic representation;

Fig. 7 is embodiment's 2 rotor end-face molded lines schematic representation.

As shown in FIG.: 1 rear bearing; 2 swelling covers; 3 gears; 4 bonnets; 5 rear bearing blocks; 6 rear end covers; 7 bonnet outside framework oil seals; 8 pump housings; 9 suction ports; 10 external intermediate bulkheads; 11 pump housings; 12 external intermediate bulkheads; 13 pump housings; 14 front covers; 15 end cap waterwaies; 16 front-end bearing pedestals; 17 protecgulums; 18 motor link press spans; 19 motors; 20 coupling; 21 coupling; 22 driving shafts; 23 protecgulum waterwaies; 24 fore bearings; Outside framework oil seal before 25; 26 relief openings; 27 aeration mouths; 28 intercaste air-flow paths; 29 intercaste air-flow paths; 30 bonnet waterwaies; 31 driven shafts; 32 water-cooling channels; 33 water-cooling channels; 34 aeration mouths; 35 air outlets; 36 suction ports; 37 fastening screw trip bolts; Intermediate bulkheads on 38; 39 fastening screw trip bolts; 40 times intermediate bulkheads; L1, L2 are rotor length.

Embodiment

Embodiment 1

Be example with three grade of three small-sized leaf Roots pump below, the utility model is further elaborated.

As Fig. 1, Fig. 3, shown in Figure 4, motor link press span 18 is fixed on the protecgulum 17, become one with the utility model, the motor 19 that is fixed on the motor link press span 18 passes through coupling 20, coupling 21 connects driving shaft 22, the trilobal rotor that 3 circumference are symmetrically distributed is housed respectively on driving shaft 22 and the driven shaft 31, it is placed on the pump housing 8 respectively, the pump housing 11, in the pump chamber of the pump housing 13, separate with external intermediate bulkheads 10 between the pump housing 8 and the pump housing 11, separate with external intermediate bulkheads 12 between the pump housing 11 and the pump housing 13, form multistage pump chamber, described external intermediate bulkheads 10, external intermediate bulkheads 12 is by forming with following intermediate bulkheads 40 being much of intermediate bulkheads 38, last intermediate bulkheads 38 and following intermediate bulkheads 40 are by fastening screw trip bolt 37, fastening screw trip bolt 39 links together, the top of last intermediate bulkheads 38 is provided with air outlet 35, the bottom of following intermediate bulkheads 40 is provided with suction port 36, driving shaft 22, driven shaft 31 two ends fore bearing 24 and rear bearing 1 support fixation, fore bearing 24 and rear bearing 1 are respectively by front-end bearing pedestal 16, rear bearing block 5 is fixed on front cover 14 and the rear end cover 6, a pair of synchromesh gear 3 is equipped with in rear bearing block 5 outer ends, be fixed on driving shaft 22 with swelling cover 2, on the driven shaft 31, front cover 14, the outer end of rear end cover 6 is respectively protecgulum 17 and bonnet 4.Be equipped with water-cooling channel 32, water-cooling channel 33 on the pump housing 8, the pump housing 11, the pump housing 13, the both sides of the afterbody pump housing 13 are provided with aeration hole 27, aeration hole 34, driving shaft 22, driven shaft 31 two ends fore bearing 24 and rear bearing 1 support fixation, fore bearing 24 and front-end bearing pedestal 16 and rear bearing 1 and rear bearing block 5 are separately fixed on front cover 14 and the rear end cover 6.

As Fig. 2, shown in Figure 6, the end face molded lines of rotor is that circular arc AB and cycloid BC form, the rotor engaged good airproof performance, and rotor length is divided into two kinds, and promptly the length of second level rotor and third level rotor is L2, less than the length L 1 of first order rotor.

Before the utility model uses, by the gap between assembling adjustment driving shaft 22, driven shaft 31 upper rotor parts, adjust the end clearance between rotor and front cover 14, the rear end cover 6, make the gap of rotor when rotary work on driving shaft 22, the driven shaft 31 suitable, thereby guarantee that the utility model reaches technical requirements when proper functioning.

In the utility model when work, is without any need for working medium, motor 19 is by coupling 20, coupling 21 rotates power rotor assembly and the gear rotation that is fixed on the driving shaft 22, drive driven rotor by synchromesh gear and change part with same velocity reversal's running, pumped gas sucks the pump housing 8 of the first order from suction port 9, send into the partial pump housing 11 by intercaste air-flow path 29, the gas that the partial pump housing 11 is discharged is sent into the pump housing 13 of the third level by intercaste air-flow path 28, gas is discharged from the relief opening 26 of the pump housing 13 bottoms of the third level, if the gas of discharging does not need to reclaim, relief opening 26 can discharging directly into atmosphere, aeration mouth 27, aeration mouth 34 can mix atmosphere coolant pump cavity temperature, obtains higher compression; If the gas of discharging needs to reclaim, after the gas that relief opening 26 is discharged is sent into the heat exchanger cooling, take out the part cooled gas and send in the pump chamber of the pump housing 13, cool off the gas in the pump chamber, can more effectively reduce the operating temperature of pump chamber by aeration mouth 27, aeration mouth 34.Preceding outside framework oil seal 25 and bonnet outside framework oil seal 7 are isolated pump chamber and fore bearing 24, rear bearing 1 and gear-box fully, guaranteed the working pressure of pump chamber, stopped to return oily phenomenon, made the fore bearing 24 at two ends, rear bearing 1 obtain proper lubrication for a long time simultaneously, working stability is reliable.The pump housing 8 of the present utility model, the pump housing 11, the pump housing 13 are equipped with water-cooling channel 32, water-cooling channel 33, also be provided with circulating water in the bonnet waterway 30 of the end cap waterway 15 of front cover 14, rear end cover 6, the protecgulum waterway 23 of protecgulum 17, bonnet 4, can significantly reduce the operating temperature of vacuum pump, the no any pollution of working procedure cleaning, through experiment, 3 grade of three leaf Roots pump limiting vacuum can reach 100Pa, realized the oil-free dry vacuum fully.

Embodiment 2

As shown in Figure 7, the end face molded lines of rotor is made up of circular arc ab, straight line bc, circular arc cd, straight line de, cycloid ef, circular arc fg.Other are with embodiment 1.

Present embodiment is with respect to embodiment 1, and the end face molded lines of rotor is fit to the rotor of relatively large multi-stage roots vacuum pump.

The utility model is not limited to above enforcement, and multistage three leaf Roots pumps can be designed and manufactured into 4 grades, 5 grades and 6 grades, and more when the progression of pump, the utility model was directly installed on the chassis special when volume was big, was connected with motor by belt pulley.

Claims

1, a kind of multistage three leaf Roots pumps, comprise the multistage pump housing, be equipped with in the pump chamber of every grade of pump housing and be installed in the master, rotor on the driven shaft, it is characterized in that described each grade pump housing is independently monolithic construction, be provided with the external intermediate bulkheads between every grade of pump housing, described external intermediate bulkheads is by forming being much of intermediate bulkheads and following intermediate bulkheads, the outer arc radius of described external intermediate bulkheads is identical with the outer arc radius of the pump housing, to go up intermediate bulkheads with screw during assembling and following intermediate bulkheads is combined and is installed between the adjacent two-stage pump housing, described rotor is the tri-lobed that circumference is symmetrically distributed.

2, multistage three leaf Roots pumps according to claim 1 is characterized in that the end face molded lines of each leaf of small rotor is made up of circular arc AB and cycloid BC.

3, multistage three leaf Roots pumps according to claim 1 is characterized in that the end face molded lines of relatively large each leaf of rotor is made up of circular arc ab, straight line bc, circular arc cd, straight line de, cycloid ef, circular arc fg.

4, according to claim 1 or 2 or 3 described multistage three leaf Roots pumps, the ratio that it is characterized in that rotor maximum outside diameter and its pitch circle is between 1.2～1.55.

5, according to claim 1 or 2 or 3 described multistage three leaf Roots pumps, it is characterized in that rotor is short than pump housing length, the gap between two ends of rotor face and the pump housing both ends of the surface is 0.05～0.8mm.

6, multistage three leaf Roots pumps according to claim 1 is characterized in that each grade pump housing is equipped with flow channel or air-flow path or is provided with current and air-flow path simultaneously.The both sides of the afterbody pump housing are provided with the aeration mouth that communicates with pump chamber.

7, multistage three leaf Roots pumps according to claim 1 is characterized in that the external intermediate bulkheads is a hollow structure, are provided with suction port, intercaste air-flow path, relief opening.

8, multistage three leaf Roots pumps according to claim 1 is characterized in that rotor length shortens step by step.

9, multistage three leaf Roots pumps according to claim 1 is characterized in that rotor length is divided into two-stage, and the length of second level rotor and other rotors is identical and less than the length of first order rotor.