CN203223383U - Screw rotor type line of strictly sealed dry type screw vacuum pump - Google Patents

Abstract

The utility model discloses a screw rotor type line of a strictly sealed dry type screw vacuum pump, and belongs to the technical field of dry type screw vacuum pumps. The rotor type line of the utility model consists of six curves comprising an involute ab, a transitional curve bc, an addendum arc cd, a prolate cycloid de, a dedendum arc ef and a transitional curve fa, wherein the transitional curves bc and fa are designed to be transitional curves of which arcs and cycloids are conjugated or cycloids and arcs are conjugated. The screw rotor type line realizes smooth connection by additionally arranging two transitional curves among the addendum arc, the dedendum arc and the involute, so that a leakage region can be avoided, and strict sealing is realized, and therefore, the change of a formed end face promotes the dynamic performance to be improved. Furthermore, the tooth root and the tooth profile of the rotor are smoothly connected through the transitional curves, and the tooth root and the tooth profile can be processed by only one cutter, so that the manufacturing cost can be effectively reduced. The dry type screw vacuum pump applying the screw rotor type line provided by the utility model can be widely applied to the fields of electrons, semiconductors, chemical engineering, food, spaceflight and the like.

Description

Strict sealing-type dry-type screw vacuum pump screw rotor molded lines

Technical field:

The utility model relates to dry screw vacuum pump, particularly a kind of dry screw vacuum pump screw rotor molded lines that is applicable to paired strict sealing.

Background technique:

Dry screw vacuum pump is a kind of displacement pump, relies on two screw rotors in the pump to carry gas with the sealed volume that pump housing inner chamber forms, in inlet's formation vacuum of pump.The key technology of dry screw vacuum pump is pair of intermeshing screw rotors, the key of intermeshing rotor is the end face molded lines of rotor, the quality of end face molded lines, the performance of screw vacuum pump will directly be had influence on, as sealing, efficient, area utilization factor etc., determined the manufacturing cost of pump simultaneously.The reasonable molded lines patent of invention of screw vacuum pump rotor performance nearly all is external or the Taiwan application, domestic applications fewer, and relevant problem is many.For example, China's application invention disclosed patent 201010605321.6, it is self conjugate a pair of molded lines of rotor, but do not seamlessly transit between the helix of its design and orthodrome, helix envelope and the little circular arc, special this incomplete conjugation in intersections of complex curve position, two places, have apparent in view leaking area, and the transition region manufacturing is more time-consuming.

Summary of the invention:

Purpose of the present invention is exactly on the basis of drawing domestic and international existing screw vacuum pump molded lines of rotor pluses and minuses, provides a kind of simple and reasonable for structure, and strictness seals fully, performance is good, the screw vacuum pump screw rotor molded lines that work efficiency is high.

Strict sealing-type dry-type screw vacuum pump screw rotor molded lines, the paired screw rotor that is used for the reverse outer gearing of parallel axes, the molded lines end face is designed to single head, a number of screw rod is more than or equal to 2, it is characterized in that, two end face molded lines that screw rotor adopts identical six sections curves to form, comprise one section involute ab, one section transition curve bc, one section tooth top circular arc cd, one segment length's cycloid de, one section tooth root circular arc ef, one section transition curve fa, described involute ab and tooth top circular arc are seamlessly transitted by transition curve bc, described involute ab and tooth root circular arc ef are seamlessly transitted by transition curve fa, and described transition curve bc and transition curve fa are designed to the transition curve of circular arc and cycloid conjugation or cycloid and circular arc conjugation.The present invention forms smooth connection by set up two curves between tooth top circular arc, tooth root circular arc and involute, can avoid forming leaking area, adopt the strict sealing of paired screw rotor of described molded lines, the variation of the end face that reaches thus impels joint with improved dynamic behaviour.The transition arc and the conjugate curve thereof that arrange, no enclose inside zone in engagement process, reduce noise, save driving source, curve transition makes tooth root and the smooth connection of flank profil position of rotor simultaneously, can only process tooth root and flank profil to cutter together with one, can effectively reduce manufacture cost, promote benefit.

Description of drawings:

Fig. 1 is the structural representation of one embodiment of the invention dry screw vacuum pump screw rotor molded lines.

Fig. 2 is the structural representation of another embodiment of the present invention dry screw vacuum pump screw rotor molded lines.

Fig. 3 is one embodiment of the invention rotor axial partial sectional view.

Fig. 4 is one embodiment of the invention screw rotor line of contact axis projection schematic representation.

Fig. 5 is one embodiment of the invention screw rotor space line of contact schematic representation.

Embodiment:

The invention will be further described below in conjunction with drawings and Examples.

The present invention is a kind of paired, conjugation, the dry screw vacuum pump screw rotor molded lines of strict sealing, as depicted in figs. 1 and 2, the end face molded lines that screw rotor 1 and screw rotor 2 adopt identical six sections curves to form, this molded lines is by one section involute ab, one section transition curve bc, one section tooth top circular arc cd, one segment length's cycloid de, one section tooth root circular arc ef, one section transition curve fa is connected to form, described involute ab and tooth top circular arc cd are seamlessly transitted by transition curve bc, described involute ab and tooth root circular arc ef are seamlessly transitted by transition curve fa, and described transition curve bc and transition curve fa are designed to the transition curve of circular arc and cycloid conjugation or cycloid and circular arc conjugation.

Among the embodiment of Fig. 1, the two screw rods rotor is when relative engagement rolling, in the end face molded lines, the end face molded lines a ' b ' of rotor 2 is that the envelope of the involute ab of rotor 1 forms, with the identical involute of involute ab, the transition cycloid f ' a ' of rotor 2 is that the envelope of the circular arc bc of commentaries on classics 1 forms the top circle camber line c ' d ' of rotor 2 and the root circle camber line ef conjugation of rotor 1, the cycloid de of rotor 1 is formed by the some f ' of rotor 2, and the cycloid d ' e ' of rotor 2 is formed by the some f of rotor 1.

Among the embodiment of Fig. 2, the transition cycloid b ' c ' of rotor 2 is that the envelope of the circular arc fa of commentaries on classics 1 forms, and the formation of other curve is identical with the embodiment of Fig. 1.

Among the embodiment of Fig. 1, transition curve bc is circular arc, and corresponding conjugate curve fa is cycloid, and the mode that screw rotor 1 end face molded lines curve forms is as follows:

1) formation of involute ab

In the formula: x, y are the right angled coordinatess of putting on the involute, Be the corner of any point on the flank profil,

Be the initial corner of involute,

Be the angle range of involute, R _bBe root radius, R _aBe Outside radius, r ₁Be transition arc radius, need given initial value, r ₀Be the generation circle radius of involute, r ₀≤ R _b

2) formation of transition arc bc

In the formula: r ₁Be transition arc radius,

It is the corner that circular arc forms;

3) formation of top circle camber line cd

ρ＝R _a

In the formula: ρ is circular arc vector radius, It is the corner that circular arc forms;

4) formation of cycloid de

In the formula: x, y are the right angled coordinatess of putting on the cycloid, R _pBe Pitch radius,

Be the cycloid corner, β is the initial angle that cycloid rotates in system of coordinates, β value-pi/2;

5) formation of tooth root circular arc ef

ρ＝R _b

In the formula: ρ is circular arc vector radius,

It is the corner that circular arc forms;

6) transition cycloid fa, its formation

x ₁＝2R _pcosα-bcos2α+r ₁cosθ

y ₁＝2R _psinα-bsin2α+r ₁sinθ

b＝R _a-r ₁， $\cos \mathrm{\&theta;}=\frac{\mathrm{<figure-callout\; id="2"\; label="b\; cos"\; filenames="HSA00000890680800012.png"\; state="\{\{state\}\}">b</figure-callout>}\cos 2\mathrm{\&alpha;}-R_p\cos \mathrm{\&alpha;}}{\sqrt{{{\mathrm{<figure-callout\; id="2"\; label="R\; p"\; filenames="HSA00000890680800012.png"\; state="\{\{state\}\}">R</figure-callout>}}_p}^2+b^2-2R_{p}b\cos \mathrm{\&alpha;}}},$ $\sin \mathrm{\&theta;}=\frac{\mathrm{<figure-callout\; id="2"\; label="b\; sin"\; filenames="HSA00000890680800012.png"\; state="\{\{state\}\}">b</figure-callout>}\sin 2\mathrm{\&alpha;}-R_p\sin \mathrm{\&alpha;}}{\sqrt{{{\mathrm{<figure-callout\; id="2"\; label="R\; p"\; filenames="HSA00000890680800012.png"\; state="\{\{state\}\}">R</figure-callout>}}_p}^2+b^2-2R_{p}b\cos \mathrm{\&alpha;}}},$

In the formula: x, y are the some right angled coordinatess on the cycloid,

Be the cycloid initial position angle, α is that cycloid changes the angle,

Among the embodiment of Fig. 2, transition curve fa is designed to circular arc, and the curve bc of corresponding conjugation is cycloid, and the mode that each segment type line curve forms is as follows:

1) formation of involute ab

In the formula: x, y are the right angled coordinatess of putting on the involute,

Be the corner of any point on the flank profil,

Be the initial corner of involute,

Be the corner initial value of involute,

R _bBe root radius, R _aBe Outside radius, r ₀Be the generation circle radius of involute, r ₀≤ R _b, r ₂Be the radius of transition arc, need given initial value;

2) transition cycloid bc, its formation

x ₁＝2R _pcosα-bcos2α+r ₂cosθ

y ₁＝2R _psinα-bsin2α+r ₂sinθ

b＝R _b+r ₂， $\cos \mathrm{\&theta;}=\frac{\mathrm{<figure-callout\; id="2"\; label="b\; cos"\; filenames="HSA00000890680800012.png"\; state="\{\{state\}\}">b</figure-callout>}\cos 2\mathrm{\&alpha;}-R_p\cos \mathrm{\&alpha;}}{\sqrt{{{\mathrm{<figure-callout\; id="2"\; label="R\; p"\; filenames="HSA00000890680800012.png"\; state="\{\{state\}\}">R</figure-callout>}}_p}^2+b^2-2R_{p}b\cos \mathrm{\&alpha;}}},$ $\sin \mathrm{\&theta;}=\frac{\mathrm{<figure-callout\; id="2"\; label="b\; sin"\; filenames="HSA00000890680800012.png"\; state="\{\{state\}\}">b</figure-callout>}\sin 2\mathrm{\&alpha;}-R_p\sin \mathrm{\&alpha;}}{\sqrt{{{\mathrm{<figure-callout\; id="2"\; label="R\; p"\; filenames="HSA00000890680800012.png"\; state="\{\{state\}\}">R</figure-callout>}}_p}^2+b^2-2R_{p}b\cos \mathrm{\&alpha;}}},$

In the formula: x, y are the some right angled coordinatess on the cycloid,

Be the cycloid initial position angle, α is that cycloid changes the angle,

3) formation of top circle camber line cd

ρ＝R _a

In the formula: ρ is circular arc vector radius,

It is the corner that circular arc forms;

4) formation of cycloid de

In the formula: x, y are the right angled coordinatess of putting on the cycloid, R _pBe Pitch radius,

Be the cycloid corner, β is the initial angle that cycloid rotates in system of coordinates, β value-pi/2;

5) formation of tooth root circular arc ef

ρ＝R _b

In the formula: ρ is circular arc vector radius,

It is the corner that circular arc forms;

6) formation of transition arc fa

In the formula: r ₂Be transition arc radius,

It is the corner that circular arc forms.

When the relative engagement rolling of two screw rods rotor, screw rotor 1 will form space pitch curve 3-4-5-6-7-8-9-10 at screw rotor 2, as Fig. 4, shown in Figure 5.Because it is continuous rotating, input cavity and the output cavity that curve has been blocked screw vacuum pump closed in the engagement of screw rotor, and constantly pushes ahead, thereby discharges the gas in the die cavity.

The formation of above-mentioned pair of meshing curve needs a pitch length, for input cavity and output cavity are isolated all the time, before the pair of meshing curve interrupts, must form another to pitch curve in the whole service process, therefore, a number of whole screw rod is greater than and equals 2.In the molded lines of rotor 1, tooth root circular arc ef and involute ab are by transition curve fa smooth connection, making rotor form between tooth root 11 and flank profil 12 seamlessly transits than deep camber, as shown in Figure 3, guaranteed that namely rotor does not have leakage region, constitute a smooth surface 13 with common processing possibility again, improved work efficiency.

In sum, a kind of dry screw vacuum pump molded lines of rotor of the present invention can be applicable to paired screw rotor, two rotor end-face molded lines conjugation, and identical, screw rotor only need adopt left-handed respectively and dextrorotation, can form meshing relation.Use the screw vacuum pump of dry screw vacuum pump molded lines of rotor of the present invention, can be widely used in fields such as electronics, semiconductor, chemical industry, food, space flight.

Certainly, those skilled in the art in the present technique territory should recognize, and above-mentioned enforcement embodiment only is explanation, and is not as limitation of the invention, as long as in the spiritual scope of reality of the present invention, all will drop in the scope of claim of the present invention the variation of above-described embodiment, modification etc.

Claims (4)

1. strict sealing-type dry-type screw vacuum pump screw rotor molded lines, the paired screw rotor that is used for the reverse outer gearing of parallel axes, it is characterized in that, two end face molded lines that rotor adopts identical six sections curves to form, this molded lines is by one section involute ab, one section transition curve bc, one section tooth top circular arc cd, one segment length's cycloid de, one section tooth root circular arc ef, one section transition curve fa is connected to form, described involute ab and tooth top circular arc cd are seamlessly transitted by transition curve bc, described involute ab and tooth root circular arc ef are seamlessly transitted by transition curve fa, and described transition curve bc and transition curve fa are designed to the transition curve of circular arc and cycloid conjugation or cycloid and circular arc conjugation.

2. strict sealing-type dry-type screw vacuum pump screw rotor molded lines according to claim 1 is characterized in that transition curve bc is designed to circular arc, and the curve fa of corresponding conjugation is cycloid, and the mode that each segment type line curve forms is as follows:

1) formation of involute ab

In the formula: x, y are the right angled coordinatess of putting on the involute,

Be the corner of any point on the flank profil, Be the initial corner of involute, Be the angle range of involute, R _bBe root radius, R _aBe Outside radius, r ₀Be the generation circle radius of involute, r ₀≤ R _b

2) formation of transition arc bc

In the formula: r ₁Be radius of arc, need given initial value, It is the corner that circular arc forms;

3) formation of top circle camber line cd

ρ＝R _a

In the formula: ρ is circular arc vector radius,

It is the corner that circular arc forms;

4) formation of cycloid de

In the formula: x, y are the right angled coordinatess of putting on the cycloid, R _pBe Pitch radius,

Be the cycloid corner, β is the initial angle that cycloid rotates in system of coordinates;

5) formation of tooth root circular arc ef

ρ＝R _b

In the formula: ρ is circular arc vector radius,

It is the corner that circular arc forms;

6) transition cycloid fa, its formation

x ₁＝2R _pcosα-bcos2α+r ₁cosθ

y ₁＝2R _psinα-bsin2α+r ₁sinθ

b＝R _a-r ₁，

In the formula: x, y are the some right angled coordinatess on the cycloid,

Be the corner that cycloid forms, α is that cycloid changes the angle,

3. strict sealing-type dry-type screw vacuum pump screw rotor molded lines according to claim 1 is characterized in that transition curve fa is designed to circular arc, and the curve bc of corresponding conjugation is cycloid, and the mode that each segment type line curve forms is as follows:

1) formation of involute ab

In the formula: x, y are the right angled coordinatess of putting on the involute,

Be the corner of any point on the flank profil,

Be the initial corner of involute, Be the corner initial value of involute, R _bBe root radius, R _aBe Outside radius, r ₀Be the generation circle radius of involute, r ₀≤ R _b, r ₂Be the radius of transition arc, need given initial value;

2) transition cycloid bc, its formation

x ₁＝2R _pcosα-bcos2α+r ₂cosθ

y ₁＝2R _psinα-bsin2α+r ₂sinθ

b＝R _b+r ₂，

In the formula: x, y are the some right angled coordinatess on the cycloid,

Be the cycloid initial position angle, α is that cycloid changes the angle,

3) formation of top circle camber line cd

ρ＝R _a

In the formula: ρ is circular arc vector radius,

It is the corner that circular arc forms;

4) formation of cycloid de

In the formula: x, y are the right angled coordinatess of putting on the cycloid, R _pBe Pitch radius, Be the cycloid corner, β is the initial angle that cycloid rotates in system of coordinates;

5) formation of tooth root circular arc ef

ρ＝R _b

In the formula: ρ is circular arc vector radius,

It is the corner that circular arc forms;

6) formation of transition arc fa

In the formula: r ₂Be radius of arc, It is the corner that circular arc forms.

4. strict sealing-type dry-type screw vacuum pump screw rotor molded lines according to claim 1, it is characterized in that: tooth root circular arc ef and involute ab are by transition curve fa smooth connection, make rotor between tooth root (11) and flank profil (12), form bigger lateral curvature radius and seamlessly transit, constitute a smooth surface (13) with common processing possibility.

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