CN200952470Y

CN200952470Y - Tooth shape screw

Info

Publication number: CN200952470Y
Application number: CN 200620046523
Authority: CN
Inventors: 陆征; 钟子健; 王玉贵; 杨毅; 李敏; 田兵兵; 肖芳
Original assignee: 711th Research Institute of CSIC
Current assignee: 711th Research Institute of CSIC
Priority date: 2006-09-29
Filing date: 2006-09-29
Publication date: 2007-09-26
Anticipated expiration: 2016-09-29

Abstract

The utility mode discloses a novel tooth-shaped screw rod. The screw rod includes a screw rod body and a plurality of spiral teeth arranged on the screw rod. Tooth-shaped curve on the cross section of the screw rod is abcdefghij, and comprises a cycloidal curve formed by connecting the points of a, b and c; a root circle arc formed by connecting the points of c, d, and e; and an addendum circle arc formed by connecting the points of i, j and a; wherein the points of a, c and g are arranged on the same diameter of the addendum circle, the points of c, d and e are arranged on the root circle, and points of i, j and a are arranged on the addendum circle. The utility model is characterized in that the tooth-shaped curve further includes an elliptical arc formed by connecting the points of g, h and i, and an elliptical envelope line formed by connecting the points of e, f and g and having the elliptical arc ghi as base line. The screw rod in the utility model has shorter sealing line which has smaller exposed part under the condition of same gap width, and can generate higher pressure.

Description

A kind of Noval tooth-type screw rod

Technical field

The utility model relates to the Noval tooth-type screw rod of a kind of two screw pump or double-screw compressor.

Background technique

The existing screw rod flute profile that is used for two screw pump or double-screw compressor, cycloid flute profile, spiral of Archimedes flute profile, circular arc flute profile and involute tooth type are arranged, when this screw rod is used for two screw pump, though can reach strict (fully) sealing, but it is long that its shortcoming is a contact line length, thereby volumetric efficiency is not high.

For addressing this problem, China's application number is that 01215031.2 utility application discloses a kind of tooth screw stem, its tooth curve is that the envelope of baseline constitutes by cycloid, root circle circular arc, top circle circular arc, cycloid and with the cycloid, but the Line of contact of this tooth-shaped screw bolt end on projection is a broken line, and the long shortcoming of broken line Line of contact, therefore the length of sealing line that forms is long, to such an extent as to influence the performances such as volumetric efficiency, pressure of pump or compressor.

The model utility content

Technical problem to be solved in the utility model provides a kind of both strict (fully) sealing, and Line of contact is the screw rod of two sections circular arcs at the screw rod end on projection, and the short Noval tooth-type screw rod of length of sealing line.

The utility model is to solve the problems of the technologies described above the technological scheme that adopts to provide a kind of Noval tooth-type screw rod, comprise the screw rod body, the screw rod body is provided with helical tooth, flute profile curve on the screw rod cross section is abcdefghij, it comprises by an a, b, the cycloid that the c line constitutes, by a c, d, the root circle circular arc that the e line constitutes, by an i, j, the top circle circular arc that a line constitutes, its mid point a, c, g is on the same diameter of top circle, point c, d, e is on root circle, point i, j, a is on top circle, it is characterized in that, described flute profile curve also comprises by a g, h, the elliptic arc that the i line constitutes is by an e, f, what the g line constituted is the oval envelope of baseline with elliptic arc ghi.

Described screw rod can be left handed screw, also can be right handed screw.

The utility model remarkable advantage compared to existing technology is:

1. the end on projection of employing and elliptic arc and oval envelope Line of contact is a camber line, and Line of contact is shorter, can reach the sealing of strict (fully) when being used for two screw pump or double-screw compressor, the volumetric efficiency height, and can not interfere phenomenon;

2. screw rod can be left-handedly, also can be dextrorotation, and end surface shape is identical, and two intermeshing screw rods only need a pitch can have Seal cage of one's own.

Noval tooth-type screw rod of the present utility model not only can be used for single-head screw, also can be used for double end and multiple thread screw, is a kind of simple, practical, new screw that effect is good.

Description of drawings

Further specify feature and advantage of the present utility model below in conjunction with the drawings and specific embodiments, wherein:

Fig. 1 is the structural representation of Noval tooth-type screw rod of the present utility model.

Fig. 2 is a flute profile curve of the present utility model.

The projection drawing of potted line on shaft section on screw rod straight-sided flank when Fig. 3 the utility model is used for the twin-screw engagement.

Fig. 4 is used for the projection drawing of potted line on shaft section of the screw rod pitch face of twin-screw engagement for the utility model.

Fig. 5 is the condition diagram of twin-screw Seal cage.

Fig. 6 is the shaft section projection drawing of Seal cage among Fig. 5.

Embodiment

See also Fig. 1 and Fig. 2, Fig. 1 is the structural representation of Noval tooth-type screw rod of the present utility model, Fig. 2 is the flute profile curve of screw rod of the present utility model, and curve abcdefghij is the flute profile curve on the screw rod cross section among Fig. 2, and wherein the some a of curve, c, g are at top circle L ₁Same diameter on, the some a at top circle L ₁On, some c, d, e are at root circle L ₂On, some i, j are at top circle L ₁On, curve abc is a cycloid, curve cde is root circle L ₂Circular arc, curve ija is top circle L ₁Circular arc, curve ghi is an elliptic arc, curve efg is for being the oval envelope of baseline with the ghi curved section.Through the selection of multiple curve and test back are found, adopt ellipse and envelope thereof, have tangible lifting for volumetric efficiency, the pressure of screw rod.

Screw rod of the present utility model can be made left handed screw, also can make right handed screw, and the end surface shape of two kinds of screw rods is identical.

Sealing mechanism when Fig. 3～Fig. 6 illustrates the utility model and is used for two screw pump or double-screw compressor:

Flute profile curve according to screw rod of the present utility model can obtain Fig. 3 and screw tooth surface sealing curve shown in Figure 4, the projection drawing of potted line on shaft section of screw rod straight-sided flank when wherein Fig. 3 meshes for twin-screw, screw rod O among the figure ₁The potted line of straight-sided flank is screw rod O ₂The np arc that marks of toothed crown, and screw rod O ₁Tooth top and screw rod O ₂The flank of tooth same form a sealing lines n ' p ', and potted line np, the n ' p ' of screw rod straight-sided flank run through the flank of tooth and housing and O separately ₁, O ₂Link to each other at the bottom of the screw rod tooth on the line.

The projection of potted line on shaft section of screw rod pitch face when Fig. 4 meshes for twin-screw, screw rod O among the figure ₂The flank of tooth bus of pitch face and screw rod O ₁The sealing curve that the tooth root flute profile of pitch face is formed is exactly arc kmg; In like manner, screw rod O ₁Pitch face toothed crown and screw rod O ₂The potted line of pitch face root edge on the flank of tooth is arc k ' m ' g, and it is connected to the g point mutually with arc kmg.This shows that the potted line of screw rod pitch face is arc kmgm ' k ', it is through the common flank of tooth of two screw rods, and and O ₁, O ₂Link to each other at the bottom of the two screw rods tooth on the line.Different with toothed screw bolt in the past is that the Line of contact of the utility model screw rod end on projection is two sections circular arcs, and no longer is broken line, this makes that the potted line that forms is shorter, under the identical condition of gap width, short potted line is revealed few, and can produce higher pressure.

According to analysis, consider screw rod O again to the screw tooth surface potted line ₁, O ₂Topland and tooth bottom surface are mutually tangent and the potted line that forms then can get screw rod Seal cage situation as shown in Figure 5, and the shaft section projection drawing of Fig. 5 Seal cage as shown in Figure 6.From Fig. 5, Fig. 6 as seen: the hydraulic fluid every grade of screw rod teeth groove is communicated with route and all forms an independent figure of eight closed loop.It is to satisfy first, second class air-proof condition of screw pump fully.

As seen, can reach the sealing of strict (fully) when screw rod of the present utility model is used for two screw pump or double-screw compressor, and the end on projection of Line of contact is camber line, Line of contact is shorter, so its volumetric efficiency height, the pressure height, and can not interfere phenomenon.

Above embodiment's explanation only is preferred embodiment explanation of the present utility model, and those skilled in the art can make the replacement and the modification of other all equivalence according to the foregoing description explanation of the present utility model.Yet these are replaced and revise according to all equivalences that the utility model embodiment is done, and belong to model utility spirit of the present utility model and reach by in the claim that claim defined.

Claims

1. Noval tooth-type screw rod, comprise the screw rod body, the screw rod body is provided with helical tooth, flute profile curve on the screw rod cross section is abcdefghij, it comprises by an a, b, the cycloid that the c line constitutes, by a c, d, the root circle circular arc that the e line constitutes, by an i, j, the top circle circular arc that a line constitutes, its mid point a, c, g is on the same diameter of top circle, point c, d, e is on root circle, point i, j, a is on top circle, it is characterized in that, described flute profile curve also comprises by a g, h, the elliptic arc that the i line constitutes is by an e, f, what the g line constituted is the oval envelope of baseline with elliptic arc ghi.

2. Noval tooth-type screw rod as claimed in claim 1 is characterized in that, described screw rod is a left handed screw.

3. Noval tooth-type screw rod as claimed in claim 1 is characterized in that, described screw rod is a right handed screw.