CN2470580Y

CN2470580Y - Teeht-shape screw stem

Info

Publication number: CN2470580Y
Application number: CN 01215031
Authority: CN
Inventors: 杨凯
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2001-01-21
Filing date: 2001-01-21
Publication date: 2002-01-09
Anticipated expiration: 2011-01-21

Abstract

The utility model relates to a tooth-shaped screw used for a double screw pump or a double screw compressor. The utility model replaces the tooth-shaped evolvent, the archimedes spiral line or the circular arc curve segment of an original screw through the evolvent and a cycloid envelope line which takes the evolvent as a base line. When used for the double screw pump or the double screw compressor, the utility model can realize strict (complete) seal, and can not cause an interference phenomenon. The tooth shape of the tooth-shaped screw is formed by the cycloid (B), the evolvent (J) and the cycloid envelope line (B) which takes the evolvent (J) as the base line, as well as a plurality of groups of line segments of the screw stem addendum circle and the screw stem root circle. The utility model has the advantages of high volumetric efficiency, simplicity, utility and excellent application effect.

Description

A kind of tooth-shaped screw bolt

The utility model is a kind of tooth-shaped screw bolt that is used for two screw pump or double-screw compressor, belongs to the improvement technology of two screw pump or the used screw rod of double-screw compressor.

The existing screw rod that is used for two screw pump or double-screw compressor, as the involute profile screw rod, its tooth curve is to be combined by cycloid, root circle circular arc, top circle circular arc, involute, when this screw rod is used for two screw pump, the shortcoming of its existence is to reach strict (fully) sealing, so volumetric efficiency is not high.

It is a kind of by changing its tooth curve that the purpose of this utility model is to provide, and seals so that it can reach strict (fully) when being used for two screw pump or double-screw compressor, and the volumetric efficiency height can not interfere the tooth-shaped screw bolt of phenomenon.

Tooth curve of the present utility model as shown in drawings, curve abcdefghij is the tooth curve on the screw rod cross section, and acg is on a diameter of top circle, and a is on top circle, c is on root circle, d, e are on root circle, and i, j are on top circle, and curve abc is a cycloid, cde is the circular arc of root circle, ija is the circular arc of top circle, and ghi is an involute, and efg is to be the cycloid envelope of baseline with the ghi line segment.

Good effect of the present utility model is by changing its tooth curve, with involute and with it is that the cycloid envelope of baseline substitutes curved sections such as original involute or spiral of Archimedes, can reach the sealing of strict (fully) when making this tooth-shaped screw bolt be used for two screw pump or double-screw compressor, and can not interfere phenomenon, it is a kind of volumetric efficiency height, simply, practicality, the tooth-shaped screw bolt that effect is good.

Describe concrete structure of the present utility model and sealing mechanism thereof in detail below by accompanying drawing.

Fig. 1 is a tooth curve of the present utility model, and abc is a straight-sided flank among the figure, and efghi is a pitch face.

Fig. 2 is the projection drawing of the potted line on the screw rod straight-sided flank on shaft section among Fig. 1.

Fig. 3 is the projection drawing of potted line on shaft section of screw rod pitch face among Fig. 1.

Fig. 4 is the condition diagram of screw rod Seal cage.

Fig. 5 is the shaft section projection drawing of Seal cage among Fig. 4.

Accompanying drawing 1 is a tooth curve of the present utility model, and abcdefghij is the tooth curve on the screw rod cross section among the figure, and acg is on a diameter of top circle, a is on top circle, C is on root circle, and on the footpath, d, e are on root circle in the flank of tooth for g, i, j are on tooth Xiang Yuan, curve abc is a cycloid, and cde is the garden arc of root circle, and ija is the circular arc of tooth Xiang Yuan, the ghi involute, efg is for being the cycloid envelope of baseline with the ghi curved section.

The utility model can be made left handed screw, also can make right handed screw.

When the utility model was used for two screw pump or double-screw compressor, adjacent screw rod was only in the hand of spiral difference, and its tooth-shape structure is identical.

Sealing mechanism when the utility model is used for two screw pump or double-screw compressor is as follows:

Can obtain Fig. 2 and screw tooth surface sealing curve shown in Figure 3 according to tooth curve of the present utility model, wherein Fig. 2 is the projection of potted line on shaft section of the utility model screw rod straight-sided flank, O among the figure ₁The potted line of screw rod straight-sided flank is O ₂The ac arc that the screw rod toothed crown marks, and O ₁The toothed crown of screw rod and O ₂Screw tooth surface is same to form a sealing lines a ' c ', and the potted line ac of screw rod straight-sided flank, a ' c ' 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.

Fig. 3 is the projection of potted line on shaft section of screw rod pitch face among Fig. 1, O among the figure ₂The flank of tooth bus and the O of screw rod pitch face ₁The sealing curve that the tooth root profile of tooth of screw rod pitch face is formed is exactly broken line abg; In like manner, O ₁Screw rod pitch face toothed crown and O ₂The potted line of screw rod pitch face root edge on the flank of tooth is broken line a ' b ' g, and it is connected to the g point mutually with broken line abg.This shows that the potted line of screw rod pitch face is broken line abgb ' a ', 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.

According to analysis, consider O again to the screw tooth surface potted line ₁, O ₂Screw rod Topland 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 4, and the shaft section projection drawing of Seal cage as shown in Figure 5 among Fig. 4.From Fig. 4, Fig. 5 as seen: the hydraulic fluid every grade of screw rod teeth groove is communicated with route and all forms independent " 8 " ' the font closed loop.The existence of this seal ring, oneself is confirmed from the actual detected of using this bright two screw pump, and it is to satisfy first and second class air-proof condition of screw pump fully.

In sum, as seen, when being used for two screw pump or double-screw compressor, the utility model can reach the sealing of strict (fully), so its volumetric efficiency height, and can not interfere phenomenon.

Claims

1. tooth-shaped screw bolt, curve abcdefjhij is the tooth curve on the screw rod cross section, and a, c, g are on a diameter of top circle, and a is on top circle, c is on root circle, d, e are on root circle, and i, j are on top circle, and curve abc is a cycloid, cde is the circular arc of root circle, ija is the circular arc of top circle, it is characterized in that ghi is an involute, and efg is that the ghi curved section is the cycloid envelope of baseline.

2. tooth-shaped screw bolt according to claim 1 is characterized in that making left handed screw, also can make right handed screw.