阅读说明：本技术 一种两段式渐变螺距双螺杆压缩机转子 (Two-section type gradual-change pitch double-screw compressor rotor ) 是由 吴华根 申瑀琦 刘健康 粱梦桃 张倍毓 林侃隆 熊保顺 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种两段式渐变螺距双螺杆压缩机转子,包括阳转子、阴转子、阳转子轴颈和阴转子轴颈；阳转子通过阳转子轴颈与压缩机外壳两侧的轴承相连；阴转子通过阴转子轴颈与压缩机外壳两侧的轴承相连；阳转子轴颈通过阳转子轴头与联轴器相连；本发明在靠近吸气侧第一段采用等螺距,并在该段已经形成完整的接触线,从而避免了由于渐变螺距使得工作容积减小的问题,保证了压缩机的气量。本发明靠近排气侧第二段螺杆螺距逐渐变小,使得压缩过程增加了螺距变化的内压缩,增大了排气孔口面积,从而降低了排气时的流动损失,减小了排气噪音,提高了压缩机效率。(The invention discloses a two-section type gradual-change pitch double-screw compressor rotor, which comprises a male rotor, a female rotor, a male rotor shaft neck and a female rotor shaft neck; the male rotor is connected with bearings on two sides of the compressor shell through a male rotor shaft neck; the female rotor is connected with bearings on two sides of the compressor shell through a female rotor shaft neck; the shaft neck of the male rotor is connected with the coupling through a shaft head of the male rotor; the first section near the suction side adopts the equal pitch, and a complete contact line is formed at the section, so that the problem of reduction of the working volume due to the gradual pitch is avoided, and the gas quantity of the compressor is ensured. The screw pitch of the second section of the screw close to the exhaust side is gradually reduced, so that the internal compression of the change of the screw pitch is increased in the compression process, and the area of an exhaust hole is increased, thereby reducing the flow loss during exhaust, reducing the exhaust noise and improving the efficiency of the compressor.)

1. A two-stage variable-pitch twin-screw compressor rotor is characterized by comprising:

the male rotor (1), the said male rotor (1) couples to bearing of both sides of compressor housing through the male rotor journal (5);

the female rotor (2), the said female rotor (2) couples to bearing of both sides of compressor housing through the female rotor journal (6);

the male rotor shaft neck (5), the male rotor shaft neck (5) is connected with the shaft coupling through a male rotor shaft head (7);

a female rotor journal (6), said female rotor journal (6) being fitted with a synchronizing gear when the compressor is injecting oil.

2. Two-stage variable-pitch twin-screw compressor rotor according to claim 1, characterised in that the male rotor (1) and the female rotor (2) each comprise a constant-pitch section (3) close to the suction side and a progressive-pitch section (4) close to the discharge orifice side.

3. Two-stage variable-pitch twin-screw compressor rotor according to claim 2, characterised in that the pitch of the progressive pitch stage (4) is progressively reduced.

4. Two-segment progressive-pitch twin-screw compressor rotor according to claim 1, characterised in that the male rotor shaft head (7) is connected to the motor by means of a coupling.

5. Two-stage progressive-pitch twin-screw compressor rotor according to claim 2, characterised in that the axial distance of the progressive pitch section (4) is related to the torsion angle as follows:

wherein the content of the first and second substances,p_sto start the pitch, p_eTo end the segment pitch, L₁The axial length of the air suction end is shown, and L is the total length of the rotor.

6. Two-stage progressive pitch twin-screw compressor rotor according to claim 3 or 6, characterised in that the progressive pitch stage (4) has a larger gas discharge area than the gas discharge area of the constant pitch stage.

Technical Field

The invention belongs to the technical field of compressor rotors, and relates to a two-section type gradual-change pitch double-screw compressor rotor.

Background

The double-screw compressor is more and more widely applied because the double-screw compressor has simple structure, convenient installation and continuous air inlet and exhaust, does not need to design an air inlet valve and an air outlet valve like a piston compressor, and does not need to consider the surge problem like a fan. The characteristics of the rotor greatly influence the performance of the screw compressor, so the design of the rotor is very important for the double-screw compressor, the research on the rotor of the double-screw compressor at present mainly focuses on the design of the rotor profile, the invention focuses on the design of the third direction of the rotor, and the two-section variable-pitch screw compressor rotor is innovatively provided.

The conventional screw compressor rotor is basically a constant pitch screw rotor, so that in the design aspect of an exhaust port, the variable range is small due to the constant pitch screw rotor, the area of the exhaust port is often small, the resistance to fluid is increased during exhaust, the energy loss is caused, the disturbance of a flow field is increased, the noise on an exhaust side is increased, and the compression rate of the constant pitch screw rotor is the same in the whole working medium compression process, so that the compression rate on the exhaust side is too high, the exhaust pulsation is larger, and the torque is larger. The two-section variable pitch twin-screw compressor rotor is constant in pitch at the first section close to the air suction port side, is gradually varied in pitch at the second section close to the air discharge port side, and is gradually reduced from the position of air suction end to the position of the axial air discharge port, so that not only is the compression process that the meshing line is pushed forward in the compression process, but also the internal compression process that the pitch is reduced, the area of the air discharge port of the variable pitch rotor is increased compared with the area of the air discharge port of the fixed-length pitch screw rotor, the flow loss is reduced, the noise is reduced, meanwhile, the compression rate is reduced by reducing the pitch in the compression process, the compression and the air discharge of the compressor are more stable, meanwhile, the air discharge process of the working medium compression process has longer time for heat dissipation, the air discharge temperature of the working medium is reduced, and the torque in the compression process is reduced, so that the load of the motor is reduced.

Chinese patent CN111878397A proposes an invention in which two pairs of variable pitch rotors compress simultaneously, but the pitch of the rotors is changed in the whole process, which results in that the working volume of the rotors is smaller than that of the constant pitch rotors, and the air volume of the compressor is reduced.

Disclosure of Invention

The invention aims to solve the problems of smaller exhaust port and large flow loss at the exhaust side of the compressor in the prior art, and provides a two-section type gradually-changed pitch double-screw compressor rotor.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a two-stage variable pitch twin screw compressor rotor comprising:

a male rotor journalled to bearings on both sides of the compressor housing;

the female rotor is connected with bearings on two sides of the compressor shell through female rotor shaft necks;

a male rotor journal connected to the coupling through a male rotor shaft head;

a female rotor journal fitted with a synchronizing gear upon injection of oil by the compressor.

The invention further improves the following steps:

the male rotor and the female rotor both comprise a constant pitch section near the suction side and a gradual pitch section near the exhaust hole side.

The pitch of the gradual pitch section is gradually reduced.

The male rotor shaft head is connected with the motor through a coupler.

The relationship between the axial distance and the torsion angle of the gradual pitch section is as follows:

wherein the content of the first and second substances,p_sto start the pitch, p_eTo end the segment pitch, L₁The axial length of the air suction end is shown, and L is the total length of the rotor.

The area of the exhaust port of the gradual change pitch section is larger than that of the exhaust port of the equal pitch section.

Compared with the prior art, the invention has the following beneficial effects:

the screw rotor pitch of the second section of the screw rotor close to the exhaust side is gradually reduced, so that the time of the compression and exhaust process is prolonged, the compression and exhaust process is more stable, the load of a motor is reduced, and the exhaust temperature of the working medium is reduced. The screw pitch of the second section of the screw close to the exhaust side is gradually reduced, so that the internal compression of the change of the screw pitch is increased in the compression process, and the exhaust hole is enlarged, thereby reducing the flow loss during exhaust, reducing the exhaust noise and improving the efficiency of the compressor. The first section close to the air suction side adopts the equal pitch, so that the problem of reduction of the working volume due to the gradual pitch is avoided, and the air quantity of the compressor is ensured.

Drawings

In order to more clearly explain the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic top view of a rotor according to the present invention;

FIG. 2 is a sectional view of a top view of the rotor of the present invention;

FIG. 3 is a schematic view of a rotor profile of the present invention;

FIG. 4 is a view of the air inlet of the enclosure of the present invention;

FIG. 5 is an isometric view of the present invention;

FIG. 6 is a graph of tooth space volume as a function of rotational angle in accordance with the present invention;

FIG. 7 is a comparison of a variable pitch axial vent port and a constant pitch axial vent port.

Wherein: 1-male rotor, 2-female rotor, 3-equal pitch section, 4-gradual pitch section, 5, 6-shaft neck, 7-shaft head, 8-two-section variable pitch rotor tooth space volume, 9-constant pitch rotor tooth space volume, 10-two-section variable pitch rotor exhaust hole and 11-constant pitch rotor exhaust hole.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. are used for indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which is usually arranged when the product of the present invention is used, the description is merely for convenience and simplicity, and the indication or suggestion that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, cannot be understood as limiting the present invention. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

Furthermore, the term "horizontal", if present, does not mean that the component is required to be absolutely horizontal, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the embodiments of the present invention, it should be further noted that unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The invention is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, the embodiment of the invention discloses a two-section type gradual pitch twin-screw compressor rotor, which comprises a uniform pitch section close to a suction side and a gradual pitch section close to an exhaust side, a bearing between the screw rotor and a compressor shell, and a part of a male rotor suction side shaft connected with a motor through a coupler.

The invention adopts a two-section rotor design, and the first section close to the air suction side is an equal-pitch section, so that the capacity between the teeth of the screw is reduced under the condition of avoiding gradually changing the pitch, thereby influencing the air quantity of the compressor. And adopting a gradual pitch at the second section close to the exhaust side, wherein the relationship between the axial distance of the gradual pitch and the torsion angle is as follows:

wherein the content of the first and second substances,p_sto start the pitch, p_eTo end the segment pitch, L₁The axial length of the air suction end is shown, and L is the total length of the rotor. p is a radical of_e<p_sThe utility model discloses a compressor, make the screw pitch reduce gradually at the exhaust side, thereby make the exhaust port area of gradual change screw pitch rotor compare in the exhaust port area grow of uniform pitch screw rotor, thereby reduce the flow loss, reduce the noise, it makes compression rate slow down to reduce the screw pitch simultaneously at compression process, make the compressor compression like this, it is more steady to exhaust, make working medium compression process exhaust process have longer time heat dissipation simultaneously, make the exhaust temperature of working medium reduce, and the moment of torsion of compression process has been reduced, make the load of motor reduce.

The gas compression steps of the double-screw rotor with the gradually-changed pitch are as follows:

(1) the rotors of the male and female rotors rotate oppositely to start air suction when the volume between the teeth is gradually increased, and finish air suction when the volume between the teeth is maximum to start a compression stage.

(2) In the compression stage, the volume between the rotating teeth is continuously reduced due to the connection with the exhaust end face, and the volume between the teeth is further reduced along with the reduction of the screw pitch, so that the compression process is achieved, and when the pressure of the working medium reaches the exhaust pressure, the compression stage is finished to prepare for starting exhaust.

(3) When the volume between the teeth is connected with the exhaust port, the working medium in the compressor is pushed to the exhaust pipeline to complete the exhaust action along with the reduction of the volume between the teeth, the exhaust process is slow because the pitch of the screw in the exhaust stage is gradually reduced, and meanwhile, the volume between the teeth is reduced because the pitch of the screw is reduced, so that the axial exhaust port is enlarged, the flow loss in the exhaust process is reduced, the temperature of the exhaust side is reduced, and the exhaust noise is reduced.

The structural principle of the invention is as follows:

as shown in fig. 1 and 2, the present embodiment provides a two-stage twin-screw compressor rotor, which performs suction, compression and discharge operations with the change of the tooth space volume during the opposite movement of the rotors.

The invention relates to a two-section type double-screw compressor rotor which comprises a uniform-pitch section and a gradual-change pitch section. The constant pitch section 3 adopts a constant pitch design with a large torsion angle, as shown in fig. 4, it can be seen that an air inlet line is already closed in the constant pitch section, as shown in fig. 6, the invention effectively avoids the air suction volume reduction caused by the variable pitch condition, which affects the air quantity of the compressor, therefore, the air inlet quantity of the rotor is not different from that of the common rotor. Second section 4 that is close to the exhaust side adopts gradual change pitch, the pitch reduces gradually, thereby make the exhaust port area of variable pitch rotor than the axial exhaust port area grow (as shown in fig. 7) of fixed length pitch screw rotor, thereby reduce the flow loss, reduce the noise, reduce the pitch simultaneously and make compression rate slow down in compression process, make the compressor compression like this, it is more steady to exhaust, make working medium compression process exhaust process have longer time heat dissipation simultaneously, make the exhaust temperature of working medium reduce, and the moment of torsion of compression process has been reduced, make the load of motor reduce.

A male rotor 1 and a female rotor 2 are respectively connected with bearings on two sides of a shell of the screw compressor through a shaft neck 5, the shaft neck 6 is connected with a synchronous gear to complete synchronous rotation of the male rotor and the female rotor, a shaft head 7 is connected with a coupler, and a motor drives the male rotor through the coupler and further drives the female rotor, so that the work of the double-screw compressor is realized.

The working process of the invention is as follows:

the motor passes through the shaft coupling and links to each other with positive rotor spindle nose 7, and drive positive rotor 1 rotates, and positive rotor 1 passes through synchronous gear drive female rotor and rotates. The volume between teeth of the female rotor and the male rotor is changed continuously along with the opposite rotation of the female rotor and the male rotor, when the volume between teeth of a pair of teeth is gradually increased and is increased to the maximum, the compressor finishes the air suction action, the axial distance of the volume between teeth is the constant pitch section shown in figure 1, and meanwhile, the air suction of the rotor is finished in the constant pitch section as seen from the spiral line position of the air inlet in figure 4. As the rotor continues to rotate, the tooth space volume is pushed to the exhaust end and is blocked by the exhaust end face on the one hand, and on the other hand, the tooth space volume is gradually reduced under the influence of the gradually reduced pitch, so that the tooth space volume is reduced, and due to two kinds of compression, the exhaust pressure can be reached at a position earlier than that of the constant pitch rotor, and as shown in fig. 5, the axial exhaust hole of the variable pitch screw rotor is larger than that of the constant pitch rotor. When the working medium pressure in the space between the pair of teeth reaches the exhaust pressure, the space between the teeth is connected with the exhaust port to finish the exhaust action.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.