CN202659903U - Mechanical seal for externally-driven intermediate rotating ring - Google Patents

Abstract

An externally driven intermediate rotary ring mechanical seal is provided with an intermediate rotary ring whose two ends are respectively opposite to the dynamic ring and the static ring, and the intermediate rotary ring is formed by An external power source drives the rotation. The output shaft of the power source is directly connected to the driving wheel of the transmission wheel set or connected to the input shaft of the drive wheel set through a coupling. Drive connection. The relative rotational speed between the sealing end surfaces of the mechanical seal is adjustable, and the rotational speed of the unit to be sealed does not directly determine the relative rotational speed of the sealing end surfaces, so that the high and low speed mechanical seals have higher stability.

Description

An externally driven intermediate rotating ring mechanical seal

technical field

The utility model belongs to the axial end face seal of a rotating machine, in particular to an externally driven intermediate rotating ring mechanical seal, and the driving type intermediate rotating ring mechanical seal can be used in various types of compressors, expanders, separators, pumps, Axial end face seal of rotating machines such as reactors.

Background technique

Mechanical seals are widely used in the axial end face seals of many rotating machines, but the stability of the seals under high-parameter conditions, especially high-speed and low-speed conditions, has always been two difficult issues that plague researchers. The specific manifestations are: the relative speed between the sealing surfaces of the contact mechanical seal is too high at high speed, resulting in serious friction, wear, heat, deformation and other phenomena of the sealing surface, the sealing performance drops rapidly, and even cannot work normally; the non-contact mechanical seal Under the condition of low speed, the fluid film between the end faces cannot generate enough opening force and rigidity, and the normal separation of the sealing surface and the stability of the gap cannot be guaranteed. For traditional mechanical seals, the moving ring is generally fixed on the rotating shaft of the sealed machine in the circumferential direction, which makes it difficult to actively change the relative speed between the moving and static ring sealing surfaces under the given conditions of the sealed machine.

By adding an intermediate rotating ring between the dynamic and static rings, changing the relative rotational speed between the two sealing surfaces of the mechanical seal is an effective method for regulating the relative rotational speed of the sealing surfaces. However, it is a difficult problem to adjust and control the speed of the intermediate rotating ring.

Here, an externally driven intermediate rotating ring mechanical seal is proposed, and the rotational speed is output to the intermediate rotating ring by setting a power source and necessary transmission parts. Its characteristics are: the middle rotating ring is equipped with a corresponding power source, and is connected with the middle rotating ring through the necessary transmission parts to actively adjust the speed of the middle rotating ring, so that the sealing end faces of the units with different speeds can obtain a suitable relative rotation speed , get rid of the influence of the speed of the sealed unit on the sealing performance, and improve the stability and service life of the mechanical seal.

Contents of the invention

The purpose of the utility model is to provide an externally driven intermediate rotating ring mechanical seal.

The utility model is an externally driven intermediate rotating ring mechanical seal, which is mainly composed of a mechanical seal part and a power source as a whole, and the two parts are connected by a transmission part. Specifically, it mainly consists of: moving ring 1, intermediate rotating ring 2, static ring 3, transmission sleeve 4, machine base 5, power source 6, coupling 7, transmission wheel Z ₁ , transmission wheel Z ₂ , power source output shaft II , Transmission shaft III and so on. The mechanical seal part includes: moving ring 1, intermediate rotating ring 2, and static ring 3.

The transmission wheel Z ₁ and the intermediate rotating ring 2 are circumferentially fixed on the transmission shaft sleeve 4, the transmission shaft sleeve 4 is spaced on the shaft I, and the transmission wheel Z ₂ is circumferentially fixed on the output shaft II or transmission shaft III of the power source. The output shaft II of the source 6 is connected with the transmission wheel Z ₂ through the coupling 7 or directly.

The working process of the utility model is: the power source 6 drives the transmission wheel Z ₂ to rotate through the shaft coupling 7 or directly, the transmission wheel Z ₂ drives the transmission wheel Z ₁ to rotate, and the rotation of the transmission wheel Z ₁ is transmitted to the middle through the transmission shaft sleeve 4 Rotate the ring 2, and finally drive the intermediate rotating ring 2 to rotate synchronously with the transmission sleeve 4 and the transmission wheel _Z1 . In this way, the middle rotating ring 2 obtains a rotation speed different from that of the rotating shaft I of the unit to be sealed. Because the middle rotating ring 2 is paired with the moving ring 1 and the static ring 2 respectively, it finally achieves the effect of changing the relative speed of rotation between the covers. Purpose.

The utility model mainly adopts the following technical measures to achieve: the external drive type intermediate rotary ring mechanical seal is between the moving ring 1 and the static ring 3 which are arranged oppositely with the sealing end faces, and the two ends are respectively connected with the moving ring 1 and the static ring 3. The stationary ring 3 is opposite to the middle rotating ring 2, the middle rotating ring 2 is connected with the external power source 6 through the transmission bushing 4, the driven wheel Z ₁ and the driving wheel Z ₂ , and the middle rotating ring 2 and the driven wheel Z ₁ are circumferentially fixed On the transmission shaft sleeve 4 , the transmission shaft sleeve 4 is vacantly sleeved on the shaft I, and the driving wheel Z ₂ is in transmission connection with the output shaft II of the external power source 6 .

The drive wheel Z ₂ of the externally driven intermediate rotating ring mechanical seal is directly connected to the output shaft II of the external power source 6. Specifically, transmission pins, keys, expansion sleeves, etc. can be used for transmission connection, but transmission is preferably used. Pin way for transmission connection.

In the externally driven intermediate rotating ring mechanical seal, the driving wheel Z ₂ is connected to the transmission shaft III through the coupling 7, and the transmission shaft III is in transmission connection with the driving wheel Z ₂ .

In the externally driven intermediate rotating ring mechanical seal, the rotating speed of the rotating shaft I of the unit to be sealed is n ₁ , the rotating speed of the intermediate rotating ring 2 is n ₂ , and the ratio of the two rotating speeds is i=n ₂ /n ₁ , then i The value range is 0.3~500. According to the current situation of mechanical seal application units, the speed of the higher speed unit is about 7000~15000rpm, the speed of the medium speed unit is about 2500~4000rpm, and the speed of the lower speed unit is about 20~1000rpm, and according to the actual use situation , if there is only one intermediate ring for the contact seal, considering the uniformity of the relative rotational speed of the two sets of sealing surfaces, the value range of the ratio i should be selected around 0.5, and the non-contact seal can obtain a relatively high speed of the sealing surface within the range of 8000~10000rpm. For high fluid film stiffness and stability, the value range of i is about 2~500. Due consideration of the particularity and transmission efficiency in the actual processing process, the value range of the speed ratio i is determined to be 0.3~500.

The externally driven intermediate rotary ring mechanical seal has an external power source 6, and the output of the power source 6 is an approximately uniform rotational motion, which can specifically be a power device such as an electric motor, a steam turbine, an internal combustion engine, or a motor, but it is preferably used An adjustable speed motor is used as an external power source.

The transmission wheel of the externally driven intermediate rotating ring mechanical seal is characterized in that it can transmit circumferential rotary motion, specifically it can be a gear, a pulley, a friction wheel, a sprocket, etc., but preferably a gear and a pulley are used As the transmission wheel, belt transmission or gear transmission are respectively correspondingly used. When the center distance between the two transmission shafts is small, the preferred gear is the transmission wheel. When the center distance between the two transmission shafts is large, the preferred belt wheel is the transmission wheel.

This externally driven intermediate rotating ring mechanical seal, the inner diameter side of the intermediate rotating ring 2 and the drive shaft sleeve 4 are driven by means of pins, keys, expansion sleeves, screws, etc., but the preferred way is to be connected by means of transmission pins.

The utility model has the following characteristics: 1. The relative rotational speed of the sealing end face is adjustable; 2. The rotational speed of the middle rotating ring is adjustable in a wide range; 3. The high and low speed mechanical seals have higher stability.

Description of drawings

Fig. 1 is a schematic diagram of a preferred embodiment 1 of the externally driven intermediate rotary ring mechanical seal of the present invention.

Fig. 2 is a schematic diagram of a preferred embodiment 2 of the externally driven intermediate rotary ring mechanical seal of the present invention.

Fig. 3 is a schematic diagram of a preferred embodiment 3 of the externally driven intermediate rotary ring mechanical seal of the present invention.

Fig. 4 is a structural schematic diagram of a mechanical seal device corresponding to Fig. 1 to Fig. 3 .

The relevant symbols in the figure are: 1—moving ring; 2—intermediate rotating ring; 3—stationary ring; 4—transmission sleeve; 5—machine base; 6—power source; 7—coupling; Z ₁ —transmission wheel ( Driven wheel) represents the diameter of the wheel; Z ₂ —drive wheel (drive wheel), represents the diameter of the wheel; Ⅰ—the rotating shaft of the sealed unit, Ⅱ—the output shaft of the power source, Ⅲ—the transmission shaft.

Detailed ways

In order to further understand the content, features and functions of the present utility model, specific embodiments are described in detail below in conjunction with the accompanying drawings.

Embodiment 1: Refer to Fig. 1, Fig. 4.

The whole of this embodiment is mainly composed of a mechanical seal part and a power source, and the two parts are connected by transmission parts. Specifically, it mainly consists of: moving ring 1, intermediate rotating ring 2, static ring 3, transmission sleeve 4, machine base 5, power source 6, pulley (ie driven wheel) Z ₁ , pulley (ie main and follower wheel) Z ₂ , Power source output shaft II and other components. The mechanical seal part includes: moving ring 1, intermediate rotating ring 2, and static ring 3.

The belt pulley Z ₁ and the intermediate rotating ring 2 are circumferentially fixed on the transmission sleeve 4, the transmission sleeve 4 is empty on the shaft I, and the belt pulley Z ₂ is fixed on the output shaft II of the power source.

The working process of this embodiment is: the power source 6 directly drives the pulley Z ₂ to rotate, the pulley Z ₂ drives the pulley Z ₁ to rotate, the rotation of the pulley Z ₁ is transmitted to the middle rotating ring 2 through the drive shaft sleeve 4, and Finally, the intermediate rotating ring 2 is driven to rotate synchronously with the drive shaft sleeve 4 and the pulley Z ₁ . In this way, the middle rotating ring 2 obtains a rotation speed different from that of the rotating shaft I of the unit to be sealed. Because the middle rotating ring 2 is paired with the moving ring 1 and the static ring 2 respectively, it finally achieves the effect of changing the relative speed of rotation between the covers. Purpose.

Assuming that the rotational speed of the rotating shaft I of the unit to be sealed is n ₁ , the rotational speed of the intermediate rotating ring 2 is n ₂ , and the output rotational speed of the power source 6 is n ₆ , the rotational speed ratio i between the intermediate rotating ring 2 and the shaft I is: i=n ₂ /n ₁ = (Z ₂ n ₆ )/(Z ₁ n ₁ ). The adjustment of the rotation speed n ₂ of the intermediate rotating ring 2 can be realized by changing the output speed n ₆ of the power source 6 and the diameter of each pulley. The speed of the moving ring 1 is the same as the speed of the rotating shaft I, which is n ₁ , then the relative speed of the sealing surface formed by the moving ring 1 and the intermediate rotating ring 2 is n ₂ ±n ₁ , and the sealing between the intermediate rotating ring 2 and the stationary ring 3 is The relative rotational speed of the plane is n ₂ .

Embodiment 2: refer to Fig. 2, Fig. 4.

The whole of this embodiment is still mainly composed of a mechanical seal part and a power source, and the two parts are connected by a transmission member. Specifically, it mainly consists of: moving ring 1, intermediate rotating ring 2, static ring 3, transmission sleeve 4, machine base 5, power source 6, gear (ie driven wheel) Z ₁ , gear (ie driving wheel) Z ₂ , power source Output shaft II and other components. The mechanical seal part includes: moving ring 1, intermediate rotating ring 2, and static ring 3.

The difference between embodiment 2 and embodiment 1 is that the two transmission wheels Z ₁ and Z ₂ in embodiment 2 are gears, while the two transmission wheels Z ₁ and Z ₂ in embodiment 1 are pulleys. The working process, speed ratio, and relative speed calculation method of the sealing surface in embodiment 2 are the same as in embodiment 1.

Embodiment 3: refer to Fig. 3, Fig. 4.

The whole of this embodiment is still mainly composed of a mechanical seal part and a power source, and the two parts are connected by a transmission member. Specifically, it mainly consists of: moving ring 1, intermediate rotating ring 2, static ring 3, transmission sleeve 4, machine base 5, power source 6, coupling 7, gear (ie driven wheel) Z ₁ , gear (ie driving wheel) Z ₂ , power source output shaft II, drive shaft III, etc. The mechanical seal part includes: moving ring 1, intermediate rotating ring 2, and static ring 3.

The difference between embodiment 3 and embodiment 2 is that in embodiment 3, the output shaft II of the power source 6 and the transmission shaft III are connected by a coupling 7, and the gear Z ₂ is fixed on the transmission shaft III in the circumferential direction, while in embodiment 1 The output shaft II of the power source 6 is directly circumferentially fixed with the gear Z ₂ . From the point of view of composition, in embodiment 3, two parts of shaft device 7 and power transmission shaft III are added. The working process, rotational speed ratio, and relative rotational speed calculation method of the sealing surface of the third embodiment are the same as those of the first embodiment.

In the above embodiments, the focus is on whether the output shaft II of the power source 6 is directly connected to the transmission wheel _Z2 , and the common ways of the transmission wheels _Z1 and _Z2 , using three types of coupling, gear transmission and belt transmission respectively. way, and in practical applications, chain drive, friction wheel drive, etc. can also achieve the same effect. In order to describe the core problem more clearly, the above embodiments only involve a single-stage sealing structure, but in actual use, the overall layout of the seal can have various types according to needs, such as: single-end seal, double-end seal, tandem seal (two seals) Level or above), series with intermediate labyrinth (two levels or more), and can also be combined with floating ring seals, carbon ring seals, labyrinth seals and other sealing types to form a combined seal.

Claims (7)

1. An externally driven intermediate rotating ring mechanical seal, which is between the moving ring (1) and the static ring (3) with the sealing end faces facing each other, and the two ends are respectively connected to the moving ring (1) and the static ring ( 3) The opposite intermediate rotating ring (2), which is characterized in that the intermediate rotating ring (2) is connected to the external power source (6) through the transmission sleeve (4), the driven wheel (Z ₁ ), the driving wheel (Z ₂ ) , and is driven to rotate by an external power source (6), the middle rotating ring (2) and the driven wheel (Z ₁ ) are circumferentially fixed on the transmission sleeve (4), and the transmission sleeve (4) is vacantly sleeved on the shaft (Ⅰ ), the drive wheel (Z ₂ ) is in transmission connection with the output shaft (II) of the external power source (6). 2. An externally driven intermediate rotary ring mechanical seal according to claim 1, characterized in that the output shaft (II) of the external power source (6) and the driving wheel (Z ₂ ) are transmitted by means of transmission pins connect. 3. An externally driven intermediate rotary ring mechanical seal according to claim 1, characterized in that the output shaft (II) of the external power source (6) is connected to the transmission shaft (III) through a coupling (7) ), and the drive shaft (Ⅲ) is connected to the driving wheel (Z ₂ ). 4. An externally driven intermediate rotating ring mechanical seal according to claim 1, characterized in that the speed ratio between the intermediate rotating ring (2) and the rotating shaft (I) of the unit to be sealed ranges from 0.3 to 500. 5. An externally driven intermediate rotary ring mechanical seal according to claim 1, characterized in that the external power source (6) is an adjustable speed motor. 6. An externally driven intermediate rotating ring mechanical seal according to claim 1, characterized in that the driving wheel (Z ₂ ) and the driven wheel (Z ₁ ) are gears or pulleys. 7. An externally driven intermediate rotating ring mechanical seal according to claim 1, characterized in that the inner diameter side of the intermediate rotating ring (2) is in transmission connection with the transmission sleeve (4) via a transmission pin.

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