CN-114962648-B - Back pressure area adjustable and opening controllable floating ring for non-contact mechanical seal

CN114962648BCN 114962648 BCN114962648 BCN 114962648BCN-114962648-B

Abstract

The invention discloses a back pressure area adjustable and opening controllable floating ring for non-contact mechanical seal, which comprises a sector plate sliding block, a rear cover, a driving gear shaft and a central transmission body. The invention is different from any existing controllable mechanical seal floating ring, the principle of the invention is that the floating ring area is changed by a pure mechanical transmission mode, the floating ring formed by the sector area is set to a maximum value, corresponding speed is applied to a driving gear shaft according to the transmission ratio between transmission mechanisms and actual conditions outside to realize the adjustment of closing force, when working conditions are high pressure, the invention can realize quick opening, lays a solid foundation for the stable operation of the device, has the characteristics of easy opening, high controllability, stable transmission and the like on the premise of determining the sealing working environment, can effectively regulate and control the closing force, and can be flexibly adapted to the transformation of the dry gas sealing working environment.

Inventors

XU HENGJIE
Qi yuanda
SONG PENGYUN
MAO WENYUAN
DENG QIANGGUO
SUN XUEJIAN

Assignees

昆明理工大学

Dates

Publication Date: 20260508
Application Date: 20220622

Claims (3)

1. The utility model provides a back pressure area is adjustable, opens controllable floating ring for non-contact mechanical seal, includes sector plate slider (1), back lid (2), drive gear axle (3), central transmission body (4), its characterized in that: The sector plate sliding block (1) comprises a sector plate body (101) and a sliding block (102) arranged on the inner side of the sector plate body (101), wherein the bottom surface of the sliding block (102) is provided with teeth; The rear cover (2) is a round cover, the edge of the rear cover is a circumferential wall surface (201), a through hole (202) is formed in the center of the rear cover, a round hole (203) is formed in the inner surface of the rear cover (2), the round hole (203) is a non-through hole, the round hole (203) is close to the through hole (202), and a first O-shaped ring (5) is arranged at the top of the circumferential wall surface (201); the center transmission body (4) comprises a disc (401) and an inner meshing gear (402), a hole (403) is formed in the center of the disc (401), a circle of plane threads (404) are formed in the top surface of the disc (401) around the hole (403), the hole (403) is connected with the top edge of the cylindrical wall (405), the inner meshing gear (402) is fixedly arranged at the bottom edge of the cylindrical wall (405), and the inner diameter of the inner meshing gear (402) is larger than the diameter of the through hole (202); The three sector plate sliding blocks (1) are circumferentially distributed, the sector plate body (101) is 120 degrees, the bottom surface of the sector plate body (101) is tightly attached to the top surface of the disc (401), teeth on the bottom surface of the sliding block (102) are in sliding fit with plane threads (404) on the top surface of the disc (401), second O-shaped rings (6) are arranged on the periphery of the plane threads (404), the second O-shaped rings (6) are tightly attached to the bottom surface of the sector plate body (101), the rear cover (2) covers the bottom surface of the central transmission body (4), the top of the circumferential wall surface (201) is in contact with the edge of the disc (401), the first O-shaped rings (5) are located between the two, the round holes (203) are exposed out of the inside of the internal meshing gears (402), cylindrical keys at the shaft end parts of the driving gear shafts (3) are embedded into the round holes (203), and the gears of the driving gear shafts (3) are meshed with the inside of the internal meshing gears (402).
2. The back pressure area adjustable and opening controllable floating ring for the non-contact mechanical seal according to claim 1, wherein the sector plate body (101) and the sliding block (102) are of an integrally formed structure.
3. The back pressure area adjustable and opening controllable floating ring for the non-contact mechanical seal according to claim 1, wherein the rear cover (2) is connected with the central transmission body (4) through an embedded structure.

Description

Back pressure area adjustable and opening controllable floating ring for non-contact mechanical seal Technical Field The invention belongs to the technical field of mechanical sealing, and particularly relates to a back pressure area adjustable and opening controllable floating ring for non-contact mechanical sealing. Background Compared with the traditional contact type seal which is easy to leak, easy to pollute, short in service life, low in economic benefit and the like, the dry gas seal has the characteristics of long service life, stability, reliability, low seal consumption power, economy, environmental protection and the like, and is widely applied to the related fields. The end face of the grooved dry gas seal movable ring is generally divided into an outer area and an inner area, when the movable ring with fluid dynamic pressure grooves (the groove depth is 2.5-10 mu m) arranged on the outer side of the end face rotates, the fluid dynamic pressure grooves pump high-pressure lubricating gas on the outer diameter side between seal end faces, the gas is compressed in the grooved outer area, namely, the gas film pressure from the outer diameter to the groove diameter is gradually increased, a local high-pressure area is formed at the root of the groove, a dynamic pressure effect is generated, and a stable gas film with a certain thickness is further formed under the state that the gas film force and the back pressure closing force of a floating ring are balanced in the gap of the seal end face. According to the working principle of dry gas sealing, the stress balance of the floating ring always exists in the dry gas sealing operation process, wherein the opening force is determined by the air film pressure distribution in a sealing gap, and the closing force is related to the inlet pressure, the balance radius and the spring specific pressure. The dry gas sealing design is generally developed according to the working condition of a matched main machine, and in the large environment where the current dry gas sealing application working condition tends to be high-pressure, the high inlet pressure can greatly improve the back pressure acting force of the floating ring, so that a certain challenge is brought to the opening of the dry gas seal. The quick opening of the dry gas seal can lay a solid foundation for the subsequent stable operation, and if the dry gas seal is opened unsmoothly, namely the seal ring is attached for a long time, the end face of the seal ring is worn or the end face temperature rise is overlarge. Therefore, on the premise of determining the sealing working environment, the closing force can be regulated and controlled to realize the characteristic of easy opening of the dry gas seal, and the dry gas seal is required to have the characteristic of controllability. The chinese patent CN104179975A proposes a device for actively controlling closing force by loading current through an electromagnet and dynamically monitoring the current by a sensor, but this requires auxiliary devices such as an electromagnet, which is relatively complex and is not described to use ac or dc, if an ac electromagnet is used, the attraction force is applied by means of the dc component superimposed by the magnetic force of two alternating magnetic fields formed by the split magnetic ring, so that the efficiency is low, the volume of the iron core is large, the energy consumption of the coil is high, and at the same time, excessive heat is generated during long-time working, and the sealing effect is disturbed, while if dc is used, the cost is increased directly, which is not economical. Chinese patent CN102128272a proposes a mechanical sealing device with controllable closing force, which forms comb teeth seal by adjusting the leakage amount of floating ring, so as to achieve the throttle effect and realize the goal of adjusting closing force. In order to achieve the above purpose, the gap between the comb seal and the outer edge of the static ring must be strictly controlled, but under the working condition of high pressure and high speed, the radial runout of the seal ring will affect the gap, and restrict the effect of the throttling effect. Chinese patent CN104896104a discloses a gas lubrication mechanical seal device with online adjustable closing force, whose core idea is to design a piston structure behind the stationary ring, and to realize the compression of the piston to the spring by adjusting the air supply pressure, so as to achieve the purpose of changing the compression amount of the spring and adjusting the closing force. This solution is viable in low pressure conditions, but for high pressure heavy load conditions the spring force is negligible compared to the static ring back pressure. For this reason, it is necessary to develop a back pressure area adjustable and opening controllable floating ring for a non-contact mechanical seal capable of solving the above-mentioned problems. Disclos