RU212262U1 - OIL FILLED SCREW COMPRESSOR MODULE - Google Patents

Abstract

The utility model relates to oil-filled screw compressor modules used in mobile compressor units, mainly in mobile compressor units of vehicles. The oil-filled screw compressor module includes an electric motor, a compressor block with driving and driven helical rotors located in the compressor block housing, and an oil level control device. The oil level control device is made using an optical level indicator. The operation of the specified optical level indicator is based on the principle of changing the refractive index at the transition boundary of two media. The oil level control device is installed in the compressor block housing at the height of registration of the minimum oil level in the compressor block housing. At the output, the electrical circuit of the optical level indicator generates a logic signal and remotely transmits via the CAN bus of the vehicle control and monitoring system to the driver/operator instrument panel. The level limit switch IL-OSS-BA is used as an optical level indicator. The utility model is aimed at providing operational remote control of the presence of oil above the minimum level in an oil-filled screw compressor module from the instrument panel of the driver/operator. This excludes the influence on the control of the formation of an oil-air mixture during the start of the compressor. This provides the convenience of control and increased speed of response to emergency situations, security, reliability, durability and the ability to build a digital control and monitoring system.

Description

The utility model relates to oil-filled screw compressor modules used in mobile compressor units, mainly in mobile compressor units of vehicles.

An oil level control device is known in the form of a float-type oil level sensor (see DE 4118896 A1). This oil level sensor generates an electrical signal corresponding to the oil level in the storage oil sump, with the possibility of transmitting it further, for example, to a computer unit. The float is positioned according to the oil level in the oil sump. The float interacts through the rod with a resistance coil to set different resistance values.

Problematic in such a mechanically acting oil level sensor is its reliability. This oil level sensor is prone to jamming, stem deformation and oil penetration into the float cavity. Float leakage and stem deformation are greatly facilitated by the presence of a large number of pressure pulsations in the oil system, as well as high operating temperatures and oil moisture, especially when the vehicle is operated under severe conditions.

An oil-filled screw compressor module is known (see Screw compressor installation LE-25.10.1.006-00 AT LOK NEXT, Operation manual LE-25.10.1.006-00 AT LOK NEXT, Korolev, 2021). This oil-flooded screw compressor module includes an electric motor, a compressor block with male and female helical rotors located in the compressor block housing, and an oil level control device. In this case, the oil level control device is made using an electronic level sensor. The specified sensor operates on the principle of impedance spectroscopy with the issuance of two logical signals corresponding to the maximum and minimum oil levels, and provides remote control and monitoring of the oil level by transmitting data via the CAN bus of the vehicle control and monitoring system to the driver / operator instrument panel. Binary level sensor LMTxlx is used as an electronic oil level sensor.

The disadvantage of this oil-filled screw compressor module is the relatively large error in the oil level readings by the oil level control device, made using an electronic sensor operating on the principle of impedance spectroscopy, associated with the dependence of the electrical impedance values on the temperature of the oil and oil-air mixture. Another disadvantage is the relatively redundant information provided by the electronic sensor.

The closest in technical essence to the claimed utility model is an oil level indicator for a screw compressor (see Patent for the invention of the Russian Federation No. 2562693, class G01F 23/292, publ. 04/13/2011). Said screw compressor can be used in vehicles. It has an oil pan. Oil is continuously pumped by a screw compressor to lubricate and cool moving parts. During operation, the oil level in the compressor unit housing can vary greatly. For example, when idle or idling, the oil level reaches a relatively high value, above the minimum level, and when subsequently switched to load operation, the oil level may rise or even fall below the minimum level. Such fluctuations, in particular towards a minimum level, are exacerbated by leaks or natural flow. Also, the oil level in the compressor block housing is affected by operating conditions, for example, distortions and acceleration-deceleration (splashing). The oil sump has a threaded hole located at the height of the minimum oil level. A mounting device with a seal is screwed into the specified hole. An optical sensor is glued into the mounting device, while the optics are directed into the oil sump. The optical sensor sends and registers light signals that change depending on the presence or absence of oil at the location of the optical sensor. To process these signals, a data analysis device is made, connected to the optical sensor by signal lines with a protective hose put on them.

The disadvantage of the known screw compressor oil level indicator is the complexity of the design due to the use of the mounting device and the use of adhesive joints, the redundancy of the information provided by the optical sensor about the current oil level, since during operation there is only enough information about the presence of oil above or below the minimum level. Another disadvantage is that the oil level is controlled not directly in the compressor unit, but in an oil sump located at a distance from the compressor unit and connected to it through an oil pipeline system, which leads to an increase in measurement errors, especially during operation that causes distortions and acceleration of braking ( sloshing). The disadvantage is also the lack of processing of light signals directly in the optical sensor and the need for a device for data analysis with signal lines with a protective hose put on them.

The technical result achieved with the claimed utility model is to provide operational remote control of the presence of oil above the minimum level in the oil-filled screw compressor module from the instrument panel of the driver/operator. This eliminates the influence on the control of the formation of an oil-air mixture when starting the compressor. This provides the convenience of control and increased speed of response to emergency situations, security, reliability, durability and the ability to build a digital control and monitoring system.

The technical result is achieved by the fact that in the oil-filled screw compressor module, which includes an electric motor, a compressor unit with a driving and driven helical rotors located in the compressor unit housing, and an oil level control device, the oil level control device is made using an optical level indicator. In this case, the operation of the optical level indicator is based on the principle of changing the refractive index at the transition boundary of two media. The oil level control device is installed in the compressor block housing at the height of registration of the minimum oil level in the compressor block housing. At the output of the optical level indicator, its electrical circuit generates a logic signal and remotely transmits it via the CAN bus of the vehicle control and monitoring system to the driver/operator instrument panel. The level limit switch IL-OSS-BA is used as an optical level indicator.

The essence of the claimed utility model is illustrated by drawings, where:

in fig. 1 shows an oil-filled screw compressor module;

in fig. 2 shows section A-A in Fig. one;

in fig. 3 shows a section B-B in Fig. one;

in fig. 4 shows a diagram of the passage of light in the optical head of an optical level indicator when its contact part is surrounded by air;

in fig. 5 shows a diagram of the passage of light in the optical head of an optical level indicator when its contact part is surrounded by oil.

Due to the fact that the graphic images of the figures of the claimed utility model are difficult to read with the vertical arrangement of the long sides of the sheet, it was advisable to arrange the sheets horizontally, which made it possible to significantly enlarge the drawings.

The oil-filled screw compressor module includes an electric motor 1, a compressor unit 2 with a driving and driven helical rotors 3 and 4, placed in the housing 5 of the compressor unit 2, and an oil level control device 6. Helical surfaces 7 and 8 are made on the helical rotors 3 and 4, respectively. Touching the screw surfaces 7 and 8 in the absence of lubrication is unacceptable, therefore, a minimum gap is left between them, which is filled during operation with an oil wedge. The oil level control device 6 is located in the housing 5 of the compressor unit 2 and is made with the help of an optical level indicator 9. An IL-OSS-BA level limit switch is used as an optical level indicator.

In the oil-filled screw compressor module, a crankcase lubrication system is used, in which oil 10 is poured into the housing 5 of the compressor unit 2 to form an oil bath 11 so that the lower part of the helical surface 8 of the driven helical rotor 4 is immersed in the oil bath 11. In addition to lubricating parts and creating oil wedge between screw surfaces 7 and 8, oil 10 is designed to remove heat induced during air compression and seal gaps in compressor block 2. Oil 10 is filled through oil filler neck 12 with screw plug 13 removed with sealing gasket 14. the oil level 10 must be between the permissible minimum and maximum levels 15 and 16. During operation of the oil-filled screw compressor module, the screw plug 13 is in the position screwed into the oil filler neck 12. The level sensor 9 is equipped with a contact part 17, which includes an optical head 18. The contact part 17 is inserted into the housing 5 of the compressor unit 2 and fixed with a nut 19. The installation of the optical level indicator 9 is sealed with a sealing gasket 20. The optical level indicator 9 is connected by cable 21 to the CAN bus 22 (not shown) of the control and monitoring system of the vehicle 23 (not shown) with the possibility of transmitting a logical signal to the instrument panel of the driver/operator 24 (not shown). The optical head 18 is equipped with an emitter 25 and a receiver 26 of the light beam 27, and the optical level indicator 9 itself is equipped with an electrical circuit 28 (not shown) for generating a logical signal about the state of the oil level.

It works as follows. The helical surfaces 7 and 8 of the helical rotors 3 and 4 and the walls of the housing 5 form working chambers in which, during the rotation of the helical rotors 3 and 4, suction, compression and air injection take place. After the electric motor 1 is turned on, during the rotation of the driven helical rotor 4, the oil 10 is entrained by the helical surface 8 and is sprayed with the formation of an oil-air mixture, which is small particles of oil 10 sprayed in air, and an oil wedge is formed between the helical surfaces 7 and 8 of the helical rotors 3 and 4 to prevent dry friction. The air-oil mixture covers the surfaces of the parts located in the housing 5 of the compressor block 2 and the walls of the housing 5, providing reliable lubrication of the rotating parts. The oil level 10 in the compressor block 2 is an important safety factor in operation. Therefore, during operation of the oil-filled screw compressor module, it must be within the limits between the permissible maximum and minimum levels 15 and 16. This is ensured by the initial filling of oil into the housing 5 of the compressor unit 2, and during operation it is necessary to prevent the oil level 10 from falling below the permissible minimum level 15 oil level 10. This is ensured by the optical oil level indicator 9, in particular by the level limit switch IL-OSS-BA. The optical oil level indicator 9 operates on a change in the refractive index at the transition boundary of two media, one of them is the optical head 18 located in the contact part 17, and the second is the environment directly surrounding the cavity of the housing 5. The environment can be air in the case when the oil level 10 does not reach the contact part 17 of the optical level indicator 9, and liquid, when the oil 10 reaches a level above the minimum level 15. The emitter 25 forms a beam of light 27, the receiver 26 analyzes the intensity of its reflection, and electrical circuit 28 (not shown) outputs a logic signal. In the case when the contact part 17 is surrounded by air, refraction occurs inside the optical head 18 in such a way that a total reflection of the light beam 27 is created. In this case, the reflected light beam 27 enters the receiver 25. If the contact part 17 of the optical level indicator 9 is surrounded by oil 10, the reflection of the light beam 27 is affected by the refractive index of the oil 10. In fact, the entire beam of light 27 penetrates through the optical head 18 into the cavity of the housing 5 of the compressor unit 2 without entering the receiver 26. The logical signal is transmitted through the cable 21 and the CAN bus 22 ( not shown) of the vehicle control system 23 (not shown) to the driver/operator instrument panel 24 (not shown). At the same time, a light, sound, or other signal, or combinations thereof, is generated on the instrument panel of the driver/operator 24 (not shown), or combinations thereof, to warn maintenance personnel about the achievement of a critical minimum level 15 of oil 10. This ensures remote operational control of the oil level without stopping the oil-filled screw compressor module and the safety, reliability and durability of the oil-filled screw compressor module. This eliminates the influence on the control of the level of oil formation when starting the oil-filled screw compressor module of the oil-air mixture.

Claims (2)

1. An oil-filled screw compressor module, including an electric motor, a compressor unit with male and female helical rotors located in the compressor unit housing, and an oil level control device, characterized in that the oil level control device is made using an optical level indicator, the operation of which is based on using the principle of changing the refractive index at the boundary of the transition of two media, and is installed in the compressor block housing at the height of registration of the minimum oil level in the compressor block housing, while at the output the electrical circuit of the optical level indicator generates a logic signal and remotely transmits via the CAN bus of the control system and control of the vehicle on the instrument panel of the driver/operator. 2. An oil-filled screw compressor module according to claim 1, characterized in that an IL-OSS-BA level limit switch is used as an optical level indicator.

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