JP6896083B2 - Screw compressor system for commercial vehicles - Google Patents

Description

The present invention has at least one screw compressor and at least one open-loop control unit and / or closed-loop control unit for driving open-loop control and / or driving closed-loop control of the screw compressor. Regarding the screw compressor system for.

According to the prior art, screw compressors for commercial vehicles are already known. This type of screw compressor is used, for example, to prepare the compressed air required for a commercial vehicle braking system.

In this connection, an oil-filled compressor, particularly a screw compressor, is also known, and control of the oil temperature is an issue in such a compressor. Control of the oil temperature is usually carried out by providing an external oil cooler connected to the oil-filled compressor and oil circulation path via a temperature control valve. In this case, the oil cooler is a heat exchanger having two circulation paths separated from each other, and is a high temperature fluid, that is, a first circulation path for compressor oil and a second circulation path for cooling fluid. Is provided. As the cooling fluid, for example, air, mixed water containing an antifreeze agent, or other oil can be used.

The oil cooler must then be connected to the compressor oil circulation via a conduit or hose, and the oil circulation must be protected against leaks.

In addition, this external volume must be filled with oil, which also increases the total amount of oil. This increases the system inertia. In addition, the oil cooler must be mechanically housed and mounted by a surrounding retainer, or a separate retainer, which also requires additional mounting means and thus configuration space. To do.

US Pat. No. 4,780,601 (US 4,780,061) already knows a screw compressor with a built-in oil cooler.

Further, German Patent Application Publication No. 3717493 (DE 37 17 493 A1) discloses a screw compressor device arranged in a compact casing, and the screw compressor device is a screw compressor. It has an oil cooler on the electric motor.

The screw compressor of the type described at the beginning is already known, for example, by German Patent Invention No. 102004060417 (DE 10 2004 060 417 B4).

An object of the present invention is to improve the screw compressor system of the type described at the beginning so that, in particular, the drive open loop control and / or the drive closed loop control of the screw compressor can be easily and surely configured.

According to the present invention, this problem is solved by a screw compressor system for a commercial vehicle having the feature of claim 1. According to this, it is a screw compressor system for commercial vehicles, in which at least one screw compressor, at least one screw compressor drive device, at least one temperature sensor, at least one open loop control unit and / or closed loop control. The open-loop control unit and / or the closed-loop control unit is connected to the screw compressor drive and the temperature sensor, and the open-loop control unit and / or the closed-loop control unit receives from the temperature sensor. A screw compressor system for commercial vehicles is provided that is configured to control the screw compressor drive device with respect to the number of revolutions based on the temperature threshold signal.

The idea underlying the present invention is that the temperature of the screw compressor system can be controlled by appropriately controlling the screw compressor drive device depending on the temperature inside the screw compressor. The temperature of the screw compressor is also greatly affected by the rotation speed of the screw compressor drive device. Once a predetermined temperature is reached, the temperature can be raised or lowered accordingly, depending on the speed of the screw compressor drive. In particular, since the screw compressor system is formed to be relatively large, it is conceivable that a predetermined inertia leading to a temperature change occurs based on the amount of oil existing in the screw compressor. Further, it is also conceivable that the screw compressor system is usually designed for partial load operation or operation with a relatively light load and does not always need to be operated at full load operation.

For example, the open-loop control unit and / or the closed-loop control unit may be a component of the screw compressor system. This forms a compact structure that does not require involvement of external components.

Basically, the open-loop control unit and / or the closed-loop control unit may be a component of the air treatment system of a commercial vehicle. In this case, there is already a suitable controller that can be easily used together.

The open-loop control unit and / or the closed-loop control unit may be a component of an engine control device or a vehicle control device of a commercial vehicle. In this case as well, the existing components of the commercial vehicle can be utilized.

However, basically, it is conceivable that the open-loop control unit and / or the closed-loop control unit is formed as a separate open-loop control unit and / or the closed-loop control unit. This allows, for example, easy assembly and easy replacement or easy upgrade.

In addition, the open-loop and / or closed-loop control units are configured to turn off the screw compressor drive when it receives a temperature threshold signal informing the screw compressor that a predetermined temperature limit has been exceeded. It is possible that there is. This makes it possible to easily and effectively achieve a temperature drop in the screw compressor in a very short time.

In the non-operating state of the screw compressor achieved by turning off the screw compressor drive device, no more heat is generated in the screw compressor, so that the screw compressor can be cooled.

Further, the open-loop control unit and / or the closed-loop control unit can turn on the screw compressor drive only when it receives a temperature threshold signal indicating that the screw compressor has fallen below a predetermined temperature limit value. It is conceivable that it is configured as follows. Basically, the temperature threshold signal indicating that the screw compressor has fallen below a predetermined temperature limit is the temperature at which the screw compressor drive is turned off, which is received by the open-loop control unit and / or the closed-loop control unit. It may be different from the threshold signal. However, these temperature threshold signals may be the same. Preventing the screw compressor from starting or restarting when the temperature is too high allows for simple yet reliable open-loop or closed-loop control of the temperature in the screw compressor system or screw compressor.

The screw compressor system does not have to have a temperature control valve. Basically, by configuring an open-loop control unit and / or a closed-loop control unit, the temperature of the screw compressor can be effectively controlled, in which case oil cooling, which usually has a temperature control valve. No connection is required depending on the heat of the circuit. Therefore, such a component of the screw compressor system can be omitted.

Basically, the screw compressor system also does not have to have a heat exchanger for oil cooling. Overall, the structure of the screw compressor system can be simplified by omitting such relatively expensive components.

Further details and advantages of the present invention will be described in detail with reference to the illustrated examples.

It is a schematic cross-sectional view of the screw compressor by this invention. It is a figure which shows schematicly the screw compressor system by this invention.

FIG. 1 shows a schematic cross-sectional view of the screw compressor 10 according to the embodiment of the present invention.

The screw compressor 10 has a mounting flange 12 for mechanically mounting the screw compressor 10 to an electric motor (not shown here).

However, an input shaft 14 is shown, through which torque is transmitted from the electric motor to one of both screws 16 and 18, i.e. to the screw 16.

The screw 18 meshes with the screw 16 and is driven by the screw 16.

The screw compressor 10 has a casing 20, and the main components of the screw compressor 10 are housed in the casing.

The casing 20 is filled with oil 22.

An inlet pipe piece 24 is provided on the air inlet side of the casing 20 of the screw compressor 10. In this case, the inlet pipe piece 24 is formed so that the air filter 26 is arranged on the inlet pipe piece. Further, the air inlet pipe piece 24 is provided with an air inlet 28 in the radial direction.

A spring-loaded valve insert 30 is provided in the area between the inlet tube piece 24 and the location where the inlet tube piece 24 is attached to the casing 20, in which case it is configured as an axial seal. Has been done.

Such a valve insert 30 functions as a check valve.

An air supply passage 32 for supplying air to both screws 16 and 18 is provided downstream of the valve insert 30.

An air outlet pipe 34 provided with an ascending pipe 36 is provided on the outlet side of both screws 16 and 18.

A temperature sensor 38 is provided in the region at the end of the riser pipe 36, and the oil temperature can be monitored by this temperature sensor.

Further, the air outlet region is provided with a holder 40 for the air / oil separation element 42.

The holder 40 for the air / oil separation element has the air / oil separation element 42 in the bottom area in the assembled state (as shown in FIG. 1).

Further, a corresponding filter screen or a known filtration and oil separation device 44 is provided inside the air / oil separation element 42, but this is not described in more detail.

The holder 40 for the air / oil separation element has an air outlet opening 46 in the central upper region with respect to the assembled and ready to operate state (ie, as shown in FIG. 1). Is connected to the check valve 48 and the minimum pressure valve 50. The check valve 48 and the minimum pressure valve 50 may be formed as one common valve combined.

Following the check valve 48, an air outlet 51 is provided.

The air outlet 51 is usually connected to a correspondingly known compressed air consumer.

An ascending conduit 52 is provided to guide the separated oil 22 existing in the air / oil separating element 42 back into the casing 20 again, and this ascending conduit is of the air / oil separating element 42. A filtration and check valve 54 is provided at a location starting from the holder 40 and moving into the casing 20.

Downstream of the filtration and check valve 54, a nozzle 56 is provided in the casing hole. The oil return guide line 58 is returned to the substantially central region of the screw 16 or screw 18 to supply the oil 22 to the screw again.

An oil discharge screw 59 is provided in the bottom surface region of the casing 20 in the assembled state. A corresponding oil discharge opening is opened through the oil discharge screw 59, and the oil 22 can be discharged through this opening.

An attachment portion 60 to which the oil filter 62 is attached is also provided in the lower region of the casing 20. The oil 22 is first guided to the temperature control valve 66 via the oil filter inlet passage 64 arranged in the casing 20.

Instead of the temperature control valve 66, an open-loop controller and / or a closed-loop controller that can monitor the oil temperature of the oil 22 in the casing 20 and adjust it to a target value may be provided. ..

Next, downstream of the temperature control valve 66 is the oil inlet of the oil filter 62, which returns the oil 22 back to the screw 18 or back to the screw 16 via the central return guide line 68. Although it is guided, it is also guided back to the oil-lubricated bearing 70 of the shaft 14. A nozzle 72 is also provided in the region of the bearing 70, and this nozzle is provided in the casing 20 so as to communicate with the return guide pipe line 68.

The cooler 74 is connected to the attachment portion 60.

In the upper region (with respect to the assembled state) of the casing 20, a safety valve 76 capable of reducing the excessively high pressure in the casing 20 is located.

A bypass line 78 leading to the pressure release valve 80 is located in front of the minimum pressure valve 50. Air can be returned and guided to the region of the air inlet 28 through the pressure release valve 80, which is controlled by the connection with the air supply passage 32. An air vent valve and nozzle (reduced diameter portion of the supply line) not shown may be provided in this area.

Further, the oil level sensor 82 can be provided on the outer wall of the casing 20 at substantially the height of the pipeline 34. The oil level sensor 82 may be, for example, an optical sensor, and the sensor signal indicates whether the oil level is above the oil level sensor 82 during operation, or the oil level sensor 82 is exposed, thereby causing oil. It is configured and adjusted to be able to detect if the surface is correspondingly lowered.

In connection with such monitoring, an alarm unit may be provided to issue or convey appropriate error notification or warning to the user of the system.

The functions of the screw compressor 10 shown in FIG. 1 are as follows:
Air is supplied via the air inlet 28 and reaches the screws 16 and 18 via the check valve 30, where the air is compressed. After exiting the screws 16 and 18, the air-oil mixture compressed 5 to 16 times rises through the outlet pipe 34 and the rise pipe 36, and is directly blown to the temperature sensor 38.

The air, still partially containing oil particles, is then guided through the holder 40 to the air / oil separation element 42 and reaches the air outlet line 51 when the corresponding minimum pressure is reached.

The oil 22 present in the casing 20 is held at the operating temperature via the oil filter 62 and, in some cases, through the heat exchanger 74.

If cooling is not required, the heat exchanger 74 is neither used nor turned on.

Corresponding switch-on is done via the temperature control valve 66. After purification in the oil filter 62, the oil is supplied to the screw 18 or screw 16 via the pipeline 68, but also to the bearing 70. Oil 22 is supplied to the screw 16 or screw 18 via the return guide pipes 52 and 58, in which case the purification of the oil 22 is performed in the air / oil separation element 42.

The torque of an electric motor (not shown) is transmitted to the screw 16 via the shaft 14, and the screw 16 meshes with the screw 18, and the screws 16 and 18 of the screw compressor 10 are driven via the electric motor. ..

Based on the pressure release valve 80 (not shown in detail), the high pressure formed on the outlet side of the screws 16 and 18, for example, in the operation ready state is not confined in the region of the supply pipe line 32, especially when the compressor is started. It is guaranteed that there is always a low inlet pressure, especially atmospheric pressure, in the region of the supply line 32. Otherwise, the start of the compressor may first create an extremely high pressure on the outlet side of the screws 16 and 18 that overloads the drive motor.

FIG. 2 is a schematic view showing a screw compressor system 100 according to the present invention having the screw compressor 10 shown in FIG.

The screw compressor system 100 further includes an open-loop control unit and / or a closed-loop control unit 110, which controls the temperature sensor 38, the drive devices of the screws 16 and 18 of the screw compressor 10, and (torque). It is connected to an electric motor (not shown) that transmits to the input shaft 14.

The open-loop control unit and the closed-loop control unit 110 are formed as components of the screw compressor 10 in this case.

However, basically, the open-loop control unit and the closed-loop control unit 110 are a component of an air treatment system (not shown) of a commercial vehicle, a component of an engine or a vehicle control device of a commercial vehicle, or a separate open-loop control unit. And it can be assumed that it is formed as a closed loop control unit 110.

The open-loop control unit and / or the closed-loop control unit 110 is configured to control the screw compressor drive device with respect to the rotation speed based on the temperature threshold signal received from the temperature sensor 38.

In this case, in particular, the open-loop control unit and / or the closed-loop control unit 110 turns off the screw compressor drive device when it receives a temperature threshold signal indicating that the screw compressor 10 exceeds a predetermined temperature limit value. Is supposed to be.

The screw compressor can be started again only when a temperature threshold signal indicating that the temperature limit value of the screw compressor 10 has fallen below a predetermined temperature limit value is transmitted from the temperature sensor 38 to the open loop control unit and / or the closed loop control unit 110. It becomes.

To allow for easy implementation, the temperature limits for turning on and off the screw compressor 10 are preferably chosen to be the same.

However, basically, it is conceivable to set different limit values for this purpose.

The temperature limit can be selected, for example, to be about 10-30% above normal operating temperature.

With the configuration shown in FIG. 2, it is possible that the screw compressor system 100 or the screw compressor 10 no longer needs to have the temperature control valve 66 and the heat exchanger 74.

10 Screw compressor 12 Mounting flange 14 Input shaft 16 Screw 18 Screw 20 Casing 22 Oil 24 Inlet pipe piece 26 Air filter 28 Air inlet 30 Valve insert 32 Air supply passage 34 Air outlet pipe 36 Rising pipe 38 Temperature sensor 40 Air / oil separation Holder for Element 42 Air / Oil Separation Element 44 Filter Screen or Known Filter or Oil Separator 46 Air Outlet Opening 48 Check Valve 50 Minimum Pressure Valve 51 Air Outlet 52 Rising Pipeline 54 Filtering and Check Valve 56 Nozzle 58 Oil return guide line 59 Oil discharge screw 60 Attachment 60a Outer ring 60b Inner ring 62 Oil filter 64 Oil filter inlet passage 66 Temperature control valve 68 Return guide line 70 Bearing 72 Nozzle 74 Cooler, heat exchanger 76 Safety valve 78 Bypass pipe Road 80 Pressure release valve 82 Oil level sensor 100 Screw compressor system 110 Open loop control unit and / or closed loop control unit

Claims (6)

A screw compressor system (100) for a commercial vehicle, which is provided in at least one screw compressor (10), at least one screw compressor drive device, and a casing (20) of the screw compressor (10). It has at least one temperature sensor (38) that monitors the temperature inside the screw compressor (10), and at least one open-loop control unit and / or closed-loop control unit (110). The / or closed loop control unit (110) is connected to the screw compressor drive device and the temperature sensor (38), and the open loop control unit and / or the closed loop control unit (110) is the temperature sensor (38). The screw compressor drive device is configured to be controlled with respect to the rotation speed based on the temperature threshold signal received from the screw compressor drive device, and the temperature of the screw compressor (10) is affected by the rotation speed of the screw compressor drive device. The screw compressor system (100) does not have a heat exchanger (74) for cooling the oil.
An air outlet pipe (34) provided with a rising pipe (36) is provided on the outlet side of the screw (16, 18) of the screw compressor (10), and is provided at the end of the rising pipe (36). The temperature sensor (38) is provided in the area.
The open-loop control unit and / or the closed-loop control unit (110) is an open-loop control unit and / or a closed-loop control unit (110) separate from the screw compressor (10).
The open-loop control unit and / or the closed-loop control unit (110) turns off the screw compressor drive device when the screw compressor (10) receives a temperature threshold signal indicating that a predetermined temperature limit value has been exceeded. Is configured to
Screw compressor system (100) for commercial vehicles. The screw compressor system (100) according to claim 1, wherein the open-loop control unit and / or the closed-loop control unit (110) is a component of the air treatment system of the commercial vehicle. The screw compressor system (100) according to claim 1, wherein the open-loop control unit and / or the closed-loop control unit (110) is a component of the engine control device or the vehicle control device of the commercial vehicle. The open-loop control unit and / or closed-loop control unit (110), both components of the previous SL commercial vehicle air treatment systems, further also different from the components of the commercial vehicle engine control unit or the vehicle control device, a separate The screw compressor system (100) according to claim 1, which is an open-loop control unit and / or a closed-loop control unit (110). The open-loop control unit and / or the closed-loop control unit (110) drives the screw compressor only when it receives a temperature threshold signal indicating that the screw compressor (10) has fallen below a predetermined temperature limit value. The screw compressor system (100) according to any one of claims 1 to 4 , which is configured so that the device can be turned on. The screw compressor system (100) is provided in the casing (20) and does not have a temperature control valve (66) for monitoring the oil temperature of the oil in the casing (20), according to claim 1. 5. The screw compressor system (100) according to any one of up to 5.

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