JP2019529803A - Systems for commercial vehicles including screw compressors with common cooling devices and electric motors - Google Patents

Abstract

The present invention is a system (1) for a commercial vehicle comprising a compressor (10), an electric motor (5), and drive electronics (6), the electric motor (5) driving the compressor (10). The electric motor (5), the compressor (10), and the drive electronics (6) relate to a system (1) for a commercial vehicle having one common cooling circuit (100).

Description

  The present invention relates to a system for commercial vehicles, including a screw compressor and an electric motor.

  Screw compressors for commercial vehicles are already known from the prior art. Such a type of screw compressor is used, for example, to prepare the compressed air necessary for the braking system of commercial vehicles.

  In this connection, in particular, compressors filled with oil, in particular screw compressors, are also known, in which oil temperature control is a problem. The oil temperature is usually controlled by providing a compressor filled with oil and an external oil cooler connected to the oil circulation path via a temperature regulating valve. In this case, the oil cooler is a heat exchanger having two circulation paths separated from each other, and includes a first circulation path for high-temperature fluid, that is, compressor oil, and a second circulation path for cooling fluid. Is provided. As the cooling fluid, for example, air, mixed water containing an antifreezing agent, or other oil can be used.

  The oil cooler must then be connected to the compressor oil circuit via a line or hose, and the oil circuit must be protected against leakage.

  Furthermore, since this external volume must be filled with oil, the total amount of oil is also increased. This increases the system inertia. Furthermore, the oil cooler must be mechanically housed and mounted by means of a surrounding holding body or a separate holding body, which requires additional mounting means and thus a construction space. To do.

  US Pat. No. 4780061 (US 4,780,061) already discloses a screw compressor with an integrated oil cooling section.

  Furthermore, DE 37 17 493 A1 discloses a screw compressor device which is arranged in a compact casing, the screw compressor device being a screw compressor device. It has an oil cooler located on the electric motor.

  German Patent Application No. 102010015151 (DE 10 2010 015 151 A1) discloses a compressor flange for a screw compressor.

  Furthermore, a connecting flange with a cooling passage for an automotive heat exchanger is known from U.S. Pat. Appl. No. 20140190674 (US 2014/0190674 A1).

  German Patent Application No. 103013011061 (DE 10 2013 011 061 B3) further discloses a heat exchanger with a flange connection, which is in the compressed gas part and has stud bolts. It has a connecting flange with a through-hole manufactured by a casting technique for housing.

  From US 2003/143090 A1 (US 2003/143090 A1), an assembly comprising an electronic device cooling device and an electric motor is already known.

  Furthermore, US Pat. No. 2012/076679 (US 2012/076679 A1) discloses a cooling device in which the electric motor and the driving electronics similarly have one cooling device.

  The object of the present invention is to improve a system for commercial vehicles, including a screw compressor and an electric motor, in particular to provide a space-saving cooling means for a system of the type mentioned at the outset. .

  This object is achieved according to the invention by a system for commercial vehicles comprising a screw compressor and an electric motor with the features of claim 1. According to this, a system for a commercial vehicle including a compressor, an electric motor, and drive electronics, the electric motor drives the compressor, and the electric motor, the compressor, and the drive electronics are one common A system for a commercial vehicle is provided having a cooling circuit.

  The idea underlying the present invention is that all components of the system for commercial vehicles, including compressors, electric motors, and drive electronics are cooled by the same coolant. This provides a particularly efficient cooling management of the corresponding compressor system.

  Preferably, the cooling elements are connected in series so that all the cooling elements have the same flow rate of cooling medium.

  The compressor may in particular be a screw compressor. This type of screw compressor is particularly suitable for the new type of use for hybrid commercial vehicles where the compressor for generating compressed air is not always driven by the drive unit of the commercial vehicle.

  Furthermore, the cooling circuit may have a coolant passage formed at least in sections through the cooling elements arranged side by side. Such a series connection allows a simple structure. Furthermore, the pressure transition in the cooling medium circuit can be easily adjusted as a whole.

  In particular, the electric motor, the compressor, and the drive electronics may each be provided with at least one cooling element. Such a type of cooling element can be, for example, a heat exchange element that can be connected side by side in a cooling circuit. By providing corresponding cooling elements for the individual system components, it is possible to discharge the heat according to the requirements.

  Furthermore, the electric motor has a stator cooling element, each cooling element having a cooling medium in the cooling circuit first flowing through the cooling element of the drive electronics, then through the stator cooling element and then into the compressor. It is conceivable that they are arranged to flow through the cooling element. This has the advantage that the cooling element that must first derive the main heat, ie the cooling element of the drive electronics, is flown through first. Thereby, the temperature rise in the drive electronic device can be easily suppressed, and in this case, the temperature control within the allowable operating temperature range can be easily adjusted. Such devices further take into account the situation that the most important range of temperature control is in the area of drive electronics since overheating must be prevented anyway. In addition, the drive electronics have a high heat release based on the high energy loss in the drive electronics and therefore a sufficient heat drain is required. Further, in the cooling circuit, it is desirable to have little pressure loss in order to maintain a small amount of pump energy required to pump the cooling medium through the cooling circuit.

  In addition, however, the electric motor may further comprise a casing cooling element, such that the cooling medium in the cooling circuit first flows through the casing cooling element before flowing through the cooling element of the drive electronics. Has been placed. This type of cooling is relatively non-critical because little heat is expected to be absorbed in the casing cooling element. The decompression is also relatively slight.

  Furthermore, the cooling element of the drive electronics may have a flow distribution part. By means of the flow distribution part, the flow through section of the cooling passage can be adjusted accordingly, so that pressure losses in the cooling elements of the drive electronics can be avoided. In particular, this further provides high cooling efficiency and heat dissipation characteristics while preventing excessive decompression in the cooling element.

  Furthermore, the cooling element of the drive electronics may have a substantially W-shaped flow path. As a result, the cooling medium can flow through the cooling element of the drive electronic device in a meander shape, thereby allowing a large surface area of the drive electronic device to flow through, so that good heat discharge as a whole is achieved. This is possible in the area of equipment.

  Further details and advantages of the invention are explained in greater detail with reference to the illustrated embodiments.

1 is a cross-sectional view schematically showing an embodiment of the invention for a system according to the invention for commercial vehicles, including a screw compressor and an electric motor. 1 schematically shows a cooling device of a system according to the invention for a commercial vehicle. It is a perspective view which shows the structure of the cooling device shown in FIG. It is the figure which showed roughly the structure of the cooling element for drive electronic devices.

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

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

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

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

  The screw compressor 10 has a casing 20 in which main components of the screw compressor 10 are accommodated.

  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 such that the air filter 26 is disposed on the inlet pipe piece. Further, the air inlet pipe piece 24 is provided with an air inlet 28 in the radial direction.

  In the region between the inlet pipe piece 24 and the location where the inlet pipe piece 24 is attached to the casing 20, a valve insert 30 to which a spring load is applied is provided. In this case, as an axial seal means It is configured.

  Such a valve insert 30 functions as a check valve.

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

  An air outlet pipe 34 having a rising pipe 36 is provided on the outlet side of both the screws 16 and 18.

  A temperature sensor 38 is provided in the region of the end portion of the ascending pipeline 36, and the oil temperature can be monitored by this temperature sensor.

  Furthermore, a holder 40 for the air / oil separation element 42 is provided in the air outlet area.

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

  Furthermore, 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 specifically described.

  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 state and ready for operation (ie the state as shown in FIG. 1). Leads to a check valve 48 and a minimum pressure valve 50. Check valve 48 and 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.

  In order to guide the separated oil 22 present in the air / oil separating element 42 back into the casing 20 again, a rising line 52 is provided, which is connected to the air / oil separating element 42. Starting from the holder 40 for this purpose, it has a filtration and check valve 54 where it moves into the casing 20.

  A nozzle 56 is provided in the casing hole downstream of the filtration and check valve 54. The oil return guide pipe line 58 is returned to the substantially middle region of the screw 16 or the screw 18 and supplies the oil 22 again to this screw.

  An oil discharge screw 59 is provided in the bottom area 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 adjustment valve 66 through the oil filter inlet passage 64 disposed in the casing 20.

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

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

  The cooler 74 is connected to the attachment portion 60.

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

  A bypass line 78 leading to the pressure release valve 80 is located before the lowest pressure valve 50. Air can be guided back to the area of the air inlet 28 via the pressure relief valve 80 controlled by connection to the air supply passage 32. This region may be provided with an air vent valve and a nozzle (reduced diameter portion of the supply pipe line) not shown.

  Furthermore, an oil level sensor 82 can be provided on the outer wall of the casing 20 substantially at the height of the conduit 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 whether the oil level sensor 82 is exposed, thereby It is constructed and adjusted so that it can detect whether the surface is correspondingly degraded.

  In the context of such monitoring, an alarm unit may be provided that issues or communicates a corresponding error notification or warning to the system user.

The function of the screw compressor 10 shown in FIG. 1 is 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. The air-oil mixture compressed 5 to 16 times exits the screws 16 and 18, passes through the outlet pipe 34, rises through the rising pipe 36, and is directly blown onto 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 a corresponding minimum pressure is reached.

  The oil 22 present in the casing 20 is maintained at the operating temperature via the oil filter 62 and possibly via the heat exchanger 74.

  If cooling is not required, the heat exchanger 74 is not used and is not turned on.

  The corresponding switch-on is effected via a temperature regulating valve 66. After purification in the oil filter 62, the oil is supplied to the screw 18 or the screw 16 through the pipe 68, but is also supplied to the bearing 70. The oil 16 is supplied to the screw 16 or the screw 18 via the return guide lines 52 and 58, and in this case, the purification of the oil 22 is performed in the air / oil separation element 42.

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

  In detail, based on the pressure release valve 80 not shown in detail, the high pressure formed on the outlet side of the screws 16, 18 in the operation ready state is not confined in the region of the supply line 32, particularly when the compressor is started. In the region of the supply line 32, it is always ensured that a low inlet pressure is present, in particular atmospheric pressure. Otherwise, when the compressor is started, a very high pressure that excessively loads the drive motor may be generated on the outlet side of the screws 16 and 18.

  FIG. 2 shows a schematic arrangement of a cooling device for an embodiment of the system 1 according to the invention for a compressor 10 as shown in FIG. 1, i.e. a commercial vehicle with a screw compressor 10. .

  Basically, however, any type of compressor can be used in the system 1.

  The system 1 further includes an electric motor 5 and drive electronics 6. In this case, the cooling circuit 100 is used to exhaust heat from the electric motor 5, the compressor 10, and the drive electronics 6.

  Therefore, the electric motor 5, the compressor 10, and the driving electronic device 6 have one common cooling circuit 100.

  The entire cooling system 100 includes a plurality of cooling elements, that is, a cooling element 102 for driving electronics, a stator cooling element 103, and a compressor cooling element 104.

  A casing cooling element 101 is first connected to the cooling medium inlet 105, and this casing cooling element directly communicates with the cooling element 102 of the drive electronics.

  In principle, however, the cooling medium inlet 105 may be directly connected to the cooling element 102 of the drive electronics. From the drive electronics cooling element 102, a fluid cooling medium 106 flows to the stator cooling element 103 for the electric motor 5 and then to the cooling element 104 of the compressor 10. The cooling medium is guided to an internal or external cooling passage or cooling hose 107. The cooling medium then flows from the cooling element 104 through the cooling medium outlet 108 into another cooling circuit, where the cooling medium can be driven, for example, by a pump.

  FIG. 3 shows a perspective view of the apparatus of the system 1 schematically shown in FIG.

  Since the cooling element 102 of the drive electronics 6 has to be dissipated most of the heat in order to avoid excessive temperature rise in the area of the drive electronics 6, a special shape is proposed.

  The cooling element 102 of the drive electronics 6 has a substantially W-shaped flow passage 102a.

  Furthermore, the cooling element 102 of the drive electronic device 6 is provided with a flow distribution portion 102b.

  In this case, the cooling medium passage 107 has a sufficient cross-section to minimize the pressure drop between the cooling element inlet 109 and the cooling element outlet 110. In this case, since the flow distribution portion 102b prevents an excessive decrease in the flow velocity, the flow velocity in the cooling passage 107 is continuously maintained high by the flow distribution portion 102b.

DESCRIPTION OF SYMBOLS 1 System 5 Electric motor 6 Drive electronic device 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 Passage 38 temperature sensor 40 holder for air / oil separation element 42 air / oil separation element 44 filter screen or known filtration or oil separation device 46 air outlet opening 48 check valve 50 minimum pressure valve 51 air outlet 52 ascending line 54 Filtration and Check Valve 56 Nozzle 58 Oil Return Guide Line 59 Oil Drain Screw 60 Attached Portion 62 Oil Filter 64 Oil Filter Inlet Path 66 Temperature Control Valve 68 Return Guide Line 70 Bearing 72 Nozzle 76 Safety valve 78 Bypass line 80 Relief valve 82 Oil level sensor 100 Cooling circuit 101 Casing cooling element 102 Cooling element for driving electronics 102a Flow passage 102b Flow distribution part 103 Stator cooling element 104 Compressor cooling element 105 Cooling medium inlet 106 Cooling Medium 107 Cooling passage / cooling hose 108 Cooling medium outlet 109 Cooling element inlet 110 Cooling element outlet

Claims (8)

  A system (1) for a commercial vehicle comprising a compressor (10), an electric motor (5), and drive electronics (6), wherein the electric motor (5) drives the compressor (10); The electric motor (5), the compressor (10), and the drive electronics (6) are a system (1) for a commercial vehicle having a common cooling circuit (100).   The system (1) according to claim 1, wherein the compressor (10) is a screw compressor (10).   The system (1) according to claim 1 or 2, wherein the cooling circuit (100) comprises a cooling medium passage (107) formed at least piecewise through cooling elements arranged side by side.   The system (1) according to claim 3, wherein the electric motor (5), the compressor (10) and the drive electronics (6) are each provided with at least one cooling element.   The electric motor (5) has a stator cooling element (103), and each of the cooling elements has a cooling medium in the cooling circuit (100). The system (1) according to claim 4 arranged to flow through the stator cooling element (103) and then through the cooling element (104) of the compressor (10). .   The electric motor (5) further includes a casing cooling element (101), and the cooling element includes a cooling medium in the cooling circuit (100), and the cooling element (102) of the driving electronic device (6). The system (1) according to claim 5, wherein the system (1) is arranged to flow first through the casing cooling element (101) before flowing through.   The system (1) according to any one of claims 4 to 6, wherein the cooling element (102) of the drive electronics (6) comprises a flow distribution part (102b).   The system (1) according to any one of claims 4 to 7, wherein the cooling element (102) of the drive electronics (6) has a substantially W-shaped flow passage (102a). ).

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