JP2019529804A - Screw compressor for commercial vehicles - Google Patents

Abstract

A screw compressor (10) for commercial vehicles, a rotor casing (20b) in which a screw rotor (16, 18) of the screw compressor (10) is disposed, a casing cover (20a), and the casing cover An air outlet pipe (34) arranged on the outlet side of (20a) and provided with a rising pipe (36), the air outlet pipe (34) having at least one oil separating means. ing.

Description

  The present invention relates to a screw compressor for commercial vehicles.

  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.

  A screw compressor of the type mentioned at the beginning is already known, for example, from DE 102 2004 060 417 (DE 10 2004 060 417 B4).

  Therefore, the object of the present invention is to improve a screw compressor for commercial vehicles of the type described at the beginning, and in particular, before the fluid compressed by the screw compressor, in particular air, reaches the oil separator, the first oil separation is already performed. Is to be able to do.

  This object is achieved according to the invention by a commercial vehicle screw compressor comprising the features of claim 1. According to this, it is a screw compressor for commercial vehicles, the casing cover in which the screw of the screw compressor is arranged, the air outlet pipe that is arranged on the outlet side of the casing cover and that has a rising pipeline A screw compressor for commercial vehicles is provided in which the air outlet pipe has at least one oil separation means.

  The idea underlying the present invention is that in a screw compressor, an initial oil separation is already carried out on the outlet side of the casing cover and on the outlet side of the screw used, for example, for compressing air or other fluids. is there. This initial oil separation is not carried out by a conventional oil separation device, but the compressed fluid, in particular the compressed air, is removed from the rotor casing, or after it has been compressed by the screw, it is further discharged in the screw compressor. Already done by outlet pipe.

  Such an oil separation already performed here in the air outlet pipe can significantly improve the efficiency of the oil separation. As a result, the first oil separation is already carried out in advance, so that the oil separation device can be of different dimensions and designs in some cases.

  Furthermore, it is conceivable that the oil separating means has an oil return guide opening. Such an oil return guide opening may be, for example, an opening provided in the wall of the air outlet pipe, from which oil condensed on the wall of the air outlet pipe can flow out.

  In particular, the oil return guide opening can connect the inside of the air outlet pipe to the oil pan. This already allows simple oil return guidance.

  Furthermore, the air outlet pipe has an attachment part, and the air outlet pipe is connected to the casing cover by the attachment part, and the oil return guide opening is arranged in the area of the attachment part or adjacent to the attachment part. It is possible that As a result, the oil return guide opening can be arranged relatively directly at the connection portion to the outlet of the casing cover, that is, at the place where the air outlet pipe is attached. Accordingly, in some cases, the oil already condensed there can be led directly from here to the air outlet pipe.

  The oil return guide opening can be formed as one simple hole. As a result, the simple positioning of the oil return guide opening and the simple positioning are possible.

  Furthermore, the air outlet pipe is at least partly conical. Due to the conical formation of the air outlet tube, oil particles can be removed from the air by the action of gravity, and further the oil particles can be prevented from leaving the air outlet tube.

  In particular, the ascending line may be conically formed on the end side. This type of widening of the riser can improve the action of removing oil particles and droplets from the air by gravity. The oil particles thus removed fall down and return to the air outlet pipe, gather in a region adjacent to the attachment portion of the air outlet pipe, and flow back to the oil pan through the oil return guide opening.

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

1 is a schematic sectional view of a screw compressor according to the present invention. It is a perspective view which shows the detail of the rotor casing of the screw compressor provided with the air outlet pipe of the screw compressor of FIG. FIG. 3 is a perspective sectional view showing the air outlet pipe of FIG. 2.

  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 is provided a valve insert 30 to which a spring load is applied, in this case configured as an axial seal. Has been.

  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 casing cover 20a of the screw compressor 10 shown in FIG. 1 in a perspective view.

  The casing cover 20a has an outlet to which an air outlet pipe 34 is attached.

  In this case, the air outlet pipe 34 has an attachment portion 34a, and the air outlet pipe 34 is connected to the casing cover 20a at this attachment portion.

  The air outlet pipe 34 further has a rising line 36.

  In this case, the ascending pipe 36 is expanded in a conical shape, that is, in the end side region 36a.

  The air outlet pipe 34 further has an oil return guide opening 100 in the region of the attachment portion 34a.

  In this case, the oil return guide opening 100 is formed as a hole.

  The oil return guide opening 100 connects the inside of the air outlet pipe 34 to the oil pan 22a.

  The air outlet pipe 34 as a whole has an oil separating means by the conical expanding portion and the oil return guide opening 100, and the oil separating means allows the air compressed by the screw compressor 10 to be supplied to the oil separating apparatus. Work for initial oil separation before being passed.

  In this case, the oil is separated as follows. That is, based on the conical expansion and the reduction in flow velocity achieved in this region, the oil particles present in the air flow can fall back by gravity and return again, In the interior of 34, it can condense on the wall and then flow back through the oil return guide opening 100 back to the oil pan 22a.

  FIG. 3 shows a perspective sectional view of the air outlet pipe of FIG.

DESCRIPTION OF SYMBOLS 10 Screw compressor 12 Mounting flange 14 Input shaft 16 Screw 18 Screw 20 Casing 20a Casing cover 22a Oil pan 22 Oil 24 Inlet pipe piece 26 Air filter 28 Air inlet 30 Valve insert 32 Air supply passage 34 Air outlet pipe 34a Attachment part 36 Rising pipe Path 36a End side region 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 discharge screw 60 Attached part 60a Outer ring 60b Inner ring 62 Oil filter 64 E Rufiruta inlet passage 66 thermostatic valve 68 return guide pipe 70 bearing 72 nozzle 76 safety valve 78 the bypass conduit 80 the relief valve 82 oil level sensor 100 oil return guide opening

Claims (7)

  A screw compressor (10) for a commercial vehicle having a casing cover (20a) in which the screws (16, 18) of the screw compressor (10) are disposed, and an outlet side of the casing cover (20a) For commercial vehicles, having an air outlet pipe (34) arranged and having an ascending line (36), said air outlet pipe (34) having at least one oil separating means Screw compressor (10).   The screw compressor (10) according to claim 1, wherein the oil separating means has an oil return guide opening (100).   The screw compressor (10) according to claim 2, wherein the oil return guide opening (100) connects the inside of the air outlet pipe (34) to an oil pan (22a).   The air outlet pipe (34) has an attachment part (34a), and the air outlet pipe (34) is connected to the casing cover (20a) by the attachment part, and the oil return guide opening (100 The screw compressor (10) according to claim 2 or 3, which is arranged in the region of the attachment portion (34a) or adjacent to the attachment portion (34a).   The screw compressor (10) according to any one of claims 2 to 4, wherein the oil return guide opening (100) is a hole.   The screw compressor (10) according to any one of the preceding claims, wherein the air outlet pipe (34) is at least partially formed in a conical shape.   The screw compressor (10) according to claim 6, wherein the rising pipe (36) is conically formed on the end side.

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