Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
  • F01C20/00—Control of, monitoring of, or safety arrangements for, machines or engines
  • F01C20/28—Safety arrangements; Monitoring

Definitions

• the invention relates to a rotary piston air motor with a rotor arranged in the interior of a housing, which is connected to a drive shaft led out of the housing and with one. Compressed air supply line connected to the housing and an exhaust air line connected to the housing.
• Rotary piston air motors are used for a wide variety of drive purposes, for example for driving drills, agitators and pumps.
• agitators or pumps they were often used in an environment that is particularly at risk of explosion, since the use of explosion-proof electric motors is more expensive.
• the object of the invention is to design a Rotationskol ben compressed air motor so that it can pose no hazard when used in an explosive environment.
• This object is achieved on the basis of a rotary piston air motor according to the invention in that the housing is pressure-tightly encapsulated and explosion-proof hermetically sealed and that both in the compressed air supply line and in an ignition arrestor is inserted in the exhaust air line.
• the invention consists of two basic measures.
• One measure is that the housing is flameproof and housing connections such. B. for the connecting lines and all bushings are designed so that the interior of the rotary piston air motor is hermetically sealed, the housing connections and housing bushings are designed so that an ignition breakdown can not occur.
• the flameproof encapsulation of the housing and the execution of spark-resistant gaps are carried out in accordance with the DE standard DIN VDE 0170/0171 part 5.
• the second basic measure consists in the fact that in the compressed air supply line and in the exhaust air line an ignition lockout is used .
• a rotary piston compressed air motor has been created which can be used in a potentially explosive environment and thereby provides a level of safety which can be expected in a similar manner in explosion-proof, explosion-proof electrical machines.
• the ignition locks are preferably made of sintered metal, in particular stainless steel, and are made of metal powders or metal granules and metal fibers. These ignition breakdown barriers can also consist of oxide ceramic in an equally advantageous manner.
• ignition breakdown barriers have to meet various requirements. On the one hand, they must be porous enough to supply the compressed air necessary for the operation of the rotary piston air motor and to be able to discharge the exhaust air in such a way that no pressure build-up occurs. Furthermore, the pores have to be so narrow that a spark that is created suffocates in the porous wall of the ignition breakdown barrier so that it cannot penetrate outwards. Furthermore, these ignition breakdown barriers must have such a high intrinsic stability that they, like the flameproof housing, can withstand any explosions occurring in the interior of the housing and the pressure surges that occur. Due to these properties, the ignition breakdown barriers are able not to disrupt the proper operation of the rotary piston air motor. In addition, these detonation barriers also act as silencers, which means that the compressed air motor is not only explosion-proof but also has a very low noise level.
• each ignition breakdown barrier can be designed as a hollow cylinder with a bottom and an open end. It is particularly advantageous if the bottom of the ignition lockout is inserted into the compressed air supply line or the exhaust air line with an all-round gap to the wall receiving it, and that the ignition lockout at its open end on the inside into the compressed air supply line or the exhaust pipe projecting inner flange is attached.
• the space inside the rotary piston air motor, in which there is an explosive ges mixture can accumulate, kept particularly small, which in the event of an explosion inside the rotary piston air motor leads to low forces that can be absorbed by the housing and the ignition breakdown.
• the ignition breakdown barrier can be screwed to the inner flange.
• all housing connections and housing bushings can be designed with a threaded connection or a narrow gap.
• all the housing connections and housing bushings which can be connected in some way to the interior of the rotary piston compressed air motor, are designed in such a way that an ignition breakdown is avoided.
• the explosion-proof hermetic seal is also guaranteed at the connection points of the housing in which no ignition breakdown barrier is used.
• a particularly advantageous development of the invention is characterized in that a safety valve is arranged in the exhaust air line and / or in the compressed air supply line, which is held in the open position by the built-in ignition breakdown barrier or an intermediate member supported by it. This measure ensures that the safety valve closes in the absence of the ignition breakdown lock, as a result of which the compressed air necessary for the operation of the rotary piston compressed air motor is prevented from flowing through.
• a particularly simple embodiment results from the fact that the safety valve can be pressed in the direction of flow of the compressed air through this into the firing position, because this means additional means such.
• the safety valve be designed as a spring-loaded valve in which the spring presses a closing body against the valve seat.
• FIG. 1 shows a longitudinal section through a rotary piston air motor according to a first embodiment.
• Fig. 2 shows a longitudinal section through a rotary piston air motor according to a second embodiment with an arrangement of a safety valve in the
• Exhaust duct shows a longitudinal section through a rotary piston compressed air motor according to a third embodiment with an arrangement of a safety valve in the compressed air supply line;
• Fig. 4 shows a longitudinal section through a rotary piston air motor according to a fourth embodiment, each with a safety valve in the compressed air supply line and the exhaust air line.
• a rotor 3 is rotatably mounted in the one tubular part 2 by means of bearings 4 and 5 and is provided in the usual way with radially movable fins 6, which alternately radially after the supply of compressed air are pressed outside to seal the space between the rotor 3 and the inner wall of the housing section 2 and thus to divide this interior space into two spaces, one of which is connected to a compressed air supply line and the other to an exhaust air line. Due to the pressure difference between the compressed air supply and exhaust air line, the rotor 3 rotates.
• the second part of the tubular housing 1 forms one
• Compressed air supply line 7 and is provided with a valve 8 which has an external thread and is screwed into a bore 9 with an internal thread which is formed transversely to the tube axis of the compressed air supply line 7.
• This threaded connection is designated by 10 in total.
• the valve 8 has a closing body 13 which can be pressed against a seat 12 by means of a spring 11 and is designed as a ball and which can be displaced against the action of the spring 11 by means of a plunger 14 which has a push button 15 on the outside, as a result of which the flow to the engine interior 16 of the rotary piston air motor is released.
• the plunger 14 is guided in a housing bushing 17 of the valve 8, the gap 18 between the plunger 14 and the housing bushing tion 17 is so long and narrow that no ignition breakdown can occur.
• the valve 8 is arranged relatively close to the housing part 2 in which the rotor 3 is mounted.
• the engine interior 16 is connected via a bore 19 to a bore 20 of the valve 8, which leads to the valve seat 12.
• a bore 21 is provided in the valve 8, which is connected to a cylindrical cavity 22 in the compressed air supply line 7.
• a threaded plug 24 is screwed in by means of a threaded connection 23 and has a stepped inner bore.
• the outer, narrower inner bore 25 serves to connect a compressed air line (not shown), while the further inner bore 26 has an internal thread with which an external thread of an ignition breakdown barrier 28 interacts.
• This threaded connection is designated 27.
• the part of the threaded plug 24 which has the inner bore 26 forms a kind of inwardly projecting inner flange 29, which carries the ignition breakdown barrier 28, with respect to the hollow cylindrical space 22 of the compressed air supply line 7.
• This has an outer diameter which is smaller than the inner diameter of the hollow cylindrical space 22, so that through this gap 30 there remains sufficient flow cross section for the air flowing through the ignition breakdown barrier 28, which reaches the bore 21 of the valve 8 via short bores 31.
• the ignition breakdown barrier 28 is designed as a hollow cylinder and has a bottom 32 which is adjacent to the valve 8 and thus to the engine interior 16.
• the bottom 32 of the ignition breakdown barrier 28 to the bottom 33 of the cylindrical cavity 22 has a gap 34 which is sufficiently large for the flow of air.
• the opposite open end 35 of the ignition breakdown lock 28 is assigned to the threaded plug 24, which serves as a connection for the compressed air line, not shown, through which the rotary piston compressed air motor can be connected to a compressed air source.
• an ignition breakdown block 28 is inserted, which is adjacent to the engine interior 16 with its bottom 32 and with its free open end 35 in the threaded plug 24 on its in the hollow cylindrical space 40 of the exhaust air line 37 as Inner flange 29 projecting part of the threaded plug 24 is screwed.
• the external thread of the ignition breakdown block 28 engages in the internal thread of the threaded plug 24 and thus forms the threaded connection 27 as in the case of the arrangement of the ignition breakdown block 28 in the compressed air supply line 7.
• a sufficiently large gap 41 is present between the ignition breakdown block 28 and the inner wall of the exhaust air line 37 , so that the exhaust air coming from the bore 36 can flow both through the base 32 and through the cylindrical wall of the ignition breakdown barrier 28 and into a line which can be screwed into the internal thread 25 of the threaded plug, but which is not shown in the drawing.
• a sufficiently large gap 43 is left between the bottom 32 of the ignition breakdown barrier 28 and the bottom 42 of the hollow cylindrical space 40 for the air flow.
• the rotor 3 is provided with a drive shaft which consists of two parts 44 and 45.
• the part 44 is connected directly to the rotor 3 and screwed into a blind hole in the part 45, which serves on the one hand as a stop for the bearing 4 and on the opposite end has a coupling 46 for driving a mixing device or a pump.
• the part 44 of the drive shaft 44, 45 is passed through a bore 47 in a housing bushing 48 designed as a threaded plug.
• This housing bushing 48 is in the housing part by means of a threaded connection 49 2 screwed in.
• the gap remaining between the shaft part 45 and the bore 47 of the housing bushing 48 is denoted by 50.
• the housing part 2 With its free end, the housing part 2 extends beyond the coupling 46 and carries at its free open end an external thread 51 which serves to receive a union nut with which a device to be driven can be connected to this rotary piston compressed air motor.
• - With 52 is an earthing screw designated, which serves for the discharge of static electricity.
• the gap 18 between the plunger 14 and the housing bushing 17 and the gap 50 between the part 45 of the drive shaft 44, 45 and the housing bushing 48 are dimensioned so narrow and so long that a sparking through is prevented here as well.
• FIGS. 2, 3 and 4 correspond to the embodiment according to FIG. 1 except for the following differences:
• a safety valve, generally designated 53, is provided within the exhaust air line 37 between the ignition breakdown barrier 28 and the bore 36 and comprises a ball 54, a valve seat 55 formed in the exhaust air line 37 and a spring 56 loading the ball 54.
• This configuration and arrangement is provided both in the embodiment according to FIG. 2 and in the embodiment according to FIG. 4.
• the ball 54 serving as a valve body projects into the hollow cylindrical space 40 receiving the ignition breakdown lock 28 and is lifted so far from its seat 55 when the ignition breakdown lock 28 is inserted that the air flowing through the rotary piston compressed air motor can escape. If the ignition breakdown barrier 28 in the exhaust air line is removed, the spring 56 presses the ball 54 against its seat 55, as a result of which the flow of air and thus the operation of the rotary piston compressed air motor is prevented.
• a safety valve is installed in the compressed air supply line 7 between the ignition breakdown block 28 and the valve 8, which comprises a valve plate 58, a valve tappet 59, a valve body 60 and a compression spring 61.
• the valve plate 58 is held in the compressed air supply line 7 by means of a locking ring 62 and is supported on a shoulder 63.
• the valve plate 58 is additionally sealed with a rubber seal 64 with respect to the compressed air supply line 7.
• the valve plate 58 is provided with a plurality of through bores 65 for the passage of the compressed air. In the center of the valve plate 58 is the valve lifter!
• the firing arrestor 28 presses the valve body 60 against the action of the spring 61 away from the valve plate 58 via the valve tappet 59, so that the compressed air supplied can flow through the bores 65 to the valve 8.
• the spring 61 presses the valve body 60 against the valve plate 58, whereby the bores 65 are covered. As a result, the compressed air supply is prevented.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Exhaust Gas After Treatment (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Compressor (AREA)

Priority Applications (2)

Applications Claiming Priority (4)

Publications (1)

Family

ID=25862160

Family Applications (1)

Country Status (4)

Citations (6)

• 1988
  • 1988-08-25 DE DE3828897A patent/DE3828897C1/de not_active Expired
  • 1988-11-19 DE DE8888909729T patent/DE3868281D1/de not_active Expired - Lifetime
  • 1988-11-19 EP EP88909729A patent/EP0401220B1/de not_active Expired - Lifetime
  • 1988-11-19 WO PCT/DE1988/000725 patent/WO1989004912A1/de not_active Ceased
  • 1988-11-19 AT AT88909729T patent/ATE72296T1/de not_active IP Right Cessation

Patent Citations (6)

Also Published As

Similar Documents

Legal Events