JPH01135962A - Protective casing for tensile means gearing - Google Patents

Abstract

PURPOSE: To cool a belt, save fuel and reduce harmful materials by forming a transfer inlet for an over-pressuring cooling medium on a wall of a protection casing, and providing a centrifugal compressor for discharging the cooling medium in an over-pressured condition. CONSTITUTION: In a protection casing 1, a transfer inlet 2 is formed on a wall of the protection casing 1 as a transfer inlet for an over-pressuring cooling medium. This transfer inlet 2 is used for introducing air stream into an interior space 4. The air stream is generated from a centrifugal compressor 8. The interior space 4 and a toothed belt transmission 5 contained within the interior space are continuously cooled down. Fuel can be saved and harmful materials discharged together with exhaust fumes can be reduced thereby.

Description

[Detailed Description of the Invention] The present invention provides a tension means transmission device (for example, an automobile engine, an automobile drive device, a chain transmission device of other machines, a belt transmission device, a toothed belt transmission device, etc.). Collection,
A one-piece or multi-piece protective casing for a traction means transmission, which is provided with at least one inlet for the introduction of a gaseous medium into the interior space it contains. be.

A belt transmission is known from DE 11 42 090, which is at least partially surrounded by a protective hood.

Furthermore, from German Patent Publication No. 2051050,
In order to completely encapsulate a traction means transmission, for example a chain or belt transmission, it is known to provide a casing which is assembled from a number of half-shells.

Furthermore, it is known from German Patent No. 1 182 008 to feed the belt pulley of a transmission with cooling air generated by a fan.

German Patent No. 2942712 also discloses that a radial packing ring with an inwardly directed packing lip (the pressing force of which can be controlled by the liquid acting on it) connects the casing and the rotating element. In devices for packing closed casings for power transmission elements of motor vehicles, in particular transmissions,
It is known to selectively couple the interior space of a closed casing for special driven elements, the front wheels and the rear axle, with a source of compressed air or a degassing unit by means of a switch.

With this configuration, the pressing force of the sealing lip is significantly increased by the action of compressed air, so that the sealing can be adapted to the respective operating conditions. In any case, the aim is to prevent dust and water from penetrating into the casing due to the pressing force that increases over time.

Finally, in the case of the transmission housing known from German Patent No. 3,201,217, the housing is constantly supplied with air or evacuated by means of an air supply device and an exhaust device which are connected to the interior space of the housing.

The purpose of installing this casing is to prevent liquids such as jet water from entering from the outside, and to allow as little oil as possible to reach the outside from the casing.

Furthermore, in a toothed belt pulley for an automobile engine, the toothed belt pulley generally includes a toothed belt pulley driven by the crankshaft of the automobile, a tensioning roller coupled to and driven by a camshaft, and a toothed belt pulley driven by the crankshaft of the automobile. and a drive belt formed as a belt. The drive belt is
For example, it is shielded by a protective cover or protective casing which is fixed by the front end face of the engine block.

While driving a toothed belt drive of this type, especially when this toothed belt drive is used in conjunction with a high speed rotating engine, the temperature characteristics
Problems therefore arise, for example, related to the stiffness of belts made of elastomeric composites.

This kind of problem is caused by the following points. If the protective casing is of completely sealed design, i.e. if the housing is completely encapsulated, the belt, especially the toothed belt, can be treated in the inner space of the protective casing by, for example, felting. It is heated strongly, thereby overheating the material of the belt, which has a negative effect on its stiffness, which can quickly deteriorate.

However, in order to eliminate or reduce the above-mentioned thermal problems, the casing must not be completely sealed, i.e. it can be formed as an at least partially open casing, for example due to the suction action of the rotating parts, the toothed belt Protection of the drive is no longer guaranteed, resulting in dust and water jets.

Snow, etc. may enter the internal space of the protective casing.

Even if the toothed belt is not destroyed, it may be damaged.

By the way, a protective casing having the components described in the preamble of claim 1 of the present invention is known from French Patent Publication No. 2,502,720.

1.An object of the present invention is to further improve the protective casing described in French Patent Publication No. 2502720, which not only allows all the components of the traction means transmission to be constantly cooled, but also allows the traction means transmission to be cooled at all times. It is to be able to be protected as much as possible from dust, water jets or other external particles.

In the protective casing described in French Patent Publication No. 2502720, dust is removed from the air inlet due to the suction action of the rotating part and the rotor blades of the fan provided on the rotating part.
Jet water or other external particles can penetrate into the interior space of the protective casing and damage the components of the transmission, in particular the belt.

Structure and Effects In order to achieve the above object, the present invention provides at least one cooling medium source, the inlet of which is formed in the wall of the protective casing as a cooling medium overpressure inlet, and which discharges pre-filtered cooling medium under overpressure. It is characterized by being connected to.

The invention makes it easy to create and maintain an overpressure of a prefiltered cooling medium supplied from a cooling medium source in the interior space of the protective casing housing the traction means transmission. And it becomes possible very effectively. Furthermore, compared to the protective casing described in French Patent Publication No. 2 502 720, it is possible in particular to cool the drive belt of the traction means transmission, for example a toothed belt, more effectively, so that overheating of the traction means transmission, in particular Belt expansion can be completely prevented, so that, for example, even when a car engine is rotating at high speeds, the following additional advantages are obtained: This means that the control times can be made very precise with respect to the intake and exhaust points of the engine valves, and therefore, with a suitable arrangement of the ignition device, it is also possible to precisely control the ignition points.

These advantages also lead to fuel savings and reduce harmful substances emitted with exhaust gas.

This is particularly advantageous in the case of motor vehicle engines.

In the protective casing according to the invention, the constant introduction of a prefiltered overpressurized cooling medium supplied from a cooling medium source prevents any external particles, such as dust, water jets, etc., from being formed by the walls of the protective casing. Intrusion into the internal space is practically completely prevented;
Damage to the components of the traction means transmission is thereby also prevented.

Advantageous embodiments of the invention are defined in claims 2 to 2.
It is described up to Section 4.

Generally speaking, a protective casing constructed in accordance with the invention, formed in one or multiple parts, in particular for a traction means transmission, can be used for power sources rotating at high speeds, such as, for example, motor vehicle engines. can do. Furthermore, it can also be used in areas where components of toothed belt transmissions, for example, must be protected from damage by dust and the like, and where overheating of the belt must be prevented.

Example Next, embodiments of the present invention will be described using the accompanying drawings.

As can be seen from FIG. 1, a toothed belt transmission 5 is covered, for example by a protective casing 1 formed in one piece.
The belt pulley 9 includes a belt pulley 9 connected to a camshaft 13, a belt pulley 10 connected to a crankshaft 14, a toothed belt 12, and a tension roller 11.

In FIG. 1, the protective housing 1 is shown partially in section from the front so that the toothed belt transmission 5 can be seen.

FIG. 2 is a side view of the toothed belt transmission 5. FIG. The protective casing 1 is shown in cross section along line 1--I in FIG. The protective casing 1 is fixed, for example, to the front end face of the schematically illustrated engine block 3 . The front end of the engine block 3 and the wall of the protective casing 1 form an interior space 4 in which a toothed belt transmission 5 is arranged.

A coolant overpressure feed inlet 2 is provided on the front wall of the protective casing 1 on the engine block 3 side. This inlet 2 is used in this embodiment for introducing an air stream into the interior space 4 . This air flow originates from a centrifugal compressor 8, such as a radial blower. The protective casing 1 is provided with an outwardly projecting connection 7 in the area of the inlet 2 . One end of the pipe 6 is connected to the connecting portion 7 .

The other end of the tube 6 leads to a centrifugal compressor 8.

The air flow supplied to the interior space 4 of the protective casing 1 via the tube 6 provides a continuous cooling of the interior space 4 and the toothed belt transmission 5 housed therein, and at the same time cools the interior space 4. There is always overpressure. This overpressure ensures that external particles, dust, water jets, etc. that enter the protective casing 1 through any air gaps are blocked.

As can be seen from FIG. 3, the centrifugal compressor 8 (which can be designed, for example, as an axial, radial or oblique flow blower) or a drive 18 for driving this centrifugal compressor 8, Connected to the regulating circuit. This adjustment circuit makes it possible to maintain the internal space 4 of the protective casing 1 shown in FIG. 2 at a predetermined overpressure at all times. In this regulating circuit, the protective housing 1 is connected via a measuring line 15 to a regulator 16 . The regulator 16 is connected via a conductor 17 to a drive 18 . The pressure in the interior space 4 of the storage housing 1 is constantly measured and the measured value is sent via a measuring line 15 to a regulator 16 .

By comparing the setpoint value and the actual value in the regulator 16, the adjustment variable for acting on the drive 18 via the line 17 is determined. Depending on this adjustment, a drive adjustment is carried out by the drive 18 via the power transmission line 19 leading to the centrifugal compressor 8, so that the pressure of the air flow supplied to the protective housing 1 is adjusted, i.e. Protective casing 1
The pressure in the internal space 4 formed by the engine block 3 and the front surface of the engine block 3 is adjusted.

Instead of generating the air flow with the centrifugal compressor 8, it is also possible to use the air flow generated when the vehicle is running and supply it to the interior space 4 through the pipe 6. In this case, the air flow is captured by a suitable air capture device, for example formed as an aerodynamic inlet, and introduced into the tube 6, thereby allowing the interior space accommodating the toothed belt transmission 5 4 can be maintained at a desired overpressure at all times.

The embodiment of the protective casing 1 shown in FIG. 4 differs from the embodiment of FIG. It is that you are. According to the embodiment of FIG. 4, the tensioning roller 11 of the toothed belt transmission 5 is also constructed as a centrifugal compressor and is arranged in the area of the inlet 2 of the protective casing 1. Therefore, tensioning roller 1
1 comprises a compressor drive part 20, for example a compressor wheel or a fan wheel.

In this case, the protective housing 1 is designed as a compressor housing in a position corresponding to the position of the compressor drive part 20 . As can be seen in FIG. 4, this protective casing 1 as a compressor casing surrounds the compressor drive part 20 of the tensioning roller 11.

Instead of or in addition to the tensioning roller 11, a belt pulley 9 provided on the camshaft 13 or a crankshaft 14 may be used.
The belt pulley 10 provided at the pump can also be designed as a centrifugal compressor or a pump.

In the embodiment shown in FIG.
It has 3. There is an intermediate space 21 between the inner wall 22 and the outer wall 23. The outer wall 23 is.

In order to introduce a gaseous medium, for example air, it has a number of inlets 25, which are designed, for example, in the form of slits. Air passes through the intermediate space 20 and enters the inlet 2 provided in the inner wall 22.
Reach 4. In the area of this inlet 24 and within the protective housing 1, a centrifugal compressor or pump 20 is arranged, similar to the embodiment according to FIG. In this case too, the tensioning roller 11 is at the same time designed as a centrifugal compressor (or pump) and has a compressor drive part 20, as shown in FIG. The compressor drive part 2o connects directly to the inlet 24, and a protective casing is formed as a compressor casing in the one-way wall 22 at a position corresponding to the position of the compressor drive part 20.

In order to ensure a pressure equilibrium of the gaseous medium introduced under overpressure into the interior space 4 of the protective casing 1, as shown in FIGS. One or more outlets 26 are arranged in the opposing wall sections 27 . This wall portion 27 is fixed to, for example, an end surface of the engine block 3.

Incidentally, although not shown in detail in FIGS. 4 and 5, a filter, in particular a dust filter, can be arranged in the area of the respective inlet 2, 24, 25. Instead of these filters, it is also possible, for example, to connect to an air filter of the internal combustion engine.

[Brief explanation of the drawing]

1 is a front view of a toothed belt transmission for a motor vehicle engine, the toothed belt transmission being covered by a protective casing shown in section; FIG. 2 shows the arrangement of FIG. 1; A partial sectional view according to the line 1--I, FIG. 3 showing a regulating circuit for the drive of a centrifugal compressor used in combination with a protective casing according to the invention, FIGS. 4 and 5 showing the protective casing FIG. 2 is a partial cross-sectional view corresponding to FIG. 2 of another embodiment. 1... Protective casing 2; 24; 25... Inlet port 4... Internal space 7... Connection section 8... Centrifugal compressor 9.10... ... Belt wheel 11 ... Tension roller 13 ... Camshaft 14 ... Crankshaft 20 ... Pump 26 ... Discharge port → 1 - 1 F7g, 2 Fig, 3 Fig・4

Claims (1)

Claims: (1) A protective casing for a traction means transmission, which is provided with at least one inlet for introducing a gaseous medium into the interior space accommodating the traction means transmission, characterized in that the inlet (2) is configured as a coolant overpressure inlet in the wall of the protective casing (1) and is connected to at least one coolant source which discharges prefiltered coolant under overpressure. Protective casing. (2) A pipe (6) is provided which is connected to the protective casing (1), one end of which is connected to the inlet (2) of the protective casing (1) and the other end is pre-filtered. 2. Protective casing according to claim 1, characterized in that the protective casing is connected to a cooling medium source which discharges the cooling medium under overpressure. (3) In the area of the inlet (2) there is a connecting part (
7), and one end of the tube (6) is connected to the connecting part (7). (4) The protective casing according to claim 3, characterized in that one end of the pipe (6) is removably connected to the connecting part (7). (5) The other end of the pipe (6) is connected to the cooling medium source which is formed as a centrifugal compressor (8) or a pump. A protective casing as described in any one of the preceding paragraphs. (6) The protective casing according to claim 5, characterized in that the centrifugal compressor (8) is an axial blower. (7) The protective casing according to claim 5, characterized in that the centrifugal compressor (8) is a radial blower. (8) Protective casing according to claim 5, characterized in that the centrifugal compressor (8) is an oblique flow blower. (9) said other end of the tube (6) is connected to at least one coolant source configured as a wind capture device, said coolant source being arranged on an aerodynamically shaped surface of the vehicle; Protective casing according to any one of claims 2 to 4, characterized in that: (10) The protective casing according to claim 9, wherein the wind trapping device is an aerodynamically formed inlet provided on the surface of the vehicle. (11) An auxiliary device such as an engine is provided as a centrifugal compressor (8), the drive for the centrifugal compressor (8) being formed by the protective casing (1) and accommodating the traction means transmission (5). Claims 5 to 8, characterized in that the pressure in the internal space (4) is connected to a regulating circuit for always maintaining the pressure in the internal space (4) at a predetermined overpressure. Protective casing as described in one. (12) In the internal space (4) of the protective casing (1),
12. Protective casing according to claim 1, characterized in that at least one centrifugal compressor or pump (20) is additionally arranged. (13) Claims characterized in that a centrifugal compressor or pump (20) is arranged in one or several of the inlets (2; 24: 25) of the protective casing (1) Protective casing according to paragraph 12. (14) Protection according to claim 12 or 13, characterized in that the centrifugal compressor or pump (20) is in driving connection with a tensioning roller (11) driven by a tensioning means. casing. (15) Protective casing according to claim 12 or 13, characterized in that the centrifugal compressor or pump (20) is drivingly connected to the camshaft (13) of the engine. (16) Protective casing according to claim 12 or 13, characterized in that the centrifugal compressor or pump (20) is drivingly connected to the crankshaft (14) of the engine. (17) Tensioning roller (11) and/or camshaft (13)
) and/or a camshaft (1
4), characterized in that the belt pulley (10) provided in 4) is at the same time designed as a centrifugal compressor or pump,
A protective casing according to claim 12 or 13. (18) Tensioning roller (11) and/or belt wheel (9)
) and/or the belt pulley (10) has a compressor drive part, in particular a compressor wheel or a fan wheel, and the protective casing (1) is formed as a compressor casing in a position corresponding to the position of the compressor wheel. 18. A protective casing according to claim 17, characterized in that: (19) The protective casing (1) is formed double-walled, the outer first wall (23) having at least one inlet (25) for introducing a gaseous medium, while the centrifugal compressor or pump (20)
is arranged in the region of the other inlet (24) of the second wall (22) inside the protective casing (1). A protective casing according to any one of the above. (20) The protective casing according to claim 19, wherein the inlet (25) provided in the outer wall (23) of the protective casing (1) is formed in the shape of a slit. (21) In accordance with one or more of claims 1 to 20, characterized in that in the area of the inlets (2; 24; 25) a filter, in particular a dust filter, is provided in each case. Protective casing as described. (22) Protective casing according to claim 21, characterized in that the inlet (2; 24:25) is connected to an air filter of the internal combustion engine. (23) at least one outlet (26) is provided in the protective casing (1) for pressure equalization of the gaseous medium introduced into the interior space (4) of the protective casing (1); Protective casing according to any one of claims 1 to 22, characterized in that: (24) Protective casing according to claim 23, characterized in that the outlet (26) is arranged in a wall part (27) facing the front side of the protective casing (1).