WO2015149773A1

WO2015149773A1 - Protective device for a torque limiter of a hydraulic or pneumatic actuating system

Info

Publication number: WO2015149773A1
Application number: PCT/DE2015/200151
Authority: WO
Inventors: Julien DURR
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2014-03-31
Filing date: 2015-03-12
Publication date: 2015-10-08
Also published as: DE112015001556A5

Abstract

The invention relates to a protective device for a torque limiter of a hydraulic or pneumatic actuating system, wherein the protective device has a hollow protective body having an outer surface, having a first opening and having a second opening, the openings being arranged to make sealing contact with a first seal seat or with a second seal seat of a feedthrough element to be protected. The outer surface of the protective body has at least one of the following properties: chemical resistance to salts; chemical resistance to salt solutions; chemical resistance to acids; and chemical resistance to corrosion-promoting fluids. With the protective device according to the invention, a known torque limiter or a known housing of a torque limiter can be used and no individual solution needs to be found for individual countries.

Description

Protective device for a torque limiter of a hydraulic or pneumatic actuation system

The invention relates to a protective device for a torque limiter of

hydraulic or pneumatic actuation system and a torque limiter and a hydraulic or pneumatic actuation system, in particular for a motor vehicle.

In the prior art torque limiters are known, which have a housing which is formed from a glass fiber reinforced plastic, usually an epoxy resin. Such plastics are very susceptible to chemical degradation by environmental influences, especially for calcium chloride (CaCl ₂ ), which is used in some countries for frost protection with a high proportion of road salt in road salt. In most countries, however, is 98% strength sodium chloride (NaCl) or potassium chloride and (KCl) or magnesium chloride (MgCl _2), which attack the epoxy resin not (excessively). In the automotive industry, however, it is desirable not to use different components in one and the same vehicle series for individual countries.

On this basis, the present invention has the object, at least partially overcome the known from the prior art disadvantages. The object is solved by the features of the independent claims. Advantageous developments are the subject of the dependent claims.

The invention relates to a protective device for a torque limiter of

hydraulic or pneumatic actuation system, wherein the protective device comprises a hollow protective body having an outer surface, with a first opening and with a second opening, wherein the openings are adapted to form a sealing contact with a first sealing seat or with a second sealing seat of a through-element to be protected in which the outer surface of the protective body has at least one of the following properties:

- chemical resistance to salts;

- chemical resistance to saline solutions;

- chemical resistance to acids; and

- Chemical resistance to corrosive fluids. The protective device is intended to protect the torque limiter against environmental influences that can damage the torque limiter, in particular against corrosion-promoting fluids. The feed-through element preferably designates a device which comprises a torque limiter, wherein the protective device is also suitable for other elements which have to be protected from environmental influences. The lead-through element is particularly susceptible to salts, salt solutions or acids. The protective device is hollow, so that a lead-through element can be arranged in the interior of the protective body.

The protective body has an outer surface which has the necessary properties in order to protect the lead-through element from harmful fluid-based environmental influences, in particular from salty, acidic and / or corrosion-promoting sprayed water. By means of the first opening and the second opening, the lead-through element can be inserted into the protective device and the openings form a sealing contact with a first sealing seat and a second sealing seat, so that the lead-through element is shielded from fluid-based environmental influences. The protective device is designed in such a way that the outer surface is chemically inert or at least sufficiently resistant over a desired service life of the leadthrough element. The outer surface is particularly resistant to salts, such as calcium chloride and their solutions, especially water solutions resistant. Most preferably, the outer surface is resistant to acids with a pH below 7, in particular between 4 and 6. In another embodiment, the outer surface is resistant to bases with a pH above 7, in particular between 8 and 10. In In a further advantageous embodiment, the outer surface is resistant to acids and bases in the range indicated above.

The protective device proposed here has the advantage that, for example, a

Torque limiter can be used with a housing of the prior art and no country-specific custom solution must be provided. Particularly advantageously, the protective device can be combined so easily with the torque limiter that the protective device can be used in such a cost-effective manner that it can be used independently of the intended countries or locations, for example of the motor vehicle.

According to a further advantageous embodiment of the protective device, at least the outer surface of the protective body is formed of an elastomer, preferably of a rubber. In this advantageous embodiment, a low-cost material, namely an elastomer is used, preferably a (synthetic) rubber. An elastomer has the advantage over at least one epoxy resin that it is (chemically) resistant to many (fluid-based) environmental influences. Most preferably, the entire protective body is formed from an elastomer. Most preferably, the protective body forms a type of hose, which can be mounted around the feedthrough element by the protective body is pushed over the feedthrough element.

According to a further advantageous embodiment of the protective device, the first opening and / or the second opening is formed in the contact region for a respective corresponding sealing seat made of an elastomer, so that the opening can be guided elastically via a sealing seat and sealingly locked under tension with the corresponding sealing seat, so the protection device is fixed.

In this advantageous embodiment of the protective device, the first opening or the second opening made of an elastomer are formed where they form a contact region to the corresponding sealing seat. In this case, the respective opening should be designed to be elastic so that it can be guided over the sealing seat and is sealingly locked under tension. As a result, the protective device is fixed overall with the lead-through element, so that the lead-through element is protected against environmental influences. Particularly advantageously, the respective opening is provided with a diameter which is smaller at least in a front region than the diameter of the sealing seat, so that here a

Widening of the opening takes place. It should be noted that the term diameter refers not only to a circular cross-section, but includes any cross-section, for example, a rectangular cross-section.

According to another aspect of the invention is a torque limiter for a

proposed hydraulic or pneumatic actuating system having a housing to be protected with a first end and a second end and a protective device as described above, wherein the housing at the first end with a first connector with a first sealing seat and at the second end with a second connector with a second sealing seat is sealingly connectable, and wherein the protective device in assembly surrounds the housing to be protected sealingly up to the sealing seats.

The torque limiter is a component for a hydraulic or pneumatic

Actuation system, in which the speed of the switching fluid or the Switching gas is throttled. By throttling an excessive engagement speed or disengagement speed is prevented in a hydraulic or pneumatic actuation system, which could result in a (short-term) excessive torque with insufficient contact force or frictional force and the at least one friction lining could be damaged. Usually, the torque limiter is equipped with a housing which must be protected from environmental influences, for example as described above from a glass fiber reinforced plastic, in particular based on an epoxy resin. The housing has a first end and a second end connected to a first connector and to a second connector which form part of a hydraulic or pneumatic actuation system. The connectors have a first sealing seat or a second sealing seat, which are set up in such a way that they can be connected to the first opening or the second opening of the protective device in such a way that, in particular, no liquid or only little to no gas can pass through and thus the Housing is protected from fluid-based environmental influences. The connectors are connected to the housing to be protected in such a way that the actuating fluid can be guided through the housing but no influences are exerted on the housing from the outside when the protective device is mounted.

According to a further advantageous embodiment of the torque limiter, the openings of the protective device have a smaller inner diameter than a maximum outer diameter of the housing to be protected, wherein the protective device is elastically formed such that at least one opening of the protective device can be guided elastically over the maximum outer diameter.

The components of the torque limiter used should have the smallest possible spatial extent, in particular radial extent, especially for use in a motor vehicle, so that it is desirable not to form any additional radially outwardly directed shoulder for the protective device. In addition, it is particularly advantageous if the protective device form radially inwardly extending flanges at the openings, so that the rigidity of the protective body is increased in this area and a particularly good sealing effect can be achieved by the thus relatively high voltages. In this particularly advantageous embodiment, at least one of the openings is formed so elastically that it can be guided over a larger maximum outer diameter of the housing of the torque limiter, without the opening is damaged and returned to its original shape, at least insofar as a reliable sealing Effect is ensured with the corresponding sealing seat. Thus, the Protective device can be combined with a housing, as it is already known in the art and can be easily mounted, at the same time a reliable seal for the fitter is easily controlled. It should be noted that the sealing contact is particularly preferably formed purely static sealing, which is sufficient for most applications of the protection device.

According to a further advantageous embodiment of the torque limiter, the first connector and / or the second connector is formed at least outward from a metal.

The formation of the at least one connector made of metal at least on the outside allows a good resistance to environmental influences. Thus, the housing of the torque limiter is completely protected against fluid-based environmental influences. Very particularly preferably connectors can be used which are standardized elements for a hydraulic line or a pneumatic line, so that the manufacturing costs for the connectors are particularly low. In addition, an outer surface of the metal connectors forms a particularly good seal combination with an elastomer by a large resistance can be exerted by the rigid metallic surface, so that a large voltage for a good sealing effect of the protective device in the contact region of the opening relative to the connector can be generated.

According to a further aspect of the invention, a hydraulic or pneumatic actuation system for a friction clutch is proposed which comprises a transmitter unit and a receiver unit, wherein between the transmitter unit and the receiver unit

Momentenbegrenzer is provided according to the above description, wherein at least the torque limiter is accessible for splashing water can be arranged.

The hydraulic or pneumatic actuation system is intended to provide a

To actuate friction clutch, that is to produce a contact force or counteract a contact force to allow a frictional transmission of a torque in the friction clutch or to solve. Hydraulic or pneumatic actuation systems are increasingly used in the field of motor vehicles, because thus high contact pressures can be generated without the clutch forces are particularly high for the driver. Thus, at low radial extensions of the friction surfaces of the friction clutch or at a total low friction surface nevertheless a high torque can be transmitted. The hydraulic or pneumatic actuation system comprises a transmitter unit comprising at least one master cylinder with a master piston, in which a fluid is compressed, so that via a hydraulic or pneumatic connection tion to the receiving unit, which in turn is composed of at least one slave cylinder with a slave piston, penetrates into the slave cylinder and the slave piston, for example, pressed against a plate spring of a friction clutch. In order to limit an excessive speed of transmission, a torque limiter is provided between the transmitter unit and the receiver unit, so that the speed of transmission is throttled. In this case, the torque limiter is arranged in many configurations in such a way that it can be sprayed, which can be interspersed with aggressive components which attack the torque limiter, in particular a torque limiter with a housing made of a glass fiber reinforced plastic, for example an epoxy resin. By the protective device described above, such a torque limiter, and in particular the sensitive housing, sufficiently protected against water spray, so that the life of the torque limiter is not affected by the aggressive spray water.

According to a further aspect of the invention, a motor vehicle is proposed, comprising a drive unit with an output shaft, a drive train and a hydraulic or pneumatic actuation system according to the above description, wherein the hydraulic or pneumatic actuation system is at least partially accessible for squirting rainwater.

Most motor vehicles today have a front-wheel drive and therefore preferably arrange the drive unit, for example an internal combustion engine or an electric motor, in front of the driver's cab and transversely to the main drive direction. The space is particularly small in such an arrangement and it is therefore particularly advantageous to use a friction clutch small size.

The installation space situation for passenger cars of the small car class according to European classification is exacerbated. The units used in a passenger car of the small car class are not significantly reduced compared to passenger cars larger car classes. Nevertheless, the available space for small cars is much smaller. The above-described hydraulic or pneumatic actuation system is particularly suitable for small vehicles, because a high torque in a small space can be transferred by the high compressive forces generated. At the same time, due to the protective device, the components can be arranged independently of accessibility for, for example, corrosion-promoting spray water. Passenger cars are classified according to vehicle class according to, for example, size, price, weight, power, but this definition is subject to constant change according to the needs of the market. In the US market, vehicles of the class small cars and microcars are classified according to European classification of the class of subcompact car and in the British market they correspond to the class Supermini, for example, the class City Car. Examples of the micro car class are a Volkswagen Fox or a Renault Twingo. Examples of the small car class are an Alfa Romeo Mito, Volkswagen Polo, Ford Fiesta or Renault Clio.

The features listed individually in the claims can be combined with one another in any technologically meaningful manner and can be supplemented by explanatory facts from the description and details from the figures, wherein further embodiments of the invention are shown.

The invention and the technical environment will be explained in more detail with reference to FIGS. The figures show particularly preferred embodiments, to which the invention is not limited. In particular, it should be noted that the figures and in particular the illustrated proportions are only schematic. Show it:

1: a torque limiter with protection device,

2: a torque limiter with protective device in section,

3: a hydraulic or pneumatic actuation system,

Fig. 4: a motor vehicle with hydraulic or pneumatic actuation system.

1, a torque limiter 2 is shown, in which the first connector 14 and the second connector 15 protrude from the protective body 4, namely at the first opening 6 and the second opening 7, respectively. The outer surface 5 extends over the entire visible protective body 4 to the openings 6 and 7, so that the torque limiter 2, in particular the housing 1 1 (see FIG. 2) is protected from fluid-based environmental influences.

2, the torque limiter 2 as shown in Fig. 1 in section, in which case the housing to be protected 1 1 inside the protective body 4 can be seen. The housing 1 1 has a first end 12, which is sealingly connected to the first connector 14, so that a switching fluid from the first connector to flow into the housing or can flow out of it and the housing 1 1 comprising before fluid-based environmental influences is protected. Likewise, at the second end 13 of the housing 1 1, a second connector 15 is introduced in the same way, so that the housing can also be flowed through from this side and is protected from fluid-based environmental influences. Particularly preferred here are the first connector 14 and the second connector 15 formed entirely of metal. The protective body 4 is in this case made entirely of an elastomer, preferably of a synthetic rubber, so that the first opening 6 is sealingly applied to the first sealing seat 8 under tension and is also applied to the second opening 7 on the second sealing seat 10. The inner diameter 16 of the second opening 10 is significantly smaller than the maximum outer diameter 17 of the housing 1 1. Due to the elastic design of the protective body 4, the second opening 7 undamaged on the housing 1 1 can be guided or pushed and the second sealing seat 9 a good Exercise sealing and fixation of the protection device 1.

In Fig. 3, a hydraulic or pneumatic actuating system 3 is shown, in which a transmitter unit 19 consisting of a master cylinder and a master piston and a slave unit consisting of a slave cylinder and a slave piston via a hydraulic line 28 are connected, with a torque limiter 2, as he For example, in Fig. 2 is shown is introduced. A switching signal, which is applied by a clutch pedal 33 to the encoder unit 19 is limited in its action or speed by the torque limiter 2 transmitted by the hydraulic line 28 to the slave unit 20, so that the slave unit 20 acts on the plate spring 29, so in this case the friction package is released and a torque of the

Output shaft 23 about the rotation axis 31 is no longer transferable to the transmission shaft 32 by means of the friction clutch 18.

4, a motor vehicle 21 is shown with a drive unit 22, which is arranged with its motor axis 27 transversely to the longitudinal axis 26 in front of the driver's cab 25. The drive unit 22 is shown here as an internal combustion engine, which has an output shaft

23 by means of a friction clutch 18 with a drive train shown here purely schematically

24 is connected. The friction clutch 18 is actuated here by means of the hydraulic or pneumatic actuation system 3.

With the protective device proposed here, a known torque limiter or a known housing of a torque limiter can be used and no individual solution for individual countries has to be found. Protective device

torque limiter

hydraulic actuation system

protective body

outer surface

first opening

second opening

first sealing seat

second sealing seat

contact area

casing

first end

second end

first connector

second connector

Inner diameter

maximum outside diameter

friction clutch

transmitter unit

receiver unit

motor vehicle

drive unit

output shaft

powertrain

cab

longitudinal axis

motor axis

hydraulic line

Belleville spring

Reibpaket

axis of rotation

gear shaft

clutch pedal

Claims

claims

1 . Protective device (1) for a torque limiter (2) of a hydraulic actuating system (3), the protective device having a hollow protective body (4) with an outer surface (5), with a first opening (6) and with a second opening (7), wherein the openings (6, 7) are arranged to form a sealing contact with a first sealing seat (8) or a second sealing seat (9) of a lead-through element to be protected, the outer surface (5) of the protective body (4) forming at least one of has the following properties:

chemical resistance to salts;

chemical resistance to saline solutions;

chemical resistance to acids; and

chemical resistance to corrosive fluids.

2. Protection device (1) according to claim 1, wherein at least the outer surface (5) of the protective body (4) is formed of an elastomer, preferably of a rubber.

3. Protection device (1) according to claim 1 or 2, wherein the first opening (6) and / or the second opening (7) in the contact region (10) for a respective corresponding sealing seat (8,9) is formed from an elastomer, so the opening (6, 7) can be guided elastically via a sealing seat (8, 9) and can be sealingly locked under tension with the corresponding sealing seat (8, 9), so that the protective device (1) is fixed.

4. torque limiter (2) for a hydraulic actuation system (3), comprising a housing to be protected (1 1) having a first end (12) and a second end (13) and a protective device (1) according to one of the preceding claims, wherein the housing (1 1) at the first end (12) with a first connector (14) with a first sealing seat (8) and at the second end (13) with a second

Connector (15) with a second sealing seat (9) is sealingly connectable, and wherein the protective device (1) in the assembly surrounds the housing to be protected (1 1) sealingly to the sealing seats (8,9).

5. torque limiter (2) according to claim 4, wherein the openings (6,7) of the protective device (1) have a smaller inner diameter (16) than a maximum outer diameter (17) of the housing to be protected (1 1), wherein the Schutzvorrich- Device (1) is elastically formed such that at least one opening (6,7) of the protective device (1) is elastically over the maximum outer diameter (17) feasible.

6. torque limiter (2) according to claim 4 or 5, wherein the first connector (14) and / or the second connector (15) is formed at least outwardly from a metal.

7. Hydraulic actuation system (3) for a friction clutch (18), comprising a transmitter unit (19) and a slave unit (20), wherein between the transmitter unit (19) and the slave unit (20) a torque limiter (2) is provided according to claim 6 , wherein at least the torque limiter (2) can be arranged accessible for spray water.

8. Motor vehicle (21) comprising a drive unit (22) having an output shaft (23), a drive train (24) and a hydraulic actuating system (3) according to claim 7, wherein the hydraulic actuating system (3) is at least partially accessible for aufspritzendes rainwater.