WO2014170113A1

WO2014170113A1 - Retarder with idling pump

Info

Publication number: WO2014170113A1
Application number: PCT/EP2014/056242
Authority: WO
Inventors: Alexander Martin; Jürgen KIBLER; Dieter Laukemann
Original assignee: Voith Patent Gmbh
Priority date: 2013-04-18
Filing date: 2014-03-28
Publication date: 2014-10-23
Also published as: CN105189225A; DE102013207001A1; CN105189225B

Abstract

The invention relates to a hydrodynamic machine, particularly a hydrodynamic retarder (1), comprising a retarder housing (2), a rotor (16) and a stator (17), wherein rotor (16) and stator (17) together form a working chamber (24), which can be filled with a working medium (15) according to the operational state of the machine, wherein the rotor (16) is arranged on a rotatably mounted shaft (3) mounted at least at one end on a bearing (18) inside the retarder housing (2), further comprising an idling pump (25), by means of which the working medium (15) can be pumped through a connecting duct (19) from a working medium reservoir (23) into the working chamber (24). To improve operating reliability in non-braking operation, it is proposed that the connecting duct is formed at least in part by the bearing (18), so that the bearing (18) is at least partially cooled and/or lubricated by the working medium (15) delivered by the idling pump (25).

Description

Retarder with idling pump

The invention relates to a hydrodynamic machine, in particular a hydrodynamic retarder. In essence, a retarder comprises a retarder housing, a bladed rotor and a bladed stator, wherein rotor and stator together form a toroidal working space, which can be filled according to the operating state of the machine with a working medium.

The rotor is arranged on a rotatably mounted shaft, which is mounted at least on one side within the retarder housing, by means of a bearing. Furthermore, an idling pump can be provided, by means of which the working medium can be pumped through a connecting channel of a working fluid storage in the working space.

Hydrodynamic retarders are constructed such that when these are filled with a working medium, they can transmit torque from a driven primary paddle wheel, rotor, to a stationary secondary paddle wheel, also called a stator, hydrodynamically.

Rotor and stator thereby form a functional unit, which have a common working space which can be filled with a working medium. By driving the rotor, which is arranged on a shaft to be braked, for example, a transmission output shaft or indirectly rotatably connected to the drive wheels of the motor vehicle shaft (PTO shaft), the working fluid is accelerated in the rotor to the outside and enters the stator, in which it is delayed radially inward flowing. The working medium is thus displaced by the formation of the common working space in a circulation flow. Due to the circulation flow thus formed, a torque - referred to here as the braking torque of the retarder - is transmitted from the rotor to the stator. It is the Rotor and in particular the rotatably connected to the rotor shaft, delayed.

The size of the transmittable braking torque depends on the so-called degree of filling of the hydrodynamic retarder. If no braking torque is required, the retarder is emptied, so that the internal resistance of the retarder and thus the power loss is minimized. The emptying and the filling of the retarder can be done for example by means of a pressure control or a pump. The working medium is pumped from a storage container into the working space or from this back into the storage container.

To reduce the internal resistance in the non-braking operation of the retarder, the rotor can be moved on the shaft, so that the interaction between the rotor and stator is minimized. However, since the remaining air in the working space causes a braking effect and thus generates heat, it is necessary in non-braking operation, working medium, water or oil to promote the work space. Furthermore, the lubrication and cooling of the retarder rotor shaft bearing must be guaranteed, which rotates constantly in non-braking operation with the transmission speed.

In DE 10 2008 049 283, for example, it is proposed to provide a lubricating channel between the pressure side of the suction pump and the bearing. At the same time it is proposed to activate the suction pump only temporarily, in order to minimize the power loss. The disadvantage of this is that no uniform lubrication and cooling of the bearing takes place.

The present invention has for its object to provide a cost-effective solution to reliably supply the retarder idle with working fluid.

A hydrodynamic machine according to the invention, in particular hydrodynamic retarder, according to the initially mentioned type or claim 1, is characterized in that the bearing has at least one Part of the connecting channel forms, so that the bearing is at least partially cooled and / or lubricated by the funded by the idle pump working fluid.

According to the advantageous embodiment it is ensured that the working space, which is formed by the rotor and the stator, in non-braking operation sufficiently with working medium, eg. As oil or water, is filled, so that the internal resistance of the retarder minimized and sufficient cooling is achieved.

Furthermore, it is ensured that the bearing of the rotor shaft, which is mounted at least on one side by means of a bearing within the retarder, is sufficiently lubricated and / or cooled even in non-braking operation.

Preferably, the working fluid is pumped by means of an idle pump through a connecting channel of a working fluid storage in the working space. The channel may include a restrictor to control or regulate the working medium flow.

For the purposes of the invention, the working fluid is pumped from the idle pump through a channel which is formed by a plurality of sub-channels. A partial channel or partial region of the connecting channel is formed by the passage cross section of the bearing, that is to say the intermediate spaces between the rolling bodies of the bearing, so that part of the working medium passes through the bearing into the working space. Another sub-channel is connected by a parallel channel connection, z. B. the inflow passage in the operating state formed.

According to an advantageous embodiment, the idle pump is driven by the shaft of the retarder. The pump shaft of the idle pump can be in direct connection with the shaft.

In a preferred embodiment, the pump housing of the idle pump is attached to the retarder housing or a Retardergehäuseteil. So the idle pump z. B. are inserted into a corresponding recess in the pump housing, in the way that the shaft and the pump shaft to each other aligned and can be connected directly.

The pump housing is constructed at least in two parts in the preferred embodiment, consisting of a pump body and a pump cover, wherein furthermore preferably the pump body is positioned or clamped between the retarder housing and the pump cover. Through this simple two-part design of the idle pump, only the contact surfaces between the pump body and pump cover need to be accurately edited, the required width tolerance of the pump chamber for the impeller can thus be very easily met or achieved. The pump housing parts may consist of a casting material.

In order to compensate for linear expansion of the retarder shaft, it is advantageous if the impeller of the idling pump is mounted axially displaceably on the pump shaft. This connection can z. B. be a feather key, a splined or an involute connection. The impeller may for example consist of plastic.

Since a relatively small volume flow is pumped by means of the idling pump, this is preferably designed such that the outer diameter of the impeller is smaller than the inner diameter of the working space or smaller than the shaft diameter. As a result, a simple assembly of the idle pump is possible.

As already mentioned, the connecting channel between reservoir and working space consists of several Teilkanalstücken. Between pump outlet, pressure side, and bearing, the connecting channel can be annular. This ensures that the bearing is always sufficiently in contact with working fluid and thus sufficient cooling and lubrication is ensured.

Furthermore, the connecting channel at the pump inlet, on the suction side, can be replaced by an inlet channel in the pump cover, at the pump outlet by an outlet. passage channel in the pump body and be formed between the annular channel and outlet channel through at least one opening in the retarder housing. The channel is thus essentially formed by the pump housing parts and the retarder housing parts, wherein sealing elements can be provided between the parts at least in the region of the channel.

In the reservoir, the connection channel ends below the working medium mirror, the inlet into the channel having a lower inlet end, which is positioned as far as possible at the lowest point of the reservoir. Furthermore, the inlet end is preferably positioned as far away from the mouth of the return. Between the inlet end and the return inlet may further be provided a separation in the reservoir. This ensures that only air-free working fluid is pumped into the workspace.

Further features of the device according to the invention and further advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings.

The invention will be explained in more detail with reference to drawings.

In these show:

Figure 1 is an idle pump in the installed state Figure 2 is a schematic representation of the working fluid circuit of

Idle pump

Figure 1 shows an idle pump 25 in the installed state. The connecting channel 19 between the working fluid reservoir 23 and the working chamber 24 via the idle pump 25 and the bearing 18 and at least one additional connection, not shown here, in the working space. Thus, at least a portion of the working medium is supplied to the bearing 18 by means of the idle pump 25.

A portion of the working medium 15 can thus pass through the bearing 18 in the working space 24. The bearing 18 is lubricated and cooled. One another part passes through the flow channel for the braking operation in the working space 24th

The idle pump 25 is driven via the shafts 3 and 4, which communicate with each other, so that the impeller 7 always rotates at shaft speed. The pump delivery rate is thus directly related to the speed of the rotor 16. The pump delivery rate is thus adapted to the requirements at the corresponding rotational speeds of the rotor 16.

To simplify the manufacture of the pump housing, this is constructed in two parts. It consists of the pump body 6 and the pump cover 8. The impeller 7 runs in the pump chamber between the pump body 6 and the pump cover 8. It is slidably mounted on the shaft 4 so that it can move freely in the axial direction. Axial movements of the shafts 3, 4 thus have no force influence on the impeller 7.

The installation of the idle pump 25 takes place in the following order. First, the seal 9 and the pump body 6 are inserted into the stator housing part 5. Subsequently, the impeller 7 is used and the pump housing is closed with the pump cover 8. The screwing takes place between the pump cover 8 and the stator housing part 5, so that the pump body 6 is clamped between the stator housing part 5 and the pump cover 8. As shown in FIG. 1, the working medium reservoir 23 can be part of the retarder housing 2, so that the working medium passes directly from the working medium reservoir 23 to the idling pump 25.

2 shows a schematic representation of the working fluid circuit for the idle pump 25 is shown. Since in this invention the Arbeitsmediumkreis- run is considered in non-braking operation, the working fluid circuit is not shown for the braking operation.

The working medium 15 is sucked from the working fluid reservoir 23 via the connecting channel 19, which may contain a throttle, sucked by the idling pump 25 and pumped into the working space 24. As can be seen from FIG. NEN, the working medium flow is divided behind the idle pump 25. A part of the working medium 15 takes the way through the bearing 18 in the working space 24, a second part of the working medium 15 passes through the feed channel 27 into the working space 24. The feed channel 27 is the channel through which the working fluid 24 in the braking operation the working space 24th is supplied.

Excessive working medium 15 is passed back into the working-medium reservoir 23 via a scooping device and the return duct 20. Since this recycled working fluid 15 may contain air, devices may be provided in the return channel 20, which vent the working fluid. Furthermore, it may be provided that the return channel 20 terminates in a region of the working medium reservoir 23, which is spaced as far as possible from the suction point for the working medium. An additional delimitation can be realized by means of a memory separation 26 or partial separation.

Another option is to guide the recycled working fluid 15 before returning it to the working fluid reservoir 23 via the radiator 21 or via a separate radiator and thus to cool it.

LIST OF REFERENCES

1 retarder

2 retarder housing

3 wave

4 pump shaft

5 stator housing part

6 pump body

7 impeller

8 pump covers

9 seal

10 inlet

1 1 expiry

12 feather key

13 screw connection

14 working fluid flow

15 working medium

16 rotor

17 stator

18 bearings

19 connecting channel

20 return

21 coolers

22 pressure control

23 working medium memory

24 workspace

25 idling pump

26 Memory separation

27 feed channel

30

Claims

claims

1 . Hydrodynamic machine, in particular hydrodynamic retarder (1), comprising a retarder housing (2), a rotor (16) and a stator (17), wherein the rotor (16) and stator (17) together form a working space (24) corresponding to Operating state of the machine with a working medium (15) can be filled, wherein the rotor (16) is arranged on a rotatably mounted shaft (3) which at least one side of the retarder housing (2) by means of a bearing (18) is mounted, comprising Furthermore, an idle pump (25), by means of the working medium (15) by a

Connecting channel (19) can be pumped from a working fluid reservoir (23) in the working space (24),

characterized,

the bearing (18) forms at least a portion of the connecting channel (19) so that the bearing (18) is at least partially cooled and / or lubricated by the working medium (15) conveyed by the idling pump (25).

2. Hydrodynamic machine according to claim 1,

characterized,

the idling pump (25) is driven by the shaft (3).

3. Hydrodynamic machine according to claim 2,

characterized,

the pump shaft (4) of the idling pump (25) is in direct connection with the shaft (3).

4. Hydrodynamic machine according to claim 1, 2 or 3,

characterized, the pump housing (6, 8) of the idle pump (25) is fastened to the retarder housing (2).

5. Hydrodynamic machine according to claim 4,

characterized,

the pump housing (6, 8) is constructed at least in two parts, a pump body (6) and a pump cover (8), between which an impeller (7) is positioned.

6. Hydrodynamic machine according to claim 5,

characterized,

the pump body (6) is positioned between the retarder housing (2) and the pump cover (8).

7. Hydrodynamic machine according to claim 5,

characterized,

that the impeller (7) of the idling pump (25) is mounted axially displaceably on the pump shaft (4).

8. Hydrodynamic machine according to claim 5 or 7,

characterized,

that the outer diameter of the impeller (7) is smaller than the inner diameter of the working space (24) or smaller than the shaft diameter (3).

9. Hydrodynamic machine according to claim 1,

characterized,

that the connecting channel (19) is annular before the bearing.

10. Hydrodynamic machine according to claim 9,

characterized, in that the connecting channel (19) is formed at the pump inlet through an inlet channel (10) in the pump cover, at the pump outlet through an outlet channel (11) in the pump body and between annular channel (26) and outlet channel (11) through at least one opening in the retarder housing (27) becomes.

1 1. Hydrodynamic machine according to claim 1, 9 or 10,

characterized,

that the connecting channel (19) protrudes into the working medium reservoir (23) below the working medium level (15), so that it is ensured that no air is sucked in.