Hydrodynamic retarder

Abstract

A hydraulic retarder is proposed, having a device for detecting the temperature of the working medium. In the proposed embodiment, the hydraulic retarder comprises at least a stator housing and a rotor housing. A stator is accommodated in the stator housing and is coupled to the stator housing in a torque-proof manner. A rotor is arranged in a rotatable bearing in the rotor housing, wherein the rotor can be driven by a shaft and is supported on the shaft in an axially movable manner, such that the rotor can be moved into a braking operating position and a non-braking operating position, wherein in the non-braking operating position an annular gap is provided between the rotor and the rotor housing, and according to the invention the device for detecting the temperature of the working medium comprises a sensor, which is positioned in the rotor housing such that a sensor tip extends into the annular gap.

Description

Technical Field

[0001] This invention relates to a hydraulic retarder having a device for detecting the temperature of the working medium. Background Technology

[0002] Hydraulic retarders are often referred to as wear-free, durable brakes, for example, used in motor vehicles, particularly commercial or rail vehicles. A hydraulic retarder comprises a working chamber formed by a primary impeller and a secondary impeller. Within this working chamber, where the two impellers rotate relative to each other, a liquid working medium is present, circulating between the impellers during the retarder's braking operation.

[0003] A typical retarder consists of a rotatably supported and driveable rotor and stator, which is securely connected to the retarder housing or similar device.

[0004] Such a retarder can be found in document DE 10 2010 010 222 A1. A temperature sensor is used to monitor the operation of the retarder. To improve the functionality of the retarder, it is recommended that the temperature sensor extend into the working chamber or the volume area used for supplying or discharging the working medium, or be thermally connected to components arranged in the working chamber. The temperature sensor is preferably arranged within the annular channel area used for venting the working chamber. This arrangement allows for a particularly simple structure. Furthermore, a temperature sensor arranged in this way enables temperature measurement in both braking and non-braking operation modes.

[0005] Another structure of a retarder with a temperature sensor is known from document CN 105697610 A. Herein is proposed a method for accurately detecting the hydraulic oil temperature of a retarder. The housing includes a working oil chamber having an oil outlet, wherein the temperature of the oil guided through the outlet is measured.

[0006] As the requirements for the controllability of retarders become increasingly stringent, the inertia of temperature measurement devices, which can be achieved using known sensor devices, becomes a limiting parameter. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to propose a retarder structure with a sensor, thereby improving the reaction time.

[0008] The technical problem described herein is solved by a hydraulic retarder.

[0009] A hydraulic retarder is proposed, which includes a device for detecting the temperature of the working medium. In the proposed embodiment, the hydraulic retarder comprises at least a stator housing and a rotor housing. The stator is housed within and torsionally coupled to the stator housing. The rotor is rotatably supported within the rotor housing, wherein the rotor can be driven by a shaft and axially movably supported on the shaft, such that the rotor can move to a braking operating position and a non-braking operating position, wherein in the non-braking operating position, an annular gap is provided between the rotor and the rotor housing.

[0010] According to the invention, an apparatus for detecting the temperature of a working medium includes a sensor positioned within the rotor housing such that a sensor tip extends into the annular gap. The sensor tip is a portion of the sensor through which actual temperature changes are detected.

[0011] Furthermore, a discharge port is provided in the rotor housing, wherein the discharge port and the sensor are arranged in a plane transverse to the axis of rotation, and wherein the sensor and the discharge port are arranged offset from each other in the circumferential direction.

[0012] In a preferred embodiment, the annular gap has a raised portion in the region of the outlet.

[0013] In addition, to improve the skimming effect, a skimming tube can be inserted into the discharge port, with the end of the skimming tube extending into the raised portion and the annular gap.

[0014] The sensor is preferably inserted into a sensor cavity, which expands the annular gap in the area surrounding the sensor to ensure circumferential flushing of the sensor tip.

[0015] The sensor is arranged in the upper region of the annular gap or retarder, wherein the sensor axis extends into the annular gap at an angle α of 30° to 50°, preferably 35° to 40°, relative to the rotor tangent and against the direction of rotor rotation. Here, the upper region is defined as the point where the intersection of the sensor axis and the rotor tangent lies within an angle δ of 20° to 40°, more preferably 30° to 35°, relative to the vertical retarder axis. This arrangement plays a crucial role in ensuring that the working medium does not accumulate in the sensor cavity, thereby distorting the measurement values.

[0016] The outlet is located in the lower region of the annular gap, wherein the axis of the outlet extends into the annular gap at an angle β of 20° to 40°, more preferably 25° to 35°, relative to the central axis in the direction of rotor rotation. Here, the lower region is defined as the point where the intersection of the outlet axis and the rotor tangent lies within an angle γ of 15° to 30°, more preferably 20° to 25°, relative to the vertical retarder axis. Attached Figure Description

[0017] The invention is described below with reference to the accompanying drawings. In the drawings:

[0018] Figure 1 A cross-sectional view of the retarder in its installation position is shown.

[0019] Figure 2 A longitudinal sectional view of a retarder with a rotor in the non-braking position is shown.

[0020] Figure 3 A longitudinal sectional view of a retarder with a rotor in the braking position is shown.

[0021] Although Figures 1 to 3 The diagram shown is a cross-sectional view of the retarder, but for the sake of simplicity, the shading of the cut parts has been omitted. Detailed Implementation

[0022] Figure 1 A cross-sectional view of the retarder 1 according to the invention in its installation position in a vehicle is shown. This section extends in the plane of the sensor 7 and the return channel 10, wherein the rotor 3 is in a non-braking position. The rotor 3 is supported on the shaft 6 such that it can move along the axis from the non-braking position to the braking position. This functionality is well known in the prior art, and therefore will not be described in further detail here with reference to the prior art.

[0023] In both non-braking and braking operation modes, rotor 3 is driven in the direction of the arrow, and even in non-braking operation mode, a certain volume of residual working medium must always exist in the working chamber 18. This residual working medium volume reduces idling losses and ensures cooling of the retarder. To regulate the volume of residual working medium, a return channel 10 with a skimming pipe 9 is provided, through which the volumetric flow can be directed into the transverse channel 11 and then guided back to the oil reservoir.

[0024] The skimming tube 9 extends into the raised portion 21 of the annular gap 20a between the rotor 3 and the rotor housing 2. Therefore, the outer periphery of the skimming tube 9 forms a guide device, through which a portion of the working medium flow is guided from the annular gap 20a to the discharge channel 10. Furthermore, the axis 23 of the skimming tube 9 or the discharge channel 10 is inclined relative to the vertical line in the direction of rotor rotation, with an inclination angle β ranging from 20° to 40°, here chosen as 30°. The dimension y or angle γ can be used to further define the lower region, i.e., the circumferential arrangement of the skimming tube 9 or the discharge channel 10. In the illustrated embodiment, the skimming tube 9 is rotated approximately 21° against the direction of rotor 3 rotation by an angle γ, where other angles γ from 15° to 30°, preferably 20° to 25°, are also considered. Therefore, a good skimming effect can be achieved, and the arrangement of the skimming device in the lower region prevents the working medium from accumulating in a larger quantity, while still leaving a remaining volume of working medium in the annular gap 20a. Alternatively, an angle γ can be achieved along the rotation direction of rotor 3.

[0025] The sensor 7 is installed or screwed into the sensor cavity 8 in the upper region of the rotor housing 2. Here, the sensor axis 22 is tilted at an angle α = 30° to 50°, preferably α = 35° to 40°, against the rotation direction of the rotor 3, relative to the tangent of the rotor 3. The dimension x or angle δ can be used to further define the upper region, i.e., the arrangement of the sensor 7 on the outer periphery. In the illustrated embodiment, the sensor 7 is rotated by an angle δ of approximately 31° in the rotation direction of the rotor 3, wherein other angles δ of 20° to 40°, preferably 30° to 35°, can also be considered. Crucially, the working medium cannot accumulate in the sensor cavity 8 for a long period of time. Alternatively, an angle δ against the rotation direction of the rotor 3 can also be implemented.

[0026] Figure 2 and Figure 3 Cross-sectional views of the retarder 1 are shown, with the sensor 7 and the discharge channel 10 shown in the cross-section. Figure 2 and Figure 3 The difference lies in the rotor position, where, Figure 2 This displays the non-braking position of rotor 3. Figure 3 The braking position of rotor 3 is displayed.

[0027] In the non-braking position, rotor 3 is positioned with the maximum gap between stator 4 and rotor 3, and the working cavity 18 reaches its maximum size. In this position, a radial annular gap 20a is formed between rotor 3 and rotor housing 2, and rotor cavity 19 is reduced to its minimum. This allows the remaining working volume to be transported to sensor 7 and from there to the skimming point via the rotation of rotor 3 within the annular gap 20a.

[0028] As is known in the prior art, in non-braking operation mode, a small volume of working medium is continuously pumped into the working chamber 18. The working medium reduces idling losses and ensures idling cooling. To adjust the filling liquid level in the working chamber 18, a return channel 10 connected to a working medium reservoir is provided. A skimming pipe 9 in the return channel 10 extends into the raised portion 21 and the annular channel 20a, thereby enabling the skimming of a defined volume of working medium, which is then guided back into the loop through the return channel.

[0029] The purpose of this invention is to detect temperature changes in the working medium as directly as possible, even in non-braking operation mode. Therefore, the sensor 7, more precisely, its sensor tip, extends directly into the annular gap 20a, so that the sensor tip is directly circulated by the working medium that has just been delivered through the annular gap 20a.

[0030] Figure 3 and Figure 2 The difference lies in the rotor being in the braking position. For braking, a large volume of working medium is conveyed into the working chamber 18 via the inlet chamber 13 and the inlet channel 14. Then, due to the pumping action between the stator 4 and the rotor 3, the working medium is drawn out of the working chamber again and returned to the circuit with a cooler (not shown) through the outlet 17 and the discharge chamber 15.

[0031] Similarly, in braking operation mode, the working medium enters the rotor cavity 19 through the annular gap 20b, which is formed between the stator 4 and the rotor 3 in this rotor position. Therefore, temperature detection can be ensured even in braking operation mode.

[0032] List of reference numerals

[0033] 1. Retarder

[0034] 2 Rotor housing

[0035] 3 rotors

[0036] 4. Stator

[0037] 5. Stator Housing

[0038] 6-axis

[0039] 7 sensors

[0040] 8 Sensor cavity

[0041] 9. Skimming tube

[0042] 10 Return Channels

[0043] 11 Horizontal passage

[0044] 12 Screw Plugs

[0045] 13. Entering the cavity

[0046] 14 Enter the passage

[0047] 15 Exhaust Chamber

[0048] 16 Connecting pieces

[0049] 17 Discharge outlets

[0050] 18 Working Chamber

[0051] 19 Rotor cavity

[0052] 20a, b Annular gaps

[0053] 21. Raised section

[0054] 22 Sensor axis

[0055] 23 Axis

[0056] 24. Retarder axis

Claims

1. Hydraulic retarder having means for detecting the temperature of the working medium, comprising a stator housing (5) and a rotor housing (2), in which a stator (4) is arranged in a torque-proof manner and a rotor (3) is arranged in a rotatable bearing, wherein The rotor can be driven by a shaft (6) and axially movably supported on the shaft (6), so that the rotor (3) can move to a braking operation position and a non-braking operation position, wherein an annular gap (20a) is provided between the rotor (3) and the rotor housing (2) in the non-braking operation position, characterized in that the device for detecting the temperature of the working medium includes a sensor (7) positioned in the rotor housing (2) such that the sensor tip extends into the annular gap (20a).

2. Hydraulic retarder (1) according to claim 1, characterized in that The rotor housing (2) is provided with a discharge port (10), wherein the discharge port (10) and the sensor (7) are arranged on a plane transverse to the axis of rotation of the shaft (6), and wherein the sensor (7) and the discharge port (10) are arranged offset from each other in the circumferential direction.

3. The hydraulic retarder (1) according to claim 2, characterized in that The annular gap (20a) has a raised portion (21) in the region of the outlet (10).

4. The hydraulic retarder (1) according to claim 3, characterized in that, A skimming tube (9) is inserted into the outlet, the skimming tube (9) extending at its end into the raised portion (21) and the annular gap (20a).

5. The hydraulic retarder (1) according to any one of claims 1 to 4, characterized in that, The sensor (7) is inserted into the sensor cavity (8).

6. The hydraulic retarder (1) according to claim 5, characterized in that, The sensor cavity (8) is arranged relative to the annular gap (20a) such that the sensor axis (22) extends into the annular gap (20a) at an angle α of 30° to 50° relative to the rotor tangent and against the direction of rotor rotation, and the intersection of the sensor axis (22) and the rotor tangent is located within an angle range δ of 20° to 40° relative to the vertical retarder axis (24), so that no working medium is left in the sensor cavity (8) in the non-braking operation mode.

7. The hydraulic retarder (1) according to any one of claims 2 to 4, characterized in that, The outlet (10) is arranged relative to the annular gap (20a) such that the axis (23) of the outlet (10) extends into the annular gap (20a) at an angle β of 20° to 40° relative to the vertical retarder axis (24) in the direction of rotor rotation, and the intersection of the axis (23) of the outlet (10) and the rotor tangent is located within an angle range γ of 15° to 30° relative to the vertical retarder axis (24).

8. The hydraulic retarder (1) according to claim 7, characterized in that, The sensor (7) is inserted into the sensor cavity (8).

9. The hydraulic retarder (1) according to claim 8, characterized in that, The sensor cavity (8) is arranged relative to the annular gap (20a) such that the sensor axis (22) extends into the annular gap (20a) at an angle α of 30° to 50° relative to the rotor tangent and against the direction of rotor rotation, and the intersection of the sensor axis (22) and the rotor tangent is located within an angle range δ of 20° to 40° relative to the vertical retarder axis (24), so that no working medium is left in the sensor cavity (8) in the non-braking operation mode.

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