DE102017112088B4 - Pump arrangement for an ABS system - Google Patents

Abstract

Pump arrangement (1) for an ABS system, with a housing (4), with a pump shaft (3) for driving at least one piston, the pump shaft (3) being mounted in the housing (4), characterized by a vibration sensor (17) ) for detecting vibrations of the pump arrangement (1) and by an evaluation unit (18) for analyzing the detected vibrations, the pump arrangement (1) having an eccentric bearing device (10,10a, b), the eccentric bearing device (10,10a, b) the pump shaft (3) is arranged to drive the piston, the vibration sensor (17) making contact with the eccentric bearing device (10, 10a, b)

Description

The invention relates to a pump arrangement for an ABS system in a vehicle with the features of the preamble of claim 1.

Motor vehicles often have driver assistance systems for driver support. One of the basic building blocks of the driver assistance systems is the form of anti-lock devices, which ensure that the wheels of the motor vehicle do not lock when the brakes are applied. The anti-lock devices have a pump in many designs in order to stabilize a brake pressure.

The publication WO 2007/118 722 A1 describes such a pump which can be used in a hydraulic unit of an ABS system, in particular an ESP system. The pump has a pump housing with a drive shaft and a drive motor, the drive shaft being mounted in the pump housing and converting a rotational movement of the drive shaft into a linear movement for a piston via an eccentric bearing.

the DE 10 2008 016 746 A1 shows an arrangement and a method for detecting and / or evaluating vibrations of moving bodies and / or structures, in particular of vehicles and / or motor vehicles, with at least one vibration sensor coupled to an evaluation unit. The at least one vibration sensor comprises a measuring transducer which is arranged on the body or on the structure to detect vibration behavior.

The invention is based on the object of proposing a pump arrangement for an ABS system which is particularly fail-safe. This object is achieved by a pump arrangement having the features of claim 1. Preferred or advantageous embodiments of the invention emerge from the subclaims, the following description and / or the attached figures.

The subject matter of the invention is a pump arrangement which is suitable and / or designed for an ABS system of a vehicle. The vehicle can be designed as a passenger car, truck, bus, etc. In particular, the pump arrangement is arranged and / or integrated in a hydraulic unit of the ABS system. The ABS system can also be referred to as an anti-lock braking system. The pump arrangement is preferably used to generate and / or stabilize a brake pressure in the brake system of the vehicle.

The pump arrangement has a housing in which components of the pump arrangement are arranged. The housing is preferably designed in one piece.

The pump arrangement has a pump shaft, the pump shaft being mounted in the housing. The pump shaft serves to drive at least one piston of the pump arrangement. The at least one piston preferably forms a component of the pump arrangement. For example, the pump arrangement can have two pistons, three pistons, four pistons or more pistons. In particular, a rotational movement of the pump shaft is converted into a linear movement of the at least one piston via the pump arrangement.

In the context of the invention, it is proposed that the pump arrangement has a vibration sensor, the vibration sensor serving to detect vibrations of the pump arrangement. In particular, the vibration sensor is used to detect the vibrations during operation of the pump arrangement. The vibration sensor is preferably positioned undamped in the pump arrangement in order to deliver measured values that are as precise as possible. The vibration sensor can be designed as a piezoelectric sensor, electrodynamic sensor, capacitive sensor or inductive sensor. Alternatively, the vibration sensor can be implemented as an optical sensor.

According to the invention, the pump arrangement has an eccentric bearing device which is arranged on the pump shaft and which drives the piston. The eccentric bearing device preferably comprises an inner ring, the inner ring being connected to the pump shaft, and an outer ring, the outer ring having a raceway for a piston or an intermediate element to the piston. The outer ring is preferably designed as an outer sleeve. It can be provided that the inner ring is arranged on a shaft section arranged eccentrically with respect to an axis of rotation of the pump shaft. In this way the inner ring is rotated eccentrically. Alternatively, the inner ring can be designed as an eccentric ring and placed on a coaxial section of the pump shaft. This alternative results in an eccentric movement through the outer surface of the inner ring. The eccentric bearing device is preferably designed as a needle bearing.

The pump arrangement also has an evaluation unit which is coupled with the vibration sensor for signaling purposes. In particular, sensor data can be transmitted from the vibration sensor to the evaluation unit. It is possible that the data transfer is wired is implemented. As an alternative to this, the sensor data are transmitted wirelessly from the vibration sensor to the evaluation unit. The evaluation unit is preferably designed as a digital data processing device, such as a microprocessor or the like, for example.

The evaluation unit is designed in terms of programming and / or software to carry out an analysis of the vibrations detected by the vibration sensor. The vibration sensor measures the vibrations of the pump arrangement, in particular the components of the pump arrangement. In the event that irregularities or incipient defects occur in the pump arrangement, these change the vibrations of the pump arrangement and are consequently detected by the vibration sensor. The vibrations of the pump arrangement are transmitted as sensor signals to the evaluation unit and analyzed by it. During the analysis, this can infer irregularities, defects or even incipient defects in the pump arrangement. In this way, it is preferably possible to detect defects before the performance of the pump arrangement deteriorates or the pump arrangement even fails completely. As a result, it can be avoided that the pump arrangement and thus the ABS system based on it fail unexpectedly, so that it can no longer support the driver in a critical situation.

In a preferred embodiment of the invention, the evaluation unit is designed to determine an operating state of the pump arrangement on the basis of the analysis. For example, a state of wear or a defect state can be determined as the operating state of the pump arrangement, in particular of the components of the pump arrangement. The pump arrangement, the ABS system or the driver assistance system optionally has an output interface for outputting a warning signal. For example, the interface can be coupled with a warning light or control light for signaling purposes. In the event that the evaluation unit determines a wear condition or a defect condition via the analysis as the operating condition, the warning lamp or control lamp can be activated via the output interface so that it is activated and the driver is warned. It can also be provided that the evaluation unit holds a threshold value, the warning light or the control light only coming on when the threshold value is exceeded. In this way, false warnings can be avoided. As a result, a defect or impending defect in the pump arrangement with the vibration sensor and the evaluation unit is detected by the analysis and thus recognized in good time, optionally displayed so that suitable measures, such as repairing the pump arrangement, can be initiated.

In a possible further development of the invention, the pump arrangement has a speed interface for taking over a speed data of the pump shaft. The speed data is preferably understood to mean the speed of the pump shaft or a date which can be converted into the speed of the pump shaft. For example, the speed data can be a relative value of the speed of the pump shaft. However, it is also possible that the speed data is a speed of an electric motor that drives the pump shaft. With known gear ratios, it is possible in a simple manner to convert the speed of the electric motor into a speed of the pump shaft. The evaluation unit is designed to carry out the analysis on the basis of the speed data. It is a consideration of this development that if the rotating and / or oscillating components of the pump arrangement are damaged, irregularities occur which are related to the speed of the pump shaft. It can therefore support the analysis if the speed of the pump shaft is taken into account when analyzing the vibrations.

In an advantageous development of the invention, the evaluation unit is designed to determine a rollover frequency of components of the pump arrangement and to check whether irregularities occur in the vibrations with the same frequency as the rollover frequency. The rollover frequency is the frequency of rotation of components of the pump arrangement. In the event that the components pass an interference point in circulation, the vibrations have irregularities with the roll-over frequency, that is to say with the frequency of the respective component. With the additional information from the speed data, the reliability of the analysis, in particular the determination of the operating state, can be improved.

For example, the analysis includes a frequency analysis step and / or an order analysis step. Through these steps, the regular disturbances in the vibrations can be clearly seen. The frequency analysis step comprises a method for determining how often certain events occur in a certain time unit, or which frequency components are represented in a signal and how much. An order analysis is the analysis of the vibrations with a view to the order of the vibrations.

In a preferred development of the invention, the pump arrangement has at least one first shaft support bearing for mounting the pump shaft in the housing. The first Shaft support bearing is preferably designed as a rolling element bearing, such as a ball bearing, for example. In preferred embodiments, the shaft support bearing has an outer ring, which is received in the housing, and an inner ring, which sits on the pump shaft. The pump shaft can also have several such shaft support bearings.

While the inner ring of the first shaft support bearing and / or the eccentric bearing device rotates at the same rotational speed as the pump shaft and thus has the rotational frequency of the pump shaft as the roll frequency, the rolling elements, i.e. in particular the balls in the shaft support bearing and / or the needles in the eccentric bearing device, can with rotate at a different speed so that they have a different rollover frequency. The outer ring in the eccentric bearing device can in turn assume a different rollover frequency.

In a first possible embodiment of the invention, the vibration sensor is arranged in such a way that it makes direct contact with one of the first shaft support bearings. The vibration sensor can be arranged on the inner ring or on the outer ring. In this way, irregularities are picked up particularly sensitively by the shaft support bearing.

In a second possible embodiment of the invention, the vibration sensor is arranged in such a way that it makes direct contact with the eccentric bearing device. It is preferred that the vibration sensor makes direct contact with the outer ring. In this way, irregularities are picked up particularly sensitively by the eccentric bearing device.

In a third possible embodiment of the invention, the vibration sensor is arranged in such a way that it makes direct contact with the housing. In this way, vibrations from all moving parts that are mounted in the housing are picked up by the vibration sensor.

The position of the vibration sensor thus makes it possible to vary the sensitivity of the vibration sensor in relation to different components of the pump arrangement. For example, it is also possible for the vibration sensor to be arranged between the outer ring of the shaft support bearing and the housing. It is also possible for the housing to have bores or receiving openings for the pistons, the vibration sensor being arranged in the area of the bores or the receiving opening.

• 1 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein erstes Ausführungsbeispiel der Erfindung,
• 2 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein zweites Ausführungsbeispiel der Erfindung,
• 3 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein drittes Ausführungsbeispiel der Erfindung,
• 4 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein viertes Ausführungsbeispiel der Erfindung,
• 5 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein fünftes Ausführungsbeispiel der Erfindung,
• 6 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein sechstes Ausführungsbeispiel der Erfindung.

Further features, advantages and effects of the invention emerge from the following description of preferred exemplary embodiments of the invention and the attached figures. These show:

• 1 in a schematic longitudinal sectional view a pump arrangement as a first embodiment of the invention,
• 2 in a schematic longitudinal sectional view a pump arrangement as a second embodiment of the invention,
• 3 in a schematic longitudinal sectional view a pump arrangement as a third embodiment of the invention,
• 4th in a schematic longitudinal sectional view a pump arrangement as a fourth embodiment of the invention,
• 5 in a schematic longitudinal sectional view a pump arrangement as a fifth embodiment of the invention,
• 6th in a schematic longitudinal sectional view a pump arrangement as a sixth embodiment of the invention.

Corresponding or identical sizes or components are identified with corresponding reference symbols.

the 1 shows a pump arrangement in a schematic longitudinal section 1 as a first embodiment of the invention. The pump arrangement 1 forms part of a driver assistance system 2 , the driver assistance system 2 can be designed as an ABS system or as a driver assistance system 2 which accesses the ABS system. The pump arrangement 1 has the function of pumping and / or applying pressure to a brake fluid. In the figures is the pump arrangement 1 only partially shown. The pump arrangement 1 has a pump shaft 3 and a case 4th on, with the pump shaft 3 in the case 4th around an axis of rotation R. is rotatably mounted. The pump shaft 3 is with an engine 5 operatively connected so that the pump shaft 3 can be rotated. For example, the pump shaft 3 with a rotor shaft of the motor 5 non-rotatably connected.

The pump shaft 3 is about a first shaft support bearing 6th in the case 4th rotatably mounted. The first shaft support bearing 6th has an inner ring 7th and an outer ring 8th on, between which rolling elements 9 are arranged rolling. The inner ring 7th sits on the pump shaft 3 , the outer ring 8th is on the other hand in the housing 4th arranged, for example pressed in. On the pump shaft 3 is an eccentric bearing device 10 arranged. The eccentric bearing device 10 has an eccentric pin 11 on which one end portion of the pump shaft 3 forms and eccentric to the pump shaft 3 is arranged. On the eccentric pin 11 is a needle bearing 12th arranged, which is rotated eccentrically during operation. The eccentric bearing device 10 , especially the needle bearing 12th has a number of rolling elements, in this case needles, and an outer ring 14th on, which is designed as a sleeve. The outer ring 14th forms a track for the rolling elements on the inner circumference and a track for pistons or intermediate elements to the pistons on the outer circumference. The pistons are not shown in the figures, but they are recordings 15th for the pistons in the housing 4th brought in. The recordings 15th run perpendicular to the axis of rotation R. the pump shaft 3 . The pump shaft 3 as well as the eccentric bearing device 10 are in a bearing bore 16 arranged, which is coaxial with the axis of rotation of the pump shaft 3 extends.

In operation, the pump shaft 3 by the engine 5 rotates. This will make the eccentric pin 11 set in an eccentric movement that affects the outer ring 14th the eccentric bearing device 10 transmits. Due to the eccentric movement of the outer ring 14th can the rotational movement of the pump shaft 3 converted into linear motion for the pistons.

The pump arrangement 1 forms a basis for the ABS system and driver assistance systems based on it 2 . A failure of the pump arrangement 1 inevitably leads to failure of the ABS system and the driver assistance systems based on it 2 . In order to improve the reliability, the pump arrangement 1 a vibration sensor 17th as well as an evaluation unit 18th on which signaling with the vibration sensor 17th connected is. These components make it possible for the pump assembly to be damaged or defective 1 , especially at one of the camps 6th , 10 To be able to identify and remedy at an early stage, before the pump arrangement 1 fails completely.

The vibration sensor 17th measures vibrations (acceleration or speed) of the pump arrangement 1 , especially the shaft support bearing 6th or the eccentric bearing device 10 . Via the evaluation unit 18th the recorded vibrations can be analyzed and searched for certain irregularities. These irregularities can be caused by slight damage to one of the raceways, the rolling elements or a bearing cage 6th , 10 develop. In this way, irregularities can be detected before the performance of the pump arrangement 1 , especially the shaft support bearing 6th and / or the eccentric bearing device 10 , subsides or a failure is imminent.

The vibrations are picked up by the vibration sensor 17th to the evaluation unit 18th either wired or wireless transmission. In the evaluation unit 18th an analysis of the detected vibrations takes place, an operating state of the pump arrangement based on the analysis 1 is determined. Depending on the exemplary embodiment, the operating state of the pump arrangement 1 also an operating state of the shaft support bearing 6th and / or the eccentric bearing device 10 to be determined. The operating state is, in particular, a wear state of the pump arrangement 1 or the warehouse 6th , 10 .

Optionally, the evaluation unit 18th an interface 19th to take over a speed data for the speed of the pump shaft 3 on. The speed of the pump shaft is derived from the speed data 3 derivable. In particular, the speed data can directly indicate the speed of the pump shaft 3 alternatively, a relative value, such as a speed of the motor, can also be used 5 can be accepted via the interface. On the basis of the speed data, a rollover frequency for the various components of the pump arrangement 1 to be determined. For components that are non-rotatably connected to the pump shaft 3 are connected, the rollover frequency corresponds to the rotational frequency of the pump shaft 3 . The rolling elements in the bearings and the outer ring 14th however, have different rollover frequencies. However, these can be derived from the speed data.

The evaluation unit 18th examines the recorded vibrations for irregularities, especially at the same frequency as the rollover frequency. This analysis is based on the consideration that if components of the pump assembly are damaged 1 Periodic vibration changes occur, with the changes having the same frequency as the causing component. This means that if the inner ring is damaged 7th or the eccentric pin 11 Irregularities with the frequency of rotation of the pump shaft 3 expected as rollover frequency. With the rolling elements or the outer ring 14th on the other hand, the irregularities at the corresponding rollover frequencies are to be expected. In order to be able to work out the irregularities particularly clearly, it is possible that the evaluation unit 18th carries out a frequency analysis step and / or an order analysis step during the analysis.

With this analysis, patterns in the recorded vibrations can be recognized by characteristic deflections in the rollover frequencies or the associated orders.

In the 1 Figure 3 is an embodiment of the pump assembly 1 shown being in the housing 4th two shots 15th in the housing 4th are introduced. The vibration sensor 17th is on the outer ring 8th the eccentric bearing device 10 arranged on an axial end face and absorbs vibrations from the eccentric bearing device 10 or their outer ring 14th on. In this measuring position, irregularities in the eccentric bearing device 10 are particularly sensitive.

the 2 shows in the same representation as the 1 a second embodiment of the pump arrangement 1 , the vibration sensor 17th on the edge of one of the recordings 15th is arranged. The vibration sensor is when the piston is inserted 17th thus between the housing 4th and arranged on the piston. In this measuring position there can be irregularities in the piston or in both bearings 6th , 10 via structure-borne noise through the housing 4th be sensitively absorbed.

In the 3 is the pump arrangement 1 in the same representation as shown in the previous figures. The vibration sensor 17th is between the outer ring 8th of the first shaft support bearing 6th and the case 4th arranged. In this measuring position, on the one hand, irregularities in the first shaft support bearing 6th are picked up particularly sensitively and, on the other hand, irregularities from the other components via structure-borne noise through the housing 4th can also be included.

In the 4th is the pump arrangement 1 in the same representation as shown in the previous figures. The vibration sensor 17th is in an imaginary extension of the pump shaft 3 edge side in the housing 4th integrated so that no direct contact with the bearings 6th , 10 consists. In this measuring position, irregularities of all components can be caused by structure-borne noise through the housing 4th are recorded.

the 5 shows a pump arrangement 1 which total of four shots 15th for pistons, which are opposite in pairs. The pump shaft 3 is about another shaft support bearing 20th , which is at the end of the pump shaft 3 is arranged and attached to the housing 4th supported, stored. The pump arrangement. 1 has two eccentric bearing devices 10 a , b on which, however, compared to the previous figures, on a coaxial section of the pump shaft 3 are put on. Each of the eccentric bearing devices 10 a , b has an inner ring 21 a , b on, with the inner rings 21 a , b with the pump shaft 3 Are rotatably connected and are designed as eccentric rings. When the pump shaft rotates 3 becomes an eccentric movement of the inner rings 21 a , b generated.

The vibration sensor 17th is in the area of the bearing bore 16 Arranged on the input side, so that irregularities in the components due to structure-borne noise via the housing 4th be transmitted.

In the 6th is the same pump arrangement 1 like in the 5 shown. The vibration sensor 17th is on the outer ring 8th of the first shaft support bearing 6th arranged so that these irregularities from the first shaft support bearing 6th can absorb particularly sensitive.

While in the embodiments each pump arrangement 1 exactly one vibration sensor 17th was assigned, it is also possible that in one of the pump arrangements 1 more than a vibration sensor 17th is arranged.

List of reference symbols

1

Pump arrangement

2

Driver assistance system

3

Pump shaft

4th

casing

5

engine

6th

first shaft support bearing

7th

Inner ring

8th

Outer ring

9

Rolling elements

10, 10a, b

Eccentric bearing device

11

Eccentric pin

12th

Needle roller bearings

13th

Needles

14th

Outer ring

15th

Recordings

16

Bearing bore

17th

Vibration sensor

18th

Evaluation unit

19th

interface

20th

another shaft support bearing

21 a, b

Inner ring

R.

Axis of rotation

Claims (9)

Pump arrangement (1) for an ABS system, with a housing (4), with a pump shaft (3) for driving at least one piston, the pump shaft (3) being mounted in the housing (4), characterized by a vibration sensor (17) for detecting vibrations of the pump arrangement (1) and by an evaluation unit (18) for analyzing the recorded vibrations, the pump arrangement (1) having an eccentric bearing device (10, 10a, b), the eccentric bearing device (10, 10a, b) is arranged on the pump shaft (3) for driving the piston, the vibration sensor (17) making contact with the eccentric bearing device (10, 10a, b) Pump arrangement (1) according to Claim 1 , characterized in that the evaluation unit (18) is designed to determine an operating state of the pump arrangement (1) on the basis of the analysis. Pump arrangement (1) according to Claim 1 or 2 , characterized in that the pump arrangement (1) has an interface (19) for taking over a speed data of the pump shaft (3), the evaluation unit (18) being designed to carry out the analysis on the basis of the speed data. Pump arrangement (1) according to Claim 3 , characterized in that the evaluation unit (18) is designed to determine a rollover frequency as a function of the speed data and to carry out the analysis on the basis of the rollover frequency. Pump arrangement (1) according to one of the preceding claims, characterized in that the analysis comprises a frequency analysis step and / or an order analysis step. Pump arrangement (1) according to one of the preceding claims, characterized in that the vibration sensor (17) makes contact with the housing (4). Pump arrangement (1) according to one of the preceding claims, characterized in that the pump arrangement (1) has at least one first shaft support bearing (6) for mounting the pump shaft (3) in the housing (4), the vibration sensor (17) the shaft support bearing ( 6) contacted. Pump arrangement (1) according to one of the Claims 1 or 7th , characterized in that the vibration sensor (17) contacts the housing (4) on the one hand and the eccentric bearing device (10, 10a, b) or the first shaft support bearing (6) on the other. Pump arrangement (1) according to one of the preceding claims, characterized in that the pump arrangement (1) is comprised by a driver assistance system (2) for a vehicle.

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