DE112009003823B4 - pump assembly - Google Patents

Abstract

Pump arrangement with an adjustable delivery volume, which delivers from an intake area (3) or tank (5) to a consumer (18), and with an adjusting device which can be adjusted as a function of temperature, characterized in that the adjusting device has an intermediate pressure via a control line ( 27) controlled sequence valve (25), which allows one of several pump flows or pump stages (1, 2) to be pumped back into the intake area (3) or tank (5) of the pump arrangement or to the consumer, depending on the level of the intermediate pressure, if the The intermediate pressure is greater than the inlet pressure and lower than or equal to the outlet pressure of at least one of several pump flows or pump stages (1, 2) of the pump arrangement, the intermediate pressure for activating the actuating device being between two hydraulic resistances (31, 32; 51, 52; 931 , 932) prevails and/or is tapped off in series between a pump outlet and the tank (5) or Intake area (3) are connected.

Description

The invention relates to a pump arrangement with an adjustable delivery volume that delivers from an intake area or tank to a consumer, and with an adjusting device that can be adjusted as a function of temperature.

From the international publication WO 02/097273 A3 a lubricating oil pump with an adjustable stroke volume and with at least one adjusting means is known, with the help of which the delivery volume of the pump can be changed as a function of the oil temperature. The oil temperature or the oil viscosity can be used as an input variable for the adjusting means. The adjusting means can be equipped with a temperature-sensitive expansion material that ensures a temperature-dependent volume adjustment. As a further adjustment option, a valve element is proposed which is connected to a bimetallic element via a bolt and a return spring. A change in temperature causes the bimetallic element to deflect accordingly and thus displaces the piston of the valve in such a way that a control oil flow for adjusting a pump or the delivery flow of a pressure kidney is influenced as a function of temperature. Furthermore, a multi-stage pump is disclosed, in which the individual pump stages are switched on or off depending on the temperature. In addition, a pump with a plurality of pump flows is proposed, of which a first pump flow continuously delivers into a consumer system, while a second pump flow is switched to pressureless circulation at low temperatures. From the DE10223466B4 a multi-flow pump with a variable delivery volume is known, in which a corresponding pump delivery volume is generated for each temperature. There is a temperature-dependent valve that switches between the two flows.

DE4302610A1 shows a single-flow pump with a variable delivery volume, the delivery volume being set via temperature and/or speed detection. In this reference there is no control that switches between two flows depending on an intermediate pressure. Similar pumps are from the DE 2648043 A1 and DE 198 29 525 C2 known.

The object of the invention is to create a pump arrangement with an adjustable delivery volume, which delivers from an intake area or tank to a consumer, and with an adjusting device that can be adjusted as a function of temperature, which is simple in design and inexpensive to produce. In addition, the pump arrangement according to the invention should have a high level of operational reliability, in particular in the event of a failure of a temperature switching valve, even in the event of malfunctions and/or failures of individual control elements and/or valves.

The task is solved in a pump arrangement with an adjustable delivery volume, which delivers from an intake area or tank to a consumer, and with an adjusting device that can be adjusted as a function of temperature, in that the adjusting device is controlled with an intermediate pressure that is greater than the inlet pressure and is less than or equal to the outlet pressure of at least one of several pump flows or pump stages of the pump arrangement. Depending on the temperature, the control device can be controlled either with the inlet pressure or with the intermediate pressure. The adjustable delivery volume is the delivery volume that reaches the consumer with the help of at least one pump flow or pump stage and is adjusted by switching on or off at least a second pump flow or pump stage. The consumer can be a single consumer, such as a lubricating oil circuit of an internal combustion engine, or multiple consumers, such as the lubricating oil circuit of the internal combustion engine and other lubricating oil circuits of ancillary units of the internal combustion engine. The pump arrangement according to the invention can also be a pump arrangement with an adjustable delivery rate. According to an essential aspect of the invention, the actuating device, for example in the form of a sequence valve, is controlled with the intermediate pressure, the pressure level of which is preferably between a tank pressure of an aspirated working medium and a high pressure that is provided at the outlet of the pump arrangement. Controlling the adjusting device with the intermediate pressure provides, among other things, the advantage that a conventionally used temperature control valve can be omitted.

According to a further essential aspect of the invention, it is proposed below to use at least one conventional temperature switching valve only to reduce a control-related leakage.

The invention is further characterized in that the adjusting device comprises a sequence valve controlled by the intermediate pressure, which allows one of several pump flows or pump stages to be pumped back into the intake area or tank of the pump arrangement or to the consumer, depending on the level of the intermediate pressure. For this purpose, an output of the pump arrangement, in particular of a pump stage or pump flow, is connected to the suction area of the pump arrangement.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve is designed as a 2/2-way valve which is pilot-controlled by the intermediate pressure. The sequence valve is preferably designed as a proportional valve.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve is biased into a closed position, in which a connection between the outlet of at least one of the pump flows or pump stages and the tank or intake area is interrupted. This ensures that the pump starts with multiple flows, preferably with two flows.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve has an open position in which the connection between the outlet of at least one of the pump flows or pump stages and the tank or intake area is released. In the open position of the sequence valve, at least one of the pump flows or pump stages delivers back into the tank or intake area.

The invention is further characterized in that the intermediate pressure for activating the adjusting device prevails between two hydraulic resistances which are connected in series between a pump outlet and the tank or intake area. The pump output is the output of the pump stage or pump flow or the outputs of the pump stages or pump flows that convey or convey to the consumer. A tap for the intermediate pressure is provided between the two hydraulic resistances, which is fed to the actuating device, for example via a control line or a control channel. With increasing temperature and decreasing viscosity, the intermediate pressure at the tap decreases. Depending on the level of the intermediate pressure, the adjusting device is actuated in order to switch on or off at least one pump stage or pump flow. According to an essential aspect of the invention, this switching process is not effected by a conventional temperature switching valve.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the first hydraulic resistance arranged in the direction of flow to the tank or intake area is designed as a temperature switching valve. The temperature switching valve is preferably biased into its open position and, according to a further essential aspect of the invention, is only used to interrupt the connection to the intake area or tank depending on the temperature in order to prevent leakage flows. This arrangement has the advantage that if the temperature switching valve fails, the switching function of the actuating device is still available. In this case, however, the delivered volume flow decreases with a reduced pressure level, since the leakage flow via the connection between the pump outlet and the intake area or tank is not prevented by the temperature switching valve.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the second hydraulic resistance arranged in the direction of flow to the tank or intake area is designed as a temperature switching valve. The temperature switching valve, like the temperature switching valve described in the previous paragraph, can contain a conventional wax element. A hydraulic resistance, for example an orifice plate, is preferably connected upstream of the temperature switching valve in order to reduce the pressure acting on the switching element when the temperature switching valve is adjusted.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve encompasses at least one bimetallic spring element. The temperature switching valve is preferably designed as a 2/2-way valve or 3/2-way valve. The temperature switching elements are preferably pressure-balanced.

A further preferred exemplary embodiment of the pump arrangement is characterized in that a further hydraulic resistance is connected upstream of the temperature switching valve. Depending on the design of the temperature switching valves, an additional hydraulic resistance can also be connected upstream of the temperature switching valves.

A preferred exemplary embodiment of the pump arrangement is characterized in that the further hydraulic resistance is designed as an orifice plate. The orifice serves to reduce the pressure in front of the temperature switching valve in order to enable low adjustment forces.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the two hydraulic resistances are designed as throttles. The throttles are preferably designed as temperature-dependent adjustable throttles.

A further preferred exemplary embodiment of the pump arrangement is characterized in this way shows that the two hydraulic resistances have variable passage cross-sections, the size of which changes with temperature. According to a further essential aspect of the invention, the hydraulic resistances are designed as temperature-dependent resistances which increase or decrease according to the prevailing temperature of the working medium.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the first hydraulic resistance arranged in the direction of flow to the tank is designed in such a way that it is open at low temperatures. This ensures that when the intermediate pressure level is sufficiently high, the adjusting device is actuated in order to switch off at least one pump flow or pump stage.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the first hydraulic resistance arranged in the direction of flow to the tank has a variable passage cross section which decreases with temperature. This ensures that the intermediate pressure level drops as the temperature increases.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the first hydraulic resistance arranged in the direction of flow to the tank is designed in such a way that it is closed at high temperatures. This prevents unwanted leakage at high temperatures.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the second hydraulic resistance arranged in the direction of flow to the tank is designed in such a way that it is closed at low temperatures. This ensures that at least one pump flow or pump stage is switched off as soon as a sufficiently large intermediate pressure has been built up.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the second hydraulic resistance arranged in the direction of flow to the tank has a variable passage cross section which increases with the temperature. This ensures that the temperature switching valve switches on the second pump flow or pump stage at high temperatures.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the second hydraulic resistance, which is arranged in the flow direction toward the tank, is open at high temperatures. This ensures that the control device switches on both pump flows or pump stages at high temperatures, or switches off one of the pump flows or pump stages.

A further preferred exemplary embodiment of the pump arrangement is characterized in that one of the hydraulic resistances is designed as an orifice plate. The orifice is temperature independent and serves to create the intermediate pressure and minimize leakage.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the orifice has a constant orifice diameter. As a result, the manufacturing costs can be reduced.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the hydraulic resistance designed as an orifice plate is connected between the pump outlet and the actuating device. This arrangement has proven to be particularly advantageous within the scope of the present invention.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the hydraulic resistance is designed as a throttle. The throttle serves to generate the intermediate pressure depending on the temperature and/or to reduce the leakage.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the throttle has a constant throttle geometry. As a result, the manufacturing costs can be reduced. The choke geometry includes in particular the choke length and the choke diameter.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve is acted upon by the outlet pressure of a first pump flow or pump stage via an additional control line. The switching valve can be acted upon by the intermediate pressure via a first control line. The additional control line improves the pressure-dependent switch-off of a pump flow or pump stage.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the sequence valve comprises a valve piston with a first control surface, which can be acted upon by the intermediate pressure, and with a second control surface, which can be connected to the pump outlet pressure via the additional control line is acted upon. The valve piston is preferably of stepped design. With the help of the two control surfaces, the switch-off behavior of the sequence valve can be specifically influenced. This achieves an additional pressure limiting function for the pump outlet pressure.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the second control surface is smaller than the first control surface. It can thereby be achieved that the pump flow or pump stage is only switched off at a higher pressure level, in particular at high speeds.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve is equipped with a temperature switching element. The temperature switching element is, for example, a conventional wax element.

A further preferred exemplary embodiment of the pump arrangement is characterized in that a temperature switching valve is connected between the pump outlet and the hydraulic resistances. The temperature switching valve is used to prevent leakage flows. The hydraulic resistances are preferably connected in series between the temperature switching valve and the tank.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve is a 2/2-way valve with a closed position in which a connection between one or the pump outlet and the hydraulic resistance is interrupted, and an open position in which the connection between the pump outlet and the hydraulic resistances is released. The temperature switching valve is biased into its open position, preferably by a spring.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the actuating device comprises a pilot-operated switching valve which allows one of a number of pump flows or pump stages to be pumped into the tank or intake area or to the consumer as a function of temperature. The pilot control can be used to switch the sequence valve in a stable manner in a simple manner.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve is designed as a 2/2-way valve which is pilot-controlled by a temperature switching valve. The sequence valve is preferably designed as a proportional valve. According to a further essential aspect of the invention, only one temperature control valve is used for pilot control of the connection valve.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connection valve is biased into a closed position, in which a connection between the outlet of at least one of the pump flows or pump stages and the tank or intake area is interrupted. This ensures that the pump starts with multiple flows, preferably with two flows. In addition, a sufficient supply is ensured even if the temperature switching valve fails.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve has an open position in which the connection between the outlet of at least one of the pump flows or pump stages and the tank or intake area is released. In the open position of the sequence valve, at least one of the pump flows or pump stages delivers into the tank or intake area.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve is designed as a 3/2-way valve with a closed position in which a control connection between the outlet of one of the pump flows or pump stages and a control line that connects the temperature switching valve to the sequence valve is interrupted . The sequence valve is switched depending on the pressure via the control line.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the control line is connected to the tank or intake area when the temperature switching valve is in the closed position. This ensures a safe pressure reduction of the control line.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve is designed as a 3/2-way valve with an open position in which the control connection between the output of one of the pump flows or pump stages and the control line is released. In the open position of the temperature switching valve, the connection to the tank is interrupted.

A further preferred exemplary embodiment of the pump arrangement is characterized in this way indicates that the temperature switching valve is designed as a solenoid valve. The solenoid valve is preferably controlled as a function of temperature.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve is designed as a bimetallic rotary piston valve. A rotary piston of the rotary piston valve is rotated as a function of temperature, preferably with the aid of a bimetallic spring element.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve comprises a bimetallic spring which is spirally wound. One end of the bimetallic spring is preferably connected to the rotary piston in a rotationally fixed manner. The other end of the bimetallic spring is preferably clamped in place in the housing.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve comprises a rotary piston with a through hole, which temperature-dependently connects the output of at least one of the pump flows or pump stages to a control line to the sequence valve. The connection between the pump outlet and the control line is achieved by turning the rotary piston depending on the temperature.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the rotary piston has a relief groove which, depending on the temperature, connects the control line to the sequence valve to a relief line to the tank. As a result, a pressure reduction in the control line is made possible in a simple manner as a function of temperature.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve encompasses at least one bimetallic spring element. The bimetallic spring element is designed, for example, as a bimetallic snap spring and/or bimetallic disc spring. A closing body or closing element of the temperature switching valve is switched depending on the temperature by a temperature-dependent deformation of the bimetallic spring element.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the bimetallic spring element can be deformed relative to at least one passage opening in such a way that the passage opening is closed or opened depending on the temperature. The bimetallic spring element is designed, for example, as a bimetallic spring leaf which, depending on the temperature, comes into contact with a closing area on the passage opening.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the bimetallic spring element has a sealing element in the area of the passage opening. This ensures that the passage opening is sealed tightly.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the bimetallic spring element can be deformed between two through-openings in such a way that the through-openings are closed or opened depending on the temperature. The bimetallic spring element alternately closes one of the two passage openings. It is also possible that in an intermediate position of the bimetallic spring element both passage openings are released.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve comprises at least two bimetallic spring elements which can be deformed relative to at least one through-opening in such a way that the through-opening or openings are closed or opened depending on the temperature. By using, for example, several bimetallic spring leaves, the demands on the individual bimetallic leaf spring elements in terms of force can be reduced.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the bimetallic spring element is pressure-balanced, apart from the region of the at least one passage opening or passage openings. The bimetallic spring element comprises, for example, a bimetallic spring leaf which is subjected to the same pressure on both sides, apart from the area of the through-opening or through-openings which can be closed, for example, by a sealing element or the bimetallic spring element itself.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the temperature switching valve comprises a housing with at least one through-channel which, depending on the temperature, connects the output of at least one of the pump flows or pump stages to a control line to the switching valve. Alternatively, the temperature switching valve can be integrated into a housing of the pump arrangement without a housing.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the housing has a relief channel which, depending on the temperature, connects the control line to the sequence valve to a relief line to the tank or intake area. The lines mentioned in the present text can be integrated as ducts in existing housing body parts. Alternatively, the lines can also be designed as separate lines.

Alternatively or additionally, the above-mentioned object is achieved with a pump arrangement with an adjustable delivery volume, which is delivered from an intake area or tank to a consumer, and with an adjusting device that can be adjusted as a function of temperature, in that the adjusting device includes a pilot-controlled connection valve that one of several pump flows or pump stages, depending on the viscosity, can be pumped into the tank or intake area or to the consumer. In this case, the pressure drop across a gap is preferably measured. The measured pressure drop is directly proportional to the viscosity. If the temperature of the working medium increases, its viscosity decreases.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve is designed as a 2/2-way valve which is pilot-controlled by a pilot valve which is subjected to a pressure difference of a laminar gap flow. The temperature switching valve is preferably designed as a proportional valve.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the laminar gap flow is generated by a hydraulic resistance which is connected to the outlet of one of a number of pump flows or pump stages. The hydraulic resistance is preferably designed as a throttle.

A further preferred exemplary embodiment of the pump arrangement is characterized in that a further hydraulic resistance is connected between the hydraulic resistance and the tank or the intake area. The further hydraulic resistance can be designed as a throttle or an orifice.

A preferred exemplary embodiment of the pump arrangement is characterized in that the further hydraulic resistance is designed as an adjustable throttle with a variable throttle cross-section, the size of which depends on the temperature. This can reduce unwanted leakage.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the pilot valve is designed as a 2/2-way valve with an open position and a closed position. When the pilot valve is in the open position, the pressure at the outlet of one of several pump flows or pump stages is applied to the sequence valve via a control line.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connection valve is biased into a closed position, in which a connection between the outlet of at least one of the pump flows or pump stages and the tank or intake area is interrupted. This ensures that the pump starts in multiple flows, preferably in two flows, or in multiple stages, preferably in two stages.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the connecting valve has an open position in which the connection between the outlet of at least one of the pump flows or pump stages and the tank or intake area is released. In the open position of the sequence valve, at least one of the pump flows or pump stages delivers back into the tank or intake area.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the pump comprises two pump flows or pump stages, between the outlets of which a non-return valve is connected. The non-return valve ensures that only the switched off pump flow or pump stage delivers back into the tank or intake area. The activated pump flow or pump stage delivers to the consumer.

• 1 einen Hydraulikschaltplan einer Pumpenanordnung gemäß einem ersten Ausführungsbeispiel mit Zuschaltventil, einem Temperaturschaltventil und zwei hydraulischen Widerständen;
• 2 eine ähnliche Pumpenanordnung wie in 1 gemäß einem zweiten Ausführungsbeispiel mit einem Zuschaltventil und einem Temperaturschaltventil;
• 3 eine ähnliche Pumpenanordnung wie in den 1 und 2 mit einem Zuschaltventil und einem Vorsteuerventil, das viskositätsabhängig angesteuert ist;
• 4 eine Pumpenanordnung gemäß einem vierten Ausführungsbeispiel mit einem Zuschaltventil und zwei hydraulischen Widerständen;
• 5 und 6 jeweils ein kartesisches Koordinatendiagramm, in welchem der Drosselquerschnitt der hydraulischen Widerstände aus 4 über der Temperatur aufgetragen ist;
• 7 eine Pumpenanordnung gemäß einem weiteren Ausführungsbeispiel mit einem Zuschaltventil und zwei hydraulischen Widerständen;
• 8 eine vergrößerte Detailansicht aus 7;
• 9 eine Pumpenanordnung gemäß einem weiteren Ausführungsbeispiel mit einem Zuschaltventil, zwei hydraulischen Widerständen und zwei Temperaturschaltventilen;
• 10 eine Pumpenanordnung gemäß einem weiteren Ausführungsbeispiel mit einem Zuschaltventil, einem Temperaturschaltventil und einem hydraulischen Widerstand;
• 11 eine ähnliche Pumpenanordnung wie in 2 mit einem Temperaturschaltventil in einer ersten Schaltstellung;
• 12 die gleiche Pumpenanordnung wie in 11 mit dem Temperaturschaltventil in einer zweiten Schaltstellung;
• 13 eine perspektivische Darstellung eines als Bimetall-Drehkolbenventil ausgeführten Temperaturschaltventils;
• 14 ein als Bimetall-Schnappfederventil ausgeführtes Temperaturschaltventil im eingebauten Zustand im Schnitt;
• 15 ein ähnliches Bimetall-Schnappfederventil wie in 14 gemäß einem weiteren Ausführungsbeispiel mit einem Gehäuse im eingebauten Zustand und 16 ein ähnliches Bimetall-Schnappfederventil wie in 15 allein in perspektivischer Darstellung.

Further advantages, features and details of the invention result from the following description, in which various examples are described in detail with reference to the drawing. Show it:

• 1 a hydraulic circuit diagram of a pump assembly according to a first embodiment with a sequence valve, a temperature switching valve and two hydraulic resistors;
• 2 a similar pump arrangement as in 1 according to a second embodiment with a sequence valve and a temperature switching valve;
• 3 a similar pump arrangement as in the 1 and 2 with a switching valve and a pilot valve which is controlled as a function of viscosity;
• 4 a pump assembly according to a fourth embodiment with a sequence valve and two hydraulic resistors;
• 5 and 6 each a Cartesian coordinate diagram, in which the throttle cross-section of the hydraulic resistances 4 is plotted against temperature;
• 7 a pump assembly according to a further embodiment with a sequence valve and two hydraulic resistors;
• 8th an enlarged detail view 7 ;
• 9 a pump arrangement according to a further exemplary embodiment with a sequence valve, two hydraulic resistances and two temperature switching valves;
• 10 a pump arrangement according to a further exemplary embodiment with a sequence valve, a temperature switching valve and a hydraulic resistor;
• 11 a similar pump arrangement as in 2 with a temperature switching valve in a first switching position;
• 12 the same pump arrangement as in 11 with the temperature switching valve in a second switching position;
• 13 a perspective view of a bimetallic rotary valve designed as a temperature switching valve;
• 14 a cross-section of a temperature switching valve designed as a bimetallic snap-action spring valve when installed;
• 15 a similar bimetal snap-action spring valve as in 14 according to a further embodiment with a housing in the installed state and 16 a similar bimetal snap-action spring valve as in 15 only in perspective.

In the 1 until 4 , 7 and 9 until 12 a pump arrangement according to various exemplary embodiments is shown in each case in the form of a hydraulic circuit diagram. The pump arrangement comprises at least a first stage or pump flow 1 and a second pump stage or pump flow 2. The pump arrangement is preferably a vane pump with a rotor containing radially displaceable vanes in slots that slide along a peripheral contour. The structure and function of such vane pumps is, for example, from the international publication WO 02/097273 A2 known. The enlarging and reducing cells between the vane, peripheral contour and rotor create suction and pressure chambers, which are connected to the pump inlet and outlet via high-pressure kidneys and low-pressure kidneys.

The pump arrangement is used, for example, to supply an internal combustion engine or a motor with lubricant, in particular lubricating oil. The pump arrangement according to the invention is therefore also referred to as a lubricating oil pump. It is known that after the warm-up phase, an engine is mainly operated with an average oil temperature of around 90 degrees Celsius. The average oil temperature of around 90 degrees Celsius is an indication of an order of magnitude. Depending on the engine design, the average oil temperature can also deviate from the specified value and can be 70 or 100 degrees Celsius, for example. For this operating condition, the pump only has to deliver half the flow rate that is required at maximum oil temperature. Therefore, the pump arrangement according to the invention is designed in multiple stages, with the individual pump stages or pump flows 1, 2 being switched on or off depending on the temperature. However, other pump types can also be used, such as gear pumps, which suck in lubricating oil via suction lines and deliver it to the engine via pressure lines.

The two pump stages and pump flows 1 , 2 suck in a working medium, for example lubricating oil, from a tank 5 via a suction region 3 and a suction line 4 . The working medium reaches the inlets of the pump stages or pump flows 1, 2 via the intake line 4. The two pump stages or pump flows 1, 2 are connected to the intake area 3 via a connecting line 10, or can be connected to the intake area 3 via the connecting line 10. The connecting line 10 and the other lines of the pump arrangement can be designed in whole or in part as a duct which is integrated into a pump or pump arrangement.

Starting from the first pump stage or pump flow 1, the connecting line 10 comprises a first connecting line section 11, a second connecting line section 12 and a third connecting line section 13. The three connecting line sections 11 to 13 establish a connection between the first pump stage or pump flow 1 and the intake area 3 of the pump arrangement created. A fourth connecting line section 14 creates a further connection between the first connecting line section 11 and the third connecting line section 13. The fourth connecting line section 14 opens out at a junction 15 tion with the first connecting line section 11 in a supply line 16, which leads to a consumer 18, in particular a motor, which is indicated by the symbol of a throttle or a variable throttle.

A check valve 20 is connected in the fourth connecting line section 14 between an output 21 of the first pump stage or pump flow 1 and an output 22 of the second pump stage or pump flow 2 . The check valve 20 is designed and arranged in such a way that both pump stages or pump flows 1, 2 can deliver to the consumer 18. The check valve 20 prevents the first pump stage or pump flow 1 from delivering to the outlet 22 of the second pump flow or pump stage 2 or via the fourth connecting line section 14 and the third connecting line section 13 back into the tank 5 . At the same time, the check valve 20 enables the second pump stage or pump flow 2 to be switched on to the first pump flow or pump stage 1.

A sequence valve 25, which is preferably designed as a proportional valve, is connected between the output 22 of the second pump stage or pump flow 2 or the check valve 20 and the third connecting line section 13 or the fourth connecting line section 14. The sequence valve 25 is designed as a 2/2-way valve and 1 shown in its closed position, in which a connection between the output 22 of the second pump stage or pump flow 2 and the third connecting line section 13 is interrupted. In this switch position of the sequence valve 25, the second pump stage or pump flow 2 delivers together with the first pump stage or pump flow 1 to the consumer 18. The sequence valve 25 is biased into the closed position shown by a spring 26. The sequence valve 25 is controlled via a control line 27 . A force is applied to a sequence valve piston of the sequence valve 25 via the control line 27 and counteracts the prestressing force of the spring 26 .

If the pressure in the control line 27 or the resulting pressure force on the sequence valve piston exceeds the prestressing force of the spring 26, the sequence valve piston moves from the closed position shown into an open position, in which the connection between the outlet 22 of the second pump stage or pump flow 2 and the third connecting line section 13 is released into the tank 5 . In the (not shown) open position of the connection valve 25, the second pump stage or pump flow 2 delivers via the fourth connecting line section 14 and the third connecting line section 13 back to the intake area 3. An undesired return flow from the first pump stage or pump flow 1 delivers is prevented by the check valve 20. The first pump stage or pump flow 1 conveys, when the sequence valve 25 is in its open position, only to the consumer 18.

The control line 27 starts at a tap 28 in the second connecting line section 12 . The tap 28 is arranged between two hydraulic resistances 31 and 32 . The first hydraulic resistance 31 is arranged between the outlet 21 of the first pump stage or pump flow 1 and the tap 28 . The second hydraulic resistance 32 is arranged between the tap 28 and the suction area 3 . In 1 the first hydraulic resistance 31 is designed as an orifice plate and the second hydraulic resistance 32 is designed as a throttle.

A temperature switching valve 35 is connected between the branch 15 and the first hydraulic resistance 31 . The temperature switching valve 35 is designed as a 2/2-way valve and is temperature-controlled, as indicated by an arrow 36 . The temperature switching valve 35 is biased into its illustrated open position by a spring 38, in which a connection between the branch 15 and the first hydraulic resistance 31 is released. When the temperature increases, the temperature switching valve 35 switches to its closed position (not shown), in which the connection between the branch 15 and the first hydraulic resistance 31 is interrupted.

The temperature switching valve 35 can include a working element that enables a temperature switching function of the temperature switching valve 35 . The working element can be filled with a wax, for example, which, due to a phase transformation for volume expansion in a selected temperature range, leads to an actuation of a valve piston of the temperature switching valve. Such a piston can actuate a closing unit directly, which enables the second pump stage or pump flow 2 to be switched on.

As a result of wear on the working element, the temperature at which the temperature switching valve with the working element made of wax is closed can increase. In the worst case, wear and tear can lead to a total failure of the working element and thus of the temperature switching element, so that the second pump stage or pump flow 2 is not switched on. Then there is the risk of a lack of oil supply to the consumer, in particular to the engine or its ancillary units. By the inventive Pump arrangement, the switching function can be performed fail-safe.

At the in 1 illustrated embodiment, the viscosity of the working medium is used as a manipulated variable. in the in 1 In the switching position of the valves 25 and 35 shown, the working medium pumped by the two pump flows 1, 2 travels from the outlets 21, 22 of the pump flows or pump stages 1, 2 via the hydraulic resistances 31, 32 to the intake area 3. With increasing temperature and thus decreasing viscosity, the Pressure of the working medium in the area of tap 28 between the orifice plate 31 and the throttle 32 to a lower level than in the connecting line 10. The higher the temperature or the lower the viscosity, the greater the pressure difference between the tap 28 and the connecting line 10.

According to an essential aspect of the invention, the sequence valve 25 is actuated by the intermediate pressure at the tap 28 in order to switch the second pump stage 2 on or off. If the intermediate pressure between the two hydraulic resistances 31, 32 is low, the sequence valve 25 remains in its closed position and both pump flows 1, 2 deliver to the consumer 18. If the pressure force acting on a valve piston of the sequence valve 25 due to the intermediate pressure exceeds the size of the prestressing force of the Spring 26 exceeds, then the sequence valve 25 opens and the second pump flow 2 delivers to the intake area 3. This switching process is independent of the purely temperature-switched temperature switching valve 35.

At the in 1 In the pump arrangement shown, the temperature switching valve 35 has the task of interrupting the second connecting line section 12 when the temperature of the working medium increases, in order to prevent unwanted leakage flows. The pump arrangement shown provides the advantage that even if the temperature switching valve 35 fails, the switching function of the switching valve 25 continues. If the temperature switching valve 35 fails, there is only a slight reduction in the delivered volume flow and reduced pressure level, since the leakage flow through the second connecting line section 12 is not interrupted by the defective temperature switching valve 35, even at high temperatures.

In the 1 The pump arrangement shown also provides the advantage that when the pump is started, both pump flows 1 and 2 suck in and promote. At low temperatures below a nominal switching temperature, the pump sucks in and delivers in two ways. Only when a minimum pressure builds up is the pressure level in the second connecting line section 12 between the orifice 31 and the throttle 32 causing the sequence valve 25 to be switched to the single-flow operating state. The double-flow pumping achieves a significantly faster pressure build-up at the consumer, especially in the engine's lubricating oil circuit. The arrangement of the hydraulic resistors 31, 32 or the temperature switching valve 35 can be 1 pump arrangement shown are interchanged. The temperature switching valve 35 can be designed as a spool valve or as a seat valve in order to create a leak-free solution.

In 2 a pump arrangement is shown according to a further exemplary embodiment which corresponds to that in 1 illustrated embodiment is similar. Reference numerals 1 to 27 in FIGS 1 and 2 same or similar parts. In order to avoid repetition, the description of the parts designated by the reference numerals 1 to 27 is referred to the previous description of the 1 referred. In the following, mainly the differences between the two exemplary embodiments will be discussed.

At the in 2 In the illustrated embodiment, a 3/2-way valve 45 is used instead of a temperature-dependent wax element, which, as indicated by a symbol 46, is electromagnetically controlled and is used to pilot the sequence valve 25. The solenoid valve 45 is in its in 2 biased closed position shown and is also referred to as temperature switching valve 45, since it is preferably actuated depending on the temperature. In the closed position of the temperature switching valve 45, the control line 27, which is used to control the sequence valve 25, is connected to the intake area 3 via the temperature switching valve 45 and the second connecting line section 12. The solenoid valve 45 is normally closed, so that the pump starts with two flows, ie with both pump flows 1, 2 or pump stages 1, 2. If the temperature switching valve 45 or the electrical energy supply fails, the spring 48 ensures that the pump works or delivers with the maximum delivery volume, ie with both pump flows 1, 2.

As soon as the temperature of the working medium, in particular the lubricating oil, falls below a critical switching temperature, the solenoid valve or temperature switching valve 45 can be switched to its (in 2 not shown) are switched open position, in which the control line 27 is filled via the first connecting line section 11 with working medium, in particular lubricating oil, so that the oil pressure on the off Gear 21 of the first pump flow 1, which is connected to the second pump flow 2, can act on the connecting valve 25 via the first connecting line section 11 and the control line 27. When the pressure is sufficiently high, the pump arrangement is switched to the single-flow operating state, in which the second pump flow 2 conveys to the intake region 3 almost without pressure via the open sequence valve 25 .

If the pressure provided by the first pump flow 1 is too low in a higher temperature range, then the solenoid valve or temperature switching valve 45 is switched back to its closed position. The pressurized fluid in the control line 27, which acts on a control surface or a control piston of the connection valve 25, flows out via the open temperature switching valve 45 and the second and third connecting line sections 12 and 13. The pressure level in the control line 27 then drops to zero or tank pressure, with the sequence valve 25 being moved into its in 2 shown closed position is switched back. The pump is then operated again with both pump flows 1, 2. In the 2 The pump arrangement shown has the advantage, among other things, that no secondary leakage occurs.

In 3 1 shows a pump arrangement according to a further exemplary embodiment which is similar to the previous exemplary embodiments. Reference numerals 1 to 22 are used in FIGS 1 until 3 used to designate the same or similar parts. To avoid repetition, the previous description of the 1 and 2 referred. In the following, mainly the differences between the individual exemplary embodiments will be discussed.

At the in 3 In the exemplary embodiment shown, a first hydraulic resistance 51 is arranged in the first connecting line section 11 between the branch 15 and the second connecting line section 12 . An optional second hydraulic resistance 52 is arranged in the second connecting line section 12 . The first hydraulic resistance 51 is preferably designed as a throttle and serves to generate a laminar, ie temperature or viscosity-dependent, gap flow across a gap. The pressure drop across the gap is measured. This pressure drop is directly proportional to viscosity. Thus, the viscosity as the most important relevant system variable can be determined and used immediately. If the temperature of the working medium, in particular the oil temperature, increases, the viscosity of the working medium decreases. The pressure drop across the gap decreases.

The pressure drop across the first hydraulic resistance 51 is used to control a switching valve 55 which is pretensioned by a spring 54 . The switching valve 55 is designed as a 2/2-way valve, which is activated by the spring 54 in its in 3 shown closed position is biased. The switching valve 55 is switched into the control line 27 in such a way that, in its closed position, it interrupts a connection between the outlet 21 of the first pump flow 1 via the control line 27 to the switching valve 25 . The switching valve 55 is activated via two control lines 57 and 58 with the pressure in front of and behind the hydraulic resistance 51 .

in the in 3 switching position shown, both switching valves 25 and 55 are closed. Both pump flows or pump stages 1 and 2 deliver to the consumer 18. If the pressure drop or the pressure in front of the hydraulic resistance 51 increases due to operation or temperature, then the switching valve 55 switches to its (in 3 not shown) open position, in which the outlet pressure of the first pump flow 1 via the control line 27 on the sequence valve 25 acts. Due to the increasing pressure in the control line 27, the sequence valve 25 is also moved from its closed position to its (in 3 not shown) moves the open position, in which the second pump flow or pump stage 2 via the open sequence valve 25 promotes almost no pressure to the intake 3.

When the temperature of the working medium increases, the viscosity of the working medium, in this example the lubricating oil, decreases. The pressure drop across the gap or across the hydraulic resistance 51 is reduced. The switching valve 55 closes so that the sequence valve 25 is also returned to its closed position, as a result of which the second pump stage 2 is switched back to the first pump stage 1 .

In the 3 The pump arrangement shown has the advantage that the viscosity is the most important relevant reference variable for the working medium. No auxiliary power is required. In addition, the design of switching valves 25 and 55 ensures that the pump starts up and delivers with both pump stages or pump flows 1 and 2, which ensures rapid pressure build-up at the consumer, particularly in the engine's lubricating oil circuit.

The optional second hydraulic resistor 52 is preferably designed as an adjustable throttle with a temperature-dependent cross section. As a result, the losses due to leakage through the connecting line sections 12 and 13 is returned to the intake area 3 can be adjusted and/or reduced.

In 4 is a similar pump arrangement as in 1 shown according to a further embodiment. With the reference numerals 1 to 32 are in the 1 and 4 designates the same or similar parts. To avoid repetition, the previous description of the 1 refer. In the following, mainly the differences between the two exemplary embodiments will be discussed.

At the in 4 illustrated embodiment is the temperature switching valve (35 in 1 ) in the second connecting line section 12 is omitted. At the in 4 In the solution shown, both hydraulic resistors 31 and 32 are designed as temperature-dependent resistors, in particular as variable throttles. In 5 is shown approximately, in principle, greatly simplified using a Cartesian coordinate diagram that the opening cross section A ₁ of the throttle point 31 initially has a constant value and then falls linearly with the temperature. In 6 is indicated that the opening cross section A _Σ of the throttle point 28 is initially equal to zero and then increases linearly with the temperature to a constant value. At the tap 28 between the two throttle points 31, 32, which are also referred to as hydraulic resistances, there is an intermediate pressure which acts on the sequence valve 25 as a control pressure via the control line 27. The control pressure present at the tap 28 corresponds at most to the system pressure, ie the pressure provided by the two pump flows or pump stages 1 and 2.

At low temperatures, the first throttle point 31 is opened and the second throttle point 32 is closed due to the possibility of adjusting the throttles, so that at a sufficiently high pressure level, which results from a minimum pressure requirement of the consumer, the sequence valve 25 is actuated at the tap 28 in the control line 27 and is moved from its illustrated closed position to its open position (not illustrated). In the open position of the switching valve 25, the second pump flow 2 is conveyed almost without pressure via the open switching valve 25 to the intake area 3. The pump arrangement is then only operated with the first pump flow 1 .

If the temperature of the working medium rises to a value at which the pump arrangement is to deliver with both pump stages or pump flows 1 and 2, then the second adjustable throttle point 32 opens due to the temperature. The first throttle point 31 closes at the same time or with a time delay. Both events result in a pressure drop, in particular down to a pressure drop of zero in the control line 27, so that the sequence valve 25 is returned to its illustrated closed position by the prestressing force of the spring 26. The pump arrangement then delivers again with both pump stages or pump flows 1 and 2.

In the 4 The pump arrangement shown has the advantage that the temperature switching valve (35 in 1 ) can be omitted. A further advantage is that the pump arrangement sucks in working medium from the tank 5 when starting with both pump flows or pump stages 1 and 2 and delivers it to the consumer 18 . Only after a pressure build-up in the pump arrangement does the second pump stage or pump flow 2 switch off via the higher working medium pressure prevailing at tap 28, which is also referred to as intermediate pressure. As a result, a better supply of bearing points and ancillary units can be ensured in the initial phase when the engine is started. If the pressure level drops below a critical value when the sequence valve 25 is open, the second pump stage or pump flow 2 is switched on again.

If the second hydraulic resistor 32 fails, it can happen that it no longer closes and remains permanently open. In the event of such a failure, it is nevertheless ensured that the pump arrangement delivers permanently in two-stage operation with the maximum delivery volume, since the sequence valve 25 remains in its closed position due to the prestressing force of the spring 26 .

In a further embodiment, the in 4 first hydraulic resistance designated 31 by a conventional temperature switching valve with a wax element as an actuator or by a 2/2-way valve with a bimetallic spring as the temperature switching element, as will be described below. Alternatively or additionally, the in 4 with 32 designated second hydraulic resistance also replaced by a 2/2-way valve with a bimetallic spring. Depending on the design of the bimetallic valve, for example as a seat valve, an optional orifice can be installed upstream of the valve in order to reduce the pilot pressure. Due to the low working capacity of bimetallic valves, they cannot counteract high pressure. This pressure is reduced by means of the orifice mentioned above. Such an embodiment is described below with reference to FIG 9 described.

In 7 is a similar embodiment as in the 1 and 4 shown. With the reference numerals 1 to 32 are in the 1 , 4 and 7 designate the same or similar parts net. To avoid repetition, the previous descriptions of the 1 and 4 referred. In the following, mainly the differences between the individual exemplary embodiments will be discussed.

At the in 7 illustrated embodiment, the first hydraulic resistor 31 is designed as an orifice plate, ie independent of viscosity, and the second hydraulic resistor 32 is designed as a throttle, ie dependent on viscosity. Alternatively or additionally, the in 7 illustrated pump assembly supplemented by a pressure-dependent shutdown of the second pump stage or pump flow 2, as indicated by a dashed control line 62. The sequence valve 25 is acted upon via the control line 62 by the pressure which prevails in front of the first hydraulic resistance 31 .

In 8th the sequence valve 25 is shown in detail with a valve piston 70, which is acted upon on one end by the prestressing force of the spring 26. The valve piston 70 has a pin with a first control surface 71 on the other end face. The first control surface 71 is acted upon via the control line 27 by the intermediate pressure which prevails at the tap 28 between the two hydraulic resistances 31 and 32 . Radially outside the journal and the first control surface 71, the valve piston 70 has a second control surface 72, which is acted upon via the additional control line 62 by the outlet pressure from the first pump flow 1 or from both pump flows or pump stages 1 and 2, which is in the first connecting line section 11 between the branch 15 and the first hydraulic resistance 31 prevails.

At high temperatures of the working medium, when the pump arrangement delivers with two flows, the second control surface 72 is directly subjected to the highest pressure via the additional control line 62 . The first control surface 71 is preferably smaller than the second control surface 72 . In this way it can be achieved that the second pump stage or pump flow 2 is already switched off at a lower pressure level. At high speeds and correspondingly high pressures, the second pump stage or pump flow 2 can be switched off by means of the stepped valve piston 70, which leads to an additional, integrated pressure-limiting function.

In 9 an embodiment is shown that the embodiments of 1 and 4 resembles. With the reference numerals 1 to 36 are in the 1 , partly in 4 and in 9 designates the same or similar parts. To avoid repetition, the previous description of the 1 and 4 referred. In the following, mainly the differences between the individual exemplary embodiments will be discussed.

In contrast to 1 is at the in 9 illustrated embodiment between two hydraulic resistors 931 and 932, both of which are designed as an aperture, the temperature switching valve 35 is arranged. The tap 28 is arranged in the direction of flow towards the tank 5 between the second hydraulic resistance 932 and a second temperature switching valve 75 which, as indicated by an arrow 76, is controlled by the temperature of the working medium. The first temperature switching valve 35, as in the embodiment of 1 , biased into its open position. The second temperature switching valve 76 is also designed as a 2/2-way valve, but is biased by a spring 78 into its closed position shown. In the closed position, a connection between the tap 28 and the third connecting line section 13 is interrupted. This connection is released when the temperature control valve 75 is in the open position (not shown).

Compared to the in 4 illustrated embodiment is in 9 the variable throttle 31 is replaced by the temperature switching valve 35. The temperature switching valve 35 is preferably designed in a conventional manner with a wax element as an actuator or as a 2/2-way valve with a bimetallic spring. Depending on the design of the bimetallic valve, for example as a seat valve, the first hydraulic resistance 931 is connected upstream of the temperature switching valve 35 in order to reduce the pressure from the temperature switching valve 35 .

The orifice plate 931 is used to reduce the pressure level directly in front of the temperature switching valve 35 if a bimetallic element is used as a temperature-dependent actuating element, adjusting element and/or actuator element instead of the wax element. The screen 932 is preferably used when the temperature switching valve 75 is controlled by a conventional wax element. In this case, the pressure must first be reduced immediately before the temperature switching valve 75 . In the 9 pump assembly shown works in the same way as in the 4 and 7 illustrated pump assemblies. in the in 9 The pump arrangement shown can have a combined pressure and temperature control, as shown in 7 is shown to be integrated. Optionally, the two screens 931, 932 can also be omitted.

In 10 another exemplary embodiment is shown, which corresponds to that in 1 illustrated embodiment is similar. With the reference number 1 to 28 are in the 1 and 10 designates the same or similar parts. To avoid repetition, the previous description of the 1 referred. In the following, mainly the differences between the two exemplary embodiments will be discussed.

At the in 10 illustrated embodiment, the sequence valve 25 is redundant. On the one hand, the switch-on valve 25, which is prestressed into its closed position shown by the spring 26, is activated via the control line 27, similar to the one shown in FIG 1 illustrated embodiment, adjusted via the intermediate pressure at the tap 28, but in the closing direction. On the other hand, the sequence valve 25 is adjusted as a function of the temperature, as indicated by an arrow 81. Another spring 82 counteracts the temperature adjustment indicated by the arrow 81 . Via a further control line 85 the sequence valve 25 is alternatively or additionally actuated with the pressure which prevails at the outlet 22 of the second pump flow 2 .

For example, a conventional wax element can be integrated into the switching valve 25 . The wax element moves out at higher oil temperatures and closes the outlet opening of a bypass that connects the pressure area of the second pump flow or pump stage 2 with the intake area 3 . With this variant, a fail-safe solution can be achieved by redundancy of the switching/actuating options.

Below a nominal switching temperature, a valve piston (not shown) of the sequence valve 25 is not pressurized on one side. When the pump is at a standstill, the spring 26 ensures that the sequence valve 25 remains in its closed position. When the pressure at the pump outlet 22 of the second pump flow 2, which acts on the valve piston via the additional control line 85, increases, the valve piston together with the actuator, which is preferably designed as a wax element, is pushed back. Then the pump arrangement delivers in one stage. If the temperature rises to the nominal switching temperature, then on the one hand the actuator, in particular the wax element, can apply the lift and the sequence valve 25 can close.

If the actuator, in particular the wax element, fails, the switching function of the connection valve 25 continues, since a pilot valve 90 opens in this case. The pilot valve 90 is connected between the branch 15 and the tap 28 in the second connecting line section 12 . As indicated by an arrow 91, the pilot valve 90 is designed as a temperature switching valve. The temperature switching valve 90 is biased into a closed position by a spring 92 . When the temperature switching valve 90 opens when the temperature rises, the pressure at the outlet 21 of the first pump stage or pump flow 1 acts via the control line 27 on the valve piston of the sequence valve 25, because a hydraulic resistance 94 downstream of the tap 28 prevents the pressure from escalating tank pressure drops. As a result, the valve piston of the sequence valve 25 is moved from its open position into the closed position shown, as a result of which the second pump flow or pump stage 2 is switched to the first pump flow or pump stage 1.

In the 11 and 12 is a similar pump arrangement as in 2 shown. With the reference numerals 1 to 28 are in the 2 , 11 and 12 designates the same or similar parts. To avoid repetition, the previous description of the 2 referred. In the following, mainly the differences between the two exemplary embodiments will be discussed.

At the in the 11 and 12 In the illustrated embodiment, the sequence valve 25 is controlled by a temperature switching valve 95, which switches depending on the temperature, as indicated by an arrow 96. The temperature switching valve 95 is designed as a 3/2-way valve and 11 shown in its open position. When the temperature switching valve 95 is in the open position, the sequence valve 25 is acted upon via the control line 27 by the output pressure of the first pump stage or pump flow 1 and optionally the second pump stage or pump flow 2 . In 12 the temperature switching valve 95 is shown in its closed position, in which the connection between the outlet pressure of the pump flows or pump stages 1, 2 and the control line 27 is interrupted. When the temperature switching valve 95 is in the closed position, the control line 27 is connected to the intake area 3 or to the tank 5 via the connecting line sections 12 and 13 .

The temperature switching valve 95 is preferably designed as a bimetallic valve and is designed in such a way that the pump arrangement shown provides a maximum volume flow during a cold start at working medium temperatures of more than 90 degrees Celsius. In 11 shows the behavior of the pump arrangement at a system temperature of around 90 degrees Celsius. Depending on the engine design, the system temperature can also be lower or higher, for example 70 to 100 degrees Celsius. The system pressure acts via the first connecting line section 11 via the open temperature switching valve 95 and the control line 27 on the spring-loaded sequence valve 25. If the in the tax line 27 prevailing system pressure is less than the opposing biasing force of the spring 26, then the second pump stage or pump flow 2 of the first pump stage or pump flow 1 remains switched on.

If the system pressure in the control line 27 rises above the counteracting prestressing force of the spring 26, the second pump stage is switched off and no longer pumps into the system but to the intake area 3 or the tank 5. If the temperature indicated by the arrow 96 is, increases, then the temperature switching valve 95 closes, as in 12 is shown. The system pressure then no longer acts on the sequence valve 25 via the control line 27. When the temperature switching valve 95 closes, the control line 27 is relieved via the connecting line sections 12 and 13 into the intake area 3 or into the tank 5. When there is no longer any back pressure in the control line, the spring 26 pushes the sequence valve 25 back into its closed position shown, so that the two pump flows 1 and 2 are conveyed to the consumer 18 again.

In the 13 until 16 Various exemplary embodiments of the temperature switching valve 95 are shown as a bimetallic valve, some in different views. The various bimetallic valves are designed in such a way that, with reference to the 11 and 12 described functions are fulfilled. The bimetallic valves shown can be used in all pump arrangements according to the invention, in particular in the 3/2-way valve designs.

In 13 a bimetallic rotary valve 100 is shown in perspective. The bimetallic rotary valve 100 comprises a rotary piston 101 with a slotted end 102 into which a first end 104 of a bimetallic spring 105 engages. The bimetallic spring 105 is non-rotatably connected to the rotary piston 101 by the first end 104 and extends spirally around the slotted end 102 of the rotary piston 101 . A second end 106 is angled from the bimetallic spring 105 and may be attached to a housing (not shown) of the bimetallic rotary valve.

The rotary piston 101 includes a through hole 108 in the form of a transverse bore which extends transversely through the rotary piston 101 . The through hole 108 is used, depending on the temperature, to establish a connection between the first connecting line section (11 in the 11 and 12 ) and the control line 27 so that the system pressure can act on a control piston of the sequence valve 25. When the temperature rises, the bimetallic spring 105 expands, as a result of which the rotary piston 101 rotates about its longitudinal axis. As soon as a defined angle of rotation of the rotary piston 101 is reached, a relief groove 109, which runs in the longitudinal direction of the rotary piston 101, creates a connection between the control line 27 and the second and third connecting line sections 12, 13. The control line 27 is then released via the relief groove 109 in the intake area 3 or the tank 5 is relieved.

In 14 an embodiment of the temperature switching valve 95 as a bimetallic snap spring valve 120 is shown in section. The bimetallic snap spring valve 120 comprises a first housing part 121, which is designed, for example, as a housing base, and a second housing part 122, which is designed, for example, as a housing cover that closes the housing base. In the first housing part 121, a relief channel 124 is recessed, the second connecting line section 12 in the 11 and 12 is equivalent to. The relief channel 124 opens out in the area of a recess 125 which serves to accommodate a bimetallic snap spring 128 .

The bimetallic snap spring 128 comprises at least one bimetallic spring leaf 127 which can be deformed in the recess 125 in such a way that it closes or opens the relief channel 124 . If necessary, a seal 129 is attached to the bimetallic snap spring 128 and serves to seal the relief channel 124 tightly. In the extension of the relief channel 124 extends in the second housing part 122, a pressure channel 131, the first connecting line section 11 in the 11 and 12 is equivalent to. The bimetallic snap spring 128 with the seal 129 can be deformed in the recess 125 in such a way that it closes either the relief channel 124 or the pressure channel 131 . The other channel is then open. Both channels 124, 131 can also be open in an intermediate position.

The first housing part 121 further includes a control line 134, the control line 27 in the 11 and 12 is equivalent to. The control line 134 opens out radially on the outside into the recess 125. In the opening area of the control line 134, which is also referred to as a control channel, an annular groove-like depression 136, 137 is provided in the two housing parts 121, 122, for example. The indentations 136, 137 allow the working medium to pass between the recess 125 and the control line 134, regardless of the position of the bimetallic snap spring 128. Preferably, the bimetallic spring leaf 127 is essentially pressure-balanced on both sides except for the sealing seat, which reduces the actuating forces.

This in 14 illustrated embodiment has the advantage that the two housing parts 121, 122 can be formed by parts of the pump assembly, so that no separate valve housing is required. When the bimetallic snap spring 128 is in the prestressed state, the relief channel 124 is closed by the seal 129 fastened to the bimetallic snap spring 128 . Alternatively, the relief channel 124 can also be closed by the bimetallic snap spring 128 or the bimetallic spring leaf 127 itself by means of a metallic seal. In this state, which in 14 is shown, the pressure channel 131 and the control line 134 are connected to one another via the recess 125 so that the system pressure builds up in the control line 134 . When the in 14 shown bending of the bimetallic snap spring 128 reverses as a function of temperature, then the other side of the seal 129 closes the pressure channel 131, a connection between the control line 134 and the relief channel 124 being released. This allows the system pressure to escape from the control line 134 . Alternatively, the seal 129 can also be integrated into the housing parts 121, 122 in order not to influence the behavior of the bimetallic snap spring 128.

In 15 shows a section of a temperature switching valve 95 designed as a bimetallic snap-action spring valve 140 in the installed state. The bimetallic snap spring valve 140 comprises a valve housing 142 which is accommodated in a recess 143 of a housing body 144 which can be designed in one or more parts. The housing body 144 is preferably part of the pump assembly and is closed by a cover 145 . In the recess 143 opens first, a pressure channel 148, the first connecting line section 11 in the 11 and 12 corresponds, secondly, a relief channel 149, the second connecting line section 12 in the 11 and 12 corresponds, and thirdly, a control channel 150, which the control line 27 in the 11 and 12 is equivalent to.

The valve housing 142 includes a first tubular housing body 152 having one end disposed in the pressure passage 148 . A first half-shell 153 extends radially outwards from the first tubular base body 152 . The second tubular base body 154 of the valve housing 142 is accommodated with one end in the relief channel 149 . A second half-shell 155 extends radially outwards from the second tubular base body 154 . The two half-shells 153, 155, as can be seen in the perspective view of the 16 sees, be provided with recesses that allow the passage of the working medium. The two tubular base bodies 152, 154 are tightly accommodated with the aid of seals 156, 157 with the respective end in the respective channel.

A bimetallic snap-action spring 158 is clamped between the two half-shells 153, 155 of the valve housing 142. A central area of the bimetallic snap spring 158 is arranged between the two tubular base bodies 152 , 154 of the valve housing 142 . In the state shown, the bimetallic snap spring 158 rests against the tubular base body 154 in such a way that the relief channel 149 is closed. At the same time, a connection between the pressure channel 148 and the control channel 150 is released by the bimetallic snap spring 158 deformed as shown. If the system pressure increases, then this acts on the sequence valve 25 in the 11 , 12 and ensures single-stage pump operation.

As the temperature of the working fluid increases, the tension in the bimetal snap spring 158 increases until the temperature dependent spring tension exceeds the preload of the bimetal snap spring 159 . When a specific temperature is reached, the bimetallic snap-action spring 158 suddenly snaps over and, due to its temperature-related deformation, comes to rest against the tubular base body 152 in order to close the pressure channel 148 . This creates a connection between the control channel 150 and the relief channel 149 . As a result, the pressurized working medium can escape from the control channel 150 . Due to an associated relief of the valve piston of the sequence valve 25 (in the 11 and 12 ) The pump arrangement works with both pump floods or pump stages 1, 2. The in the 14 and 15 illustrated embodiments enable rapid switching, are inexpensive to produce and build smaller.

In 16 is the same valve body 142 as in 15 shown in perspective in half section. However, at the in 16 illustrated embodiment, two bimetallic disc springs 161, 162 clamped between the two half-shells 153, 155 of the valve housing 142. The functional principle corresponds to that in 15 illustrated embodiment. However, the two bimetallic disc springs 161, 162 are not prestressed and are not designed as snap springs. in the in 16 In the illustrated state of the bimetal disk spring valve, the deformed bimetal disk spring 162 closes the second tubular base body 154, which is preferably located in a relief channel (149 in 15 ) is included.

The non-deformed bimetallic disc spring 161 is at a distance from the first tubular base body 152, which is preferably located in a pressure channel (148th in 15 ) is included. This creates a connection between the pressure port and a control port (150 in 15 ) Approved. If the system temperature rises, then the in 16 to deform undeformed bimetallic disc spring 161 itself until it rests against the first tubular base body 152 . When it rests against the first tubular base body 152, it begins to build up a closing pressure. In turn, the second bimetallic disc spring 162 begins to move away from the second tubular body 154 . The system pressure can thus escape via the second tubular base body 154 and the associated relief channel. As a result, the valve piston of the sequence valve (25 in the 11 and 12 ) is relieved and can return to its original position.

Reference List

1

first pump stage or pump flood

2

second pump stage or pump flood

3

intake area

4

intake line

5

tank

10

connection line

11

first connecting line section

12

second connecting line section

13

third connecting line section

14

fourth connecting line section

15

branch

16

supply line

18

consumer

20

check valve

21

Exit

22

Exit

25

sequence valve

26

Feather

27

control line

28

tap

31

first hydraulic resistance

32

second hydraulic resistance

35

temperature switching valve

36

Arrow

38

Feather

45

temperature switching valve

46

symbol

48

Feather

51

first hydraulic resistance

52

second hydraulic resistance

54

Feather

55

switching valve

57

control line

58

control line

62

additional control line

70

valve piston

71

first control line

72

second control line

75

second temperature switching valve

76

Arrow

78

Feather

81

Arrow

82

Feather

85

control line

90

temperature switching valve

91

Arrow

92

Feather

94

hydraulic resistance

95

temperature switching valve

96

Arrow

100

Bimetal rotary valve

101

rotary piston

104

first end

105

bimetallic spring

106

second end

108

through hole

109

relief groove

120

Bimetal snap spring valve

121

first housing part

122

second housing part

124

relief channel

125

recess

127

bimetallic spring leaf

128

bimetallic snap spring

129

poetry

131

pressure channel

134

control line

136

deepening

137

deepening

140

Bimetal snap spring valve

142

valve body

143

recess

144

one or more part housing body

145

lid

148

pressure channel

149

relief channel

150

control channel

152

first tubular body

153

first half shell

154

second tubular body

155

second half shell

156

poetry

157

poetry

102

slotted end

158

bimetallic snap spring

161

bimetallic disc spring

162

bimetallic disc spring

931

first hydraulic resistance

932

second hydraulic resistance

Claims (57)

Pump arrangement with an adjustable delivery volume, which delivers from an intake area (3) or tank (5) to a consumer (18), and with an adjusting device which can be adjusted as a function of temperature, characterized in that the adjusting device has an intermediate pressure via a control line ( 27) controlled sequence valve (25), which allows one of several pump flows or pump stages (1, 2) to be pumped back into the intake area (3) or tank (5) of the pump arrangement or to the consumer, depending on the level of the intermediate pressure, if the The intermediate pressure is greater than the inlet pressure and lower than or equal to the outlet pressure of at least one of several pump flows or pump stages (1, 2) of the pump arrangement, the intermediate pressure for activating the actuating device being between two hydraulic resistances (31, 32; 51, 52; 931 , 932) prevails and/or is tapped off in series between a pump outlet and the tank (5) or r intake area (3) are connected. Pump arrangement according to one of the preceding claims, characterized in that the connecting valve (25) is designed as a 2/2-way valve which is pilot-controlled by the intermediate pressure. Pump arrangement according to one of the preceding claims, characterized in that the connecting valve (25) is biased into a closed position, in which a connection between the outlet of at least one of the pump channels or pump stages (1, 2) and the tank (5) or intake area (3 ) is interrupted. pump arrangement claim 3 , characterized in that the connecting valve (25) has an open position in which the connection between the output of at least one of the pump flows or pump stages (1, 2) and the tank (5) or intake area (3) is released. Pump arrangement according to one of the preceding claims, characterized in that the first hydraulic resistance arranged in the direction of flow to the tank (5) or intake region (3) is designed as a temperature switching valve (35). pump arrangement claim 5 , characterized in that the second hydraulic resistance arranged in the direction of flow to the tank (5) or intake area (3) is designed as a temperature switching valve (75). pump arrangement claim 6 , characterized in that the temperature switching valve (35, 75) comprises at least one bimetallic spring element. Pump arrangement according to one of Claims 6 until 7 , characterized in that the temperature switching valve (35, 75) is preceded by a third hydraulic resistance (31, 32). pump arrangement claim 8 , characterized in that the third hydraulic resistance (31, 32) is designed as an orifice. Pump arrangement according to one of Claims 5 until 9 , characterized in that the two hydraulic resistances (31, 32) are designed as throttles. Pump arrangement according to one of Claims 5 until 10 , characterized in that the two hydraulic resistances (31, 32) have variable passage cross-sections, the size of which changes with the temperature. Pump arrangement according to the preceding claim, characterized in that the first hydraulic resistance (31) arranged in the direction of flow towards the tank (5) is designed to be open at low temperatures. Pump arrangement according to the preceding claim, characterized in that the first hydraulic resistance (31) arranged in the direction of flow towards the tank (5) has a variable passage cross-section which decreases with temperature. Pump arrangement according to the preceding claim, characterized in that the first hydraulic resistance (31) arranged in the direction of flow towards the tank (5) is designed in such a way that it is closed at high temperatures. Pump arrangement according to the preceding claim, characterized in that the second hydraulic resistance (32) arranged in the direction of flow towards the tank (5) is designed in such a way that it is closed at low temperatures. Pump arrangement according to the preceding claim, characterized in that the second hydraulic resistance (32) arranged in the flow direction towards the tank (5) has a variable passage cross-section which increases with the temperature. Pump arrangement according to the preceding claim, characterized in that the second hydraulic resistance (32) arranged in the direction of flow towards the tank (5) is open at high temperatures. Pump arrangement according to one of Claims 5 until 9 , characterized in that one of the hydraulic resistances (31, 32) is designed as an orifice. Pump arrangement according to the preceding claim, characterized in that the orifice has a constant orifice diameter. Pump arrangement according to the preceding claim, characterized in that the hydraulic resistance (31, 32) designed as an orifice plate is connected between the pump outlet and the adjusting device. Pump arrangement according to one of Claims 5 until 9 or 18 until 20 , characterized in that one of the hydraulic resistances (31, 32) is designed as a throttle. pump arrangement Claim 21 , characterized in that the throttle has a constant throttle geometry. Pump arrangement according to one of Claims 10 until 22 , characterized in that the sequence valve (25) is acted upon via an additional control line (62) with the outlet pressure of a first pump flow or pump stage (1, 2). Pump arrangement according to the preceding claim, characterized in that the sequence valve (25) comprises a valve piston (70) with a first control surface (71) which can be acted upon by the intermediate pressure and with a second control surface (72) which can be connected via the additional control line (62) can be acted upon by the pump outlet pressure. Pump arrangement according to the preceding claim, characterized in that the second control surface (72) is smaller than the first control surface (71). Pump arrangement according to one of Claims 10 until 22 , characterized in that the sequence valve (25) is equipped with a temperature switching element. Pump arrangement according to one of Claims 10 until 26 , characterized in that a temperature switching valve (35) is connected between the pump outlet and the hydraulic resistances (31, 32). Pump arrangement according to the preceding claim, characterized in that the temperature switching valve (35) as a 2/2-way valve with a closed position, in which a connection between a pump outlet and the hydraulic resistances (31, 32) is interrupted, and an open position, in which the connection between the pump outlet and the hydraulic resistances (31, 32) is released. Pump arrangement according to the preamble of claim 1 , especially after claim 1 , In particular according to one of the preceding claims, characterized in that the adjusting device comprises a pilot-operated switching valve (25), which one of several pump flows or pump stages (1, 2) depending on the temperature in the tank (5) or intake area (3) or to the consumer ( 18) can be promoted. Pump arrangement according to the preceding claim, characterized in that the connecting valve (25) is designed as a 2/2-way valve leads, which is pilot-controlled by a temperature switching valve (45; 95). Pump arrangement according to the preceding claim, characterized in that the connecting valve (25) is biased into a closed position in which a connection between the outlet of at least one of the pump flows or pump stages (1, 2) and the tank (5) or intake area (3) is interrupted. Pump arrangement according to the preceding claim, characterized in that the connecting valve (25) has an open position in which the connection between the outlet of at least one of the pump flows or pump stages (1, 2) and the tank (5) or intake area (3) is released . Pump arrangement according to the preceding claim, characterized in that the temperature switching valve (45; 95) is designed as a 3/2-way valve with a closed position in which a control connection between the outlet of one of the pump flows or pump stages (1, 2) and a control line ( 27) is interrupted, which connects the temperature switching valve (45; 95) to the switching valve (25). Pump arrangement according to the preceding claim, characterized in that the control line (27) is connected to the tank (5) or intake area (3) when the temperature switching valve (45; 95) is in the closed position. Pump arrangement according to at least one of Claims 33 , 34 , characterized in that the temperature switching valve (45; 95) is designed as a 3/2-way valve with an open position in which the control connection between the output of one of the pump flows or pump stages (1, 2) and the control line (27) is released. Pump arrangement according to one of claims 29 until 34 , characterized in that the temperature switching valve (45) is designed as a solenoid valve. Pump arrangement according to one of claims 29 until 36 , characterized in that the temperature switching valve (95) is designed as a bimetallic rotary piston valve (100). Pump arrangement according to the preceding claim, characterized in that the temperature switching valve (95) comprises a bimetallic spring (105) which is spirally wound. Pump arrangement according to one of Claims 37 , 38 , characterized in that the temperature switching valve (95) comprises a rotary piston (101) with a through-hole (108) that connects the output of at least one of the pump flows or pump stages (1, 2) with a control line (27) to the sequence valve ( 95) connects. Pump arrangement according to the preceding claim, characterized in that the rotary piston (101) has a relief groove (109) which, depending on the temperature, connects the control line (27) to the switching valve (95) with a relief line to the tank (5) or intake area (3). . Pump arrangement according to one of claims 30 until 37 , characterized in that the temperature switching valve (95) comprises at least one bimetallic spring element (161, 162; 128; 158). Pump arrangement according to the preceding claim, characterized in that the bimetallic spring element (161, 162; 128; 158) is deformable relative to at least one through-opening such that the through-opening is closed or opened depending on the temperature. Pump arrangement according to the preceding claim, characterized in that the bimetallic spring element (161, 162; 128; 158) has a sealing element (129) in the region of the passage opening. Pump arrangement according to one of Claims 42 , 43 , characterized in that the bimetallic spring element (161, 162; 128; 158) between two through-openings is so deformable that the through-openings are closed or released depending on the temperature. Pump arrangement according to one of Claims 41 until 44 , characterized in that the bimetallic spring element (161, 162; 128; 158) is pressure-balanced, apart from the area of the through-opening or the through-openings. Pump arrangement according to one of Claims 41 until 45 , characterized in that the temperature switching valve (95) comprises at least two bimetallic spring elements (161, 162) which are deformable relative to at least one through-opening so that the through-opening or openings are closed or opened depending on the temperature. Pump arrangement according to at least one of Claims 41 until 46 , characterized in that the temperature switching valve (95) has a housing (142) with at least one passage comprises a channel which connects the output of at least one of the pump flows or pump stages (1, 2) to a control line (27) to the sequence valve (25) as a function of temperature. Pump arrangement according to the preceding claim, characterized in that the housing (142) has a relief channel which temperature-dependently connects the control line (27) to the switching valve (25) with a relief line to the tank (5) or intake area (3). Pump arrangement according to the preamble of claim 1 , especially after claim 1 , characterized in that the adjusting device comprises a pilot-operated switching valve (25) which allows one of several pump flows or pump stages (1, 2) to be pumped into the tank (5) or intake area (3) or to the consumer (18) depending on the viscosity. Pump arrangement according to the preceding claim, characterized in that the connecting valve (25) is designed as a 2/2-way valve which is pilot-controlled by a pilot valve (55) which is subjected to a pressure difference of a laminar gap flow. Pump arrangement according to the preceding claim, characterized in that the laminar gap flow is generated by a first hydraulic resistance (51) which is connected to one of several pump channels or pump stages (1, 2). Pump arrangement according to the preceding claim, characterized in that a second hydraulic resistance (52) is connected between the hydraulic resistance (51) and the tank (5) or intake area (3). Pump arrangement according to the preceding claim, characterized in that the second hydraulic resistance (52) is designed as an adjustable throttle with a variable throttle cross section, the size of which depends on the temperature. Pump arrangement according to one of Claims 50 until 53 , characterized in that the pilot valve (55) is designed as a 2/2-way valve with an open position and a closed position. Pump arrangement according to one of Claims 49 until 54 , characterized in that the sequence valve (25) is biased into a closed position in which a connection between the outlet of at least one of the pump flows or pump stages (1, 2) and the tank (5) or intake area (3) is interrupted. Pump arrangement according to the preceding claim, characterized in that the connecting valve (25) has an open position in which the connection between the outlet of at least one of the pump flows or pump stages (1, 2) and the tank (5) or intake area (3) is released . Pump arrangement according to one of the preceding claims, characterized in that the pump comprises two pump flows or pump stages (1, 2), between whose outlets (21, 22) a non-return valve (20) is connected.

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