Patent Application
20240426296
The present invention is directed to an automotive pendulum-slider pump for providing a lubrication system of an internal combustion engine with pressurized lubricant.
Pendulum-slider pumps are among the most frequently used pump types for providing lubricant to an internal combustion engine. Lubricant pumps of this type are usually designed as mechanical pumps and can, for example, be driven mechanically via the crankshaft of an internal combustion engine.
State-of-the-art internal combustion engines are subject to high requirements regarding noise emissions and vibrations. These high requirements accordingly also include the entire peripheral components of the combustion engine.
Lubricant pumps contribute significantly to total noise emissions so that vehicle manufacturers request low-noise and low-vibration lubricant pumps from pump manufacturers. Pendulum-slider pumps in particular generate a disruptive noise spectrum due to their high possible operating speed. The partially abrupt hydraulic pressure equalizations within the pumping chamber generate high-frequency pressure pulsations which contribute to a major amount of noise and vibrations. The abrupt hydraulic pressure variations occur in particular at the discharge opening of the pump. Every time the fluidic connection between a single rotating pumping compartment and the discharge opening is opened, the hydraulic pressure is abruptly equalized resulting in an acoustic opening noise.
These abrupt pressure equalizations generate an accumulated and constant pressure pulsation frequency spectrum with a significant noise level due to the equiangular arrangement of the pumping compartments.
DE 10 2010 023 068 A1 describes a pendulum-slider pump with an asymmetric arrangement of the pendulum vanes over the circumference of a pumping chamber. The resulting variation of the circumferential distance between the single pendulum vanes provides irregular opening intervals of the fluidic connection between each pumping compartment and the discharge opening, which result in an aperiodic and wide-spread pressure pulsation frequency spectrum, so that the noise emissions and the vibrations of the pump are reduced. The asymmetric arrangement of the pendulum vanes spreads the pressure pulsation frequency spectrum, but has no effect on the intensity of the acoustic opening noise resulting from the abrupt pressure equalizations, which generates the actual noise emissions.
An aspect of the present invention is to provide a cost-effective automotive pendulum-slider pump with particularly low noise emissions and an improved vibration behavior.
In an embodiment, the present invention provides an automotive pendulum-slider pump for providing a pressurized lubricant. The automotive pendulum-slider pump includes a rotor housing which is non-rotatable, a rotor ring which is configured to rotate within the rotor housing and to enclose a pumping chamber which comprises a suction opening, a discharge opening, and an automatically switching pressure adaption valve, a rotor hub which is connected with the rotor ring so as to co-rotate therewith, and a plurality of pendulum vanes which are arranged over a circumference of the rotor ring. Each of the plurality of pendulum vanes are pivotably hinged via a separate pendulum hinge at the rotor ring. The plurality of pendulum vanes are configured to fluidically separate the pumping chamber into a plurality of pumping compartments. The automatically switching pressure adaption valve of the pumping chamber is configured to pre-open a fluidic connection between at least one of the plurality of pumping compartments and the discharge opening immediately before the at least one of the plurality of pumping compartments has arrived at the discharge opening.
The present invention is described in greater detail below on the basis of embodiments and of the drawings in which:
An automotive pendulum-slider pump according to the present invention comprises a non-rotatable rotor housing, a rotatable rotor ring rotating within the rotor housing and enclosing a pumping chamber with a suction opening and a discharge opening. The pump further comprises a rotatable rotor hub, which is co-rotatably connected with the rotor ring and a plurality of pendulum vanes, which can, for example, but need not necessarily be, equiangularly arranged over the circumference of the rotor ring. Each pendulum vane is pivotably hinged by a separate pendulum hinge at the rotor ring. The pendulum vanes fluidically separate the pumping chamber into a plurality of pumping compartments.
The pressure difference between the suction opening and the discharge opening can be relatively high. The suction opening is generally at a low pressure level and can be below atmospheric pressure. The pressure level at the discharge opening is in contrast generally high compared to the suction opening pressure. The sudden opening of the fluidic connection between an arriving pumping compartment and the discharge opening results in an abrupt pressure equalization generating an audible acoustic opening noise. The acoustic opening noise appears with every pumping compartment arriving at the discharge opening causing a substantially constant pressure pulsation frequency spectrum. For modifying this pressure pulsation frequency spectrum, the pumping chamber is provided with an automatically switching pressure adaption valve for pre-opening a fluidic connection between at least one pre-openable pumping compartment and the discharge opening.
The pressure adaption valve is arranged so that the fluidic connection between the pre-openable pumping compartment and the discharge opening is provided right before the pre-openable pumping compartment has arrived at the discharge opening. Relevant hydraulic losses during the suction process are thereby avoided. The fluidic connection between the pre-openable pumping compartment and the discharge opening can be provided directly or indirectly. A direct fluidic connection can be realized by directly fluidically connecting the pre-openable pumping compartment with the discharge opening, for example, via a connection channel. An indirect fluidic connection can alternatively be provided by fluidically connecting the pre-openable pumping compartment with (as seen in the rotational direction) an adjacent leading pumping compartment which arrives at the discharge opening before the pre-openable pumping compartment. By fluidically connecting the pre-openable pumping compartment which has not arrived at the discharge opening with the leading pumping compartment which has already arrived at the discharge opening and is, as a result, at discharge pressure, the pre-openable pumping compartment is indirectly connected to the discharge opening. The pressure of the pre-openable pumping compartment is thereby adapted to the discharge pressure.
The adaption of the pressure in the pre-openable pumping compartment to the discharge pressure before the pre-openable pumping compartment arrives at the discharge opening reduces the relative pressure difference between the pre-openable pumping compartment and the discharge opening at the moment of the pre-openable pumping compartment arrives at the discharge opening. This results in a less abrupt pressure equalization when the pre-openable pumping compartment arrives at the discharge opening and opens the actual direct fluidic connection for discharging the lubricant so that the thereby caused hydraulic pressure pulsations and the acoustic opening noise at the discharge opening are reduced without relevantly affecting the pump efficiency. The pre-opened fluidic connection of the pre-openable pumping compartment accordingly only opens temporarily right before its arriving at the discharge opening, where the acoustic opening noise is most disruptive. The other non pre openable pumping compartments remain fluidically separated from the discharge opening before and after the discharging process so that the pumping efficiency is not substantially affected by the pressure adaption valve. Due to the pressure adaption valve, every pre-openable pumping compartment is fluidically earlier connected to the discharge opening before the actual discharging process, respectively. The pressure pulsation frequency spectrum is spread as a result, thereby resulting in a lower noise emission of the pump. The combination of this wide-spread pressure pulsation frequency spectrum in combination with the reduced acoustic opening noise significantly reduces the noise emission and the vibrations of the pendulum slider pump.
The automatically switching pressure adaption valve is designed so that the switching functionality of the pressure adaption valve can, for example, be achieved by a temporary overlapping of specifically arranged valve openings, wherein the overlapping depends on the angular position of the rotor ring. One of the valve openings can, for example, be static and one of the valve openings can, for example, co-rotate with the pre-openable pumping compartment, so that the valve openings do not permanently overlap and overlap only temporarily at least once per full rotation of the rotor. The switching functionality is thereby provided fully automatically and without requiring any additional switching element or control devices. When the valve openings are overlapping, the pressure adaption valve and accordingly the fluidic connection is open. The pressure adaption valve and, as a result, the fluidic connection, is otherwise closed.
The bypass flow quantity at every pressure adaption valve opening interval can, for example, be relatively low to avoid substantial pressure losses during the suction process or the discharging process. The valve opening area is relatively small to provide a throttling effect of the pressure adaption valve.
A similar pressure pulsation effect generally occurs at the opposite side of the pumping chamber when the pumping compartments arrive at the suction opening after the discharging process. The acoustic opening noise caused by the arriving of a pumping compartment at the suction opening is, however, lower than the acoustic opening noise at the discharge opening, so that the pressure adaption is more relevant at the discharge opening. It can thus be advantageous to provide another pressure adaption valve at the suction opening.
In an embodiment of the automotive pendulum-slider pump according to the present invention, some but not all pumping compartments can, for example, be pre-openable. The number of vanes can, for example, be odd and the number of pre-openable pumping compartments can, for example, be smaller than the number of pendulum vanes divided by two. In this configuration, the pre-openable pumping compartments define an asymmetric arrangement over the circumference of the pumping chamber. Due to the odd number of vanes, a pump with, for example, seven pendulum vanes, comprises three pre openable pumping compartments which are provided with a pressure adaption valve, so that the other four pumping compartments are not pre openable. The asymmetric arrangement of pre-openable pumping compartments (B) in relation to the non-pre-openable pumping compartments (A) can, for example, be defined as follows: B-A-B-A-B-A-A. This particularly asymmetric arrangement can, for example, cause more irregular opening intervals and thereby an even wider spreading of the noise spectrum than a pump with an even number of pendulum vanes does. The noise emissions and the vibrations are even more reduced as a result.
In an embodiment of the present invention, the rotor housing can, for example, be provided with one single static connection channel. The static connection channel comprises two openings. One opening is permanently connected to the discharge opening so that the connection channel is permanently at discharge pressure. The other valve opening can, for example, temporarily correspond to a valve opening of the pre-openable pumping compartment at the rotor ring in an overlapping manner. The valve openings of every pre-openable pumping compartment successively overlap with the corresponding valve opening of the connection channel at least once during one full rotation of the rotor ring so that the fluidic connection between the arriving pre-openable pumping compartment and the discharge opening is open for a defined pre-opening angle. The fluidic connection is closed after the valve opening of the pre-openable pumping compartment has passed the valve opening of the connection channel. The pressure adaption valve thereby switches automatically at least once per rotation of the rotor ring so that the pressure adaption valve intermittently opens and closes the fluidic connection during one rotation of the rotor ring and thereby provides a pressure adaption of the pre-openable pumping compartment to the discharge pressure right before the pre-openable pumping compartment actually arrives at the discharge opening.
In an alternative embodiment of the present invention, two adjacent pumping compartments within the pumping chamber, namely the pre-openable pumping compartment and a (as seen in the rotational direction) leading adjacent pumping compartment are fluidically connected by an automatically switching pressure adaption valve. The pressure adaption valve can, therefore, for example, comprise, in addition to the valve opening at the pre-openable pumping compartment, another separate valve opening at the adjacent leading pumping compartment, so that these two separate valve openings at the rotor ring define a valve opening pair. The two valve openings of the valve opening pair can, for example, be fluidically connected by a single static connection channel in the rotor housing to thereby allow a fluidic connection between the two adjacent pumping compartments. In contrast to a static connection channel which directly connects the pre-openable pumping compartment with the discharge opening, this embodiment with an alternative static connection channel connects the pre-openable pumping compartment with the adjacent leading pumping compartment. The fluidic connection between the pre-openable pumping compartment and the discharge opening is thereby provided via the leading pumping compartment already being in a direct fluidic contact with the discharge opening. The pre-openable pumping compartment is accordingly indirectly connected to the discharge opening right before the pre-openable pumping compartment arrives at the discharge opening.
The resulting shortcut between the adjacent pumping compartments causes a bypassing flow between the pumping compartments to provide a pressure adaption of the pre-openable following pumping compartment to the pressure of the leading pumping compartment or vice versa. Because of the adaption of the pressure of the pre-openable pumping compartment to the pressure of the adjacent leading pumping compartment being already connected to the discharge opening and thereby being at discharge pressure, the pressure of the (following) pre-openable pumping compartment is indirectly adapted to the discharge pressure. The pressure equalization between the pre-openable pumping compartment and the discharge opening is nevertheless equally smooth and the resulting reduction of the noise emissions is substantially as effective as in an embodiment with a direct fluidic connection between the pre-openable pumping compartment and the discharge opening.
The alternative static connection channel is arranged so that the fluidic connection between the two valve openings of the valve opening pair is opened and closed intermittently, so that the indirect pressure adaption valve is also a switching valve. Each valve opening of the valve opening pair passing-by the connection channel is opened and closed by temporarily fluidically connecting the valve openings via the connection channel once per rotation of the pump so that the pressure adaption valve is automatically and intermittently switching. The fluidic connection between the adjacent pumping compartments is thereby provided individually at a specific angular position within the pumping chamber and once per rotation. The fluidic connection is only open at a defined position of the pumping chamber with this static connection channel so that the fluidic connection is only open if needed. No pumping efficiency losses therefore occur between the adjacent pumping compartments during the suction process or the discharging process.
When the valve opening of the leading compartment arrives at the opening edge of the connection channel, the connection channel is pre-filled with lubricant flowing-in from the leading compartment via its valve opening so that the connection channel is at discharge pressure. The moment for opening the pressure adaption valve depends only on the angular extent and the angular position of the valve opening of the following compartment and of the connection channel. When the valve opening of the following pumping compartment arrives at the opening edge of the connection channel, the pressure adaption valve opens and thereby pre-opens a fluidic connection between the leading compartment and the following compartment. This fluidic connection is open until the valve opening passes the closing edge of the connection channel. Irrespective of the actively open fluidic connection of the pressure adaption valve itself, the effective pressure adaption functionality of the pressure adaption valve is only active until the pendulum vane separating the leading and the following compartment passes the opening edge of the discharge opening. The angular extent of the connection channel is larger than the angular extent of the valve opening pair in either case. The effective valve opening angle depends on the angular position and the angular extent of the connection channel with respect to the discharge opening edge and on the angular extent and the circumferential position of the valve openings in relation to the pendulum vane between the following pre-openable pumping compartment and the adjacent leading pumping compartment.
A pre-opening angle generally defines the angular extent from the pre-opening point of the fluidic connection between the pre-openable pumping compartment and the discharge opening to the opening of the actual fluidic connection between the pumping compartment and the discharge opening for the discharging process. The pre-opening angle accordingly substantially defines the effective valve opening angle. The pre-opening angle is significantly defined by the angle between the opening edge of the connection channel and the opening edge of the discharge opening, i.e., the theoretical circumferential overlap between these two opening edges. This pre-opening angle can, for example, be from 0.5 to 25.0°.
In an embodiment of the present invention, the valve opening can, for example, be defined by a valve opening groove at an axial front surface of the rotor ring. The groove has a very low depth of, for example, from 0.1 to 5.0 mm to provide the throttling effect.
In an embodiment of the present invention, the valve openings of each valve opening pair can, for example, be arranged adjacent to the pendulum hinge so that the fluidic connecting length between the adjacent pumping compartments is relatively short. The short connecting length allows a short but effective opening interval of the valve, which is in particular needed at higher rotational speeds.
In an embodiment of the automotive pendulum-slider pump according to the present invention, the rotor housing can, for example, be defined by a non-rotatable and radially shiftable control ring. The control ring is radially shiftable to vary the eccentricity between the rotor ring and the rotor hub. With this variable eccentricity, the displacement volume of the pumping compartments rotating within the pumping chamber is variable and, for example, adjustable to the lubrication requirements of the internal combustion engine so that the pump flow rate does not depend on the rotational speed of the pump. The valve openings can, for example, be arranged so that the opening and closing of the fluidic connection is independent of the eccentricity of the control ring. The switching functionality of the pressure adaption valve is therefore effective at any eccentricity position of the control ring.
In an embodiment of the present invention, the connection channel can, for example, be defined by a connection groove at an axial front surface of the rotor housing at the same axial end of the pumping chamber as the valve opening groove provided in the rotor ring. Similar to the valve opening groove, the connection groove is also provided with a very low depth of from 0.1 to 5.0 mm to provide a throttling effect of the pressure adaption valve for reducing the pump efficiency losses over the valve openings. It can be advantageous to provide both axial front surfaces with valve opening grooves and with corresponding connection grooves to provide two fluidically parallel pressure adaption valves at each pre-openable pumping compartment.
An embodiment of the present invention is described below with reference to the drawings.
The radially shiftable control ring 15 varies the eccentricity of the rotor ring 20,20′ with respect to the rotor hub 35 to thereby vary the specific displacement volume of the pumping compartments 40 so that the pump flow rate can be regulated independently of the rotational speed of the automotive pendulum-slider pump 10,10′.
In the embodiment of
The connection channel 55 is defined by a connection groove 59 at an axial front surface 16 of the control ring 15 at the same corresponding axial end of the pumping chamber 25 as the valve opening groove 56,57 at the rotor ring 20. The connection groove 59 is arranged in theoretical circumferential overlap with the opening edge 17 of the discharge opening 19, and extends in both circumferential directions at the inner cylinder surface 29 of the control ring 15 referring to the opening edge 17. The axial depth of the connection groove 59 is from 0.1 to 5.0 mm. A gap at the inner cylinder surface 29 of the control ring 15 is opened with this connection groove 59 so that the connection groove 59 is fluidically opened to the passing-by radially oriented valve openings 52,53 in the rotor ring 20.
The angular extent of the connection groove 59 defines a connection channel angle R of 20°, which is larger than the angular extent of the valve opening pairs 51. The angular extent of the valve opening pairs 51 is defined by the angle being spanned between the extreme valve opening edges of each valve opening pair 51. The effective fluidic valve opening angle substantially depends on the pre-opening angle P which is defined by the angular extent between the circumferential opening edge of the connection groove 59 and the opening edge 17 of the discharge opening 19. As the opening edge 53′ of the valve opening 53 of the following pre-openable pumping compartment 40B is circumferentially centrically arranged with respect to the pendulum hinge 32, the effective fluidic valve opening angle is significantly defined by the pre-opening angle P. This pre-opening angle P is about 5°.
The pressure adaption valve is an automatically switching valve, so that the connection groove 59 intermittently fluidically connects the two valve openings 52,53, and thereby fluidically connects the leading non-pre-openable pumping compartment 40A and the following pre-openable pumping compartment 40B. The connection groove 59 is arranged so that a fluidic connection between the leading non-pre-openable pumping compartment 40A and the following pre-openable pumping compartment 40B is provided right before the following pre-openable pumping compartment 40B has arrived at the discharge opening 19. When the first valve opening 52 of the leading non-pre-openable pumping compartment 40A overlaps with the connection groove 59, the connection groove 59 is therefore pre-filled with lubricant from the leading non-pre-openable pumping compartment 40A so that the connection groove 59 is at discharge pressure. After that, when the second valve opening 53 of the following pre-openable pumping compartment 40B overlaps with the connection groove 59, i.e., if both valve openings 52,53 simultaneously overlap with the connection groove 59, the pressure adaption valve 50 pre-opens a fluidic connection between the leading non-pre-openable pumping compartment 40A and the following pre-openable pumping compartment 40B. The following pre-openable pumping compartment 40B is as a result indirectly fluidically connected to the discharge opening 19 via the leading non-pre-openable pumping compartment 40A until the pendulum vane 30′ between the leading non-pre-openable pumping compartment 40A and the following pre-openable pumping compartment 40B passes the opening edge 17 of the discharge opening 19. The pressure of the following pre-openable pumping compartment 40B is thereby adapted to the discharge pressure for lowering the pressure difference before opening the actual direct fluidic connection between the following pre-openable pumping compartment 40B and the discharge opening 19. The lower pressure difference results in a reduction of the pressure pulsations caused by the abrupt pressure equalization of the following pre-openable pumping compartment 40B with the discharge opening 19.
The rotor ring 20 is provided with a defined number of valve opening pairs 51 depending on the number of pendulum vanes 30 separating the pumping chamber 25. In this configuration, the automotive pendulum-slider pump 10 is provided with an odd number of seven pendulum vanes 30. The number of following pre-openable pumping compartments 40B is smaller than the number of pendulum vanes 30 divided by two, so that an automotive pendulum-slider pump 10 with seven pendulum vanes 30 is provided with three valve opening pairs 51, each at one following pre-openable pumping compartment 40B. The valve opening grooves 56,57 are arranged adjacent to and on both sides of the pendulum hinge 32. The arrangement of the valve opening pairs 51 over the circumference is asymmetrical. Every second pendulum hinge 32 is provided with a valve opening pair 51. Because of the odd number of pendulum vanes 30, one single pumping compartment 40C is not fluidically connected to any of its adjacent pumping compartments 40. An asymmetrical arrangement of the following pre-openable pumping compartments 40B is therefore provided. The thereby asymmetrically arranged pressure adaption valves 50 cause a spreading of the pressure pulsation frequency spectrum. The acoustic opening noise is additionally reduced at three pendulum vanes 30, which further reduces the noise emissions of the automotive pendulum-slider pump 10.
In the embodiment of
Compared to the first embodiment of
The circumferential arrangement of the following pre-openable pumping compartments 40B is identical to the asymmetric arrangement of the following pre openable pumping compartments 40B of
The present invention is not limited to embodiments described herein; reference should be had to the appended claims.
This application is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2021/052128, filed on Jan. 29, 2021. The International Application was published in English on Aug. 4, 2022 as WO 2022/161617 A1 under PCT Article 21 (2).
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/052128 | 1/29/2021 | WO |
