Patent Publication Number: US-10316847-B2

Title: Pump

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 USC 119 to German Patent Appl. No. 10 2015 106 671.8 filed on Apr. 29, 2015, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field of the Invention 
     The invention relates to a pump, such as a water pump for a water circuit of a motor vehicle. 
     2. Description of the Related Art 
     Pumps, such as water pumps, are used in motor vehicles, for example, to supply a coolant circuit with a flow of water to cool the motor vehicle engine and possibly other assemblies. Water flows as coolant through the drive engine and is heated there. Subsequently, the coolant flows through a coolant radiator where it is cooled again in a heat exchange, for example, with air, before the coolant is conveyed to the drive engine again by the pump. 
     The pump need not always perform in the maximum range, and can be reduced depending on the operating state of the motor vehicle. The pump performance is dependent, however, on the drive. If the pump is driven by the drive engine itself, however, the speed of the pump is determined by the speed of the drive engine, which does not have to correlate with the required pump performance. 
     A controllable pump therefore is desired. Very complicated solutions tend to be unsuitable in automotive applications due to high costs. 
     DE 10 2010 005 731 A1 discloses a pump having a delivery element and a valve element arranged downstream thereof and configured as a slide or rotary slide. There is an ability to control the pump via actuating means, but intermediate positions cannot be set satisfactorily by every actuating means. 
     WO 2013/120543 A1 discloses a pump having a valve element downstream of an impeller. The valve can be adjusted between two end positions by a vacuum cell. As a result, however, satisfactory control is not achieved because the vacuum cell usually cannot be moved satisfactorily into intermediate positions and held there. 
     It is the object of the invention to provide a pump that is of simple and inexpensive construction and nevertheless permits good control. 
     SUMMARY 
     The invention relates to a pump having a pump housing with an intake opening and an outlet opening. A drivable impeller is arranged in the pump housing and enables a fluid to be conveyed from the intake opening toward the outlet opening. A valve element is provided in the pump housing and can be set by an actuator to set the fluid flow that is conveyed by the pump. The setting of the valve element can be influenced by a magnetorheological braking element. As a result, the valve element can advantageously be set reliably in every operating position and also for a predefined time period by the controllable interaction of actuator and braking element, even if the actuator tends merely to be capable of being set briefly or unstably in intermediate positions. 
     The actuator for setting the valve element may be a pressure or vacuum actuator. The actuator can thus be a hydraulic or pneumatic actuator that can be loaded with pressure or with a vacuum to adjust or set the valve element. Actuators of this type are actuable between two end positions, and can be set briefly at intermediate positions. 
     The actuator may be a vacuum cell. Vacuum cells of this type can be manufactured simply and inexpensively and are therefore readily used, in particular, in automotive engineering. 
     The valve element may be arranged rotatably in the housing. As a result, a type of rotary slide or rotary valve can be formed and can simply control the conveyed fluid flow from a maximum fluid flow to a minimum fluid flow with a rotation of approximately 90°. The maximum fluid flow can be the fluid flow that the pump can convey at most and the minimum fluid flow can, for example, be a fluid flow of zero if the valve element interrupts the fluid flow completely. An intermediate position can correspond to a fluid flow between the maximum fluid flow and the minimum fluid flow. 
     The actuator may have a substantially linearly adjustable output element that acts via an actuating mechanism on the valve element that is arranged rotatably in the housing. As a result, a rotational movement of the valve element can be brought about via an actuator of simple configuration. A simple actuator is not expensive, but nevertheless brings about reliable control because the setting of the valve element is performed simply. The actuating mechanism may be a lever mechanism. As a result, the actuator can be articulated simply and reliably on the valve element, and secure articulation can be achieved over the service life nevertheless. 
     The magnetorheological braking element may be connected to the valve element and may act on the valve element. As a result, a direct action of the braking element can be transmitted to the valve element to bring about a rapid and direct action without external influences. 
     The magnetorheological braking element may be connected to the actuating mechanism and may act on the actuating mechanism. As a result, the magnetorheological braking element can be integrated simply into the actuating mechanism, while achieving installation space advantages and simplified assembly. 
     The magnetorheological braking element may act upon the output element of the actuator to provide a structural unit that can be assembled satisfactorily and can be manufactured simply and inexpensively. 
     The valve element may be mounted rotatably in the housing, and the magnetorheological braking element may act on a side of the valve element opposite the actuator. As a result, a satisfactory division of installation space can be achieved by mounting the two elements that act on the valve element on opposite sides of the housing. 
     In the following text, the invention will be explained in detail using one exemplary embodiment with reference to the drawing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic, perspective illustration of one embodiment of a pump according to the invention. 
         FIG. 2  is a further illustration of the pump of  FIG. 1 . 
         FIG. 3  is a partially sectioned illustration of the pump according to  FIG. 1 . 
         FIG. 4  is a sectional view of the pump according  FIG. 1 . 
         FIG. 5  is a perspective view of a pump with a completely open valve element. 
         FIG. 6  is a perspective view of a pump with a valve element that is only partially open. 
         FIG. 7  is a perspective view of a pump with a completely closed valve element. 
         FIG. 8  is perspective view of a further embodiment of a pump according to the invention. 
         FIG. 9  is a perspective view, partly in section, of a vacuum cell with a magnetorheological braking element as actuator for setting the valve element of the pump of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 to 4  show an embodiment of a coolant or water pump  1  for a motor vehicle. The pump  1  has a pump housing  2  with an intake opening  3  and an outlet opening  4 . As an alternative, the pump housing  1  can have more than one intake opening  3  and/or more than one outlet opening  4 . In the exemplary embodiment of  FIGS. 1 to 4 , the pump housing is partially of approximately tubular configuration, with the outlet opening  4  being configured as a tube opening in the longitudinal direction of the tubular part of the pump housing  2 . The intake opening  3  is a tube stub that extends approximately radially toward and connects to the tubular part of the pump housing  2 . 
     An impeller  5  is arranged within the pump housing  2  and is followed in the axial direction by a compression stage  6  and a sealing body  7 . The impeller  5  advantageously is configured as a fan wheel. The impeller  5  is received on a shaft  8  that is mounted rotatably in the pump housing  2 . The shaft  8  protrudes in the axial direction out of the pump housing  2  and is connected to a pulley wheel  9 . The pulley wheel  9  is drive-connected to a belt (not shown) of a belt drive, so that the impeller  5  in the pump housing  2  can be driven. 
     The impeller  5  conveys a fluid, such as water or coolant, from the intake opening  3  toward the outlet opening  4 . The delivery quantity of the pump  1  depends on the drive performance or the drive speed for driving the impeller. 
     A valve element  10  is provided to further control the pumped fluid volume flow. The valve element  10  is arranged downstream of the impeller  5  in the tubular part of the pump housing  2 . The valve element  10  is a rotary slide that has an approximately spherical form  11  radially on the outside, and a through channel  12  is formed therethrough. The valve element  10  is mounted rotatably in the housing by two pins  13 . As a result, the through channel  12  can be released so that the conveyed volume flow is at a maximum, or the through channel  12  is closed so that no volume flow is conveyed. Intermediate positions also are possible so that the volume flow can be varied. The valve element  10  is arranged downstream of the sealing body  7  to bring about a sealing action between the pump housing  2  and the valve element  10  if the valve element  10  is set with a closed through channel  12 . 
     The valve element  10  is influenced from the outside via the two pins  13 . The rotation of the valve element  10  can be performed via a lever  14  at the one pin  13 . To this end, an actuator  15  is provided and is configured as a vacuum cell in the exemplary embodiment of  FIGS. 1 to 4 . The actuator  15  has a longitudinally displaceable output element  16 , such as a tappet, that is connected to the lever  14  to rotate the valve element  10 . The output element  16  is displaced and the valve element  10  is adjusted by supplying the vacuum element with vacuum. 
     As an alternative, the actuator  15  can be configured as a pressure or vacuum actuator or as a pneumatic or hydraulic actuator here. 
     The setting of the valve element  10  is therefore performed by the actuator  15 . 
     A braking element  17 , such as a magnetorheological braking element  17 , is provided on the other pin  13  for influencing the movement of the valve element  10 . The movement can also be fixed so that the valve element  10  can be blocked in one position. 
     The braking element  17  has a housing in which a magnetorheological material is received. A piston-like element also is provided in the housing. The piston-like element moves through the magnetorheological material when the pin  13  moves. If a defined magnetic field then is applied, the elements of the magnetorheological material are linked and the viscosity of the magnetorheological material increases. This leads to an action of force on the piston-like element, and the movement of the valve element  10  experiences a braking force. The braking force is dependent on the magnetic field that is applied. This can lead to blocking of the movement of the valve element  10 . 
     The magnetorheological material can be a dry powder or a fluid in which magnetorheological elements are received. 
     The position of the valve element  10  in the pump housing  2  is therefore controlled in the interaction of the actuator  15  with the braking element  17 . 
       FIGS. 1 to 4  show an actuator  15  with a substantially linearly adjustable output element  16  that acts via the lever  14  as an actuating mechanism on the valve element  10  that is arranged rotatably in the pump housing  2 . As an alternative, other actuating mechanisms also can be provided. 
     The magnetorheological braking element  17  is connected directly to the valve element  10  and therefore also acts directly on the valve element  17 . As an alternative, the magnetorheological braking element  17  could be connected to and act on the actuating mechanism to control the position of the valve element. 
       FIGS. 5 to 7  show the pump  1  from  FIGS. 1 to 4  in different operating positions. In  FIG. 5 , the valve element  10  is set so that the through channel  12  is free. The fluid volume flow that can be conveyed is not influenced or reduced as a result. In  FIG. 6 , the valve element  10  is set so that the through channel  12  is released only proportionately. Thus, the fluid volume flow that can be conveyed is reduced. In  FIG. 7 , the valve element  10  is set so that the through channel  12  is blocked completely. Thus, the fluid volume flow that can be conveyed is interrupted as a result. 
       FIG. 8  shows an embodiment of a pump  100 , in which the braking element  117  is integrated into the actuator  115 . Otherwise, the pump  100  is identical to the pump  1  from  FIGS. 1 to 4 , so that a repetition in this regard is superfluous. 
       FIG. 9  shows the actuator  115  in this regard. The actuator  115  has a housing  120  with a diaphragm  121  arranged therein and defines a pressure space  122  together with the housing  120  that can be loaded with pressure or vacuum via a connector  124 . 
     A tappet  125  is connected as an output element to the diaphragm  121 , with the result that the tappet can be displaced in the case of pressure or vacuum loading in the pressure space  122 . A spring  123  also is provided in the pressure space  122  and loads the tappet with force. If no pressure or vacuum prevails, the spring loads the tappet into a defined position that is known as a fail-safe position. 
     The braking element  117  is provided on the actuator  115  and has a housing  126  with a chamber  127  in which a magnetorheological material is received. A piston-like element which moves through the magnetorheological material is provided in the chamber  127  and is connected to the tappet  125 . A magnetic field generating means  128  applies a magnetic field to change the viscosity of the magnetorheological material and hence to control the position of the tappet  125  as output element in interaction with the pressure or vacuum loading. 
     LIST OF DESIGNATIONS 
     
         
           1  Pump 
           2  Pump housing 
           3  Intake opening 
           4  Outlet opening 
           5  Impeller 
           6  Compression stage 
           7  Sealing body 
           8  Shaft 
           9  Pulley wheel 
           10  Valve element 
           11  Spherical form 
           12  Through channel 
           13  Pin 
           14  Lever 
           15  Actuator 
           16  Output element, tappet 
           17  Braking element 
           100  Pump 
           115  Actuator 
           117  Braking element 
           120  Housing 
           121  Diaphragm 
           122  Pressure space 
           123  Spring 
           124  Connector 
           125  Output element, tappet 
           126  Housing 
           127  Chamber 
           128  Magnetic field generating