Patent Publication Number: US-2023145178-A1

Title: Pumping assembly, piston pump and water flosser

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to Chinese patent application No. 202122725514.1, filed on Nov. 8, 2021, the entire content of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to the field of oral cleaning technologies, and in particular, to a pumping assembly, a piston pump, and a water flosser. 
     BACKGROUND 
     A water flosser is a new oral cleaning appliance, which can clean teeth and gaps between the teeth by spraying water jets, and also has an effect of massage. Strength of a cleaning fluid pumped by the water flosser is a key factor to determine cleaning effects of the water flosser. 
     In the related art, the cleaning fluid is generally pumped from a water storage device such as a water tank, into an oral cavity by a hydraulic pump such as a piston pump, so as to achieve a purpose of cleaning the oral cavity. 
     However, when the cleaning fluid is driven by using a piston pump, a piston may be subject to greater friction resistance during movement, which may increase the load on a drive mechanism in the water flosser and reduce the battery life of the water flosser. 
     SUMMARY 
     According to various embodiments, a pumping assembly, a piston pump, and a water flosser are provided. 
     A pumping assembly includes: 
     a cylinder provided therein with at least two chambers with different inner diameters;
 
a piston mechanism successively extending through the at least two chambers, the piston mechanism being in slidable cooperation with walls of the chambers, and a gap being formed between a sidewall of part of the piston mechanism and the walls of the chambers; and
 
a drive mechanism connected to the piston mechanism, the drive mechanism being configured to drive the piston mechanism to move.
 
     In one of the embodiments, the piston mechanism is provided with a separation groove. When the piston mechanism moves, at least part of the separation groove is located in a chamber with a larger inner diameter of the at least two chambers. 
     In one of the embodiments, the piston mechanism includes a piston head, and the separation groove is provided on a sidewall of the piston head. The piston head includes a mating end. At least part of the mating end is kept in sealing cooperation with a wall of a chamber with a smaller inner diameter of the at least two chambers. 
     In one of the embodiments, the piston mechanism further includes a connecting rod, the piston head further includes a connecting end. The connecting end is connected to the drive mechanism through the connecting rod. The connecting end and the mating end are distributed on different sides of the separation groove, and the gap is formed between a sidewall of the connecting end and the wall of the chamber a larger inner diameter of the at least two chambers. 
     In one of the embodiments, the separation groove is provided with a bottom wall and a sidewall connected to the bottom wall, the sidewall is arranged obliquely relative to the bottom wall. 
     In one of the embodiments, the at least two chambers with different inner diameters include a first accommodating cavity and a second accommodating cavity. An inner diameter of the second accommodating cavity is larger than that of the first accommodating cavity. A wall of the first accommodating cavity is in slidable cooperation with the piston mechanism, and the gap is formed between the second accommodating cavity and the sidewall of the piston mechanism. 
     In one of the embodiments, the at least two chambers with different inner diameters further include a flared cavity. Two ends of a wall of the flared cavity are connected to the wall of the first accommodating cavity and the wall of the second accommodating cavity respectively. an inner diameter of the flared cavity gradually increases along a direction from the first accommodating cavity to the second accommodating cavity. 
     In one of the embodiments, a side of the piston mechanism away from the drive mechanism is provided with an accommodating groove, and a wall of the accommodating groove is elastic. 
     A piston pump includes: 
     the pumping assembly according to any one of the above embodiments. 
     A water flosser includes: 
     the pumping assembly according to any one of the above embodiments. 
     In the pumping assembly, at least two chambers with different inner diameters are provided in the cylinder, and the gap is formed between the sidewall of part of the piston mechanism and the walls of the chambers. With this configuration, the contact area between the piston head and the walls of the chambers can be reduced, thereby the resistance to a piston during reciprocating movement is reduced. Moreover, since at least two chambers with different inner diameters are provided in the cylinder, the resistance encountered by the piston mechanism is reduced while ensuring the sealing performance of the piston mechanism during movement without reducing a size of the piston mechanism, which ensures the overall strength of the piston mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic exploded view of a pumping assembly according to an embodiment. 
         FIG.  2    is a cross-sectional view taken along a line A-A in  FIG.  1   ; 
         FIG.  3    is a cross-sectional view of the pumping assembly shown in  FIG.  2   ; and 
         FIG.  4    is a partial enlarged view of a portion B in  FIG.  3   . 
     
    
    
     In the drawings, the reference numerals as following: 
       10 : pumping assembly;  100 : cylinder;  110 : first accommodating cavity;  120 : second accommodating cavity;  130 : flared cavity;  200 : piston mechanism;  210 : piston head;  211 : mating end;  211   a : accommodating groove;  212 : connecting end;  212   a : engaging groove;  213 : separation groove;  213   a : bottom wall;  213   b : sidewall;  220 : connecting rod;  221 : engagement body;  222 : rod body;  223 : drive portion; K: included angle; M: gap. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In order to make the above objectives, features and advantages of the present disclosure more obvious and understandable, specific implementations of the present disclosure are described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth in order to fully understand the present disclosure. However, the present disclosure can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present disclosure. Therefore, the present disclosure is not limited by the specific embodiments disclosed below. 
     In the description of the present disclosure, it should be understood that the orientation or position relationship indicated by the terms “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc. are based on the orientation or position relationship shown in the accompanying drawings and are merely intended to facilitate the description of the present disclosure and simplify the description, rather than indicating or implying that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore are not to be interpreted as limiting the present disclosure. 
     In addition, the terms “first” and “second” are used for descriptive purposes only, which cannot be construed as indicating or implying a relative importance, or implicitly specifying the number of the indicated technical features. Thus, the features defined with “first” and “second” may explicitly or implicitly include one or more of the features. In the description of the present disclosure, “a plurality of” means two or more, for example, two or three, unless specifically stated otherwise. 
     In the present disclosure, unless otherwise explicitly specified and defined, the terms “mount”, “couple”, “connect” and “fix” should be understood in a broad sense, such as, a fixed connection, a detachable connection, or an integral connection; a mechanical connection, or an electrical connection; a direct connection, an indirect connection through an intermediate medium, an internal connection between two elements, or an interaction between two elements, unless otherwise explicitly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to the specific situation. 
     In the present disclosure, unless otherwise explicitly specified and defined, a first feature being “on” or “under” a second feature may mean that the first feature is in direct contact with the second feature, or the first feature is in indirect contact with the second feature via an intermediate medium. Furthermore, the first feature being “over”, “above” and “on top of” the second feature may mean that the first feature is directly above or obliquely above the second feature, or only means that the level of the first feature is higher than that of the second feature in a horizontal direction. The first feature being “below”, “underneath” or “under” the second feature may mean that the first feature is directly underneath or obliquely underneath the second feature, or only means that the level of the first feature is lower than that of the second feature. 
     It is to be noted that, when one element is referred to as “being fixed to” or “being disposed on” another element, the element may be directly on another element or there may be an intermediate element therebetween. When one element is considered to be “connected to” another element, the element may be directly connected to another element or there may be an intermediate element therebetween. The terms “vertical”, “horizontal”, “up”, “down”, “left”, “right” and similar expressions used herein are for illustrative purposes only and do not mean that they are the only means of implementation. 
     Referring to  FIG.  1   ,  FIG.  1    is a schematic exploded view of a pumping assembly  10  according to an embodiment of the present disclosure. The pumping assembly  10  according to the embodiment of the present disclosure includes a cylinder  100 , a piston mechanism  200  and a drive mechanism (not shown, same below).  FIG.  2    is a cross-sectional view taken along a line A-A in  FIG.  1   . 
     At least two chambers with different inner diameters are provided in the cylinder  100 . The piston mechanism  200  successively extends through the at least two chambers. The piston mechanism  200  is in slidable cooperation with walls of the chambers, and a gap is formed between a sidewall of part of the piston mechanism  200  and the walls of the chambers. The drive mechanism is connected to the piston mechanism  200 . The drive mechanism is configured to drive the piston mechanism  200  to move. Driven by the drive mechanism, the piston mechanism  200  is in slidable cooperation with the walls of the chambers to realize a pumping function. 
     In the pumping assembly  10 , at least two chambers with different inner diameters are provided in the cylinder  100 , and the gap is formed between the sidewall of part of the piston mechanism  200  and the walls of the chambers. With this configuration, a contact area between the piston mechanism  200  and the walls of the chambers is reduced. Thereby the resistance during reciprocating movement of the piston mechanism  200  is reduced. In this way, the load on the drive mechanism is reduced, which facilitates the drive mechanism to drive the piston mechanism  200  and reduces power consumption of the piston mechanism  200 . The gap is shown in  FIG.  4    and is indicated by the arrow M. 
     Moreover, at least two chambers with different inner diameters are provided in the cylinder  100 . As such, the resistance encountered by the piston mechanism  200  is reduced, while ensuring sealing performance of the piston mechanism  200  during movement without reducing a size of the piston mechanism  200 , which ensures the overall strength of the piston mechanism  200 . 
     Referring to  FIG.  2   , in an embodiment, the piston mechanism  200  is provided with a separation groove  213 . When the piston mechanism  200  moves, the separation groove  213  is at least partially located in the chamber with a larger inner diameter of the at least two chambers. The piston mechanism  200  can reciprocates in the cylinder  100 . Since the at least two chambers with different inner diameters are provided in the cylinder  100 , and when the piston mechanism  200  moves, at least part of the separation groove  213  is located in the chamber with a larger inner diameter of the at least two chambers, the contact area between the piston mechanism  200  and the wall of the chamber is reduced, thereby reducing the friction force to the piston mechanism  200  during the reciprocating movement and facilitating the reciprocating movement of the piston mechanism  200 . 
     Referring to  FIG.  3   , in an embodiment, the piston mechanism  200  includes a piston head  210 . The separation groove  213  is disposed on a sidewall of the piston head  210 . The piston head  210  includes a mating end  211 . At least part of the mating end  211  is kept to be in sealing cooperation with the wall of the chamber with a smaller inner diameter of the at least two chambers. In other words, when the piston head  210  moves, the mating end  211  of the piston head  210  is always kept to be in sealing cooperation with the wall of the chamber with a smaller inner diameter of the at least two chambers. In this way, the sealing performance of the piston head  210  during the reciprocating movement is ensured, which prevents reduction of the sealing performance of the piston mechanism  200  due to the reduction of the contact area between the piston head  210  and the wall of the chamber in the cylinder  100 . 
     Referring to  FIG.  3   , in an embodiment, the piston mechanism  200  further includes a connecting rod  220 . The piston head  210  further includes a connecting end  212 . The connecting end  212  is connected to the drive mechanism through the connecting rod  220 . The connecting end  212  and the mating end  211  are distributed at two sides of the separation groove  213 . The gap is formed between a sidewall of the connecting end  212  and the walls of the chambers. Specifically, during the reciprocating movement of the piston mechanism  200  in the chamber, the mating end  211  is always kept to be in sealing cooperation with the wall of the chamber with a smaller inner diameter of the at least two chambers, so as to ensure the sealing performance of the piston head  210  during the reciprocating movement. As such, it is possible to prevent the leakage of formed positive pressure and negative pressure to affect a pumping effect of the pumping assembly  10 . 
     When the piston mechanism  200  reciprocates, the gap is formed between the sidewall of at least part of the connecting end  212  and the wall of the chamber with a larger inner diameter of the at least two chambers. It can be understood that, when the piston mechanism  200  reciprocates, the connecting end  212  may be always located in the chamber with a larger inner diameter. In this way, when the piston mechanism  200  moves, the gap is always formed between the connecting end  212  and the wall of the chamber, so as to further reduce the contact area between the piston head  210  and the cylinder  100 , which further reduces the resistance encountered by the piston mechanism  200  during the reciprocating movement, therefore the piston mechanism  200  is easy to be driven to move. 
     Further, referring to  FIG.  2   , the connecting end  212  is connected to the drive mechanism through the connecting rod  220 . That is, the connecting rod  220  transfers motion of the drive mechanism to the piston head  210  through the connecting end  212 , so as to realize the reciprocating movement of the piston head  210 . In an embodiment, specifically, the connecting rod  220  includes a rod body  222 , an engagement body  221  and a drive portion  223 . The drive portion  223  and the engagement body  221  are provided at two ends of the rod body  222 . The drive portion  223  is configured to be connected to the drive mechanism to transfer the motion of the drive mechanism to the piston head  210 . One side of the connecting end  212  adjacent to the drive mechanism is provided with an engaging groove  212   a . A shape of a sidewall of the engaging groove  212   a  matches the engagement body  221 . The engagement body  221  is engaged with the engaging groove  212  to drive the piston head  210  to move. 
     In the above embodiments, since the connecting end  212  is always located in the chamber with a larger inner diameter, the inner diameter of the chamber with a larger inner diameter may be reasonably adjusted to ensure that the connecting end  212  has a sufficient thickness. Referring to  FIG.  3   , the thickness of the connecting end  212  refers to a distance from a wall of the engaging groove  212   a  to an outer wall of the connecting end  212  in a Y direction. In this way, the connecting end  212  has certain structural strength, so that a transmission connection relationship between the engaging groove  212   a  and the engagement body  221  is more stable, thereby preventing the connecting rod  220  from being separated from the piston head  210 . 
     Referring to  FIG.  4    and  FIG.  3   , in an embodiment, the separation groove  213  is provided with a bottom wall  213   a  and a sidewall  213   b  connected to the bottom wall  213   a . The sidewall  213   b  is arranged obliquely relative to the bottom wall  213   a . It can be understood that the separation groove  213  includes the bottom wall  213   a  and sidewalls  213   b  connected to two opposite sides of the bottom wall  213   a . The two opposite sidewalls  213   b  are both arranged obliquely relative to the bottom wall  213   a . In other embodiments, only one sidewall  213   b  is arranged obliquely relative to the bottom wall  213   a  according to actual requirements. The two sides include one side of the bottom wall  213   a  adjacent to the mating end  211  and one side adjacent to the connecting end  212 . 
     In this way, compared with the case where the sidewall  213   b  and the bottom wall  213   a  of the separation groove  213  are perpendicular to each other, the case where the sidewall  213   b  is arranged obliquely relative to the bottom wall  213   a  ensures thicknesses of the connecting end  212  and the mating end  211  as much as possible on the basis of reducing the contact area between the piston head  210  and the cylinder  100 , the structural strength of the piston head  210  is enhanced. It is possible to prevent damages to the connecting end  212  and the mating end  211  caused by compression during the reciprocating movement of the piston mechanism  200 . Moreover, as described above, the increase in the thickness of the connecting end  212  ensures strength of the connection to the connecting rod  220 , thereby ensuring stable connection between the connecting rod  220  and the piston head  210 . 
     Referring to  FIG.  4   , in an embodiment, a depth of the separation groove  213  is ⅛ to ½ of a width of the separation groove  213 . It should be understood that a ratio of the depth of the separation groove  213  to the width of the separation groove  213  is reasonably set according to requirements of different output strength or different driving manners. Referring to the coordinate system in the figure, the depth of the separation groove  213  is a dimension of the separation groove  213  in the Y direction, and the width of the separation groove  213  is a dimension of the separation groove  213  in an X direction. 
     Referring to  FIG.  2    and  FIG.  3   , in an embodiment, the at least two chambers with different inner diameters include a first accommodating cavity  110  and a second accommodating cavity  120 , an inner diameter of the second accommodating cavity  120  is larger than that of the first accommodating cavity  110 . A wall of the first accommodating cavity  110  is in slidable cooperation with the piston mechanism  200 , and the gap is formed between the second accommodating cavity  120  and the sidewall of the piston mechanism  200 . Specifically, the mating end  211  movably extends through the first accommodating cavity  110 , and at least part of the mating end  211  is kept in slidable cooperation with the wall of the first accommodating cavity  110 . In this way, through the slidable cooperation relationship between the mating end  211  and the wall of the first accommodating cavity  110 , the sealing performance of the cylinder  100  during the reciprocating movement of the piston mechanism  200  is ensured, and leakage of the pressure is avoided. 
     The connecting end  212  movably extends through the second accommodating cavity  120 , and the gap is formed between the connecting end  212  and the wall of the second accommodating cavity  120 . In this way, the friction between the wall of the second accommodating cavity  120  and the connecting end  212  during the sliding of the piston mechanism  200  is avoided. Thus, the friction resistance encountered by the piston mechanism  200  during the reciprocating movement is reduced. In this way, the load to the drive mechanism is reduced, which facilitates the drive mechanism to drive the piston mechanism  200 , and thus which reduces the power consumption of the piston mechanism  200 . 
     That is, in the above embodiments, referring to  FIG.  3    and  FIG.  4   , the sidewall  213   b  of the piston head  210  is provided with the separation groove  213 . The piston head  210  includes the mating end  211  and the connecting end  212 , and the mating end  211  and the connecting end  212  are located on two sides of the separation groove  213  on the piston head  210  respectively. The mating end  211  is configured to be in slidable cooperation with the chamber in the cylinder  100 , so as to realize the pumping function of the piston head  210 . The connecting end  212  is configured to be connected to the connecting rod  220 , so as to transfer the driving action of the drive mechanism to the piston head  210  through the connecting rod  220 , to realize the reciprocating movement of the piston head  210 . 
     Moreover, a diameter of the mating end  211  may be the same as an inner diameter of the first accommodating cavity  110 , and along the X-axis direction, diameters of the mating end  211  are the same everywhere. That is, the mating end  211  has a substantially cylindrical contour, so that it is more beneficial to be kept in slidable cooperation with the wall of the first accommodating cavity  110 , thereby ensuring the sealing performance of the piston head  210  during the reciprocating movement. In an embodiment, a diameter of the connecting end  212  is the same as that of the mating end  211 , in other embodiment, the diameter of the connecting end  212  is slightly greater than that of the mating end  211 , so as to ensure the thickness of the wall of the engaging groove  212   a , and ensure stability of connection between the piston head  210  and the connecting rod  220 . In addition, referring to  FIG.  3   , diameters of the connecting end  212  are the same everywhere along the X-axis direction, so that the thickness of the wall of the engaging groove  212   a  is uniform, thereby ensuring the stable connection transmission relationship between the piston head  210  and the connecting rod  220 . 
     Referring to  FIG.  2   , it can be understood that the piston head  210  successively includes a straight cylinder section, a diameter reducing section, a straight cylinder section, a diameter increasing section, and a straight cylinder section in a direction from the mating end  211  to the connecting end  212 . 
     Referring to  FIG.  3    and  FIG.  4   , in an embodiment, the at least two chambers with different inner diameters further include a flared cavity  130 . Walls of the flared cavity  130  at two ends are connected to the wall of the first accommodating cavity  110  and the wall of the second accommodating cavity  120  respectively. Along a direction from the first accommodating cavity  110  to the second accommodating cavity  120 , an inner diameter of the flared cavity  130  gradually increases. The flared cavity  130  with a gradually increasing inner diameter is provided between the wall of the first accommodating cavity  110  and the wall of the second accommodating cavity  120 , on the one hand, which further reduces the contact area between the cylinder  100  and the piston mechanism  200 , the resistance to the reciprocating movement of the piston mechanism  200  is reduced. On the other hand, as the inner diameter of the flared cavity  130  gradually increases, the wall of the flared cavity  130  enables the mating end  211  to be easily inserted into the first accommodating cavity  110 , facilitating the mounting of the piston head  210 . 
     Referring to  FIG.  4   , in an embodiment, an included angle formed between the wall of the flared cavity  130  and the wall of the second accommodating cavity  120  is specifically in a range from 90° to 170°. The included angle shown in  FIG.  4    is indicated by a reference numeral K. 
     Referring to  FIG.  3    and  FIG.  4   , in an embodiment, a side of the piston mechanism  200  away from the drive mechanism is provided with an accommodating groove  211   a . A wall of the accommodating groove  211   a  is elastic. One end of the piston mechanism  200  away from the drive mechanism is an end for driving the water to move, that is, the end used to contact the water. Referring to  FIG.  3   , when the piston mechanism  200  moves toward a positive direction of the X-axis direction, the positive pressure is formed in the chamber with a smaller inner diameter. That is, a liquid with higher pressure is formed. The liquid with higher pressure enter the accommodating groove  211   a . Since the wall of the accommodating groove  211   a  is elastic, the wall of the accommodating groove  211   a  is attached more closely to the wall of the chamber under the action of the liquid with higher pressure. In this way, the sealing performance of the piston mechanism  200  during the sliding is improved. 
     Further, when the liquid with higher pressure in the chamber with a smaller inner diameter is driven by the piston mechanism  200  to flow out of the chamber, the pressure of the liquid with higher pressure is decreased. In this case, since the wall of the accommodating groove  211   a  is elastic, the wall of the accommodating groove  211   a  has elastic restoring force. Thus, the liquid in the accommodating groove  211   a  flows out under the elastic restoring force, which forms “secondary pumping”. That is, the liquid in the accommodating groove  211   a  has a stable outlet pressure, and an excessively rapid decrease in the outlet pressure is avoided, thereby improving the pumping effect. 
     Still referring to  FIG.  3    and  FIG.  4   , in an embodiment, the accommodating groove  211   a  is provided on the sidewall of the piston mechanism  200  in a ring shape. In this way, the walls of the ring-shaped accommodating groove  211   a  is pressed against the wall of the chamber tightly under the action of the liquid, so as to further improve the sealing performance of the piston mechanism  200  during the reciprocating movement. 
     Specifically, the accommodating groove  211   a  is provided on a side surface of the mating end  211  away from the connecting end  212 . 
     In an embodiment, a piston pump (not shown) includes the pumping assembly  10  according to the above embodiments, as such, the piston pump is driven more labor-saving. A device adopting the piston pump saves the energy required to drive the piston mechanism  200 , thereby reducing the energy consumption of the piston mechanism  200 . 
     In one embodiment, a water flosser (not shown) includes the pumping assembly  10  according to the above embodiments. As such, the water flosser has lower energy consumption, so that the battery life of the water flosser is improved. 
     The technical features in the above embodiments may be randomly combined. For concise description, not all possible combinations of the technical features in the above embodiments are described. However, all the combinations of the technical features are to be considered as falling within the scope described in this specification provided that they do not conflict with each other. 
     The above embodiments only describe several implementations of the present disclosure, and their description is specific and detailed, but cannot therefore be understood as a limitation on the patent scope of the present disclosure. It should be noted that those of ordinary skill in the art may further make changes and improvements without departing from the conception of the present disclosure, all of which fall within the protection scope of the present disclosure. Therefore, the patent protection scope of the present disclosure should be subject to the appended claims.