Pump and pump with motor

Abstract

A pump (3) converts rotational motion of a shaft (4) of a motor (2) into reciprocating motion in an axial direction of the shaft (4) to discharge fluid. The pump includes a pump housing (30) that has a pedestal part (35) disposed so as to face, in the axial direction, a housing (20) of the motor (2) into which the shaft (4) is inserted. The pump housing (30) comprises: a protruding part (39) that protrudes in the axial direction from the pedestal part (35) and is press-fitted and fixed into a hole part (25) formed in the housing (20); and a claw part (40) that, in a state in which the protruding part (39) is press-fitted and fixed into the hole part (25), engages with a recessed part (26) formed in the housing (20).

Description

Pumps and pumps with motors

[0001] The present invention relates to a pump and a motorized pump that includes a motor for driving the pump.

[0002] A pump is driven by a driving device such as a motor to discharge a fluid. Known methods for fixing a pump to a motor include a method in which a claw extending from the motor engages with the pump (see, for example, Patent Document 1), and a method in which the pump is placed on the motor and then fixed by crimping a connecting piece extending from the motor (see, for example, Patent Document 2).

[0003] JP 2022-180336 A Patent No. 6876323 A

[0004] However, with the method of engaging a claw portion with the pump as in Patent Document 1, it is difficult to sufficiently suppress rattle of the pump relative to the motor (especially axial rattle). In particular, in a pump that converts the rotational motion of the motor shaft into reciprocating axial motion to discharge fluid, axial rattle of the pump relative to the motor can affect the axial reciprocating motion of the pump and reduce pump performance. On the other hand, with the method of fixing the pump to the motor by crimping as in Patent Document 2, although it is expected to suppress rattle of the pump relative to the motor, it requires crimping after the pump is placed on the motor. Therefore, there is room for improvement in terms of making it easier to fix the pump to the motor.

[0005] The pump and motorized pump of the present invention were devised in consideration of these problems, and one of the objects of the present invention is to easily fix the pump to the motor and to improve the performance of the pump. However, this object is not limited to this object. Another object of the present invention is to achieve effects that cannot be obtained by conventional techniques, which are derived from the configurations shown in the detailed description of the invention described below.

[0006] The disclosed pump and motorized pump can be realized as the following disclosed aspects (application examples), which solve at least part of the above-mentioned problems. Aspects 2 to 9 are all aspects that can be selected as appropriate and are all aspects that can be omitted. None of Aspects 2 to 9 discloses an aspect or configuration that is essential to the present invention.

[0007] Aspect 1. The disclosed pump discharges a fluid by converting the rotational motion of a motor shaft into reciprocating motion in the axial direction of the shaft, and includes a pump housing having a base portion disposed axially opposite a motor housing through which the shaft is inserted. The pump housing is provided with a convex portion that protrudes in the axial direction from the base portion and is press-fitted into a hole formed in the housing, and a claw portion that engages with a concave portion formed in the housing when the convex portion is press-fitted into the hole.

[0008] Aspect 2. In any aspect including Aspect 1 described above, the pump housing preferably has a wall portion extending from the base portion toward the housing. In this case, the claw portion preferably projects from the wall portion toward the inside in the radial direction of the shaft.

[0009] Aspect 3. In any aspect including Aspect 2 described above, the pump housing preferably has at least two auxiliary wall portions provided across the wall portion and the base portion. In this case, the at least two auxiliary wall portions are preferably provided at positions sandwiching the claw portion in the extending direction of the wall portion as viewed from the axial direction, and are preferably in surface contact along the shape of the corners of the housing.

[0010] Aspect 4. In any aspect including Aspect 2 above, it is preferable that a plurality of the wall portions are provided spaced apart from each other and sandwich the housing.

[0011] Aspect 5. In any aspect including Aspect 1 above, the pump housing preferably has a connecting portion connecting the base portion and the claw portion, and a protrusion protruding from the base portion. In this case, the protrusion is preferably disposed at a position separated from the connecting portion, and the protrusion is preferably press-fitted and fixed in the hole portion and abuts against the housing.

[0012] Aspect 6. In aspects including Aspect 5 above, it is preferable that the protrusion be provided near the shaft. Aspect 7. In aspects including Aspect 6 above, it is preferable that the pump housing be provided with two of the claws arranged opposite each other with the shaft in between. In this case, it is preferable that the protrusion be provided on a line connecting the two claws and a line perpendicular to the axis of the shaft.

[0013] Aspect 8. In any aspect including Aspect 1 above, it is preferable that the pump housing is made of an elastic material and the housing is made of a rigid material. Aspect 9. In any aspect including Aspect 1 above, it is preferable that at least two of the holes and protrusions are provided, and at least two of the recesses and claws are provided.

[0014] Aspect 10. The disclosed motorized pump includes the pump according to any one of Aspects 1 to 9 above, and a motor that drives the pump.

[0015] According to the disclosed pump and motorized pump, the pump can be easily fixed to the motor and the performance of the pump can be improved.

[0016] 7 is an exploded perspective view of a motorized pump to which the pump of the embodiment is applied; FIG. 8 is an axial sectional view of a motorized pump to which the pump of the embodiment is applied, taken along a first diameter line D in FIG. 1, and viewed from the direction of arrow A in FIG. 1; FIG. 9 is an axial sectional view of a bottom body of a pump housing included in the pump of FIG. 2; FIG. 10 is a plan view of the bottom body of the pump housing of FIG. 3, viewed from the motor side; FIG. 11 is a perspective view of the bottom body of the pump housing of FIG. 3; FIG. 12 is an axial sectional view (axial sectional view cut along the first diameter line D in FIG. 7) of a main part of a pump housing included in a pump of a modified example; FIG. 13 is a plan view of the pump housing of FIG. 6, viewed from the motor side; and FIG. 14 is an enlarged view of part B of FIG. 6, showing the pump housing of FIG. 6 attached to the housing of the motor.

[0017] A pump and a motorized pump will be described as embodiments with reference to the drawings. The embodiments described below are merely examples, and are not intended to exclude various modifications and applications of techniques not explicitly described in the following embodiments. The configurations of the present embodiments can be modified in various ways without departing from the spirit of the embodiments.

[0018] The pump of the embodiment is a reciprocating positive displacement pump that converts the rotational motion of a motor shaft into reciprocating motion in the axial direction of the shaft to discharge a fluid. The motor-equipped pump of the embodiment includes the pump and a motor that drives the pump, with the pump and motor attached (fixed). The pump of the embodiment includes a pump housing. The pump housing has a base portion that is disposed axially opposite the motor housing through which the shaft is inserted. The pump housing is also provided with a protrusion that protrudes axially from the base portion and a claw portion. The protrusion is a portion that is press-fitted and fixed into a hole formed in the housing. The claw portion is a portion that engages with a recess formed in the housing when the protrusion is press-fitted and fixed into the hole. The pump of the embodiment is characterized in that the provision of such protrusion and claw portion facilitates the fixing of the pump to the motor and reduces axial rattle when attached to the motor, thereby improving the performance of the reciprocating positive displacement pump.

[0019] 1 is an exploded perspective view of a motorized pump 1 to which a pump 3 of this embodiment is applied, and FIG. 2 is an axial cross-sectional view of the motorized pump 1 (a view of the motorized pump 1 cut along a first diameter line D, described below, in FIG. 1 , and viewed from the direction of arrow A in FIG. 1 ). As shown in FIGS. 1 and 2 , the motorized pump 1 includes a pump 3 and a motor 2. The pump 3 is attached to the motor 2 in a first direction, which is the axial direction of a shaft 4 of the motor 2. Hereinafter, the axial direction in which the pump 3 is attached to the motor 2 will be referred to as the "first direction," and the axial direction opposite to the first direction will be referred to as the second direction. The pump 3 is a reciprocating positive displacement pump that is driven by the motor 2 and converts the rotational motion of the shaft 4 into reciprocating motion in the axial direction of the shaft 4 to discharge a fluid.

[0020] As shown in Fig. 2, the motor 2 is, for example, an inner rotor type motor, and is configured by incorporating a rotor 5 that rotates integrally with a shaft 4 and a stator 6 located radially outward of the rotor 5 into a cylindrical housing 20 with a bottom. An end bell 7 serving as a cover member may be combined with the open side (lower side in the figure) of the housing 20. The shaft 4 is rotatably supported relative to the housing 20 by a bearing 8 held in the housing 20. Although not shown, the end bell 7 may also hold a bearing that rotatably supports the shaft 4.

[0021] The housing 20 is a rigid (e.g., metal) member that forms the outer shell of the motor 2, and has a side surface 21 and a bottom surface 22. The side surface 21 is a portion that forms the cylindrical portion of the bottomed cylindrical housing 20, and forms a space that accommodates the rotor 5 and the stator 6. For example, as shown in FIG. 1 , the side surface 21 is cylindrical in shape with a substantially uniform diameter in the axial direction.

[0022] The bottom surface portion 22 is a portion that forms the bottom of the bottomed cylindrical housing 20, located further from the side surface portion 21 in the first direction. For example, as shown in FIG. 2 , the bottom surface portion 22 has a flat plate shape that has a uniform thickness in the axial direction and is expanded in a direction perpendicular to the axial direction. As shown in FIG. 1 , the bottom surface portion 22 in this embodiment is disc-shaped when viewed from the axial direction, and has a circular center hole that is concentric with the axis C of the shaft 4 at its center. The shaft 4 is inserted through the center hole of the bottom surface portion 22. The bottom surface portion 22 may be provided with a bearing accommodating portion 24 that defines the center hole and forms an accommodating space for the bearing 8, and that is convex toward the first direction. As shown in FIG. 2 , an outer peripheral surface 23 a of a corner portion 23 connecting the side surface portion 21 and the bottom surface portion 22 may be rounded (R) to smoothly connect the outer peripheral surface 21 a of the side surface portion 21 and an outer end surface 22 a of the bottom surface portion 22 facing the first direction.

[0023] The housing 20 is provided with the above-described hole 25 and recess 26. In this embodiment, the hole 25 is provided in the bottom surface 22, and the recess 26 is provided in the side surface 21. The hole 25 is a portion recessed from the outer end surface 22a of the bottom surface 22 in the second axial direction, and forms a space (hole, recess) into which a protrusion 39 (described later) of the pump 3 is press-fitted. As shown in FIG. 2, the hole 25 in this embodiment is provided so as to penetrate the bottom surface 22 in the axial direction, and forms a circular through-hole when viewed from the axial direction, as shown in FIG. 1.

[0024] The number of holes 25 provided in the bottom surface portion 22 may be at least one, but is preferably two or more. Here, two holes 25 are provided on either side of the shaft 4. More specifically, the two holes 25 are provided on a first diameter line D perpendicular to the axis C of the shaft 4, with the shaft 4 on either side (180 degrees apart in the circumferential direction). Note that the holes 25 may function not only to press-fit and fix the protrusions 39 of the pump 3, but also as positioning holes during manufacture of the motor 2. In other words, in this case, rather than forming holes 25 (dedicated to press-fitting and fixing), the holes that serve as positioning holes during manufacture of the motor 2 may be used as locations for fixing the pump 3.

[0025] The recess 26 is a portion recessed radially inward from the outer circumferential surface 21a of the side surface portion 21, and forms a space (hole, recess) into which a claw portion 40 (described later) of the pump 3 fits. In this embodiment, the recess 26 not only functions to engage with the claw portion 40 of the pump 3, but also functions as a protrusion for determining the axial position of a magnet (not shown) provided on the stator 6. In other words, the pump 3 utilizes the protrusion for positioning the magnet as the recess 26 for fixing the pump 3.

[0026] For example, as shown in Fig. 2, the recess 26 is provided so as to recess a portion of the side surface portion 21 on the first direction side of the stator 6 without radially penetrating the side surface portion 21, and forms a long, narrow recess (depression) extending in the circumferential direction as shown in Fig. 1. As shown in Fig. 2, the radially inner portion of the recess 26 protrudes radially inward beyond the inner circumferential surface 21b (inner surface) of the side surface portion 21. This portion serves as a protrusion for positioning the magnet.

[0027] The number of recesses 26 provided in the side surface portion 21 may be at least one, but is preferably two or more. Here, four recesses 26 are provided. Two of the four recesses 26 are provided on the first diameter line D on which the hole portion 25 is provided, with the shaft 4 sandwiched between them. The remaining two recesses 26 are provided at positions spaced apart in the counterclockwise direction from the first two recesses 26, as shown in FIG. 1 . The latter two recesses 26 are provided, for example, on a second diameter line E, which is a diameter line perpendicular to the axis C and out of phase with the first diameter line D, with the shaft 4 sandwiched between them.

[0028] As described above, the pump 3 is a reciprocating positive displacement pump. Here, as shown in Fig. 2, a diaphragm pump is shown as an example of the pump 3. The pump 3 is configured by incorporating, in a pump housing 30, a drive mechanism 11 that converts the rotational motion of the shaft 4 into reciprocating motion in the axial direction, and a diaphragm 12 having a diaphragm portion 12a whose volume increases and decreases in accordance with the reciprocating motion of the drive mechanism 11.

[0029] Within the pump housing 30, a pump chamber 3A, which is partitioned by the pump housing 30 and the diaphragm portion 12a, and a suction chamber 3B and a discharge chamber 3C, which communicate with the pump chamber 3A, are formed. In the pump 3, when the volume of the pump chamber 3A increases, a valve element provided in the suction chamber 3B opens, allowing air to be taken into the pump chamber 3A. When the volume of the pump chamber 3A decreases, a valve element provided in the discharge chamber 3C opens, allowing the air in the pump chamber 3A to be sent to the discharge chamber 3C and discharged from the discharge port 3D.

[0030] The diaphragm 12 is a component made of a flexible material (e.g., rubber), and has a cup-shaped diaphragm portion 12a that forms the pump chamber 3A, and a connecting piece 12b that protrudes from the bottom of the diaphragm portion 12a toward the motor 2. Note that although Fig. 2 shows one diaphragm portion 12a, the diaphragm 12 may have a plurality of diaphragm portions 12a and the same number of connecting pieces 12b.

[0031] The drive mechanism 11 has, for example, a support part 13 fixed to the shaft 4 so as not to rotate relative to the shaft 4, and a driver 14 supported by the support part 13. The support part 13 has an axial hole formed therein that extends at an angle relative to the shaft 4 and at a position eccentric to the shaft 4. The driver 14 has a shaft part 14a that fits into the axial hole, and an arm part 14b that protrudes radially outward from the shaft part 14a.

[0032] The connecting piece 12b of the diaphragm 12 is engaged with the arm 14b in a penetrating manner. Therefore, the rotation of the driver 14 is restricted by the diaphragm 12. As a result, the rotation of the support part 13, which rotates together with the shaft 4, is converted into reciprocating motion of the arm 14b in the axial direction and transmitted to the diaphragm part 12a via the connecting piece 12b. This causes the volume inside the diaphragm part 12a to increase or decrease. Note that although one arm 14b is shown in FIG. 2, if the diaphragm 12 is provided with multiple diaphragm parts 12a, the driver 14 may have the same number of arms 14b.

[0033] The pump housing 30 is a component that forms the outer shell of the pump 3 and is made of an elastic material (e.g., resin). In this embodiment, the pump housing 30 is formed by combining multiple components 31 to 34 in the axial direction. Specifically, the pump housing 30 has a bottom body 31, a first intermediate body 32, a second intermediate body 33, and a cover body 34, and is formed by combining these components 31 to 34 so that they are arranged in this order from the second direction.

[0034] The bottom body 31 is a cylindrical member with a bottom that houses the drive mechanism 11, and has a pedestal portion 35 that is disposed axially opposite the housing 20 when the pump 3 is attached to the motor 2 (hereinafter referred to as the "attached state"). The first intermediate body 32 is a member that forms the mounting surface for the diaphragm 12, and forms the suction chamber 3B together with the second intermediate body 33 and the diaphragm 12. The second intermediate body 33 is a member that holds the diaphragm 12 together with the first intermediate body 32. The lid body 34 is a member that covers the members 31 to 33 from a first direction, and forms the discharge chamber 3C together with the second intermediate body 33. The discharge port 3D is formed radially inward of the lid body 34.

[0035] The above-described protrusions 39 and claws 40 are provided on the bottom body 31 having a base 35. The protrusions 39 are provided on the base 35. The claws 40 in this embodiment are provided on a wall 37 extending from the base 35 toward the housing 20 (in the second direction). More specifically, the claws 40 are provided at positions on the wall 37 that intersect with the first diameter line D and the second diameter line E.

[0036] The bottom body 31 will be described in detail below with reference to FIGS. 2 to 5. FIG. 3 is an axial cross-sectional view of the bottom body 31, and FIG. 4 is a plan view of the bottom body 31 as viewed from a second direction. FIG. 5 is a perspective view of the bottom body 31 as viewed from the second direction and from the radially outer side. As shown in FIG. 3, the bottom body 31 has a base portion 35 and a cylindrical portion 36. The bottom body 31 may further be provided with a wall portion 37 and an auxiliary wall portion 38. In this embodiment, the bottom body 31 is made of resin, and these portions 35 to 38 are integrally molded with the above-mentioned protrusions 39 and claw portions 40.

[0037] The base 35 is a portion that forms the bottom of the cylindrical bottom body 31 and has, for example, a flat plate shape that has a uniform thickness in the axial direction and is expanded in a direction perpendicular to the axial direction. A base surface 35a of the base 35 facing the second direction abuts against the outer end surface 22a of the motor 2 in the attached state, for example, as shown in FIG.

[0038] 4, the base portion 35 of this embodiment has an oval outer shape. That is, the base portion 35 has, as its periphery, two arcuate edges 35j that are spaced apart and extend in the circumferential direction, and a linear edge 35k that connects the ends of the two arcuate edges 35j. The two arcuate edges 35j are provided point-symmetrically with respect to the axis C, and each of them straddles the first diameter line D and the second diameter line E.

[0039] A central hole is provided in the radially inner portion of the base portion 35, through which the shaft 4 passes and into which the bearing accommodating portion 24 fits when mounted. A through hole 35h is provided in the arcuate end edge 35j of the base portion 35 at a position that overlaps with the claw portion 40 when viewed from the axial direction. By providing the through hole 35h, the bottom body 31 does not have an undercut portion, which makes it easier to mold it integrally with resin.

[0040] The cylindrical portion 36 is a portion that forms the cylindrical portion of the bottom body 31, which has a cylindrical shape and is extended in a first direction from the periphery of the bottom body 31 as shown in FIG. 3 to form a space that accommodates the drive mechanism 11. Since the base portion 35 in this embodiment is oval-shaped, the cylindrical portion 36 is also oval-shaped when viewed in the axial direction. As shown in FIG. 5, the outer peripheral surface of the cylindrical portion 36 may be provided with a protrusion for engaging with the cover body 34. When the cover body 34 engages with the protrusion provided on the cylindrical portion 36, the pump housing 30 is integrated with the bottom body 31 and the cover body 34, with the first intermediate body 32 and the second intermediate body 33 sandwiched between them.

[0041] As described above, the wall portion 37 is a portion extending in the second direction from the base portion 35. In the pump 3 of this embodiment, a plurality of (here, two) wall portions 37 are provided spaced apart from each other and sandwich the housing 20. More specifically, as shown in Fig. 4, the two wall portions 37 extend in the second direction from each of the two arcuate end edges 35j and sandwich the side surface portion 21 of the housing 20 in the attached state as shown in Fig. 2. The circumferential length of each arcuate end edge 35j and the circumferential length of the wall portion 37 extending from that arcuate end edge 35j are set to be equal to each other, for example.

[0042] As shown in FIG. 4 , the wall portion 37 extends circumferentially along the entire arcuate edge 35j of the base portion 35, straddling the first diameter line D and the second diameter line E. As shown in FIG. 2 , the wall portion 37 is formed so that, in an attached state, the wall portion 37 conforms to the shape of the side surface 21 of the housing 20 and is in surface contact with the outer circumferential surface 21a of the side surface 21. The wall portion 37 is formed so that its inner wall surface 37a extends on the circumference of an imaginary circle having a diameter substantially equal to the outer diameter of the side surface 21 of the motor 2, as viewed in the axial direction. The circumferential length of the arcuate edge 35j and the circumferential length of the wall portion 37 may be different. The circumferential length of the wall portion 37 on the first direction side may be different from the circumferential length on the second direction side. For example, the wall portion 37 may have a shape in which its circumferential length decreases in the second direction.

[0043] The auxiliary wall portion 38 is a portion that reinforces the wall portion 37 and suppresses rattle of the pump 3, and is provided across the base portion 35 and the wall portion 37. More specifically, as shown in Figures 3 to 5, the auxiliary wall portion 38 is provided across the base surface 35a of the base portion 35 and the inner wall surface 37a of the wall portion 37. The auxiliary wall portion 38 in this embodiment also has the function of preventing leakage of operating sounds of components housed within the pump housing 30 (e.g., the drive mechanism 11 and the diaphragm 12).

[0044] 5, the auxiliary wall portion 38 is provided with an auxiliary surface 38a that connects the seat surface 35a of the seat portion 35 and the inner wall surface 37a of the wall portion 37, and that faces radially inward in the second direction. The auxiliary surface 38a is rounded (R) to approximately the same extent as the outer circumferential surface 23a of the corner portion 23 so as to follow the shape of the corner portion 23 of the motor 2 in the mounted state and to be in surface contact with the outer circumferential surface 23a of the corner portion 23.

[0045] At least two auxiliary wall portions 38 are provided on each wall portion 37. As shown in Fig. 4 , the two auxiliary wall portions 38 provided on each wall portion 37 are provided at positions that sandwich the claw portion 40 in the extension direction of the wall portion 37 as viewed from the axial direction, i.e., at positions that sandwich the first diameter line D and the second diameter line E in the extension direction. In this embodiment, the two auxiliary wall portions 38 provided on each wall portion 37 are arranged at both circumferential ends of each wall portion 37.

[0046] As described above, the base portion 35 has a through hole 35h formed in a position overlapping the claw portion 40 when viewed in the axial direction. Therefore, there is a possibility that the operating noise of the pump 3 will leak from the through hole 35h to the outside of the pump housing 30. In addition, the outer peripheral surface 23a of the corner portion 23 of the motor 2 is rounded (R). Therefore, there is a possibility that the operating noise of the pump 3 that has leaked to the outside of the pump housing 30 via the through hole 35h will leak from gaps between the outer peripheral surface 23a of the corner portion 23, the base surface 35a of the base portion 35, and the inner wall surface 37a of the wall portion 37.

[0047] In contrast, in this embodiment, an auxiliary wall portion 38 is provided at each end of each wall portion 37 in the extension direction. As a result, the gap is closed by the corner portion 23, the wall portion 37, and the two auxiliary wall portions 38, thereby preventing the operating noise of the pump 3. Furthermore, the auxiliary surface 38a of each auxiliary wall portion 38 is in surface contact with the outer peripheral surface 23a of the corner portion 23 in the attached state, thereby preventing the pump 3 from wobbling in the axial direction relative to the motor 2 along the outer peripheral surface 23a of the corner portion 23. In other words, the auxiliary wall portions 38 fulfill three roles: reinforcing the wall portions 37, preventing the operating noise of the pump 3, and preventing the pump 3 from wobbling.

[0048] The protrusion 39 is a portion that protrudes from the seat surface 35a of the seat 35 toward the second direction, and is provided at a position that overlaps with the hole 25 of the housing 20 in the attached state. The protrusion 39 is columnar in shape and has an outer shape that can be press-fitted into the hole 25 of the housing 20, and is press-fitted and fixed into the hole 25 of the housing 20 in the attached state, thereby determining the axial position of the pump 3. In this embodiment, the protrusion 39 is cross-shaped when viewed in the axial direction.

[0049] The number of protrusions 39 provided on the bottom body 31 may be at least one, but is preferably two or more. Here, the number of protrusions 39 is the same as the number of holes 25 in the housing 20, i.e., two. In other words, two holes 25 and two protrusions 39 are provided. The two protrusions 39 are provided on the first diameter line D, sandwiching the axis C.

[0050] The claws 40 are portions that engage with the recesses 26 of the housing 20 when the protrusions 39 are press-fitted and fixed in the holes 25 of the housing 20, i.e., when the housing is attached. In this embodiment, the claws 40 protrude radially inward from the tips (ends on the second direction side) of the wall portions 37. Therefore, the wall portions 37 can also be described as portions (connection portions) that connect the base portion 35 and the claws 40. As shown in FIG. 5 , the claws 40 form elongated protrusions in the circumferential direction that correspond to the shape of the recesses 26 described above.

[0051] The number of claws 40 provided on the bottom body 31 may be at least one, but is preferably two or more. In this embodiment, as shown in FIG. 4 , the number of claws 40 is the same as the number of recesses 26 of the housing 20, i.e., four. That is, four recesses 26 and four claws 40 are provided. Of the four claws 40, two claws 40 are provided on the first diameter line D, with the axis C sandwiched between them. The remaining two claws 40 are provided on the second diameter line E, with the axis C sandwiched between them. One claw 40 located on the first diameter line D and one claw 40 located on the second diameter line E are protruding from each of the two wall portions 37.

[0052] [2. Actions and Effects] (1) In the pump 3 and motorized pump 1 described above, the pump housing 30 is provided with a protrusion 39 that is press-fitted and fixed into the hole 25, and a claw 40 that engages with the recess 26. The protrusion 39 is provided to protrude in the axial direction from the base 35 of the pump housing 30, and the claw 40 engages with the recess 26 when the protrusion 39 is press-fitted and fixed into the hole 25. The pump 3 is also a reciprocating positive displacement pump that converts the rotational motion of the shaft 4 of the motor 2 into reciprocating motion in the axial direction of the shaft 4 to discharge fluid.

[0053] With this pump 3, fixing of the pump 3 to the motor 2 is completed simply by inserting the protrusion 39, which protrudes axially from the base 35, into the hole 25 from the first direction to the second direction. In other words, simply inserting the protrusion 39 into the hole 25 from the first direction completes both the press-fitting of the protrusion 39 into the hole 25 and the engagement of the claws 40 into the recesses 26. This makes it easy to fix the pump 3 to the motor 2.

[0054] Furthermore, with the above-described configuration, the pump 3 can be fixed (coupled) to the motor 2 after the motor 2 and pump 3 have been assembled, thereby improving the productivity and versatility of both the pump 3 and the motor 2. Note that the pump 3 (bottom body 31) does not have to be fixed to the motor 2 after the motor 2 and pump 3 have been assembled. In other words, the pump 3 is intended to include not only a completed product but also its precursors. In the motor-equipped pump 1 described above, it is also possible to assemble the pump 3 by first fixing only the bottom body 31 to the motor 2, and then assembling the other components 11, 12 and members 32 to 34 that make up the pump 3 to the bottom body 31.

[0055] Furthermore, in the pump 3 described above, not only are the claws 40 engaged with the recesses 26, but the protrusions 39 are press-fitted and fixed into the holes 25, thereby fixing the pump 3 to the motor 2. This allows the pump 3 to be fixed to the motor 2 more stably.

[0056] In a reciprocating positive displacement pump 3, axial wobble of the pump 3 relative to the motor 2 can affect the axial reciprocating motion of the pump 3. In contrast, in the above-described pump 3, the protrusion 39 is press-fitted into the hole 25, eliminating wobble (axial wobble) that can occur with snap-fit ​​fixation using the claws 40 alone, and also achieving axial positioning. This improves pump performance.

[0057] Additionally, in the pump 3 and motorized pump 1 described above, the portions 39, 40 for fixing the pump 3 are provided to protrude from the pump housing 30. In other words, the motor 2 is not required to have any protrusions or projections on its housing 20 for fixing the pump 3. In this way, the pump 3 does not require the motor 2 to have any functions (protrusions) that are unnecessary for the motor 2, thereby improving the productivity of the motor 2 itself. Furthermore, by utilizing existing holes that serve as positioning holes during manufacturing of the motor 2 as the holes 25 and existing projections for positioning the magnet as the recesses 26, versatility can be improved.

[0058] (2) The pump housing 30 is provided with a wall portion 37 extending from the base portion 35 toward the housing 20. The claw portions 40 protrude radially inward from the wall portion 37. By providing the claw portions 40 on the wall portion 37 in this manner, the claw portions 40 can be strengthened. This makes it possible to prevent the claw portions 40 and the wall portion 37 from breaking when the claw portions 40 are snap-fit ​​into the recesses 26.

[0059] (3) The pump housing 30 is provided with a plurality of wall portions 37, and each wall portion 37 is provided with a plurality of claw portions 40. In the pump housing 30 described above, two wall portions 37 are each provided with two claw portions 40, for a total of four claw portions 40. The housing 20 is provided with four corresponding recesses 26.

[0060] In this way, by providing a plurality of wall portions 37 and by engaging the plurality of claws 40 provided on each wall portion 37 with the plurality of recesses 26, respectively, the pump 3 can be more stably fixed to the motor 2. Furthermore, if the plurality of claws 40 and the plurality of recesses 26 are provided symmetrically on the diameter lines D and E so as to sandwich the shaft 4, it is possible to reduce unevenness in the engagement points. Therefore, the pump 3 can be more stably fixed to the motor 2.

[0061] Furthermore, the pump housing 30 is provided with a plurality of protrusions 39, and the housing 20 is provided with a plurality of corresponding holes 25. In this manner, each of the plurality of protrusions 39 is press-fitted into each of the plurality of holes 25, thereby more stably fixing the pump 3 to the motor 2. Additionally, the axial positioning accuracy of the pump 3 can be improved, thereby improving pump performance. Furthermore, if the plurality of protrusions 39 and the plurality of holes 25 are symmetrically arranged on the first diameter line D so as to sandwich the shaft 4, bias in the press-fit locations can be reduced. Therefore, the stability of fixing the pump 3 to the motor 2 and the pump performance can be further improved.

[0062] Furthermore, in the pump 3 described above, the multiple wall portions 37 are spaced apart from one another to sandwich the housing 20. By spaced apart from one another in this manner, the wall portions 37 are more likely to deform when the claw portions 40 are snap-fit, thereby preventing chipping or breaking of the claw portions 40.

[0063] Furthermore, since the multiple wall portions 37 are provided on either side of the housing 20, the engagement of the claw portions 40 with the recesses 26 can be released when the attached pump 3 is removed from the motor 2 without disassembling the motor 2 or the pump 3. In other words, the pump 3 can be removed from the motor 2 without the need to disassemble the motor 2 or the pump 3. This improves the product quality and versatility of both the pump 3 and the motor 2.

[0064] (4) When multiple wall portions 37 are provided on either side of the housing 20, if each wall portion 37 is in surface contact with the side surface portion 21 of the housing 20 in the attached state, the wall portions 37 can restrict radial movement of the pump 3 relative to the motor 2. Therefore, radial rattle of the pump 3 relative to the motor 2 can also be suppressed.

[0065] (5) In the pump housing 30, the two auxiliary walls 38 provided on each wall 37 are positioned to sandwich the claws 40 and are in surface contact with the corners 23 of the housing 20 along the shape of the corners 23. This reinforces the walls 37, prevents the pump 3 from rattling, and reduces the operating noise of the pump 3.

[0066] (6) In the pump 3 and motor-equipped pump 1 described above, the pump housing 30 is made of an elastic material, and the housing 20 is made of a rigid material. By forming the pump housing 30 from an elastic material with higher elasticity than the housing 20, elastic deformation of the pump housing 30 is permitted when the claw portions 40 are snap-fit, preventing chipping or breaking of the claw portions 40. Furthermore, by forming the housing 20 from a rigid material with higher rigidity than the pump housing 30, the protrusions 39 can be more firmly press-fit into the holes 25.

[0067] [3. Modifications] The configurations of the pump 3 and motorized pump 1 described above are merely examples and are not limited to the above configurations. In addition to the above-described portions 35 to 40, the pump housing 30 may be provided with portions for more closely fitting the claw portion 40 to the recess 26 in the attached state.

[0068] A modified pump 3' will be described below with reference to Figures 6 to 8. In the following description, the same components as those described in the embodiment will be assigned the same reference numerals, and a description of the components and effects will be omitted. Furthermore, components corresponding to those described in the embodiment will be assigned a prime (') to the reference numerals of the embodiment, and a detailed description will be omitted.

[0069] The pump 3' of the modified example differs from the pump 3 of the above embodiment mainly in the following points: The pump housing 30' is provided with a protrusion 42; The pump housing 30' is provided with two claws 40 instead of four; The pump housing 30' is provided with two connection pieces 41 (connection portions) instead of the wall portion 37; and The outer shape of the base portion 35' is circular.

[0070] The modified pump 3' includes a pump housing 30', and is attached to the motor 2 of the embodiment to form a motorized pump. As shown in Figures 6 and 7, the pump housing 30' is provided with a base 35', two protrusions 39, two claws 40, two connecting pieces 41, and one protrusion 42.

[0071] In this modified example, as shown in Fig. 7, the base portion 35' has a circular shape that covers the motor 2 from the first direction. As shown in Fig. 6, the two protrusions 39 protrude in the axial direction from a base surface 35a' of the base portion 35', and as shown in Fig. 7, are provided on a first diameter line D on which the hole 25 of the housing 20 is provided, with the axis C sandwiched between them. The two claws 40 are also provided on the first diameter line D, with the axis C sandwiched between them, and in the mounted state, engage with the two recesses 26 provided on the first diameter line D, respectively. Although not shown in Figs. 6 to 8, the base portion 35' may have holes corresponding to the through holes 35h of the embodiment at positions that overlap with the claws 40 when viewed from the axial direction.

[0072] As shown in FIG. 6 , the connection piece 41 is a portion that connects the base portion 35′ and the claw portions 40, and extends from the base portion 35′ in the second direction. In this modified example, two connection pieces 41 are provided, corresponding to the number of claw portions 40. As shown in FIG. 7 , the two connection pieces 41 are provided on the first diameter line D, sandwiching the axis C. The claw portions 40 protrude radially inward from the tip of the connection piece 41. In this modified example, the connection piece 41 extends from the peripheral edge 35e of the base portion 35′. The connection piece 41 and the base portion 35′ form an L-shaped cross-section (the portion surrounded by a rectangle B in FIG. 6 ) by a portion that extends from the radially inner side to the outer side (a part of the base portion 35′) and a portion that extends and then bends to extend in the second direction (the connection piece 41).

[0073] The protrusion 42 protrudes from the base 35' and is a portion that abuts against the outer end surface 22a of the housing 20 in the attached state, and is located at a position spaced apart from the connecting piece 41. In this modified example, the protrusion 42 protrudes slightly in the second direction from the base surface 35a' of the base 35'. Furthermore, the protrusion 42 is located at a position spaced apart from the connecting piece 41, near the center hole of the base 35' through which the shaft 4 is inserted, in other words, near the shaft 4.

[0074] 7, the protrusion 42 has a circular ring shape that goes around the central hole when viewed in the axial direction near the central hole. The amount of protrusion 42 protruding from the base surface 35a' is set to be much smaller than the amount of protrusion 39 protruding from the base surface 35a' so as not to hinder the press-fitting and fixation of the protrusion 39 into the hole 25.

[0075] As shown in FIG. 8 , the pump 3′ of the modified example includes a protrusion 42. When the pump 3′ is mounted, the portion of the base 35′ surrounding the protrusion 42 is slightly raised without abutting against the outer end surface 22a of the housing 20. As a result, as shown by the dashed line in FIG. 8 , a portion of the L-shaped base 35′ and the connecting piece 41 deform around the protrusion 42. More specifically, the base 35′ elastically deforms, as indicated by the hollow arrow in FIG. 8 , so that the portion surrounding the connecting piece 41 is positioned in the second direction relative to the portion surrounding the protrusion 42. Furthermore, as indicated by the solid arrow in FIG. 8 , the connecting piece 41 deforms so that its tip moves radially inward in response to the deformation of the base 35′. This allows the claw 40 provided at the tip of the connecting piece 41 to fit more closely into the recess 26. This makes it more difficult for the claw 40 to come off the recess 26, thereby more stably securing the pump 3′ and the motor 2.

[0076] Furthermore, in the modified pump 3', the force of the base portion 35' and the connecting piece 41 attempting to return to their original shape after the deformation described above applies tension that urges the connecting piece 41 in the first direction. This prevents the connecting piece 41 from moving in the direction that loosens the engagement between the claw portion 40 and the recess 26 (i.e., the second direction). This also makes it more difficult for the claw portion 40 to come off the recess 26.

[0077] In the modified pump 3', the protrusion 42 is provided near the shaft 4. By providing the protrusion 42 at a position farther away from the connecting piece 41 in this way, the above-described deformation of the base portion 35' and the connecting piece 41 can be further promoted. This makes it more difficult for the claw portion 40 to come out of the recess 26. In addition, the modified pump 3' also provides the same effects as the pump 3 described above.

[0078] The modified pump 3' is merely an example and is not limited to the one shown in Figures 6 to 8. The position at which the protrusion 42 is provided is not limited to the above-mentioned position, as long as it is at least separated from the connecting piece 41. However, from the viewpoint of promoting the above-mentioned deformation of the base portion 35' and the connecting piece 41, it is preferable that the protrusion 42 be provided at a position further away from the connecting piece 41.

[0079] 7, the protrusions 42 are preferably provided on a first diameter line D (straight line) connecting the two claws 40 and a third diameter line F (line) perpendicular to the axis C of the shaft 4. This promotes the above-described deformation of the base 35' and the connecting piece 41 and also makes it possible to make the degree of engagement of the two claws 40 with the recesses 26 approximately the same, thereby more stably fixing the pump 3' to the motor 2.

[0080] [4. Other] The configurations of the pumps 3, 3' and motorized pump 1 described above are merely examples and are not limited to the above configurations. The pumps 3, 3' are not limited to diaphragm pumps as long as they convert at least the rotational motion of the shaft 4 into reciprocating motion in the axial direction of the shaft 4. The pumps 3, 3' may be plunger pumps or bellows pumps, for example.

[0081] The shape of the housing 20 of the motor 2 does not have to be cylindrical, and the shape of the pump housings 30, 30' of the pumps 3, 3' does not have to be oval or circular. The housing 20 does not have to be made of a rigid material, and the pump housings 30, 30' do not have to be made of an elastic material.

[0082] In the pump 3 of the embodiment, two or more auxiliary wall portions 38 may be provided on each wall portion 37. Also, the auxiliary wall portions 38 may be omitted. In the pump 3 of the embodiment, instead of the wall portions 37, portions corresponding to the connecting pieces 41 of the modified example may be provided in the same number as the claw portions 40. Similarly, in the pump 3' of the modified example, instead of the connecting pieces 41, portions corresponding to the wall portions 37 of the embodiment may be provided. In the pump 3 of the embodiment, portions corresponding to the protrusions 42 of the modified example may be provided. Depending on the relative positions of the housing 20 and the pump housings 30, 30', the wall portions 37 and the connecting pieces 41 may also be omitted.

[0083] The hole portion 25 of the housing 20 need only be a portion that forms a hole (recess) into which the protrusion 39 can be press-fitted and fixed, and does not need to penetrate the bottom surface portion 22 in the axial direction. The recess portion 26 of the housing 20 also need only be a portion that can engage with the claw portion 40 in the attached state. The recess portion 26 may be, for example, a portion that forms a through-hole that penetrates the side surface portion 21 in the radial direction. The portion where the recess portion 26 is provided does not need to be the side surface portion 21.

[0084] DESCRIPTION OF SYMBOLS 1 Motor-equipped pump 2 Motor 3, 3' Pump 4 Shaft 20 Housing 23 Corner portion 25 Hole portion 26 Recessed portion 30, 30' Pump housing 35, 35' Base portion 37 Wall portion (connecting portion) 38 Auxiliary wall portion 39 Convex portion 40 Claw portion 41 Connecting piece (connecting portion) 42 Projecting portion C Axis line D First diameter line (straight line) F Third diameter line (line)

Claims

1. A pump that converts the rotational motion of a motor shaft into a reciprocating motion in the axial direction of the shaft to discharge a fluid, comprising a pump housing having a pedestal portion disposed opposite to the housing of the motor through which the shaft is inserted in the axial direction, wherein the pump housing is provided with a convex portion that protrudes from the pedestal portion in the axial direction and is press-fitted and fixed into a hole formed in the housing, and a claw portion that engages with a concave portion formed in the housing in a state where the convex portion is press-fitted and fixed into the hole.

2. The pump according to claim 1, wherein the pump housing has a wall portion extending from the pedestal portion toward the housing, and the claw portion protrudes from the wall portion toward the inner side in the radial direction of the shaft.

3. The pump according to claim 2, wherein the pump housing has at least two auxiliary wall portions provided across the wall portion and the pedestal portion, the at least two auxiliary wall portions are provided at positions sandwiching the claw portion in the extending direction of the wall portion viewed from the axial direction, and are in surface contact along the corner shape of the housing.

4. The pump according to claim 2, wherein a plurality of the wall portions are provided spaced apart from each other so as to sandwich the housing.

5. The pump according to claim 1, wherein the pump housing has a connecting portion connecting the pedestal portion and the claw portion, and a protruding portion protruding from the pedestal portion, the protruding portion is disposed at a position spaced apart from the connecting portion, and abuts against the housing in a state where the convex portion is press-fitted and fixed into the hole.

6. The pump according to claim 5, wherein the protruding portion is provided in the vicinity of the shaft.

7. The pump according to claim 6, wherein two of the claw portions are provided opposite to each other with the shaft interposed therebetween, and the protruding portion is provided on a line connecting the two claw portions and a line orthogonal to the axis of the shaft.

8. The pump according to claim 1, wherein the pump housing is made of an elastic body, and the housing is made of a rigid body.

9. The hole portion and the convex portion are provided in at least two each, and the concave portion and the claw portion are provided in at least two each. The pump according to any one of claims 1, 4, and 7, characterized in that.

10. A pump with a motor, characterized in that it comprises the pump according to any one of claims 1 to 8 and a motor for driving the pump.

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