WO2009031768A1

WO2009031768A1 - Diaphragm assembly for pump and eccentric bushing retainer for the same

Info

Publication number: WO2009031768A1
Application number: PCT/KR2008/004747
Authority: WO
Inventors: Ei Jae Sung
Original assignee: CSE Co Ltd
Current assignee: CSE Co Ltd
Priority date: 2007-09-07
Filing date: 2008-08-14
Publication date: 2009-03-12
Anticipated expiration: 2010-03-07
Also published as: CN101796298A; KR100807840B1; CN101796298B

Abstract

The present invention provides a diaphragm assembly and an eccentric bushing retainer for the diaphragm assembly. The diaphragm assembly includes a retainer (10) which has a center seating hole (11) for seating an eccentric bushing assembly therein. The eccentric bushing assembly includes an eccentric bushing having a shaft hole, which is fitted over a drive shaft of a motor, and a bearing (C2), which is fitted over the outer surface of the eccentric bushing. The retainer includes coupling parts (17), which are provided on the outer portion of the sidewall of the retainer. The diaphragm assembly further includes a diaphragm (20), which has coupling holes at positions corresponding to the respective coupling parts of the retainer, and head members (30), each of which has a piston surface and a fastening hole. The diaphragm assembly further includes relay members (40), which are interposed between the retainer and the diaphragm.

Description

DIAPHRAGM ASSEMBLY FOR PUMP AND ECCENTRIC BUSHING RETAINER FOR THE SAME

Technical Field

[1] The present invention relates, in general, to diaphragm assemblies for pumps used in water purifiers or the like and, more particularly, to a diaphragm assembly, which includes a retainer for holding a bearing and eccentric bushing assembly coupled to a drive shaft of a motor, a diaphragm, head members for serving as pistons, and relay members, and which meets necessary conditions in which the diaphragm must be soft and flexible so that a wobbling motion may be conducted by the eccentric bushing but the head members for conducting pumping functions and the relay members for fastening the head members and the diaphragm to the retainer must be relatively hard. In addition, the diaphragm assembly facilitates the assembly process of the whole and ensures superior sealing ability and structural reliability. The present invention also relates to a retainer for holding an assembly including the diaphragm, the head members and the relay members and an assembly including a bearing and the eccentric bushing (hereinafter, referred to simply as 'an eccentric bushing assembly'). Background Art

[2] Generally, in diaphragm pumps used in water purifiers or the like, in order to improve the characteristics of pulsation, three head members, each of which has a piston surface, are provided in a diaphragm, which is wobbled by an eccentric bushing coupled to a drive shaft of a drive motor.

[3] In addition, three inlet valves for three respective pumping chambers having the three head members are provided in a valve plate.

[4] A representative example of such a diaphragm pump was proposed in Korean Patent

Laid-open Publication No. 1997-0066091 (Oct. 13, 1997), which was fielded by Shurflo Pump Manufacturing Co., entitled ^TRIPLE DISCHARGE PUMP HAVING DIAPHRAGM-INTEGRATED PISTONJ .

[5] However, in this technique, as shown in the assembled sectional view of FIG. 1, a diaphragm 120 is constructed such that each head member 130 having a piston surface is integrated with a part (called 'foot 140' in the patent application) for fastening the diaphragm to a retainer 110 (called 'wobble plate' in the patent application) which holds an assembly including an eccentric bushing Cl and a bearing C2.

[6] As such, because the diaphragm 120 must be relatively soft and flexible and it is integrally formed with the head member 130 for pumping and with the foot 140 having a fastening function, there is a problem of defective products pertaining to coupling force between the retainer and the foot.

[7] The reference numerals of FIG. 1 which are not mentioned will be explained in the description of the present invention with reference to FIG. 2 and the following drawings.

[8] With regard to the reference numerals of elements of the conventional technique of

FIG. 1 and the present invention of FIG. 2 and the following drawings, the same reference numerals throughout the drawings, that is, the same reference numerals for the second digit or the first digit, or for the second digit, the first digit and a letter of the alphabet, denote elements having the same function. If not specifically mentioned otherwise, the elements denoted by the reference numerals are assumed to comply with the above-mentioned reference scheme.

[9] Meanwhile, a construction, in which head members having piston surfaces are provided separately from a diaphragm and the head members and the diaphragm are fastened to a retainer using bolts, was proposed in Korean Patent Laid-open Publication No. 1997-0011404 (Mar. 27, 1997), which was filed by Aquatec Water Systems, Inc., entitled ^TRIPLE DISCHARGE PUMP HAVING DIAPHRAGM- INTEGRATED PISTON J .

[10] However, pumping ability is unsatisfactory in this technique because heads of the bolts interfere with the head members.

[11] Furthermore, there is a disadvantage in that watertightness between the diaphragm, the head members and the bolts is not ensured.

Disclosure of Invention

Technical Problem

[12] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a diaphragm assembly which solves problems of the conventional diaphragm caused by the integration of each head member with the corresponding foot, and problems of the conventional technique which is constructed such that separate components are assembled with each other using bolts.

[13] Another object of the present invention is to provide a diaphragm assembly in which head members serving as pistons are formed separately, the head members are inserted into corresponding coupling holes of a diaphragm and are coupled to corresponding relay members, and the assembly including the diaphragm, the head members and the relay members is coupled to a retainer for holding an eccentric bushing assembly through the relay members, thus meeting necessary conditions in which the diaphragm must be soft and flexible and the head members and the relay members must be relatively hard, and facilitating the assembly process, and ensuring the reliability of the coupling between the components.

[14] A further object of the present invention is to provide a diaphragm assembly, in which positioning elements are provided at contact surfaces between the head members and the diaphragm, contact surfaces between the head members and the relay members, and contact surfaces between relay members and the retainer in consideration of coupling orientation between components such that thin portions of the head members are disposed at positions adjacent to the perimeter of the diaphragm and thick portions of the head members are disposed at positions adjacent to the center of the diaphragm, thus optimizing the pumping ability of the head members.

[15] Yet another object of the present invention is to provide a diaphragm assembly, in which sealing protrusions are provided on the contact surfaces between the diaphragm, the head members and the relay members to enhance watertightness.

[16] Still another object of the present invention is to provide a diaphragm assembly which has a coupling structure such that heads of bolts, which are a means for coupling the head members to the relay members via the diaphragm which is interposed between the head members and the relay members, are prevented from interfering with the coupling between the relay members and the retainer, and such that the heads of the bolts enhance the coupling force between the relay members and the retainer.

[17] Still another object of the present invention is to provide a retainer for the assembly including the diaphragm, the head members and the relay members and for an eccentric bushing assembly which ensures the reliability of the coupled state between the components and has a compact structure. Technical Solution

[18] In an aspect, the present invention provides a diaphragm assembly for pumps, including: a retainer, having a center seating hole for seating an eccentric bushing assembly therein, the eccentric bushing assembly including an eccentric bushing having a shaft hole, which is fitted over a drive shaft of a motor, and a bearing fitted over an outer surface of the eccentric bushing, the retainer further having coupling parts provided on an outer portion of a sidewall of the retainer which defines the center seating hole therein, the coupling parts being arranged in a circumferential direction; a diaphragm having coupling holes at positions corresponding to the respective coupling parts of the retainer; a plurality of head members, each of which has a piston surface, with a fastening hole formed in a rear surface of each of the head members, the rear surface of the head member being opposite the piston surface and being brought into contact with the diaphragm, the head members fastening the diaphragm to the coupling parts of the retainers; and a plurality of relay members interposed between the retainer and the diaphragm, the relay members being coupled both to the corresponding coupling parts of the retainer and to the fastening holes of the corresponding head members.

[19] Preferably, in the diaphragm assembly according to the present invention, to facilitate setting of orientation of the head members with respect to the diaphragm, each head member may include an insert boss to be inserted into the corresponding coupling hole of the diaphragm, and each relay member may have an insert depression, into which the insert boss of the corresponding head member is fitted.

[20] Furthermore, each insert boss and the corresponding insert depression may have non- circular shapes to specify a coupling orientation therebetween.

[21] To specify the coupling orientation between the components (fundamentally, this is to specify the orientation of the head members), each coupling part of the retainer may have a positioning hole, and each relay member may have a positioning protrusion to be inserted into the positioning hole of the corresponding coupling part.

[22] In addition, each coupling part of the retainer may have a bolt head seating hole for seating therein a head of a corresponding bolt, which is tightened into the fastening hole of the corresponding head member through the corresponding relay member.

[23] As well, each relay member may include a coupling protrusion, which has therein a screw hole for coupling of the relay member to the retainer, and each coupling protrusion of the retainer may have a seating depression for seating the coupling protrusion of the corresponding relay member therein.

[24] Preferably, a sealing protrusion may be provided on a surface of each relay member which contacts the diaphragm to ensure watertightness.

[25] Furthermore, a sealing protrusion may also be provided on a surface of each head member which contacts the diaphragm.

[26] In another aspect, the present invention provides a retainer for an eccentric bushing assembly, including: a center seating hole for seating an eccentric bushing assembly therein, the eccentric bushing assembly including an eccentric bushing having a shaft hole, into which a drive shaft of a motor is fitted, and a bearing fitted over an outer surface of the eccentric bushing; and coupling parts provided on an outer portion of a sidewall of the retainer which defines the center seating hole therein, the coupling parts being arranged in a circumferential direction, with a bolt head seating hole formed in a surface of each coupling part which faces a diaphragm, and three positioning holes formed around the bolt head seating hole in the surface of each coupling part which faces the diaphragm.

[27] Preferably, a notch may be formed in the sidewall of the retainer to provide an elastic structure to the retainer. A snap bracket, which has a hook to snap an outer surface of the bearing, may be provided on the sidewall of the retainer, thus ensuring the structural reliability, facilitating the assembly process, and ensuring the reliability of the coupled state between the components.

Advantageous Effects

[28] In a diaphragm assembly for pumps according to the present invention, an assembly including a diaphragm, head members and relay members which are separately formed is coupled to a retainer, which holds an eccentric bushing assembly, using the relay members. Therefore, the present invention meets necessary conditions in which the diaphragm must be soft and flexible and the head members and the relay members must be relatively hard. In addition, the present invention facilitates the assembly process and ensures the reliability of the coupling between the components.

[29] Furthermore, in the present invention, positioning elements are provided at contact surfaces between the head members and the diaphragm, contact surfaces between the head members and the relay members, and contact surfaces between relay members and the retainer in consideration of a coupling orientation between components.

[30] Thus, thin portions of the head members can be easily disposed at positions adjacent to the perimeter of the diaphragm and thick portions of the head members can be easily disposed at positions adjacent to the center of the diaphragm. Hence, the pumping ability of the head members is sufficient.

[31] Moreover, sealing protrusions are provided on the contact surfaces between the diaphragm, the head members and the relay members, thus enhancing the water- tightness of the diaphragm assembly.

[32] The present invention is constructed such that heads of bolts, which are a means for coupling the head members to the relay members via the diaphragm which is interposed between the head members and the relay members, are prevented from interfering with the coupling between the relay members and the retainer, and such that the heads of the bolts enhance the coupling force between the relay members and the retainer.

[33] Furthermore, the present invention provides a retainer for the assembly including the diaphragm, the head members and the relay members and for an eccentric bushing assembly. The retainer of the present invention can ensure the reliability of the coupled state between the components and have a compact structure. Brief Description of the Drawings

[34] FIG. 1 is a sectional view showing a conventional diaphragm pump;

[35] FIGS. 2 and 3 are respectively an assembled sectional view and an exploded sectional view of a diaphragm assembly for pumps, according to the present invention;

[36] FIG. 4 is an exploded perspective view of the diaphragm assembly for pumps according to the present invention; and

[37] FIG. 5 is a front view and a rear view of an eccentric bushing retainer according to the present invention.

[38] <Description of the elements in the drawings>

[39] M: motor Hl, H2, H3: housing

[40] S: pressure switch V: valve plate

[41] E: inlet part G: outlet part

[42] A: diaphragm assembly C: eccentric bushing assembly

[43] 10: retainer 11: center seating hole

[44] 13: sidewall 15: snap bracket

[45] 17: coupling part 17A: bolt head seating hole

[46] 17B: positioning hole 17C: screw hole

[47] 18: weight reducing hole 19A, 19B: reinforcement

[48] 20: diaphragm 21: coupling hole

[49] 21A: recess 21B: coupling rim

[50] 23: partition 25 A, 25B: flange

[51] 30: head member 31 : piston surface

[52] 33: insert boss 33 A: fastening hole

[53] 33B: stop protrusion 35: sealing protrusion

[54] 40: relay member 41: insert depression

[55] 41A: fastening hole 41B: stop notch

[56] 41C: bolt seating rim 43: coupling depression

[57] 45: sealing protrusion 47: positioning protrusion

[58] 49: coupling protrusion 49A: screw hole

Best Mode for Carrying Out the Invention

[59] Hereinafter, the present invention will be described in detail with reference to the attached drawings.

[60] Although FIG. 1 is a view pertaining to the conventional pump, because only the construction of a diaphragm assembly A according to the present invention mainly differs from that of the conventional diaphragm assembly, the construction of the present invention of FIG. 2 and the following drawings that is related to components other than the diaphragm 120 and the retainer 110 of FIG. 1, will cite the corresponding construction of FIG. 1.

[61] Furthermore, in the description of the diaphragm assembly A according to the present invention, the approximate direction will be defined as follows with reference to FIGS. 2 and 4, for the convenience of description.

[62] The side of a head member 30 is defined as 'front side' or 'front part', and the side of a retainer 10 is defined as 'rear side' or 'rear part'.

[63] Portions adjacent to a shaft are designated as 'inside', and portions away from the shaft are designated as 'outer' or 'perimeter'.

[64] As shown in FIGS. 1, 2, 3 and 4, the diaphragm assembly A according to the present invention includes a retainer 10, a diaphragm 20, head members 30 and relay members 40.

[65] The construction of the present invention will be described in consideration of other components of the pump with reference to FIG. 1. A motor M, which has a double bearing M2 for supporting a drive shaft Ml, is installed in a first housing Hl.

[66] A second housing H2 has therein a bushing assembly C. The bushing assembly C includes an eccentric bushing Cl, which has a shaft hole CIa and transmits the rotation of the motor to the diaphragm 20 such that wobbling motion is generated, and a bearing C2, which serves to reduce frictional resistance of the eccentric bushing. The second housing H2 is disposed ahead of the first housing Hl.

[67] A third housing H3, which has a mounting seat for a pressure switch S and a mounting seat for a valve plate V, is coupled to the front end of the second housing using a coupling means.

[68] The pressure switch S measures a pressure in the pump or in a passage connected to the pump and turns on or off depending on whether the measured pressure is less or greater than a reference value.

[69] The valve plate V is provided with three inlet valves El and one outlet valve Gl.

Thus, the diaphragm has three coupling holes 21, three head members 30, three relay members 40, and the retainer 10 has three coupling parts 17. The installation positions of these components correspond to the installation positions of the inlet valves. However, the number of these components and the installation positions thereof are not to be construed as limiting the present invention.

[70] An inlet chamber E2 and pumping chambers E3, which constitute an inlet part E along with the inlet valves El, and an outlet chamber G2 and an outlet G3, which constitute an outlet part G along with the outlet valve Gl, are defined between the diaphragm 20, the valve plate V and the third housing H3.

[71] The outlet valve Gl of the outlet part G is disposed at the central portion of the valve plate V.

[72] In the valve plate V, a packing ring GIa is provided around the outlet valve Gl. A partition wall G2a, which contacts the packing ring and defines the outlet chamber G2 therein, protrudes into the housing H2.

[73] The three inlet valves El are disposed on the valve plate V at positions corresponding to respective vertices of an equilateral triangle, at the center of which triangle the outlet valve Gl is disposed. Furthermore, the inlet valves El are able to communicate with the inlet chamber E2, which is formed between the outer surface of the partition wall G2a of the third housing H3 and the valve plate V and forms a single space.

[74] The pumping chambers E3, which are formed between the valve plate V and the diaphragm 20, are disposed at positions corresponding to partitions 23 (refer to FIG. 4) of the front surface of the diaphragm 20 and to corresponding portions of the valve plate V. The pumping chambers E3 are separated from each other by separation recesses V2 (refer to FIGS. 1 and 2), which engage with the respective partitions 23.

[75] The number of pumping chambers E3 corresponds to the number of the inlet valves

E.

[76] The pumping chambers E3 communicates with the outlet chamber G2 through the outlet G3.

[77] As shown in FIG. 2, first and second flanges 25A and 25B are provided on the outer edge of the diaphragm 20 according to the present invention. The first and second flanges 25 A and 25B engage with an outer flange Vl, which is provided on the outer edge of the valve plate V.

[78] The front surface of the perimeter of the valve plate V is compressed by the inner surface of the perimeter of the third housing H3.

[79] The rear surface of the perimeter of the diaphragm 20 is in close contact with and is compressed by the front surface of the perimeter of the second housing H2.

[80] Therefore, watertightness between the components can be ensured.

[81] As depicted in FIG. 2 and the circle "Ll" of FIG. 4 showing an enlargement of a portion of the rear surface of the diaphragm 20, sealing protrusions 29 are provided on the perimeter of the rear surface of the diaphragm 20 to increase the watertightness.

[82] As shown in FIGS. 2 through 5, in the retainer 10 having the diaphragm assembly A according to the present invention, a center seating hole 11 is defined by a sidewall 13. The bushing assembly C including the bearing C2 and the eccentric bushing Cl (refer to FIG. 1) is seated into the center seating hole 11.

[83] In particular, as depicted in FIG. 5, notches 13a are formed in the sidewall 13 of the retainer to provide an elastic structure to the retainer. Snap brackets 15 are provided on the sidewall 13 of the retainer. Each snap bracket 15 has a hook 15A (refer to a sectional view taken along the line 15-15' of FIG. 5), which snaps the outer surface of the bearing C2 (see, FIG. 1).

[84] The three snap brackets 15 are disposed at positions alternating with the coupling parts 17 for coupling of the relay members 40.

[85] Each hook 15A includes an inclined portion 15a, which guides the bushing assembly

C such that the hook 15 can be smoothly fitted over the bushing assembly C through an automatic assembly process, and a locking portion 15b, which is locked to the perimeter of the rear surface of the bearing C2 of the bushing assembly C to prevent the bushing assembly C from being undesirably removed from the hook (refer to the partial sectional view taken along the line 15-15' of FIG. 5).

[86] The retainer 10 includes the three coupling parts 17, which are provided on the sidewall 13 at positions spaced apart from each other at regular intervals. Each coupling part 17 has a disk shape.

[87] Furthermore, each coupling part 17 is coupled to an axial reinforcement 19A, which increases the coupling strength between each coupling part 17 and the sidewall 13.

[88] The three coupling parts 17 are securely coupled to each other by a lateral reinforcement 19B.

[89] Weight reducing depressions 18 are formed in each coupling part 17 inside the axial reinforcement 19 A.

[90] In addition, each coupling part 17 has a bolt head seating hole 17 A, which is formed in the central portion, two positioning holes 17B, which are formed at inside positions, and a screw hole 17c which is formed at an outside position. These will be explained in detail as part of the description of the coupling relationship between the coupling parts and the relay members 40.

[91] The diaphragm 20 has a triangular shape, the vertices of which are rounded.

[92] As stated above, the partitions 23, which engage with the separation recesses V2 of the valve plate V and form a tripod shape, are provided on the front surface of the diaphragm 20.

[93] When the diaphragm 20 wobbles, the first and second flanges 25A and 25B, which are provided on the front surface of the perimeter of the diaphragm 20, and the sealing protrusions 29, which are provided on the rear surface of the diaphragm 20, reliably maintain the diaphragm 20 at the correct position and ensure the watertightness of the diaphragm 20.

[94] The diaphragm 20 has three coupling holes 21 at positions adjacent to the vertices of the triangle defined by the diaphragm 20. A recess 21 A is formed around each coupling hole 21 in the front surface of the diaphragm 20. A portion of each head member 30 is inserted into the corresponding recess 21A.

[95] A coupling rim 21B (refer to FIG. 3 and the circle "Ll" of FIG. 4 showing an enlargement of the portion of the rear surface of the diaphragm) is provided around each coupling hole 21 on the rear surface of the diaphragm 20, thus increasing the coupling force between the corresponding coupling part and the corresponding relay member 40, and facilitating the positioning when coupling therebetween.

[96] As well, positioning protrusions 27 are provided on the front surface of the diaphragm 20 around each coupling hole 21 and within the area of the corresponding recess 21A.

[97] The positioning protrusions 27 are fitted into corresponding positioning holes 37, which are formed in the rear surface of the corresponding head member 30 (see, FIGS. 2 and 3, as the positioning protrusions and the positioning holes are not shown in FIG.

4).

[98] Meanwhile, with regard to the head members 30, which are provided as separate components, a piston surface 31 is formed on the front surface of each head member 30. When the diaphragm 20 wobbles, the head members 30 alternately open the corresponding inlet valves El such that fluid is drawn from the inlet chamber E2 into the corresponding pumping chambers E3. Thereafter, the fluid is discharged into the outlet chamber G2 via the outlet G (at this time, the corresponding valves El are closed).

[99] To optimize the pumping ability, each head member 30 has a well known shape, in which a thin portion 3 IB is disposed at a position corresponding to the outer portion of the diaphragm, a thick portion 31A is disposed at a position corresponding to the inner portion of the diaphragm, and a convex portion is formed between the thin portion 3 IB and the thick portion 3 IA.

[100] An insert boss 33, which is fitted into the corresponding coupling hole 21 of the diaphragm, is provided on the rear surface of each head member which is opposite the piston surface 31. Preferably, the insert boss has a hexagonal cross-section.

[101] An insert depression 41, which corresponds to the corresponding insert boss 33, is formed in the front surface of each relay member 40. Preferably, the insert depression 41 also has a hexagonal cross-section corresponding to that of the insert boss 33.

[102] Due to the hexagonal cross-sectional shapes of the insert bosses and the insert depressions 41, the orientation of the piston surfaces 31 of the head members 30 can be maintained in the correct directions.

[103] Furthermore, when a bolt Bl is tightened using a tool (for example, a screwdriver) into a fastening hole 33A of the insert boss 33 of the head member through a fastening hole 41 A of the rely member, the orientation of the head member can be prevented from becoming incorrect.

[104] In other words, due to the hexagonal cross-sectional shapes of the insert boss 33 and the insert depression 41, the head member and the relay member, which are coupled to each other, can be prevented from undesirably rotating with respect to each other.

[105] Moreover, this purpose may be achieved by necessary conditions, in which the insert boss and the insert depression have non-circular cross-sections to specify the coupling orientation therebetween.

[106] In addition, a stop protrusion 33B (refer to the circle "L2" of FIG. 4 showing an enlargement of a portion of the rear surface of the head member 30) is provided on one surface of the insert boss 33 of each head member 30. A stop notch 41B, into which the stop protrusion 33B of the corresponding head member 30 is inserted, is formed in a corresponding surface of the insert depression 41 of each relay member 40. Therefore, the orientation of the head members can be easily determined, thus fa- cilitating the process of assembling the head members with the corresponding relay members.

[107] Such structure serves to complement the coupling structure between the positioning protrusions 27 of the front surface of the diaphragm 20 and the positioning holes 37 of the rear surfaces of the head members 30.

[108] In consideration of that the present invention is constructed such that the coupling orientation between the relay member 40 and the retainer 10 is specified, inclusion of the positioning protrusions of the front surface of the diaphragm and the positioning holes of the head members is not deemed to be essential. The specification of the coupling orientation between the relay member 40 and the retainer 10 will be explained herein later.

[109] As depicted in the circle "Ll" of FIG. 4 showing an enlargement of a portion of the rear surface of the diaphragm, each coupling hole 21 of the diaphragm 20 has a hexagonal shape corresponding to the shape of the insert boss 33 of the corresponding head member 30.

[110] A stop notch 21a, which engages with the stop protrusion 33B of the corresponding insert boss 33, is formed in one surface of each hexagonal coupling hole 21.

[I l l] Furthermore, the coupling rim 2 IB also has a hexagonal shape.

[112] A coupling depression 43 of each relay member 40 into which the corresponding coupling rim 2 IB is fitted may have a hexagonal shape corresponding to that of the coupling rim 2 IB.

[113] In the present invention, as well as the coupling structure described above, various coupling structures can be used to determine the coupling orientation of the piston surfaces 31 of the head members 30.

[114] Meanwhile, sealing protrusions 35 which have a double circular structure, are provided on the rear surface of each head member which comes into contact with the diaphragm 20, thus further increasing the watertightness.

[115] Each relay member 40 has the fastening hole 41A, which corresponds to the fastening hole 33 A of the corresponding head member, the insert depression 41, which corresponds to the insert boss 3 of the head member, and the coupling depression 43, which is coupled to the corresponding coupling rim 2 IB of the diaphragm 20. In a ddition, sealing protrusions 45, which form a double circular structure, are concentrically provided on the front surface of the relay member 40. The sealing protrusions 45 come into contact with the rear surface of the diaphragm 20.

[116] The hexagonal insert depression 41 has the stop notch 4 IB in one surface thereof.

[117] Furthermore, a bolt seating rim 41C is provided around the fastening hole 41A on the rear surface of each relay member 40 (refer to the circle "L3" of FIG. 4 showing an enlargement of a portion of the rear surface of the relay member 40). A coupling bolt B 1 couples the relay member to the corresponding head member such that the head member and the relay member are disposed on the respective opposite surfaces of the diaphragm.

[118] In particular, a counter sink head bolt is preferably used as the coupling bolt B 1 to prevent the head of the bolt from protruding from the relay member. In addition, the bolt seating rim 41C preferably has a shape which corresponds to the shape of the front surface of the head of the coupling bolt so that the bolt head is completely seated into the bolt seating rim 41C without protruding from the relay member.

[119] The bolt seating rim 41C is inserted into the bolt head seating hole 17 A of the corresponding coupling part 17 to more reliably prevent the retainer and the relay member from becoming spaced apart from each other due to the bolt head, thus further increasing the reliability of the coupling between the components.

[120] Furthermore, three weight reducing holes 48 are formed around the bolt seating rim in each relay member.

[121] Two positioning protrusions 47 are provided on the inside portion of each relay member, so that the positioning protrusions 47 are inserted into the corresponding positioning holes 17B of the corresponding coupling part 17 of the retainer.

[122] In addition, a coupling protrusion 49, which has a screw hole 49A therein, is provided on the outer portion of each relay member. The coupling protrusion 49 is inserted into a seating depression 17C, which is formed in each corresponding coupling part 17 of the retainer 10 at a position closer to the circumference of the coupling part 17 than the screw hole 17c.

[123] In each coupling part 17 of the retainer, the screw hole 17C communicates with the bolt head seating hole 17 A.

[124] Here, a typical pan head bolt is used as a bolt B2, which is tightened into the screw hole 49 A of each relay member 40 via the corresponding screw hole 17c of the retainer 10 to couple the relay member 40 and the retainer 10 to each other. Typically, a washer B2a is interposed between the retainer and each bolt B2.

[125] As described above, various positioning elements are provided on the junctions between the components of the diaphragm assembly A and the retainer 10 therefor according to the present invention, so that the components are prevented from being displaced from their correct positions when bolts are tightened thereinto.

[126] Moreover, the positioning elements complement each other to reliably ensure the coupling orientation of the head members 30.

[127] Therefore, the present invention facilitates the assembly of the components and ensures the reliability of the coupling between the components.

[128] In the above-mentioned description, although the explanation of the well-known techniques, such as the diaphragm pump, the eccentric bushing Cl, the wobbling movement of the diaphragm 20, movement of the inlet valve El of the inlet part E and the outlet valve Gl of the outlet part G, the flow of fluid depending on the movement of the valves, control of the motor M pertaining to the pressure switch S, etc., has been omitted, those skilled in the art will easily understand these techniques. Furthermore, although the diaphragm assembly and the retainer for the same according to the preferred embodiment, having a special shape and construction, has been disclosed for illustrative purposes with reference to the attached drawings, those skilled in the art will appreciate that various modifications, additions and substitutions are possible. In addition, such modifications, additions and substitutions must be interpreted as falling within the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] A diaphragm assembly for pumps, comprising: a retainer, having: a center seating hole for seating an eccentric bushing assembly therein, the eccentric bushing assembly including an eccentric bushing having a shaft hole, which is fitted over a drive shaft of a motor, and a bearing fitted over an outer surface of the eccentric bushing; and coupling parts provided on an outer portion of a sidewall of the retainer which defines the center seating hole therein, the coupling parts being arranged in a circumferential direction; a diaphragm having coupling holes at positions corresponding to the respective coupling parts of the retainer; a plurality of head members, each of which has a piston surface, with a fastening hole formed in a rear surface of each of the head members, the rear surface of the head member being opposite the piston surface and being brought into contact with the diaphragm, the head members fastening the diaphragm to the coupling parts of the retainers; and a plurality of relay members interposed between the retainer and the diaphragm, the relay members being coupled both to the corresponding coupling parts of the retainer and to the fastening holes of the corresponding head members.

[2] The diaphragm assembly according to claim 1, wherein each of the head members includes an insert boss to be inserted into the corr esponding coupling hole of the diaphragm, and each of the relay members has an insert depression, into which the insert boss of the corresponding head member is fitted.

[3] The diaphragm assembly according to claim 2, wherein each of the insert bosses and the corresponding insert depressions have non-circular shapes to specify a coupling orientation therebetween.

[4] The diaphragm assembly according to claim 1, wherein each of the coupling parts of the retainer has a positioning hole, and each of the relay members has a positioning protrusion to be inserted into the positioning hole of the corresponding coupling part.

[5] The diaphragm assembly according to any one of claims 1 through 4, wherein each of the coupling parts of the retainer has a bolt head seating hole for seating therein a head of a corresponding bolt, which is tightened into the fastening hole of the corresponding head member through the corresponding relay member.

[6] The diaphragm assembly according to any one of claims 1 through 4, wherein each of the relay members includes a coupling protrusion, which has therein a screw hole for coupling of the relay member to the retainer, and each of the coupling protrusions of the retainer has a seating depression for seating the coupling protrusion of the corresponding relay member therein.

[7] The diaphragm assembly according to any one of claims 1 through 4, wherein a sealing protrusion is provided on a surface of each relay member which contacts the diaphragm.

[8] The diaphragm assembly according to any one of claims 1 through 4, wherein a sealing protrusion is provided on a surface of each head member which contacts the diaphragm.

[9] The diaphragm assembly according to any one of claims 1 through 4, wherein a notch is formed in the sidewall of the retainer to provide an elastic structure to the retainer, and a snap bracket is provided on the sidewall of the retainer, the snap bracket having a hook to snap an outer surface of the bearing.

[10] A retainer for an eccentric bushing assembly, comprising: a center seating hole for seating an eccentric bushing assembly therein, the eccentric bushing assembly including an eccentric bushing having a shaft hole, into which a drive shaft of a motor is fitted, and a bearing fitted over an outer surface of the eccentric bushing; and coupling parts provided on an outer portion of a sidewall of the retainer which defines the center seating hole therein, the coupling parts being arranged in a circumferential direction, with a bolt head seating hole formed in a surface of each coupling part which faces a diaphragm, and three positioning holes formed around the bolt head seating hole in the surface of each coupling part which faces the diaphragm.

[11] The retainer according to claim 10, wherein a notch is formed in the sidewall of the retainer to provide an elastic structure to the retainer, and a snap bracket is provided on the sidewall of the retainer, the snap bracket having a hook to snap an outer surface of the bearing.

[12] The retainer according to claim 11, wherein the snap bracket comprises three snap brackets disposed at positions alternating with the coupling parts.