DIAPHRAGM PUMP

Abstract

A diaphragm pump comprises a housing, a motor supported by the housing, a drive assembly operably connected to the motor and a wobble plate operably connected to the drive assembly. The motor includes a drive shaft defining a rotational axis. The wobble plate orbits about the rotational axis of the drive shaft. The drive assembly includes a reduction gear assembly and a drive member connected to the gear assembly. The gear assembly provides a predetermined gear reduction to reduce the speed of the motor and increase the torque needed to drive the pump.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority from U.S. Provisional Patent Application Ser. No. 611082,370 filed Jul. 21, 2008; which provisional patent application is expressly incorporated herein by reference, in its entirety.

BACKGROUND

Exemplary embodiments herein relate to a diaphragm pump for a hydraulic system. Diaphragm pumps possess many advantages and are widely used. Generally, the diaphragm pump defines a variable volume chamber by using a space between a pump casing and a diaphragm, which is controlled by a wobble plate. Typically, the wobble plate, driven by a shaft, operates to lift away from and then compress against the diaphragm in a wavelike or peristaltic motion. An inlet and an outlet are provided through the pump casing with one-way valves for preventing backflow. These cooperate with the diaphragm to create an appropriate variable pumping chamber with a peristaltic action. The conventional diaphragm pumps require a relatively large motor to generate the torque needed to drive the pump. However, the use of the large motors increases the weight, size and cost of the diaphragm pumps.

An improved diaphragm pump is provided which employs a relatively smaller, lighter and more cost effective motor and drive assembly which can produce equivalent speed and torque as the previously used larger motors.

BRIEF DESCRIPTION

According to one aspect, a diaphragm pump comprises a housing, a motor supported by the housing, a drive assembly operably connected to the motor and a wobble plate operably connected to the drive assembly. The motor includes a drive shaft defining a rotational axis. The wobble plate orbits about the rotational axis of the drive shaft. The drive assembly includes a reduction gear assembly and a drive member connected to the gear assembly. The gear assembly provides a predetermined gear reduction to reduce the speed of the motor and increase the torque needed to drive the pump.

According to another aspect, a diaphragm pump comprises a housing and a generally small, lightweight motor supported by the housing. The motor includes a drive shaft defining a rotational axis. A drive assembly is operably connected to the motor. The drive assembly includes a reduction gear assembly including a planetary gear train having a plurality of compound gears and a ring gear. A wobble plate is rotatably connected to the gear assembly. The wobble plate orbits about the rotational axis of the drive shaft. The gear assembly provides a predetermined gear reduction to reduce the speed of the motor and increase the torque needed to drive the pump.

According to yet another aspect, a diaphragm pump comprises a housing and a permanent magnet motor supported by the housing. The motor includes a drive shaft defining a rotational axis. A drive assembly is positioned within the housing and is operably connected to the motor. The drive assembly includes a reduction gear assembly for reducing the speed and increasing the torque of the permanent magnet motor needed to drive the pump. The gear assembly includes a planetary gear train comprised of a plurality of drive gears and a stationary ring gear. Rotation of the drive shaft causes the plurality of drive gears to rotate about the ring gear. A drive member is rotatably connected to the reduction gear assembly. A wobble plate is rotatably connected to the drive member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of a diaphragm pump with a portion thereof removed according to the present disclosure.

FIG. 2 is a side elevational view of the diaphragm pump of FIG. 1.

FIG. 3 is an exploded perspective view of the diaphragm pump of FIG. 1.

FIGS. 4-6 are enlarged perspective views of the illustrated components of the diaphragm pump of FIG. 3.

FIG. 7 is a partial cross-sectional view of the diaphragm pump of FIG. 1.

DETAILED DESCRIPTION

It should, of course, be understood that the description and drawings herein are merely illustrative and that various modifications and changes can be made in the structures disclosed without departing from the present disclosure. It will also be appreciated that the various identified components of the diaphragm pump disclosed herein are merely terms of art that may vary from one manufacturer to another and should not be deemed to limit the present disclosure. All references to direction and position, unless otherwise indicated, refer to the orientation of the diaphragm pump illustrated in the drawings and should not be construed as limiting the claims appended hereto.

Referring now to drawings, wherein like numerals refer to like parts throughout the several views, a diaphragm pump 100 according to the present disclosure is illustrated. With reference to FIGS. 1-3 and 7, the diaphragm pump 100 comprises a housing 102, a motor 104 supported by the housing, a drive assembly 106 operably connected to the motor and a wobble or swash plate 108 operably connected to the drive assembly. The housing 102, which houses the drive assembly 106, includes a first housing part 112, an intermediate, second housing part 114, and a third housing part 116.

As shown in FIGS. 3 and 4, the first housing part 112 includes a first enclosure 120 supported on a suitable base 122. The first enclosure 120 includes a generally cylindrical shaped wall 124 having an outer surface 126 and an inner surface 128, and a back wall 130. The inner surface includes a plurality of circumferentially spaced first notches 140 and second notches 142. The first and second notches are generally U-shaped and extend axially on the inner surface 128, an end of each notch being spaced from the end wall 130. As will be discussed in greater detail below, the second notches 142, which can be slightly larger than the first notches, serve as guides to properly align the first and second housing parts 112 and 114. Located on the wall 124 are a pair of tabs 146 having openings 148 which are dimensioned to receive fasteners (not shown). A suitable fastener is shown in FIG. 7.

With continued reference to FIG. 4, the base 122 includes a center member 160 having a front wall 162 and a rear wall 164 and opposed side walls 166 and 168. The front wall is generally flush with an end 170 of the first enclosure 120 and includes openings 172 dimensioned to receive fasteners. The rear wall 164 is spaced from the back wall 130. A top surface 174 of the center member includes an upwardly extending shelf 176 that spans from the rear wall 164 to the back wall 130 and has a top surface 178 configured to support the motor 104. First and second flanges 184 and 186 extend from the respective side walls 166 and 168. Each flange includes mounting holes 188 which allow the base 122 to be mounted to a subjacent flat surface.

With reference now to FIG. 5, the second housing part 114 includes a second enclosure 200 having a generally cylindrical shaped wall 202 and a vertical wall 204 located within the enclosure. The wall 202 includes an outer surface 206 and an inner surface 208. A flange 210 extends outwardly from a first end portion 212 of the wall 202. The flange includes a plurality of circumferentially spaced first projections 220 and second projections 222. The first and second projections 220, 222 are generally U-shaped and are dimensioned to be received in the respective first and second notches 140, 142 of the first housing part 112. Located on the wall 202 are spaced apart first bosses 230 having openings (not shown). Spaced apart second bosses 236 having openings 238 are disposed on the inner surface 208 of the wall 202. Ends 240 of the second bosses 236 project from a second end portion 242 of the wall 202.

The vertical wall 204, which separates the second enclosure 200 into a first portion 250 and a second portion 252, includes an opening 260. A generally circular flange 262 is secured to the wall 204 and extends into the second portion 252. The flange 262 includes an outer wall 264 and an inner wall 266. The inner wall defines an opening 270 having an axis which is coincident with an axis defined by the wall opening 260. The opening 270 is dimensioned to receive a first bearing 272. At least one support 274 is provided for the flange 262. The support is connected to the wall 204 and spans between the inner surface 208 of the wall 202 and the outer surface 264 of the flange 262. As shown, three spaced apart supports 274 are provided for the flange 262; although, this is not required.

With reference to FIG. 7, the third housing part 116 includes a third enclosure 290 having fluid inlet section (not shown) and a fluid outlet section (not shown). An inlet valve 292 is operably connected to the inlet section and an outlet valve 294 is operably connected to the outlet section. The third enclosure at least partially defines a pump chamber 296. Located on a wall 300 of the third enclosure are tabs 302 having openings 304 which are dimensioned to receive fasteners F.

To secure the second housing part 114 to the first housing part 112, the first and second projections 220, 222 are aligned with the first and second notches 140, 142. Once properly aligned, the projections can be at least partially slidingly received in the notches. In this position, the openings of the first bosses register with the openings 148 of the tabs 142 and the openings 172 of the base 122. Fasteners (not shown) extend through the openings 148, 172 and threadingly engage the boss openings. To secure the third housing part 116 to the second housing part 114, the openings 304 of the tabs 302 are aligned with the openings 238 of the second bosses 236. The fasteners F extend through the tab openings 304 and threadingly engage the boss openings 238.

With reference again to FIGS. 3 and 4, the motor 104, which can be a relatively small, lightweight permanent magnet motor, includes a motor housing 320, a power switch or connection to the power source 322 located on the housing and an output or drive shaft 324. The power source can be alternating current or direct current batteries or a cable attached to a dc power source, like a motor vehicle battery. The at least one battery can have, for a non-limiting example, a voltage in the range of about 6 to around 42 volts. The watt rating for the motor can be for a non-limiting example in the range of 1 to 500. The output shaft of the motor defines a longitudinal axis. As indicated above, the motor 104 can be supported on the shelf 176 of the base 122. The output shaft extends through an opening (not visible) located on the wall 130 of the first housing part 112 (see FIG. 2). With additional reference to FIG. 6, the drive assembly 106 can comprise a reduction gear assembly 340 and a drive member 342 operably coupled to the reduction gear assembly. In the depicted embodiment, the reduction gear assembly is a planetary gear train including a spur gear 350, a plurality of compound gears 352 and a ring gear 354. The spur gear is mounted to an end portion 358 of the motor output shaft 324 which projects through the opening of the wall 130. Each compound gear 352 includes a first gear 360 and a smaller second gear 362. An axis of rotation of the first gear is coincident with an axis of rotation of the second gear. The second gear 362 is at least partially surrounded by the first gear 360; although, this is not required. For each compound gear 352, a portion of the second gear 362 extends outwardly from the first gear 360 to engage the ring gear 354.

The ring gear 354 includes a wall 370 having an outer surface 372 and an inner surface 374. The inner surface defines an opening 376. The inner surface includes a plurality of circumferentially spaced teeth 378 configured to simultaneously engage the second gears 362. This configuration provides for a compact gear assembly. The outer surface includes a plurality of circumferentially spaced first projections 380 and second, larger projections 382. The first and second projections 380, 382 engage the first and second projection 220, 222. Particularly, the first and second projections 380, 382 are dimensioned to be received in respective recesses (not visible) formed by the generally U-shaped first and second projections 220, 222 of the second housing part 114. Once positioned within the recesses, the ring gear 354 is non-rotatably secured to the second housing part 114.

The drive member 342 comprises a base 390 and a shaft 392 extending outwardly from a central raised portion 394 of the base. The base is generally triangular in shape; although, it should be appreciated that alternative shapes for the base are contemplated. To some extent, the shape of the base 390 would be dependent on the number of compound gears 352 in the gear assembly 340. The base is dimensioned to be rotatably positioned within the opening 376 of the ring gear and includes posts 396 which extend from corner sections 398 of the base. Each post 396 extends through an opening 400 of each compound gear 352 to non-rotatably secure the compound gear 352 to the drive member 342. In the assembled condition, the compound gears are spaced from each other so that the spur gear 350 can simultaneously engage the first gears 360. The raised portion 394 is received in the opening 260 of the wall 204. The shaft 392 defines a longitudinal axis which is coincident with the rotational axis of the drive shaft 324. The shaft 392 extends through an opening 406 of the first bearing 272 (see FIG. 5) and includes a keyed section 410. As shown in FIG. 5, a coupling 420 is secured to the shaft keyed section. The coupling can be generally mushroom shaped and includes a head 422, a post 424 projecting from the head, and an opening 426 for receiving the shaft 392. The post 424 is sized to be frictionally received within the bearing opening 406. Once positioned with the opening, the head 422 engages a surface of the bearing.

With reference to FIG. 7, housed within the third housing part 116 is the wobble plate 108. The wobble plate is rotated by the shaft 392 of the drive member 342, which is, in turn, rotated by the drive shaft 324 of the motor 104. A plurality of pistons (only one piston 440 is shown) are reciprocated by the wobble plate 108. The piston 440 is attached to a diaphragm 442 which provides an internal seal for the pump. The piston reciprocates within the pump chamber 296 that is at least partially defined by a manifold plate 450. The manifold plate includes the one-way inlet valve 292 that allows water to flow into the pump chamber and the one-way outlet valve 294 that allows water to flow out of the pump chamber.

The wobble plate 108 is coupled to a rocker arm 460 by a second bearing 462. The wobble plate provides an inclined and radially offset mounting for the second bearing. The second bearing defines the normal central axis of the wobble plate. This normal central axis of the wobble plate 108 is angularly displaced about 3° to 6° from the rotational axis of the shaft 392. The wobble plate has a surface 466 which cooperates with the first bearing 272 to move the rocker arm in a reciprocating motion in response to a rotation of the shaft 392. The pistons are attached to the rocker arm 460 by a plurality of screws 470. The pistons are located symmetrically about the drive shaft and swing about a radial arc relative to the drive shaft centerline. The swinging motion of the pistons cause the outer portion of the diaphragm 442 to move a greater distance than the inner portion of the diaphragm.

In use, rotation of the motor drive shaft 324 causes the spur gear 350 secured thereto to simultaneously engage the first gears 360 of the compound gears 352. Rotation of the first gears rotates the second gears 362 within the ring gear 354. The gear assembly provides a predetermined gear reduction (for example, a 13.8:1 gear reduction) to reduce the speed of the drive shaft 324 thereby allowing the smaller, lighter and more cost effective motor 104 to generate the increased torque needed to drive the diaphragm pump 100. As the compound gears 352 rotate, the shaft 392 of the drive member 342 rotates about the axis of the drive shaft 324. The drive shaft, in turn, engages the wobble plate 108 which reciprocates the pistons 440. During an intake stroke, the volume of the pump chamber 296 increases and draws in water through the inlet section and inlet valve 292. During the power stroke, the piston pushes the water out of the pump chamber and through the outlet valve 294 and outlet section. The cycle is repeated as the output shaft 392 rotates the wobble plate 108.

The housing 102, drive member 342 and coupling 420 can be made of a suitable metal or polymeric material. The diaphragm can be made of a suitable flexible, resilient material, which can be a polymeric material or an elastomer.

It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art. It is intended that all of these, or equivalents thereof are encompassed by the following claims.

Claims

1. A diaphragm pump comprising:

a housing;

a motor supported by the housing, the motor including a drive shaft defining a rotational axis;

a drive assembly operably connected to the motor, the drive assembly including a reduction gear assembly and a wobble plate rotatably connected to the gear assembly, the wobble plate orbiting about the rotational axis of the drive shaft; and

wherein the gear assembly provides a predetermined gear reduction to reduce the speed of the motor and increase the torque needed to drive the pump.

2. The diaphragm pump of claim 1, wherein the reduction gear assembly comprises a planetary gear train.

3. The diaphragm pump of claim 2, wherein the planetary gear train includes a plurality of compound gears and a ring gear, the ring gear at least partially surrounding the plurality of compound gears providing for a compact reduction gear assembly.

4. The diaphragm pump of claim 3, wherein the reduction gear assembly further comprises a spur gear coupled to the drive shaft of the motor, each compound gear including a first gear and a second smaller diameter gear, the spur gear simultaneously engaging the first gears of the plurality of compound gears.

5. The diaphragm pump of claim 4, wherein the ring gear includes a wall having an outer surface and an inner surface, the inner surface including a plurality of circumferentially spaced teeth configured to simultaneously engage the second gears of the plurality of compound gears.

6. The diaphragm pump of claim 3, wherein the ring gear is non-rotatably secured to the housing.

7. The diaphragm pump of claim 3, wherein the drive assembly further includes a separate drive member rotatably coupled to the housing and located between the reduction gear assembly and wobble plate.

8. The diaphragm pump of claim 7, wherein the drive member is at least partially positioned within the ring gear.

9. The diaphragm pump of claim 7, wherein the drive member includes a base, a first outwardly extending shaft for engaging the wobble plate and a plurality of second outwardly extending shafts, each compound gears being non-rotatably secured to one of the second shafts.

10. The diaphragm pump of claim 9, wherein the first shaft of the drive member defines a longitudinal axis which is coincident with the rotational axis of the drive shaft and each second shaft of the drive member defines a longitudinal axis offset from and parallel to the rotational axis of the drive shaft.

11. The diaphragm pump of claim 9, wherein the second shafts extend in a direction opposite to the direction that the first shaft extends.

12. The diaphragm pump of claim 1, wherein the reduction gear assembly provides about a 14:1 gear reduction to reduce the speed of the drive shaft thereby allowing the motor to generate increased torque needed to drive the diaphragm pump.

13. A diaphragm pump comprising:

a housing;

a generally small, lightweight motor supported by the housing, the motor including a drive shaft defining a rotational axis;

a drive assembly operably connected to the motor, the drive assembly including: a reduction gear assembly including a planetary gear train having a plurality of compound gears and a ring gear, and a wobble plate rotatably connected to the gear assembly, the wobble plate orbiting about the rotational axis of the drive shaft; and

wherein the gear assembly provides a predetermined gear reduction to reduce the speed of the motor and increase the torque needed to drive the pump.

14. The diaphragm pump of claim 13, wherein the housing includes a first housing part and a second housing part releasably connected to the first housing part, the first and second housing parts together defining a chamber for housing the reduction gear assembly.

15. The diaphragm pump of claim 14, wherein the ring gear is non-rotatably secured to one of the first housing part and the second housing part, the ring gear including an inner surface configured to engage the plurality of compound gears allowing rotation of the plurality of compound gears about the inner surface of the ring gear.

16. The diaphragm pump of claim 15, wherein the reduction gear assembly further comprises a spur gear coupled to the drive shaft of the motor for simultaneously engaging the plurality of compound gears.

17. The diaphragm pump of claim 14, wherein the drive assembly further includes a separate drive member rotatably coupled to both the reduction gear assembly and wobble plate, the drive member being at least partially positioned within the ring gear.

18. The diaphragm pump of claim 13, wherein the motor is a permanent magnet motor and the reduction gear assembly provides about a 14:1 gear reduction to reduce the speed of the drive shaft thereby allowing the permanent magnet motor to generate increased torque needed to drive the diaphragm pump.

19. A diaphragm pump comprising:

a housing;

a permanent magnet motor supported by the housing, the motor including a drive shaft defining a rotational axis;

a drive assembly positioned within the housing and operably connected to the motor, the drive assembly including: a reduction gear assembly for reducing the speed and increasing the torque of the permanent magnet motor needed to drive the pump, the gear assembly including a planetary gear train comprised of a plurality of drive gears and a stationary ring gear, a rotation of the drive shaft causing the plurality of drive gears to rotate about the ring gear, a drive member rotatably connected to the reduction gear assembly, and a wobble plate rotatably connected to the drive member.

20. The diaphragm pump of claim 19, wherein each drive gear includes a first gear and a second gear, the first gears being simultaneously engaged by the drive shaft, the second gears being mounted to the drive member and simultaneously engaging the ring gear.