JP4668493B2 - Airless spray pump - Google Patents

Description

[0001]
(Technical field)
Airless spray pump for spraying paints and other coatings.
[0002]
(Background technology)
Airless spray pumps for spraying paints and other coatings using an airless method are well known, and conventionally classified into two types: diaphragm pumps for the lower layer market and reciprocating piston pumps for the upper layer.
[0003]
(Disclosure of the Invention)
The airless spray pump includes a single acting piston pump that allows the use of a low cost yoke drive. The motor and pump shaft are offset for the most efficient use of force. The main drive housing has a motor attached to the rear. The gear assembly uses teeth formed with a 5 ° twist angle and a 25 ° pressure angle. This geometry combines the high efficiency of spur gears with the noise reduction that is a typical feature of helical designs.
[0004]
An eccentric part is formed in the front part of the gear assembly, and a bearing assembly supported in the yoke is provided around the eccentric part. The yoke moves up and down with respect to the guide rod held in the pocket of the drive housing. Since the yoke is molded of plastic like the gear assembly, it can be easily manufactured at low cost.
[0005]
A cap having a bearing is provided at the upper end of the pump rod. The pump assembly is designed as a single acting pump. That is, the pump performs only the pumping action in the downward stroke and receives a load in the downward stroke. Since the yoke ultimately becomes a guide rather than a force applicator, the components of the drive train including the yoke and gear can be made much lighter.
[0006]
The motor and pinion are offset from the centerline of the pump assembly. Since the pump rod, the pinion, the yoke, the eccentric part, and the cap are all arranged on the same plane, such a configuration is not an extreme cantilever structure. The thrust load on the yoke is reduced by the position of the rod and the single-acting pump with respect to the gear center line. The position of the pinion in the gear is partially offset, reducing the pumping force on the gear shaft and bearing. By placing an eccentric bearing directly on the end of the press-fitted pump rod cap, pump force is not transmitted via an intermediate member such as a yoke, extending life and increasing efficiency, and a cheaper yoke assembly Enables the production of
[0007]
The shaft packing assembly includes a packing housing that is screwed into the pump housing and includes a felt member impregnated with a throat seal lubricant or other solvent or lubricant. The V-packing laminate is compressed into place by a wave spring that is tightened by tightening the seal housing to the pump housing.
[0008]
The entrance check includes a check ball and a check sheet that is press-fitted into the check housing and held at a predetermined position by the retainer. All of these parts are press-fitted together so that they can be replaced simply by screwing the completed assembly into the main pump housing. Similarly, an outlet check assembly formed from an outlet check housing that is screwed into the pump housing similarly includes a check ball that is held in place by a retainer. This outlet passage is angled with respect to the axis of the pump shaft. This allows the exit check assembly to operate essentially by gravity, requiring only a single passage to be drilled while essentially maintaining a vertical ball-seat relationship.
[0009]
The above and other objects and advantages of the present invention will become more fully apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters refer to the same or like parts throughout the several views. .
[0010]
(Best Mode for Carrying Out the Invention)
The present invention, indicated generally at 10, includes a main drive housing 12 with a motor 14 attached to the rear. A gear assembly 16 having a rear bearing 17 and gear teeth 22 is inserted into the bearing housing 20 of the drive housing 12. The gear teeth 22 of the gear assembly 16 engage with the teeth of the pinion 24 at the end of the motor 14. The teeth 22 and the teeth of the pinion 24 are formed with a torsion angle of 5 ° and have a pressure angle of 25 °. This geometry combines the high efficiency of spur gears with the noise reduction that is typical of helical designs.
[0011]
An eccentric portion 25 is also formed on the front portion of the gear assembly 16, and a bearing housing 28 supported in the yoke 30 is disposed around the eccentric portion 25. The yoke 30 moves in the vertical direction with respect to the guide rod 32 held in the pocket 34 of the drive housing 12. The yoke 30 is molded from plastic. The gear assembly 16 is cast in ZA-12 with an integral counterweight, making manufacture simple and low cost.
[0012]
The pump rod 36 includes a cap 38 having a bearing 28 on the upper end. The pump assembly 40 is designed as a single-acting pump, which is a pump that performs only the pump operation in the downward stroke and receives a load in the upward stroke. At that time, since the yoke 30 finally becomes a guide device rather than a force applying device, the components of the drive train including the yoke and the gear can be made much lighter.
[0013]
As can be seen in more detail from FIG. 2, the motor and pinion 24 are offset from the centerline of the pump assembly 40, and the bearing 20 is also offset in the opposite direction. Further, since the pump rod, the pinion, the yoke, the eccentric portion, and the cap are all arranged on the same plane, this configuration does not become an extreme cantilever structure. The thrust load on the yoke is reduced by the position of the rod and the single-acting pump with respect to the gear center line. The position of the gear pinion is partially offset, reducing the pumping force on the gear shaft and bearing. By placing an eccentric bearing directly on the end of the press-fitted pump rod cap, pump force is not transmitted via an intermediate member such as a yoke, extending the service life, increasing efficiency, and reducing the cost. Enables the manufacture of yoke assemblies.
[0014]
The shaft packing assembly 44 illustrated in FIG. 4 includes a packing housing 46 that is threaded into a pump housing 48 and includes a felt member 50 impregnated with a throat seal lubricant or other solvent or lubricant. The V-shaped packing laminate 52 is compressed to a predetermined position by a wave spring 54 that is tightened by tightening the seal housing 46 to the pump housing 48.
[0015]
In FIG. 7, the inlet check 56 includes a check ball 58, a check seat 60 that is press-fitted into the check housing 62 and held at a predetermined position by a retainer, and an integral ball guide 64. These parts are all press-fitted together so that the complete assembly can be screwed into the main pump housing 48 for replacement. Similarly, an outlet check assembly formed from an outlet check housing 60 that is screwed into the pump housing 48 similarly includes a check ball 62 that is held in place by a ball seat 65. As can also be seen in FIG. 7, the outlet passage 66 is angled with respect to the axis of the pump shaft 36. Thus, the outlet check assembly 58 is essentially actuated by gravity and only requires a single passage through the perforations while maintaining an essentially vertical ball-seat relationship.
[0016]
FIGS. 8 and 9 show an outlet filter assembly 80 that includes a filter element 82 that is received in the passage 84 of the pump assembly 40 and is held by a fitting 86.
[0017]
Now, in FIG. 10, the inlet pipe 70 includes a female screw end portion 70a. The inlet filter screen assembly 72 has a male threaded end 72a for threaded engagement with the end 70a. The ends 70a and 72a are the same size and thread as a typical garden hose so that the user only has to remove the screen assembly 72, attach the garden hose to the inlet tube 70, flush the water and wash the assembly. Is used.
[0018]
It will be appreciated that various changes and modifications may be made to the airless spray pump without departing from the spirit and scope of the invention as defined by the following claims.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an airless spray pump according to the present invention.
FIG. 2 is a schematic front view of a drive assembly and pump according to the present invention.
FIG. 3 is a side view of the assembly shown in FIG.
FIG. 4 is a detailed exploded view showing the circular area of FIG. 3;
FIG. 5 is a cross-sectional view showing a pump according to the present invention.
FIG. 6 is a more detailed view of a drive assembly according to the present invention.
FIG. 7 is another cross-sectional view showing the pump unit of the present invention.
FIG. 8 is a cross-sectional view showing an outlet filter of the present invention.
FIG. 9 is an exploded view showing the outlet filter of the present invention.
FIG. 10 is an exploded perspective view of the present invention.

Claims (2)

A spray pump powered by a rotary motor having a pinion,
A housing;
A single-acting piston pump having a pump rod and connected to the housing;
A drive gear assembly including a gear and an eccentric portion disposed on the gear;
A bearing disposed around the eccentric portion;
A yoke disposed reciprocally around the bearing in the housing;
Have
To offset and reduce the pump forces acting on the shaft and the bearing of the gear together to reduce the thrust load acting on the yoke, the rotational center of the center line and the eccentric portion of the yoke from the center line of the pump The spray pump is offset.  2. The spray pump of claim 1, wherein the gear teeth are formed with a 5 [deg.] Twist angle and a 25 [deg.] Pressure angle.

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