HK1118757B - Self starting vibrator - Google Patents

Description

Self-starting vibrator

Technical Field

The present invention relates generally to vibrators, and more particularly to non-impact vibrators having an integrated on-demand start-up and delivery system, wherein one vibrator is externally secured to a conveyor line for discharging material that should be contained therein.

Background

The concept of non-impact linear vibrators known in the prior art is typically that a cylinder vibrates back and forth within a cylindrical chamber as air flows into and out of the cylindrical chamber. The vibrator is generally not lubricated because the air is used to support the cylinder as it oscillates back and forth. If a lubricant such as oil or the like is used, it can result in oil mist being vented into the atmosphere. One of the difficulties with these systems, when they generate vibrations, is that the vibrator does not always start vibrating as desired. That is, as air or other fluid is introduced into the cylindrical chamber, the air may pass along the cylinder without inducing the desired vibration of the mass therein.

In one embodiment of the known linear vibrator, the vibrator comprises a cylindrical piston driven by an air flow to oscillate back and forth within a chamber, while the air pushes the piston back and forth as it forms an air bearing around the piston to form a substantially frictionless surface between the piston and the housing. One disadvantage of such vibrators is that to ensure that the vibrator responds to the introduction of fluid into the chamber, some mechanical means, such as a spring, is typically required to bias the piston to facilitate the initial vibratory movement of the piston. That is, when a fluid such as air is introduced into the chamber, the piston, which is supported by the air bearing, may not start to vibrate immediately when the air enters the chamber. Thus, to ensure start-up, it is necessary to initiate the vibration of the piston by incorporating a mechanical device, such as a spring or the like, within the vibrator. However, introducing a mechanical activation means like a spring will reduce the lifetime of the vibrator, as the spring may break due to metal fatigue.

The present invention provides, in one embodiment, an on-demand immediate start linear vibrator that avoids lubricant contamination problems and failure problems due to fatigue of the starting mechanism. In another embodiment, the on-demand immediate start-up of the linear vibrator includes a back-up on-demand start-up system.

Disclosure of Invention

Briefly, the present invention comprises a housing having a cylindrical support surface for forming a chamber therein, and an inlet for directing fluid into the chamber. A one-piece piston is slidably disposed within the chamber, the piston having an internal set of fluid passages therein and an external bearing surface on the piston. The flow of air between the inner cylindrical bearing surface of the housing and the outer bearing surface of the piston creates a substantially frictionless fluid bearing that allows the piston to move back and forth within the chamber with little energy loss and virtually no wear on the inner cylindrical bearing surface of the housing or the outer bearing surface of the piston. To provide on-demand start-up without contaminating the atmosphere, one embodiment of the present invention includes an internal non-contaminating start-up system wherein at least one of the support surfaces contains a lubricant-adhering surface to provide an on-demand static start-up system while inhibiting or eliminating contamination of the atmosphere. In another embodiment, the on-demand start-up system is a non-polluting dynamic system that includes a chamber port that unbalances the various forces on the piston therein to ensure that the vibrator begins to vibrate as desired. Thus, two boot systems can be used, one being an on-demand static boot system and the other being an on-demand dynamic boot system. And both systems can be used separately or, if desired, can be used in combination to provide a back-up system.

Drawings

FIG. 1 is a perspective view of a non-impact vibrator mounted on a transmission line;

FIG. 1A is an exploded view of a mounting bracket for holding a vibrator on a transfer line;

FIG. 2 is a cross-sectional view of a non-impacting vibrator having a cylindrical body therein in a first position;

FIG. 2A shows an enlarged view of the inner shell with its surface being honed and the coating on the inner surface of the shell;

FIG. 3 is a cross-sectional view of a non-impact vibrator with an activation port and a piston in a first position;

FIG. 4 shows the vibrator of FIG. 3 with the piston in a second position;

FIG. 5 shows the vibrator of FIG. 3 with the piston in a third position;

FIG. 6 is a perspective view of the slidable piston in the vibrator; and is

FIG. 7 shows a discharge system that may be controlled by a pressurized air source.

Detailed Description

Fig. 1 is a perspective view of a conveyor system 10 to which a vibrator 11 is fastened. The transmission system comprises a pneumatic transmission pipe 12 to which a non-impact vibrator 11 is fastened by means of a first end mounting plate 14 having a top part 14b fastened to the end of the vibrator 11 by means of bolts (not shown) and a curved end in contact with the pipe 12 and extending partly around the outer surface of the pipe 12. The bottom piece 14a of the rack tray 14 is fastened to the top piece 14b by bolts 14 c. Likewise, a second end mounting plate 15 having a top piece 15b is fastened to the opposite end of the vibrator 11 by bolts 17 and has a curved end extending partially around the outer surface of the pipe 12 and contacting the pipe 12. The bottom part 15a of the mounting plate 15 is fastened to the top part 15b by means of bolts 15c, which are arranged on the opposite side of said mounting plate 15, to clamp the pipe 12 therebetween. The end mounting discs 14 and 15 are identical to each other and can be clamped tightly around the outer wall of the rigid pipe 12 so that the vibrating motion of the vibrator 11 can transfer vibration energy to the pipe 12 in order to expel any material adhering within the transmission pipe. Typically, the vibrator is installed where the pipe is bent, because substances can adhere more frequently where the transport pipe changes direction, although the vibrator can be placed elsewhere where adhesion can occur.

The mounting plate 15 clamping the transfer tube 12 is shown in a separate perspective view in fig. 1A to show the top part 15b with a semi-cylindrical surface 15e and the bottom part 15a with a semi-cylindrical surface 15f, which cooperate and form a jaw engagement with the outer surface 12a of the pneumatic tube 12, so that vibrations from the oscillator 11 are transmitted to the transfer tube 12, thereby expelling the substance in the transfer tube.

Fig. 1 shows that the vibrator 11 comprises a housing 23 having a fluid inlet 20 and first and second discharge valves 21, 22 which allow fluid to be discharged from the vibrator 11. In operation, the fluid inlet 20 is connected to a source of high pressure fluid, such as compressed air, which flows into the fluid inlet 20 and is alternately discharged through the discharge valve 21 and the discharge valve 22.

Referring to fig. 2, there is shown a cross-sectional view of the vibrator 11 showing the vibrator end plates 30 and 31 fastened to the cylindrical housing 23 by bolts (not shown) so that the end plates and the housing form an elongated cylindrical chamber having an elongated cylindrical support surface 32a for a single piston 35 to vibrate back and forth therein. The piston 35 is shown in cross-section in fig. 2 and in isolated perspective view in fig. 6 and includes a first circumferential groove 38 that allows fluid to flow around and into a radial port 40, the radial port 40 being connected to an axially extending inner end 44 terminating at the right end of the piston 35. The piston 35 also includes a second circumferential groove 39 that allows fluid to flow around and into a radial port 41 (fig. 2), the radial port 41 being connected to an axially extending port 46 that terminates at the opposite end 35a of the piston 35.

The housing 23 includes a set of three circumferential grooves forming an annular chamber. The first circumferential groove 51 is connected to the outlet port 50, the second circumferential groove 52 is connected to the inlet port 20, and the third circumferential groove 61 is connected to the outlet port 60. In addition, there is sufficient clearance to form an annular gap between the outer diameter of piston 35 and the inner diameter of cylindrical surface 32a to allow a portion of the fluid to pass through the gap, forming a fluid bearing therebetween. The fluid bearings allow the piston 35 to slide back and forth relatively frictionless. Another portion of the fluid from the inlet 20 flows through the piston 35 before exiting the outlet port 50 or the outlet port 60.

While the fluid bearing created by the air flow into the vibrator port 20 provides relatively frictionless vibration of the piston 35, it does not always provide for the desired activation of the vibrator. The dynamic forces maintain the vibration once the piston 35 begins to vibrate, however, when air enters the inlet tube 20, sometimes the adhesion between the piston 35 and the housing 23 may cause the piston to clog or otherwise fail to begin vibrating. It has been found that the use of the adhesive lubricant on the inner surface of the housing enables the piston to overcome the static adhesive force between the piston 35 and the housing 23 to allow the piston to begin vibrating as required when a fluid such as air enters the vibrator inlet 20, thereby eliminating the need for a mechanical activation system such as a spring or the like.

The embodiment shown in fig. 2 includes an integrated, static, on-demand start-up system. Fig. 2A shows that the inner support surface 32A comprises a wear resistant anode layer 19 impregnated with an adhering lubricant like teflon 19 a. By adhering lubricant, which is a kind of lubricant that is firmly adhered to the anode layer 19 or impregnated in the anode layer 19 and remains thereon, the lubricant is suppressed from being released and the contamination or contamination of the atmosphere is suppressed, while allowing the vibrator 11 to vibrate as needed (i.e., when the fluid enters the inlet port 20).

Therefore, the adherent lubricant 19a of the present invention is different from those liquid lubricants such as oils or the like which contaminate the atmosphere by liquid separation or complete atomization of the oils because the lubricating oil remains inside the vibrator 11. One way of providing the housing with the adherent lubricant is to use an aluminum or aluminum alloy housing and harden the surface of the aluminum or aluminum alloy housing by a hardening process. This involves oxidizing the outer surface of the aluminum or aluminum alloy housing.

Aluminum anodization is a well-known technique involving electrochemical treatment wherein an outer layer of aluminum or aluminum alloy is converted to an aluminum oxide layer for producing a surface wear-resistant coating. After the alumina hardening treatment, a lubricant is fastened thereon. It has been found that lubricants such as polytetrafluoroethylene work well because the alumina coating can be impregnated with polytetrafluoroethylene (TEFLON)). The process is commercially known as "teflon dip-hardened coating" whereby a film of lubricant is created on or within the anodized aluminum, which becomes an adherent lubricant because the lubricant remains on the alloy shell. Fig. 2A shows an enlarged view of the surface of the housing 23, the housing 23 having an anodized layer 19 of thickness t with a hardened layer 19a impregnated with polytetrafluoroethylene thereon to form an inner cylindrical support surface 32A.

Although the vibrator 11 has been described using gas or air, other fluids may be used to drive the piston and provide a frictionless fluid bearing between the piston and the chamber in the housing. However, air is often the fluid of choice because it can be vented to the atmosphere, and fluids including various gases may have to be recovered. The vibrator 11 and the piston 35 can be scaled up or down to provide the necessary vibratory force. In order to provide sufficient mass within the piston 35 to produce effective vibration, the piston 35 may be made of metal and in the illustrated embodiment comprises bronze and the housing comprises aluminum or an aluminum alloy. Although shown as being anodized on the inner bearing surface of the housing 23, it is envisioned that if the piston is made of aluminum, the outer bearing surface of the piston could also be anodized and could have a teflon dip-hardened coating thereon. In addition, if desired, both the bearing surfaces of the housing and the piston may have an adherent lubricant such as a Teflon dip-hardened coating. Although an aluminum or aluminum alloy housing is described, other types of materials may be used so long as the lubricant adheres thereto in a manner that inhibits release of the lubricant into the atmosphere.

To explain the operation method of the linear vibrator, reference should be made to fig. 2 to 4. During operation of the vibrator 11, a fluid, such as air, is introduced into the inlet 20. The air flows into an annular cavity formed by the circumferential groove 52 where it enters the radial port 40 and flows through the axial port 44 and into the tail cavity 32b on the right side of the vibrator 11, thereby increasing the pressure in the tail cavity 32 b. Air is introduced into the aft chamber 32b through the radial port 40 and the axial port 44, the opposite occurs in the chamber 32 to the left of the piston 35, and the air is exhausted to atmosphere through the port 50. As the pressure in chamber 32b increases and the pressure in chamber 32 decreases, this creates a pressure differential across piston 35 that drives piston 35 to the left. While air flows between the piston outer support surface 35c and the housing inner support surface 32a, thereby creating an air bearing. As chamber 32b becomes more pressurized creating a pressure differential across piston 35, piston 35 begins to move to the left of chamber 32 (fig. 4). This has the dual effect of, firstly, forcing air out through the outlet port 50 as the piston 35 moves towards the end plate 30. As the piston end 35a approaches the end plate 30, the outlet port 50 is completely sealed by the piston 35, allowing the pressure in the chamber 32 to increase to create an air cushion to prevent the piston 35 from contacting the end plate 30. In addition, movement of the piston 35 to the left causes air from the inlet port 20 to enter into the radial port 41 and the axial port 46, which increases the pressure in the chamber 32. At the same time, chamber 32b is vented to atmosphere through port 60, thereby reducing the pressure in chamber 32b, while the pressure in chamber 32 increases, thereby creating a pressure differential across piston 35, thereby driving the piston 35 toward the opposite end. An axial vibration of the piston 35 is generated in the housing 23 due to the alternating pressure difference across the piston 35. As a result, the housing 23 vibrates in response to the vibration of the piston 35. Thus, the monobloc piston 35 can oscillate back and forth within the housing to produce the necessary vibrations.

Referring to fig. 3 to 5, the vibrator 11 has been modified to incorporate a dynamic on-demand start-up system. Fig. 3-5 show the piston 35 in three different positions and a fluid port 70 for biasing the piston 35 when actuated. That is, in some instances it may be desirable to bias the piston 35 toward one end or the other of the chamber 32 when the piston is activated to ensure that the piston begins to vibrate when air is introduced into the vibrator 11. The dynamic on-demand start-up system described herein can be used alone or it can be used in conjunction with a static on-demand start-up system using an adherent lubricant. Thus, both static and dynamic on-demand start-up systems can incorporate a vibrator to provide a backup start-up system, if desired. This is a useful feature for human intervention and monitoring of very small remote devices.

In the dynamic on-demand priming system, the priming port 70 may be momentarily connected either to a pressure source to bias the piston 35 to the left end of the chamber 32 or to a vacuum source to bias the piston 35 to the right end of the chamber 32. The bias of the piston 35 towards one end or the other of the chamber 32 causes the piston to displace and ensures that the piston will start to vibrate immediately when fluid is introduced into the inlet port 20, since the pressure differential across the piston 35 can be overcome by the fluid flowing from the inlet port 20 and past the piston 35 into the chamber 32 or 32 b. This bias is well suited for those housings where no lubricant is used on the housing 23 or piston 35.

In addition, the dynamic on-demand start-up system with offset port 70 may be used as a backup to start up the vibrator with adhered lubricant, thereby providing a backup to the start-up operation of the vibrator 11.

When the piston begins to vibrate, the port 70 closes, allowing air flow within the housing 11 to sustain the vibration.

FIG. 7 illustrates a venting system 80 with a dynamic on-demand system. The dynamic on-demand start-up system comprises a transmission pipe 81 to which a vibrator 82 is fastened by end plates 83 and 84. A first pressure source 86 is connected to the inlet port 85 for introducing a gas, such as air, into the vibrator 82. The outlet ports 87 and 88 alternately discharge gas from the vibrator 82 as the mass in the vibrator 82 vibrates back and forth to induce vibration in the transmission pipe 81. In the illustrated embodiment, a pressure differential generating device 89, which is either a vacuum source or a pressure source, is connected to the end port 90 by a fluid line 90 a. In operation of the venting system 80, an operator introduces a gas, such as air, from a gas source 86 through an inlet port 85 into the vibrator 82. To provide dynamic on-demand activation of vibrator 82, pressure generator 89 can increase or decrease the pressure in port 90 through conduit 90a to change the pressure across the mass. If the system is used with a static on-demand start-up system, the piston therein will begin to vibrate as air is introduced into the vibrator 82 without using the port 90. If a dynamic on-demand system is used, the dynamic system will create the necessary pressure differential across the piston in the event that air is introduced into the vibrator 82 without the piston beginning to vibrate. If dynamic on-demand activation is used, the vibration of the mass within the vibrator 82 will be driven by momentarily increasing or decreasing the pressure within the tip chamber. That is, the instantaneous flow of air into or out of one of the end chambers within the vibrator 82 may create a pressure differential that causes the mass within the vibrator 82 to move while the incoming gas within the port 85 maintains the necessary vibration of the mass therein. Once vibration of the mass begins, the end port 90 closes to allow vibration to continue.

Thus, in one embodiment, the system comprises a non-impact linear vibrator having an integrated on-demand static start-up system comprising a housing 11 having an internal bearing surface with an adherent lubricant located therein, and a fluid inlet port 30 for directing fluid into the chamber. The block 35 has a set of fluid passages 41, 46, 40, 44 therein and an outer support surface 35c thereon for allowing the block 35 to slide back and forth within the chamber under the influence of fluid bearings formed between the outer support surface 35c and the inner support surface 19 to provide an on-demand static start-up system that prevents or inhibits atmospheric contamination. In another embodiment, the system includes a non-impacting linear vibrator having a dynamic on-demand start-up train. Or in yet another embodiment, the boot system may include both a static on-demand boot system and a dynamic on-demand boot system.

Claims (22)

1. A non-impact vibrator comprising:

a housing having an inlet port and first and second outlet ports, the housing having an inner surface forming a chamber therein with an adherent lubricant thereon;

a piston having an outer surface, the piston being slidable within the chamber, the piston having a first radial port fluidly connected to a first end port on a first end of the piston, and a second radial port fluidly connected to a second end port on an opposite end of the piston, such that when gas is introduced into the inlet port, the piston is alternately driven in two opposite directions; and

an on-demand start-up system to ensure initial vibration of the piston within the vibrator, the on-demand start-up system comprising an end port to vary the pressure at one end of the piston.

2. The non-impact vibrator according to claim 1, wherein the on-demand start-up system comprises an inner surface comprising a hardened coating with an anodized layer impregnated with a polytetrafluoroethylene polymer.

3. The non-impact vibrator according to claim 1, comprising a first mounting plate secured to a first end of the housing and a second mounting plate secured to a second end of the housing.

4. A non-impact vibrator according to claim 3, comprising a fluid conducting duct having fluid conducting conduits fastened to the first mounting plate and the second mounting plate for conducting vibrations to the fluid conducting duct.

5. The non-impact vibrator according to claim 4, wherein the first mounting plate and the second mounting plate are fastened to an outer surface of the fluid transmission pipe by clamping.

6. A non-impact vibrator comprising:

a housing having an internal support surface defining a chamber therein, and a fluid inlet for introducing a fluid into the chamber;

a block having a set of fluid passages therein and outer support surfaces thereon for allowing the block to slide back and forth within the chamber under the influence of a fluid bearing formed between the inner and outer support surfaces, at least one of the support surfaces comprising anodized aluminum or an anodized aluminum alloy; and

the system is activated on demand to prevent or prevent atmospheric pollution.

7. A vibrator according to claim 6, characterized in that the start-up system comprises an adherent lubricant carried by the anodized aluminium or anodized aluminium alloy.

8. The vibrator according to claim 7, wherein the adherent lubricant is polytetrafluoroethylene.

9. A vibrator according to claim 8, characterized in that the polytetrafluoroethylene is impregnated on at least one of the supporting surfaces.

10. A vibrator according to claim 9, characterized in that the vibrator is fastened to a pneumatic conveying pipe.

11. A vibrator according to claim 10, characterized in that the vibrator is clamped on the pneumatic conveying pipe.

12. A vibrator according to claim 11, characterized in that the axis of vibration of the piston is parallel to the axis of flow of the pneumatic conveying duct.

13. A vibrator according to claim 12, characterised by comprising a bracket, one end of which is clamped to the pneumatic conveying pipe and the other end of which is fixed to the vibrator housing.

14. The vibrator according to claim 6, wherein the on-demand activation system comprises a dynamic activation system that creates a pressure differential across the mass.

15. A vibrator according to claim 6, characterized by comprising a static on-demand start-up system and a dynamic on-demand start-up system, and that the static on-demand start-up system comprises an integrated on-demand start-up system.

16. The vibrator according to claim 15, wherein the dynamic on-demand activation system includes a fluid port proximate one end of the chamber for momentarily varying a pressure differential across a mass within the chamber to initiate movement of the mass.

17. A vibrator according to claim 16, wherein the dynamic on-demand activation system includes a vacuum source connected to the fluid port proximate the end of the chamber.

18. A vibrator according to claim 16, wherein the dynamic on-demand activation system includes a pressure source connected to the fluid port immediately adjacent the end of the chamber.

19. A method of ensuring vibration of a vibrator, comprising the steps of:

hard coating the support surface with the adhered lubricant;

introducing a fluid between the support surface with the adherent lubricant and a piston slidable therein, thereby providing a fluid bearing therebetween; and

venting both ends of a chamber with a slidable piston such that fluid introduced into the chamber is alternately expelled from opposite ends of the chamber such that when the fluid is introduced into the vibrator, the piston within the vibrator begins to vibrate as desired; and

momentarily venting an end port of the chamber to provide a second on-demand system.

20. The method of claim 19, wherein the step of hard coating the support surface with the adherent lubricant comprises hard coating an aluminum oxide layer and then impregnating polytetrafluoroethylene on the aluminum oxide layer.

21. The method of claim 20, wherein the step of impregnating a support surface with polytetrafluoroethylene comprises impregnating a support surface of the housing.

22. The method of claim 21 including the steps of forming said bearing surface on said housing using aluminum or an aluminum alloy and forming said slidable piston using bronze.