WO2016066906A1

WO2016066906A1 - Automatic lubrication system and method for lubricating parts

Info

Publication number: WO2016066906A1
Application number: PCT/FI2015/050750
Authority: WO
Inventors: Jukka Moksi
Original assignee: Jukka Moksi
Priority date: 2014-10-30
Filing date: 2015-10-30
Publication date: 2016-05-06
Also published as: FI20155437A; DK3212985T3; FI126493B; EP3212985A4; EP3212985A1; EP3212985B1

Abstract

The present invention relates to an automatic lubrication system (201, 401) comprising a lubricant container (230, 330, 430) supplying a lubricant, preferably grease, to a number of lubricant feeder units (100),a number of lubricant feeder units, which lubricant feeder units supply the lubricant to a work device, wherein each lubricant feeder unit comprises a piston chamber allowing a piston to reciprocate,a piston to supply the lubricant to the work device and which piston sepa-rates a working pressure inlet and a lubricant inlet,a working pressure inlet actuating the piston by supplying pressure to the piston from the work device when the work device is used,a lubricant inlet for supplying lubricant from the lubricant container to the piston chamber,returning means, preferably a spring, configured to return the piston to its starting position,a valve member, preferably a check valve, allowing the lubricant to flow out from the piston chamber and blocking the flow back to the piston chamber. The presented invention includes related methods thereof.

Description

AUTOMATIC LUBRICATION SYSTEM AND METHOD FOR

LUBRICATING PARTS

FIELD OF THE INVENTION

Generally the present invention relates to lubrication systems. In particular, however not exclusively, the present invention concerns automatic lubrication systems that are connected to work devices' drive systems utilizing the inherent power of the lubricated device as the feeding force for the lubricant.

BACKGROUND

Hydraulic and pneumatic devices tend to have mechanical parts that are under a lot of stress and mechanical wear. These devices need regular service and maintenance; i.e. several parts need timewise lubrication. Today, for many devices the lubrication is taking place in a manual fashion.

For example, transportation vehicles such as trucks with (tail) lifts and other working equipment need to be taken to service centers for lubrication maintenance. At these service centers mechanics go through the parts manually. This is time-consuming and affects availability of the truck for the intented purpose. Maintenance and repair operations add costs to the truck owner as well. The truck owner has to pay for extra gasoline (for taking the truck of its planned route), for the maintenance services and the truck driver's salary. Furthermore, all the maintenance time the truck is out of service means missed earning opportunities for the owner.

Some central lubrication systems exist today. However, these are mainly intend- ed for larger machinery such as power plants, conveyor belts, paper machines etc.. Primary they apply oil as the lubricant fluid. Also these lubrication systems utilize a separate driving force such as an electric pump. Appliances without central lubrication systems are in a need of a simple and reliable lubrication system that may also be retrofitted into devices already in use. There is a need for a lu- brication system that works automatically when the work device is used such that the user do not have to worry about painful maintenance tasks and may instead concentrate on his/her main work. A lubrication system with proper notification arrangements that informs of low lubricant levels is needed as well. SUMMARY OF THE INVENTION

The objective is to at least alleviate the problems described hereinabove not satis- factorily solved by the known arrangements, and to provide a feasible lubrication system that may be arranged to a variety of work devices. Another objective is to provide a lubrication system that may inform the user when lubricant levels are low. The aforesaid objective is achieved by the embodiments of a system in accordance with the present invention. The solution may be applied to work devices, for example hydraulic or pneumatic devices, needing regular lubrication.

Accordingly, in one aspect of the present invention an automatic lubrication sys- tern comprises

-a lubricant container supplying a lubricant, preferably grease, to a number of lubricant feeder units, -a number of lubricant feeder units, which lubricant feeder units supply the lubricant to a work device, wherein each lubricant feeder unit comprises

-a piston chamber allowing a piston to reciprocate, -a piston to supply the lubricant to the work device and which piston separates a working pressure inlet and a lubricant inlet,

-a working pressure inlet actuating the piston by supplying pressure to the piston from the work device when the work device is used,

-a lubricant inlet for supplying lubricant from the lubricant container to the piston chamber,

-returning means, preferably a spring, configured to return the piston to its starting position, -a valve member, preferably a check valve, allowing the lubricant to flow out from the piston chamber and blocking the flow back to the piston chamber. In one embodiment the lubrication system comprises a plurality of lubricant feeder units that are attachable/detachble to each other forming a modular construction and wherein the lubricant inlets connect the piston chambers such that lubricant is supplied from the lubricant container to all piston chambers. The system may for example comprise one lubricant container and multiple lubricant feeder units. In some embodiments the system is modular, i.e. the amount of lubricant feeder units may be easily changed depending on the implementation. For example a tail lift may need a lubrication system with 12 lubricant feeder units whereas an excavator may need more if it has more parts that need to be lubricated. A lubrication system according to the present invention may also comprise less than 12 lubricant feeder units, e.g. 2 or 3 units.

In a further, either supplementary or alternative, embodiment the piston chambers are connected in parallel with the lubricant inlets such that the lubricant flow passes a piston chamber when its piston is in the stroke position. In some embod- iment the lubricant inlet to the piston chamber is arranged adjacent the piston chamber such that the lubricant flows pass the piston chamber when the piston is in its stroke position. Multiple lubricant feeder units may be connected in series and/or in parallel. Furthermore, if one unit gets jammed and the piston gets stuck in its stroke position, the lubricant may pass the piston chamber and still provide lubrication to the following lubricant feeder units.

In a further, either supplementary or alternative, embodiment the lubricant feeder unit comprises adjustment means, preferably an adjustement screw, to adjust the stroke of the piston, and thereby the amount of lubricant supplied from the piston chamber to the work device.

In a further, either supplementary or alternative, embodiment the adjustment means is arranged to close a lubricant feeder unit by blocking the stroke of the piston.

In a further, either supplementary or alternative, embodiment a body of the lubricant feeder unit is arranged of a uniform piece, preferably steel, and wherein the working pressure inlet, lubricant inlet and piston chamber are grooves in the body.

The lubricant feeder units may be produced from steels, plastics, composites or other hard materials suitable for such lubrication solutions. In some embodiments the body of a lubricant feeder unit is produced of one uniform piece (e.g. steel). The inlets and/or chamber are processed as grooves or holes in the piece. In some embodiments, these pieces may be combined with screws or other attaching materials (e.g. glues and/or presses). The attached pieces may form a compact inte- gral set of multiple lubricant feeder units.

In a further, either supplementary or alternative, embodiment the lubrication system is connected to a hydraulic drive system of a working device, or a pneumatic drive system of a working device via a pneumatic to hydraulic converter, and which hydraulic or pneumatic drive system provides the working pressure to the piston when the working device is used. The pneumatic to hydraulic converter converts pneumatic pressure in the work device to hydraulic pressure in the lubricant feeder unit. In a further, either supplementary or alternative, embodiment the lubricant container comprises force applying means to supply the lubricant to the lubricant feeder unit. In a further, either supplementary or alternative, embodiment the lubricant container comprises a spring and a piston, optionally a shaft, and wherein the spring pushes the piston, optionally along the shaft. The force created by the spring presses the lubricant out from the container.

In a further, either supplementary or alternative, embodiment a first set of lubricant feeder units form a uniform structure, for example by attaching lubricant feeder units with screws, and which first set of lubricant feeder units is connected in series to a second set of lubricant feeder units that form a uniform structure.

In a further, either supplementary or alternative, embodiment at least two sets of lubricant feeder units are connected in series such that lubricant is supplied from a previous set of lubricant feeder units to the next one, and that each set of lubri- cant feeder units is connected to an own drive system that provides working pressure when the drive system is used. In a further, either supplementary or alternative, embodiment the lubrication system comprises a number of pressure amplifiers to supply the lubricant further in the lubrication system, such as from one set of lubricant feeder units to a next set of lubricant feeder units.

In a further, either supplementary or alternative, embodiment the lubricant container comprises lubricant level notification means.

In a further, either supplementary or alternative, embodiment the lubricant level notification means comprises

-at least one reed switch, preferably in the shaft of the container,

-a magnet that moves along with the piston,

-a wireless transmitter, preferably in the cover of the container, and wherein the reed switch notifies the transmitter when the magnet reaches the level of the reed switch.

In a further, either supplementary or alternative, embodiment the transmitter sends notification data from the reed switch to a remote server.

The reed switch, may preferably be arranged in the shaft of the container. In some embodiments the reed switch may be located in the body structure of the container. In some embodiments there may be multiple reed swithes, arranged for example on different heights in the shaft. Thereby, different lubricant levels may be signalled. The magnet may preferably be arranged close to the piston, for example inside the piston, above the piston or underneath the piston. A wireless transmitter may preferably be arranged in the cover of the container. The reed switch may be arranged to notify the transmitter when the magnet reaches the level of the reed switch. The transmitter may be further arranged to send such notification data to a remote server. In some embodiments, the data sent to a server may include other information as well such as location data, battery lifetime information data and/or, current speed data (if the lubrication is installed to a vehicle, for example).

In a further, either supplementary or alternative, embodiment the lubrication system is connected to a tail lift, preferably comprising 12 lubricant feeder units. In a further, either supplementary or alternative, embodiment the valve member is a check valve (one-way valve). The valve allows the lubricant to flow one way but blocks the flow the opposite way. Thereby the piston presses the lubricant out of the piston chamber and the valve blocks the flow back to the piston chamber. In some embodiments there may be an outlet channel between the piston chamber and the valve member.

In a further, either supplementary or alternative, embodiment the lubricant is grease. Grease or other high viscosity lubricant liquids may be suitable in some applications as the high viscosity liquid may stay longer on the lubricated sight than lower viscosity liquids.

In a further, either supplementary or alternative, embodiment the piston is sealed to the piston chamber and may create suction to the lubricant inlet when return- ing to the starting position. The piston may assist the lubricant to flow into the piston chamber by creating suction to the lubricant inlet. The piston may be sealed with conventional sealing means such as a rubber O-ring. The piston may be configured to separate the lubricant inlet and the working pressure inlet. A sealing may improve such separation and/or improve the movement of the piston. In a further embodiment, the shaft of the piston may be sealed to the body of the lubricant feeder unit.

In another aspect of the present invention, a method for lubricating a work device comprises at least the steps

-assembling, installing and/or adjusting a lubrication system,

-filling a lubricant container,

-supplying lubricant to a number of piston chambers,

-using a work device,

-applying work pressure to a number of pistons,

-supplying the lubricant to a number of parts of the work device that need lubrication, and

-moving a piston of the lubricant container. In one embodiment the piston of the lubricant container reaches a reed switch, which reed switch notifies of lubricant levels. In a further, either supplementary or alternative, embodiment the reed switch notifies a, preferably wireless, transmitter, which transmitter sends notification data to a, preferably remote, server. The utility of the present invention follows from a plurality of factors depending on each particular embodiment. Embodiments of the suggested solution may be easily installed to hydraulic and/or pneumatic work devices even after the device has been taken into use. Some embodiments may be initial installations in the work devices as part of original equipment. Embodiments of the suggested solu- tion may be modular and scalable to suit a variety of use cases. Because of its modularity it may fit into small/tight places and suit relatively small devices, but it may also be scaled up and utilized in larger appliances where several parts need lubrication. Embodiments of the innovation create a system for multipurpose lubrication applications, in some context referred to as System MovaLube™.

The suggested solution may be fail-proof such that in an embodiment with multiple lubricant feeder units the lubricant may pass a piston chamber if a piston gets jammed. Embodiments of the suggested solution may be durable. Embodiments of the suggested solution may also be easy to assemble due to a rigid body and threaded parts. Embodiments of the solution may also be easily maintained as different parts of the solution may be replaced easily. Embodiments of the suggested solution may also improve the work efficiency and the work convenience for many workers as the solution may provide lubrication to different work devices automatically when the device is used. Therefore, a worker may not even notice the lubrication process and may focus fully on his/her main work. As the solution only provides lubrication when a device is used, the suggested solution may also provide lubricant efficiently.

Embodiments of the suggested solution may also notify when the lubricant levels are low. Therefore, a lubricant filling service may be combined with embodiments of the present solution. A service provider and/or a user may be informed when the lubrication system needs a refill. Embodiments of the suggested solution may therefore provide regular lubrication without any breaks. The expression "a number of refers herein to any positive integer starting from one (1), e.g. to one, two, or three.

The expression "a plurality of refers herein to any positive integer starting from two (2), e.g. to two, three, or four.

Different embodiments of the present invention are disclosed in the dependent claims.

BRIEF DESCRIPTION OF THE RELATED DRAWINGS

Next the invention is described in more detail with reference to the appended drawings in which

Fig. 1 is a sketch representing a cross-section of an embodiment of a lubricant feeder unit in accordance with the present invention.

Fig. 2 is a sketch of an embodiment of a lubrication system in accordance with the present invention.

Fig. 3 is a sketch of an embodiment of a lubricant container in accordance with the present invention.

Fig. 4 is a sketch of an embodiment of a lubrication system in accordance with the present invention with various system components and multiple drive system connections.

Fig. 5 is a flow diagram of an embodiment of a method in accordance with the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Figure 1 illustrates a cross-section of an embodiment of a lubricant feeder unit 100 in accordance with the present invention. The embodiment of the lubricant feeder unit 100 comprises a body 102, a piston chamber 104, a piston 106, a working pressure inlet 108, a lubricant inlet 1 10, returning means 1 12, a valve member 1 14, adjustment means 1 16, an adjustment means support 1 18, a stopper 120 and sealing means 122 and 124. The body 102 may be produced from one uniform piece. For example, it may be machined of a piece of steel, plastic, composites or any other, preferably hard material, suitable for such lubrication application. In an embodiment where the body 102 constitutes of one unified piece, the piston chamber 104 may be a groove/hole in the body 102. The piston 106 may also be produced, for example, of steel, plastics, composites or any other hard suitable material. The piston's 106 dimensions are such that it fits the piston chamber 104 and may slide back and forth in the piston chamber between the stopper 120 and the adjustment means 1 16. However, the dimensions of the piston must be such that the lubrication from the lubricant inlet 1 10 does not flow from the lubricant inlet 1 10 side to the working pressure inlet side. Also, the pressure from the working pressure inlet 108 side may not either pass the piston to the lubricant inlet 1 10 side.

In figure 1 the piston 106 is presented in its starting position, i.e. the piston 106 is in the far right end of the piston chamber 106, the piston 106 against the stopper 120. The returning means 1 12 (e.g. a spring) pushes the piston 106 against the stopper 120.

The lubricant feeder unit 100 may be connected to a work device's hydraulic sys- tern (not in the figure) via its working pressure inlet 108. A work device may for example be a hydraulic device such as a tail lift or excavator, for example. When the work device is used a hydraulic pressure is supplied via the working pressure inlet 108 to the piston chamber 104. The hydraulic pressure creates a force on the piston 106, moving the piston 106 along the piston chamber 104 towards the ad- justment means 1 16. When the piston 106 reaches the far left end of the piston chamber 104, either by hitting the adjustment means 1 16 (e.g. a screw) or the (left) end of the piston chamber 104, the piston 106 is in its stroke position.

The lubricant inlet 1 10 may be connected to a lubricant container (not shown in the figure). The lubricant container supplies lubricant via the lubricant inlet 1 10 to the piston chamber 104. The lubricant inlet 1 10 and the working pressure inlet 108 may be holes or grooves in the body 102 structure. When the piston 106 is in its stroke position, it may block the lubricant inlet 1 10 such that lubricant cannot flow into the piston chamber 104. However, the lubricant inlet 1 10 may be ar- ranged adjacent the piston chamber 104 such that the lubricant may pass the particular piston chamber 104 when the piston 106 is in its stroke position and flow to a next lubricant feeder unit and its piston chamber, if there are multiple lubricant feeder units connected to each other. Adjustment means 1 16 such as an adjustment screw is arranged on one side of the body 102 structure, facing the end of the piston 106. A support 1 18 is arranged to hold the adjustment screw 1 16. The stroke length, i.e. the movement of the piston 106 can be adjusted with the adjustment screw 1 16. The stroke length affects how much lubricant is supplied from the piston chamber 104 to the part that is lubricated. Therefore, by adjusting the adjustment screw 1 16, one can adjust the amount of lubrication supplied to a lubricated part. A returning spring 1 12 is arranged between the support 1 18 and the piston. The spring 1 12 is arranged around the adjustment screw 1 16 and in the end of the piston. The piston 1 16 may have a smaller shaft for the placement of the spring 1 12. The spring 1 12 will work against the pressure from the working pressure inlet 108. When the hydraulic pressure releases the spring force exceeds the force from the working pressure inlet, whereupon the spring 1 12 will push the piston 106 back to its starting position. The liquid that provides the hydraulic pressure returns along the working pressure inlet 108 back to the work device.

The support 1 18, the stopper 120 and the valve member 1 14 may comprise threads such that they are attachable/detachable to/from the body 102 structure by screwing. The body 102 structure may have suitable threads to fit the attachment of said parts. The spring 1 12 may be easily arranged around the adjustment screw 1 16 when the support 1 18 is detachable. The valve member 1 14, e.g. a check valve (i.e. one-way valve), is arranged after the piston chamber 104, preventing the lubricant flow back to the piston chamber 104. The piston 106 may create suction when returning to its starting position. A one-way valve 1 14 arranged after the piston chamber 104 prevents the lubricant flow back to the piston chamber 104, regardless of the suction effect.

The stopper 120 is arranged on one side of the body 102 such that it faces the piston 106. The piston chamber 104 may be machined in a body 102 of a steel block. The piston 106 is then placed inside the piston chamber 104. The hole is then blocked with the stopper 120. The piston may comprise conventional seal- ing means 122 and 124 such as O-rings or X-rings. A groove may be arranged in the piston 106 for the sealing 122 and another groove may be arranged in the body 102 for the sealing 124. Figure 2 is a sketch of an embodiment of a lubrication system 201 in accordance with the present invention. The lubrication system 201 comprises a lubricant container 230 and a plurality of lubricant feeder units 200. The lubricant feeder units 200 form a compact undiform structure. In figure 2 is presented an embodiment with 12 lubricant feeder units. The lubricant container is connected to the lubricant feeder units 200 such that it supplies lubricant to all the lubricant feeder units. The lubricant inlets may be arranged such that lubricant flows through the piston chambers, supplying lubricant to the piston chambers for the lowest lubricant feeder units. When the lowest lubricant feeder units are filled up, the follow- ing feeder units are filled up and so on. Finally, all lubricant feeder units are filled with lubricant. A spring-loaded container 230 may supply lubricant automatically to the piston chambers, after the lubricant has been supplied to the part of the working device that needs lubrication. The lubricant feeder units may be arranged such that one hydraulic working pressure inlet 208 connects to all lubricant feeder units. The hydraulic working pressure inlet 208 may be arranged in the bottom part of the set of lubricant feeder units 200 such that it connects to all piston chambers of the individual lubricant feeder units. The right sided lubricant feeder units 200b may be connected with one essentially vertical working pressure inlet line. The left sided lubricant feeder units 200a may also be connected with one essentially vertical working pressure inlet line. The two vertical working pressure lines may then be connected with at least one essentially horizontal line such that the working pressure is supplied to all piston chambers. The hydraulic working pressure inlet 208 may be connected to a work device's drive system, such as a hydraulic drive system or a pneumatic drive system via a pneumatic/hydraulic converter.

Each lubricant feeder unit has an own adjustment screw 216a-2161 to adjust the stroke of the piston and thereby the amount of lubricant supplied. An adjustment screw 216a-2161 can be used to fully close a particular lubricant feeder unit as well.

Each lubricant feeder unit comprises a lubricant outlet 232a-2321 that supplies lubricant to the part of the work device that needs lubrication. Conventional pip- ing/tubes can be used to carry the lubrication. The lubrication system 201 comprises a backboard 234 that may be used to attach the lubrication system 201 near a work device or onto a work device. For example, if the lubrication system 201 is used to lubricate a tail lift, the lubrication system 201 may be attached to the rear end of a transportation vehicle, close to the tail lift.

The lubrication system 201 comprises a lubricant container filling inlet 236 that is used to fill the lubricant container 230. The filling inlet 236 may be connected to the container 230 through the lubricant inlets of the left sided lubricant feeder units 200a, for example. The lubrication system 201 comprises also a pressure relief valve/outlet 238 that lets lubricant out when the lubricant container 230 is full. The pressure relief valve/outlet 238 may be connected to the lubricant con- tainer 230 through the right sided lubricant feeder units 200b, for example. The lubrication system 201 comprises also a breather valve 240 to improve the movement of the piston of the lubricant container 230.

The body 202 of the set of lubricant feeder units 200 may be manufactured from two blocks of steel, for example. Each piece may comprise 6 lubricant feeder units, for example. The pieces may be connected with screws or other conventional attachment means. Alternatively, each lubricant feeder unit may be produced independently and connected to each other. Further, lubricant feeder units 200 may be constructed from pieces with some other amount, for example 2, 3 or 8 lubricant feeder units. As the body 202 may be machined from a block of steel, for example, multiple lubricant feeder units 200 combined together may still build a compact system.

A lubricant container may have a volume that fits preferably 0,1 - 20 kg, more preferably 0,2 - 10 kg and most preferably 0,5 - 5 kg lubricant, i.e. e.g. grease. In some alternative embodiments the container may even have a volume for more than 20 kg lubricant.

In some embodiments a lubricant feeder unit may be arranged to supply on one stroke preferably 0 - 20 g, more preferably 0 - 5 g and most preferably 0 - 3 g lubricant, i.e. e.g. grease. For some alternative embodiments the lubricant feeder unit may supply more than 20 g lubricant per stroke.

Figure 3 illustrates an embodiment of a lubricant container 330 in accordance with the present invention. The lubricant container 330 comprises a shaft 342, a piston 344 and a spring 346. The spring 346 pushes the piston 344 along the shaft 342 such that lubricant is supplied to a lubricant feeder unit (not in the figure). The lubricant container 330 comprises also a rubber bag 356. The rubber bag 356 may improve the sealing of the container 330 as the container may for example change shape in some conditions. A magnet 348 is arranged close to the piston 344, for example in, above or under the piston, such that it moves with the piston 344. A reed switch 350 is arranged in the shaft 342. A transmitter 352 with con- ventional data transfer means is arranged in the lid 354 of the container 330. Data wires are arranged inside the shaft 342 between the transmitter 352 and the reed switch 350. The spring 346 pushes the piston 344 along the shaft 342. The reed switch 350 sends a signal to the transmitter 352 when the magnet 348 reaches the reed switch 350. The transmitter 352 sends the data further to a remote server. Such notification system may be used to alert when the lubricant container 330 is becoming empty and needs a refill. In some embodiments, there may be multiple reed switches on different heights signaling different lubricant levels.

The transmitter 352 may work on conventional batteries (e.g. lithium battery) and have a few years' service lifetime. The transmitter 354 may be configured to collect and send location data (e.g. GPS coordinates), battery lifetime information data and/or a vehicle's current speed data, for example. The transmitter 352 may be configured to stay in an energy saving mode and turn on for example once a day to send relevant data to a remote server and then go back to energy saving mode.

Figure 4 shows an embodiment of a lubrication system 401 in accordance with the present invention with multiple drive system connections 465, 466, 467. The lubrication system 401 comprises a lubricant container 430, lubricant feeder units 400a-400c, pressure amplifiers 460a, 460b and a pneumatic/hydraulic converter 462.

The lubricant container 430, comprising a spring 446 and a piston 444, supplies lubricant to the lubricant feeder units 400a-400c. Each set of lubricant feeder units 400a-400c may comprise multiple lubricant feeder units. The lubricant feeder units 400a-400c comprises adjustment means 416a-416c to adjust the amount of lubrication to the targets 471, 472, 473.

Each set of lubricant feeder units 400a-400c is connected to a work device's drive system 465, 466, 467, e.g. a vehicle's hydraulic or pneumatic drive system. The lubricant feeder units 400a-400c supply lubricant to the targets 471, 472, 473 when the vehicle's drive system is used. For example the lubricant feeder units 400a may receive a hydraulic pressure from a vehicle's crane drive system 465. A pressure amplifier 460a is arranged close to the lubricant feeder units 400a to supply the lubricant longer distances to the next set of lubricant feeder units 400b.

The lubricant feeder units 400b may receive work pressure from a vehicle's break's pneumatic pressure 466, for example. The lubricant feeder units 400b works every time the breaks are used. A pneumatic to hydraulic pressure converter 462 is arranged in connection with the set of lubricant feeder units 400b to convert the pneumatic pressure into hydraulic pressure.

The lubricant feeder units 400c receive work pressure 467 from a vehicle's interchangeable container arrangement, for example. A pressure amplifier 460b is arranged in connection with the lubricant feeder units 400b to supply the lubricant to the lubricant feeder units 400c.

A lubrication system in accordance with the present invention may be connected to any device with a hydraulic or pneumatic drive system that have parts that need to be lubricated regularly. The device may therefore be called a work de- vice. For example the lubrication system may be arranged to a tail lift. Every time the tail lift is used, the lubrication system will lubricate the necessary parts. Many tail lifts have 12 parts that need to be lubricated and therefore a lubrication system with 12 lubricant feeder units suits such applications. A lubrication system according to the present invention may also be connected to excavators, ship equipment, such as opening deck arrangements, or different types of vehicles, for example.

A drive system may for example be hydraulic or pneumatic. A hydraulic drive system may be directly connected to the lubrication system, creating a hydraulic pressure to the piston when the work device is used. A pneumatic drive system may be connected via a converter that converts pneumatic pressure to hydraulic pressure such that hydraulic pressure is applied to the piston when the work device is used. The lubricant used in the lubrication system may be grease. Grease can be considered to be high viscosity liquids and suits well for some work devices that needs lubrication. Figure 5 is a flow diagram of an embodiment of a method in accordance with the present invention.

At method start-up 502, preparatory actions may take place.

At 504, a lubrication system in accordance with the present invention is assembled, installed and adjusted. This step may include, for example, combining and/or modifying a number of lubricant feeder units to a lubricant container. A preferred amount of lubricant feeder units suitable for a specifc use case may be selected. The step may also include installing sets of lubricant feeder units in series. The step may also include connecting the lubricant feeder units to a work device's drive system(s). The lubricant feeder units may be connected to a work device's drive systems such that work pressure may be supplied via working pressure inlets to the piston chambers of the lubricant feeder unit(s). The lubri- cant outlets from the lubricant feeder units may also be connected to the target parts that need lubrication, for example via pipings/conduits suitable for such usage. At this step the stroke length of the pistons may be adjusted individually chamber by chamber according to estimated lubricant need. Some chambers may even be closed at this stage. The stroke length of the pistons may also be adjusted later on when the lubrication system is in use.

At 506, the lubricant container is filled up. The lubricant container may be filled up before installing it to the use application and/or it may be (re)filled when in use. The arrow from step 520 to step 506 represents a refill when the lubricant container is getting empty. In some embodiments the lubricant container may be filled up only once every 6 months or once a year, for example, depending on the consumption.

At 508, the lubricant container supplies lubricant from the container to the piston chamber(s) of the lubricant feeder unit(s).

At 510, the work device that is connected to the lubrication system is used.

At 512, pressure from the work device's drive system is supplied to the piston(s) the lubricant feeder unit(s). The pressure applied to the piston(s) is hydraulic pressure. The hydraulic pressure may be supplied directly from a work device. Alternatively, hydraulic pressure may be a result of pneumatic/hydraulic conversion. At 514, the lubricant feeder unit(s) supply lubricant to the target part(s) that need lubrication.

At 516, the piston of the lubricant container moves and lubricant is supplied to the piston chambers. For example, a spring may automatically press the piston of the lubricant container after the lubricant feeder units have supplied lubricant to the target parts.

At 518, the piston of the lubricant container reaches a reed switch arranged in the container. The reed switch may be arranged in the shaft of the container. The shaft may comprise multiple reed swtiches or only one reed switch. A reed switch may be located in the lower end of the shaft such that low lubricant levels may be signaled. At 520, lubricant levels are notified. The step may include the reed switch signalling a, preferably wireless, transmitter of the lubricant levels. The transmitter may be located in the cover of the container. The step may also include the transmitter sending such notification data to a remote server. Users and/or service providers may be informed of the (low) lubricant levels. The lubricant container may be (re)filled after (low) lubricant level notifications, which is presented in the figure with an arrow from step 520 to 506.

At 522, the method execution is ended. As is understood by a person skilled in the art, some of the steps may change order depending on the use case. For example, a container may be filled in step 506 when the lubrication system is taken into usage. After that there may not be a need to fill the container in a while and thereby no need to execute step 506 before the container is empty. Therefore, method embodiments may start from step 508 in many instances.

Consequently, a skilled person may on the basis of this disclosure and general knowledge apply the provided teachings in order to implement the scope of the present invention as defined by the appended claims in each particular use case with necessary modifications, deletions, and additions.

Claims

1. An automatic lubrication system (201, 401) comprising -a lubricant container (230, 330, 430) supplying a lubricant, preferably grease, to a number of lubricant feeder units (100),

-a number of lubricant feeder units, which lubricant feeder units supply the lubricant to a work device, wherein each lubricant feeder unit comprises

-a piston chamber allowing a piston to reciprocate,

-a piston to supply the lubricant to the work device and which piston separates a working pressure inlet and a lubricant inlet,

-returning means, preferably a spring, configured to return the piston to its starting position, -a valve member, preferably a check valve, allowing the lubricant to flow out from the piston chamber and blocking the flow back to the piston chamber.

2. The lubrication system of claim 1, which lubrication system comprises a plurality of lubricant feeder units that are attachable/detachble to each other forming a modular construction and wherein the lubricant inlets connect the piston chambers such that lubricant is supplied from the lubricant container to all piston chambers.

3. The lubrication system of claim 2, wherein the the piston chambers are connected in parallel with the lubricant inlets such that the lubricant flow passes a piston chamber when its piston is in the stroke position.

4. The lubrication system of any preceding claim, wherein the lubricant feeder unit comprises adjustment means (1 16), preferably an adjustement screw, to adjust the stroke of the piston, and thereby the amount of lubricant supplied from the piston chamber to the work device.

5. The lubrication system of claim 4, wherein the the adjustment means is arranged to close a lubricant feeder unit by blocking the stroke of the piston.

6. The lubrication system of any preceding claim, wherein a body (102) of the lubricant feeder unit (100) is arranged of a uniform piece, preferably steel, and wherein the working pressure inlet, lubricant inlet and piston chamber are grooves in the body.

7. The lubrication system of any preceding claim, wherein the lubrication sys- tern is connected to a hydraulic drive system of a working device, or a pneumatic drive system of a working device via a pneumatic to hydraulic converter (462), and which hydraulic or pneumatic drive system provides the working pressure to the piston when the working device is used.

8. The lubrication system of any preceding claim, wherein the lubricant container (230, 330, 430) comprises a spring (346) and a piston (344), optionally a shaft (342), and wherein the spring (346) pushes the piston (344), optionally along the shaft (342).

9. The lubrication system of claim 2, wherein a first set of lubricant feeder units form a uniform structure, for example by attaching lubricant feeder units with screws, and which first set of lubricant feeder units is connected in series to a second set of lubricant feeder units that form a uniform structure.

10. The lubrication system of claim 9, wherein at least two sets of lubricant feeder units are connected in series such that lubricant is supplied from a previous set of lubricant feeder units to the next one, and that each set of lubricant feeder units is connected to an own drive system that provides working pressure when the drive system is used.

1 1. The lubrication system of claim 2, comprising a number of pressure amplifiers (460a, 460b) to supply the lubricant further in the lubrication system, such as from one set of lubricant feeder units to a next set of lubricant feeder units.

12. The lubrication system of any preceding claim, wherein the lubricant container comprises lubricant level notification means.

13. The lubrication system of claim 12, wherein the lubricant level notification means comprises

-at least one reed switch (350), preferably in the shaft of the container,

-a magnet (348) that moves along with the piston,

-a wireless transmitter (352), preferably in the cover of the container, and wherein the reed switch notifies the transmitter when the magnet reaches the level of the reed switch.

14. The lubrication system of claim 13, wherin the transmitter sends notifica- tion data from the reed switch to a remote server.

15. The lubrication system of any preceding claim, wherein the lubrication system is connected to a tail lift, preferably comprising 12 lubricant feeder units.

16. A method for lubricating parts that need lubrication, comprising at least the steps of

-assembling, installing and/or adjusting a lubrication system,

-filling a lubricant container,

-supplying lubricant to a number of piston chambers,

-using a work device,

-applying work pressure to a number of pistons,

-moving a piston of the lubricant container.

17. A method of claim 16, wherein the piston of the lubricant container reaches a reed switch, which reed switch notifies of lubricant levels.

18. A method of claim 17, wherein the reed switch notifies a, preferably wireless, transmitter, which transmitter sends notification data to a, preferably remote, server.