# US 10,307,931 B2 · Oil delivery system for the lubrication of a chainsaw

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- Number: US 10,307,931 B2
- Document ID: US10307931B2
- Status: Granted
- Kind: B2
- Application number: 15/219,225
- Filed: 2016-07-25
- Published: 2017-01-26
- Granted: 2019-06-04
- Earliest claimed: 2015-07-24
- Assignees: The Research Foundation for SUNY
- Applicants: The Research Foundation for SUNY
- Inventors: Neil Haney
- Web page: https://patentgrep.com/patent/US10307931B2

## CPC

- B27B 17/12: Lubricating devices specially designed for chain saws
- F04C 2/102: {the two members rotating simultaneously around their respective axes}
- F04C 14/24: characterised by using valves controlling pressure or flow rate, e.g. discharge valves {or unloading valves}(F04C14/10 takes precedence)
- F16N 7/385: {Central lubrication systems}
- F01M 2001/0238: {Rotary pumps}
- F04C 15/0007: {Radial sealings for working fluid}
- F04C 2210/14: Lubricant
- F16N 13/20: Rotary pumps (with distributing equipment F16N13/22)
- F16N 2210/33: Chains
- B27B: SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR (saws specially adapted for pruning or debranching A01G3/08; sawing apparatus specially adapted for felling trees A01G23/091; features not restricted to a particular type of wood saw B23D, e.g. attaching saw blades B23D51/00; machine tool frames, beds, pillars or like members, in general B23Q1/01)
- F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F16N: LUBRICATING
- F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING

## Abstract

The disclosure provides a method of oil delivery to a chainsaw chain blade using a gerotor pump in sequence with flow control valves to provide lubrication to the chain blade to reduce friction with the chainsaw bar guide and prevent overheating and damage to the chain blade or guide bar.

## Claims

### Claim 1

A chainsaw having a fluid lubrication system, configured to lubricate an interface between a chain blade and a bar channel of a guide bar, comprising:
the guide bar, comprising an elongated member with the bar channel located around a perimeter of the elongated member, wherein the chain blade is configured to interface with and ride along the bar channel of the guide bar, and wherein the bar channel is configured to guide the chain blade to rotate around the guide bar to saw through a material;
a motor having a motor drive shaft that extends from the motor to spin a chain blade gear configured to drive the chain blade along the bar channel of the guide bar;
a fluid reservoir;
a fluid lubricant contained in the fluid reservoir;
a gerotor pump, comprising:
a pump housing, having a fluid inlet port and a fluid outlet port, wherein the fluid inlet port and the fluid outlet port are each connected to a system of fluid feed lines, and wherein the motor drive shaft extends from the motor further into the pump housing;
an inner gerotor gear, having a number of gear teeth, wherein the inner gerotor gear is secured to the motor drive shaft, such that it will spin with the motor drive shaft;
an outer gerotor gear, having a number of gear notches equal to the number of gear teeth plus an additional notch, such that for n gear teeth there are a total of n+1 gear notches, wherein the inner gerotor gear is positioned within the outer gerotor gear such that it transfers the spinning rotation of the motor drive shaft to the outer gerotor gear;
one or more fluid pocket recesses formed by the pump housing and configured to create one or more dynamic fluid enclosures by spinning of the inner and outer gerotor gears, wherein the dynamic fluid enclosures are configured to receive the fluid lubricant as it travels from the fluid inlet port to the fluid outlet port, wherein the fluid lubricant provides lubrication between the inner and outer gerotor gears and the pump housing;
a fluid-tight seal positioned around the inner and outer gerotor gears inside the pump housing; and
the system of fluid feed lines, wherein the system of fluid feed lines establishes fluid communication between the fluid reservoir, the gerotor pump and a point of application within the bar channel, and wherein the gerotor pump is configured to pump the fluid lubricant from the fluid reservoir, through the system of fluid feed lines and to the point of application.

### Claim 2 (depends on 1)

The chainsaw having a fluid lubrication system described in claim 1 including a gate valve located between, connected to and in fluid communication with the gerotor pump—and the point of application via the system of fluid feed lines, wherein the gate valve downregulates the flow of the fluid lubricant from the gerotor pump to the point of application, resulting in an increasing pressure within one or more feed lines within the system of fluid feed lines between the gerotor pump and the gate valve, and also including a pressure relief valve located between, connected to and in fluid communication with the fluid reservoir and the system of fluid feed line between the gerotor pump and the gate valve, wherein the pressure relief valve returns excess fluid lubricant to the fluid reservoir and maintains the pressure within the system of fluid feed line between the gerotor pump and the gate valve at or below a set threshold.

### Claim 3 (depends on 1)

The chainsaw having a fluid lubrication system of claim 1, wherein the inner gerotor gear further has inner gerotor gear pin notches and is secured to the motor drive shaft by an inner gerotor gear pin placed within a pin hole located in the motor drive shaft.

### Claim 4 (depends on 1)

The chainsaw having a fluid lubrication system of claim 1, wherein the point of application is a point between the guide bar and the chain blade.

### Claim 5

A chainsaw fluid lubrication system configured to lubricate an interface between a chain blade and a guide bar, comprising:
an elongated bar member comprising the guide bar, wherein the guide bar is configured to guide the chain blade to rotate around the guide bar to saw through a material, wherein the chain blade is configured to interface with and ride along an edge of the guide bar;
a chainsaw motor drive configured to drive the chain blade along the edge of the guide bar;
a fluid reservoir;
a gerotor pump, comprising:
a pump housing, having a fluid inlet port and a fluid outlet port, wherein the fluid inlet port and the fluid outlet port are each connected to a system of fluid feed lines, and wherein the motor drive shaft extends from the motor further into the pump housing;
a gerotor pump motor, having a motor drive shaft that extends from the motor into the pump housing;
an inner gerotor gear, having a number of gear teeth, wherein the inner gerotor gear is secured to the motor drive shaft, such that it will spin with the motor drive shaft;
an outer gerotor gear, having a number of gear notches equal to the number of gear teeth plus an additional notch, such that for n gear teeth there are a total of n+1 gear notches, wherein the inner gerotor gear is positioned within the outer gerotor gear such that it transfers the spinning rotation of the motor drive shaft to the outer gerotor gear;
one or more fluid pocket recesses formed by the pump housing and configured to create one or more dynamic fluid enclosures by spinning of the inner and outer gerotor gears, wherein the dynamic fluid enclosures are configured to receive a fluid as it travels from the fluid inlet port to the fluid outlet port, wherein the fluid provides lubrication between the inner and outer gerotor gears and the pump housing;
a fluid-tight seal positioned around the inner and outer gerotor gears inside the pump housing; and
the system of fluid feed lines, wherein the system of fluid feed lines establishes fluid communication between the fluid reservoir, the gerotor pump and a point of application at the interface between the guide bar and the chain blade, and wherein the gerotor pump is configured to pump a fluid from the fluid reservoir, through the system of fluid feed lines and to the point of application.

### Claim 6 (depends on 5)

The chainsaw fluid lubrication system of claim 5, including one or more pressure relief valves, wherein the pressure relief valves are in fluid communication with the gerotor pump and one or more gate valves, and wherein the one or more pressure relief valves are configured to return surplus fluid back to the fluid reservoir if the fluid pressure in the system of fluid feed lines exceeds a set threshold.

### Claim 7 (depends on 6)

The chainsaw fluid lubrication system of claim 6, wherein the pressure threshold is set between 0 and 21 PSI.

### Claim 8 (depends on 7)

The chainsaw fluid lubrication system of claim 7, wherein the pressure threshold is set between 1 and 5 PSI.

### Claim 9 (depends on 5)

The chainsaw fluid lubrication system of claim 5, including one or more gate valves, wherein the gate valves are in fluid communication with the gerotor pump and one or more pressure relief valves, wherein the gate valves are configured to regulate the rate and amount of fluid flowing through the system of fluid feed lines.

### Claim 10 (depends on 5)

The chainsaw fluid lubrication system of claim 5 wherein the fluid is oil having a viscosity equivalent to SAE 10 to SAE 50.

### Claim 11 (depends on 10)

The chainsaw fluid lubrication system of claim 10 wherein the fluid is oil having a viscosity equivalent to SAE 20 to SAE 30.

### Claim 12 (depends on 5)

The chainsaw fluid lubrication system of claim 5, wherein the inner gerotor gear further has inner gerotor gear pin notches and is secured to the motor drive shaft using an inner gerotor gear pin placed within a pin hole located in the motor drive shaft.

### Claim 13 (depends on 5)

The chainsaw fluid lubrication system of claim 5, wherein the chainsaw guide bar further comprises:
a bar channel formed at an edge of the elongated bar member by two or more bar channel rails, wherein the bar channel and the bar channel rails are configured to guide the chain blade as it rides along the edge of the elongated bar member;
a fluid inlet port located on a surface of the elongated bar member, configured to allow fluid to flow from the system of fluid feed lines into a fluid conduit, wherein the fluid conduit is configured to allow fluid to flow from the system of fluid feed lines, through the fluid inlet port and fluid conduit and into the formed by the guide bar rails.

### Claim 14 (depends on 13)

The chainsaw fluid lubrication system of claim 13, including a gate valve located between, connected to and in fluid communication with the gerotor pump and the point of application via the system of fluid feed lines, wherein the gate valve downregulates the flow of the fluid lubricant from the gerotor pump to the point of application, resulting in an increasing pressure within one or more feed lines within the system of fluid feed lines between the gerotor pump and the gate valve, and also including a pressure relief valve located between, connected to and in fluid communication with the fluid reservoir and the system of fluid feed line between the gerotor pump and the gate valve, wherein the pressure relief valve returns excess fluid lubricant to the fluid reservoir and maintains the pressure within the system of fluid feed line between the gerotor pump and the gate valve at or below a set threshold.
