Pump system for conveying lubricating oil

Abstract

A pump system for conveying lubricating oil to a cutting chain of a chain saw is provided. The pump system comprises at least one first oil pump, wherein a quantity of oil being conveyed thereby is adjustable by an operator of the chain saw. The pump system also includes a basic oil pump that is connected in parallel to the adjustable oil pump.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a pump system for conveying lubricating oil to a cutting chain of a chain saw. [0002] Chain saws have a guide bar on the peripheral edge of which is guided a cutting chain having individual chain links. The pivotable connection of the chain links, as well as the cutting teeth, are subjected to high stresses during operation. To avoid excessive wear, and to achieve an improved cutting result, a lubricating oil is supplied to the cutting chain via a pump system. [0003] A certain quantity of oil is desired depending upon the material that is to be cut. With different types of wood that are to be cut, it has been shown that different quantities of lubricating oil are expedient for a good cutting result. For this purpose, pump systems are known having oil pumps that can be adjusted by an operator, where the operator of a chain saw can adapt the quantity of lubricating oil being supplied to the material that is to be cut....

AI Technical Summary

Benefits of technology

[0019] It can be expedient to make the basic oil pump adjustable. For example, by adjusting the basic oil pump it can be possible to adapt the basic capacity to a specific type of wood or to a specific type of lubricating oil, whereas via the adjustable oil pump fluctuations of the operating parameters, for example as a consequence of fluctuations in viscosity due to the temperature, are compensated for. Pursuant to an expedient further development, the capacity of the basic oil pump is fixed. This prevents the user from unintentionally making an incorrect adjustment. The adjustable oil pump advantageously has a reduced maximum capacity in comparison to the basic oil pump. Incorrect adjustments of the pump system are prevented via the appropriately small adjustment range.

[0020] Pursuant to an advantageous further development, the oil pump is embodied as a piston pump having a piston portion that can be rotatably driven about its longitudinal axis, whereby a peripheral inclined groove is provided on the piston portion into which a control pin that is fixed to a housing in the axial direction extends. The piston portion can be continuously rotatably driven, whereby via the control pin and the inclined groove, an oscillating axial movement is produced with little mechanical effort. S

Problems solved by technology

The pivotable connection of the chain links, as well as the cutting teeth, are subjected to high stresses during operation.

However, this can change during operation.

It has been shown that the viscosity-dependent capacity is subjected to unexpectedly high fluctuations.

An at least approximately optimum oil capacity at operati

Images