LV11709B

LV11709B - Stoker conveyor system heating plants

Info

Publication number: LV11709B
Application number: LVP-96-340A
Authority: LV
Inventors: Jorgen Overdahl Pedersen
Original assignee: Jorgen Overdahl Pedersen
Priority date: 1994-02-22
Filing date: 1996-08-22
Publication date: 1997-06-20
Also published as: AU1806295A; WO1995022721A1; EP0749555B1; LV11709A; NO963466D0; ATE195173T1; FI963295A0; EE9600110A; CN2262173Y; DK9400090U3; PL105431U1; DE69518232T2; FI963295A; DE69518232D1; PL57657Y1; EP0749555A1

Abstract

This invention relates to a gearing and overload safety device for use in connection with worm conveying of solid fuel. The novelty of the invention consists in a drive system for a stoker worm, which system has a high gear ratio and a minimum of power loss, and in a spring for adjustment of the maximum load, which spring simultaneously acts as an overload safety device for the stoker worm. Also, the system is of simple construction with few wearing parts.

Description

,ι LV 11709

STOKER CONVEYOR SYSTEM HEATING PLANTS

Fields of application of the invention.

This invention relates to a gearing and overloading safety system for worm conveying of solid fuel.

The present invention is especially well suited for stoker furnaces needing very high gear ratios and rapid exchange of gears. This may be desirable in the case of various volume/weight ratios.

Known technique.

Existing stokers of various makes most often use of gear ratio of 600:1. The first step in the change is a worm gear with ratio of 100:1, and then a chain gear with ratio of 6:1. This method gives a grat loss of power and a great moment.

If the vvorm is blocked by a foreign body the motor must stop, or possibly the safetv pin is cut, or at worst the chain breaks if it is worn.

From DK, A, 48762 a gear device for stoker worms for stokers is known. The stoker worm is driven through a ratchet mechanism by a linked driving arm with a hinge ana a hinge pin vvhich moves in a slot the inclination of vvhich may be varied vvhereby the gear ratio may be varied. Further a friction clutch is incorporated in the gear. This knovvn gear device is complicated in its construction and therefore is expensive to manufacture. Further it has manv vvearing parts and the gear ratio and the change in gear ratio vvhich is obtainable is small. By excess load the friction clutch is heated and therefore is not long- time durable.

From NO, A, 58078 a stoker conveyor system is knovvn in vvhich one type of safety pins are used.

From SE, A, 117967 a stoker conveyor system is knovvn in vvhich another tvpe of safety pins are used.

The knovvn technique suffer the dravvback that the chain is caused to break or that the motor seizes as a consequence of a possible blocking of the vvorm.

It is a purpose of the present invention to provide an improved stoker system. A system of simple construction, which has a high gear ratio with a minimum of power loss, and which has a spring for adjustment of maximum load, and where the said spring at the same time acts as an overload safetv device for the worm conveyor.

This purpose is met thereby that a stoker conveyor system is characteristic by the subject matter of the characterizing clause of claim 1.

Claim 2 describes a preferred embodiment of an overload safetv device for a stoker conveyor system according to the invention.

The new technique.

The novelty according to the invention is the use of a crank movement to pull th idling bearings which pull the worm a distance forward, and on the return stroke the worm comes to a standstill. Whether the rotation of the worm is caused by push or pull a safetv arrangement in the form of a compression spring is to be used in push rotation. In the case of pull rotation the drive arm is prolonged so that the spring is mounted on the side of the gear arm, which thus makes the spring function as a compression spring. Furthermore, a rapid change in the gearing can be effected by changing the length of the drive arm, either by moving the push/pull rod into holes or infinitely variably in a slit.

The overload safety device can, in principle, run endlessly vvithout damage to vital parts.

The technical effect.

By applying the above mentioned technique the result will be a functional heating plant, which is simple of construction and has a convevor system consisting of few components.

The invention itself and the forms of embodiment are explained below with reference to the drawing.

Figurēs.

Fig.l shows a fuel hopper with stoker conveyor system.

Examples of embodiment.

Fig.l shows the stoker conveyor system mounted on a fuel hopper, and which consists of an idling bearing on which is mounted a gear arm and a drive arm with an overload safetv device.

It will be seen that the drive arm with the overload safety device (1) is loosely mounted on the gear change arm (2).

This makes it possible to change the gearing, which will cause a change in the speed of rotation of the stoker worm body (4). The gear change arm (2) is built integral with an idling bearing (3), which is mounted on the stoker

Lv 11709 worm (4) itself. Thew whole stoker conveyor system is driven by an electric motor (5).· The electric motor (5) transmits the drive to the drive arm (1) via an eccentric disk (6).

The drive arm (1) is of a cylindrical construction with an overload spring (7), and by means of the tensioner device (8) it is possible to change the maximum load of the overload safety device.

! I ! ILV 11709

CLAIMS 1. Stoker conveyor svstem for heating plants vvhich comprises a stoker worm (4) which is driven by a driving arm through a ratchet mechanism mountedontheshaftofthestokerworm/ characterized bythefact that the ratchet mechanism is designed as an idling bearing (3), that the driving arm is designed as a gear change arm (2) which extends radially from and is integral with the idling bearing (3) and is shaped with either a longitudinal slot or with a row of holes (2') through an arbitrary of vvhich one end of a driving arm (1) the other end of vvhich is hinged to and driven by an eccentric disk (6) can come into a one way engagement -either push or pull - with the gear change arm (2) in a distance from the idling bearing (3) vvhich can be varied and thus the gear ratio can be varied and that an overload safety device is incorporated in the driving arm (1). 2. Stoker conveyor system according to claim 1, characterized by the fact that the overload safety device comprises an overload spring (7) vvhich is mounted so it can either push or pull the end of the driving arm (1) in position against the gear change arm (2) in an elected hole (2') and the initial tension of the spring (7) can be varied by means of a tensioner device (8) vvhich is led through a hole (2') adjoining the hole (2') vvith vvhich the end of the driving arm is in engagement. :j :jLV 11709

ABSTRACT

STOKER CONVEYOR SYSTEM HEATING PLANTS

This invention relates to a gearing and overload safety device for use in connection with worm conveying of solid fuel. The nove!ty of the invention consists in a drīve system for a stoker worm, which system has a high gear ratio and a mimimum of power loss, and in a spring for adjustment of the maximum load, which spring simultaneously acts as an overload safety device for the stoker worm. Also, the system is of simple construction with few wearing parts.

Claims

ii EN 11709 DESCRIPTION OF THE INVENTION 1. A system for feeding fuel in a heating installation consists of a working snail (4) actuated by a guidewire with a actuator positioned on a snail shaft and characterized in that the actuator is formed as a free-wheel bearing (3), but the guide wire is provided with a guide (2) radially connected to the freewheel bearing (3) and having either a longitudinal gap or a plurality of single-row openings (2 ') through which one end of the conductive transmission (1), furthermore its other end is movably connected and is actuated by an eccentric disc (6), can be independently coupled - in a push or pull - with a guide (2) at a certain distance from the free-wheel bearing (3), which can be adjusted, thereby changing the gear ratio. to change the speed of rotation of the working snail and is equipped with an overload protector located on the lead transmission (1).

2. A system for supplying fuel in a heating installation according to claim 1, characterized in that the overload protection device has an overload spring (7) positioned so as to press or pull the end of the guide transmission (1) towards the guide (2) in the selected opening (21). and, in this way, the starting tension of the spring (7) can be changed by a retractor (8) passed through the opening (2 ') through which the end of the guide transmission (1) in the clutch is connected.