AU645660B2

AU645660B2 - High ratio reduction gear transmission system

Info

Publication number: AU645660B2
Application number: AU11090/92A
Authority: AU
Inventors: Roy William Sandham
Original assignee: Eimco Mining Machinery Pty Ltd
Current assignee: Eimco Mining Machinery Pty Ltd
Priority date: 1991-02-21
Filing date: 1992-02-20
Publication date: 1994-01-20
Anticipated expiration: 2012-02-20
Also published as: AU1109092A

Description

Our Ref: 421587

Q

P/00/011 Regulation 3:2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT r Applicant(s): Address for Service: Invention Title: Eimco Mining Machinery (Proprietary) Limited 64 Jet Park Road ELANDSFONTEIN Transvaal Province SOUTH AFRICA DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 High ratio reduction gear transmission system The following statement is a full description of this invention, including the best method of performing it known to me:- 5020 'I ~THIS INVENTION relates to a high ratio reduction gear transmission system. It relates more specifically to such a oo oo ~system which comprises, in series, a spur gear reduction stage and a worm gear reduction stage.

An application to which this invention is advantageously applicable is the transmission of drive to a coal shuttle car. A coal shuttle car is a wheeled load vehicle for transporting coal. A floor of the car is (partially) provided by a chain conveyor of the kind having transverse slats. The conveyor extends boom fashion over an end of the car. The conveyor unloads from the car.

The conveyor is driven by an electric motor via a high ratio reduction gear transmission system of the kind described above. The transmission system is mounted at one side of the boom to have its output shaft aligned with and drivingly connected to the head rollers/gear wheels. The electric motor 3 is mounted on a casing of the transmission about an axis at right angles to and not intersecting the axis of the output shaft.

The drive (motor and transmission system) is mounted to one side of the car. The transmission is a-symmetrical and is, conventionally, dedicated for use at one side only. Thus, so-called "left hand" and "right hand" transmission systems are provided respectively for use on the left and on the right sides of the car.

In accordance with a first aspect of the invention, there is provided a high ratio reduction gear transmission system comprising, drivingly interconnected in series, a spur gear reduction stage and a worm gear reduction stage, the spur gear reduction stage including an input or pinion shaft and a pinion mounted thereon, an output or spur gear wheel shaft and a spur gear wheel mounted thereon, the pinion and spur gear wheel shafts being arranged parallel and transversely spaced to have the pinion and spur gear wheel in meshing arrangement, and a spur gear casing; the worm gear reduction stage including an input or worm shaft and a worm mounted thereon, an output or worm wheel shaft and a worm wheel mounted thereon, the worm and worm wheel shafts being at right angles and transversely spaced to have the worm an 'worm wheel in meshing arrangement, and a worm gear casing; the worm gear reduction stage being convertible to have its worm wheel shaft projecting trom its casing selectively to either side, and the spur gear reduction stage being pivotal about that 4 one of the axes of its pinion shaft and its spur gear wheel shaft which is drivingly connected to the worm gear reduction stage, to render the transmission system selectively convertible between left and right handed configurations.

In accordance with a second aspect of the invention, there is provided a high ratio reduction gear transmission system comprising, drivingly interconnected in series, a spur gear recaction stage and a worm gear reduction stage, in which a casing of the system is in the form of a composite casing S. .OV comprising ooeo eere a worm gear casing accommodating a worm and worm wheel, the worm gear casing being convertible from a condition appropriate for drive to one side thereof to a condition appropriate for drive to an opposed side thereof, the worm gear casing including 0t** means for passing a worm shaft aligned with and connected to the worm, ~a worm wheel flange plate mountable selectively at either side of the worm gear casing to pass a worm wheel shaft aligned with and connected to the worm wheel, a cover plate mountable at either side of the worm gear casing to cover the side not occupied by the worm wheel flange plate; a spur gear casing accommodating a pinion mounted on a pinion shaft and a spur gear wheel mounted on a spur gear wheel shaft in speed reducing meshing arrangement, the spur gear casing and the worm gear casing having complemental mounting means for mounting the spur gear casing on the worm gear casing selectively in orientations appropriate respectively for the two conditions of the worm gear casing.

In a preferred embodiment, the spur gear reduction stage may be a primary reduction stage, the worm gear reduction stage being a secondary reduction stage. Then, the pinion shaft may provide an input shaft for the transmission system, the spur gear wheel shaft being aligned with and being drivingly connected to the worm shaft, and the worm wheel shaft being an output shaft of the reduction system as a whole.

Advantageously, the spur gear wheel shaft and the worm shaft may be provided by a common, intermediate shaft.

When the system is converted from one condition to the other, the worm gear casing may retain its orientation, the worm wheel shaft being arranged to extend from an opposite side. However, the spur gear casing may be re-orientated or pivoted through 1800 around an axis Jefined by the spur gear wheel shaft and the worm shaft.

The invention is now described by way of example with reference to the accompanying diagrammatic drawings. In the drawings Figure I shows, in tragmentary, three dimensional view, a drive in accordance with the invention drivingly connected to a chain conveyor of a coal shuttle car; Figure 2 shows, in solid lines to one side, partially in section, the drive of Figure I and, to the opposed side, in dotted, a mirror image of the drive; h \miiaec.) I 1ll0 9 0/92\lgS, Figure 3 shows, in three dimensional view, the drive of Figure 1; Figures 4 and 5 show, respectively in plan view and in front view, a composite casing of the drive of Figure 1 in its condition as shown in Figure 1 i.e. the "left-hand" condition; and Figures 6 and 7 correspond respectively to Figures 4 and but show the drive in the opposite hand condition i.e. the "right hand" condition.

With reference to Figures 1, 2 and 3 of the drawings, eeee 4, •age a drive in accordance with the invention, for a coal shuttle car, is generally indicated by reference numeral The shuttle car is represented by an end portion of a chain conveyor 12 extending from an end of the shuttle car, boom fashion. The conveyor 12 comprises left-hand and right-hand side S. plates respective 14 and 16 with which respectively left and right hand chains 18 and 20 are associated. Transverse slats 22 extend between the chains 18 and 20. The chains 18 and 20 are deflected around a head stock 24 comprising a head stock shaft and left hand and right hand cogged wheels 26, 28 over which the chains are drivingly received.

In use, coal loaded on the shuttle car is unloaded by operating the chain conveyor 12 which transports the coal out of the shuttle car.

Ct 7 The drive 30 comprises an electric motor 32 and a high ratio reduction gear transmission system generally indicated by reference numeral 34 which interconnects the electric motor 32 and an output shaft 36 connected to the head stock shaft The transmission system 34 includes a primary stage 38 which is in the form of a spur gear reduction stage utilizing spur gears and a secondary reduction stage 40 utilizing a worm gear system.

a. The transmission system 34 comprises a composite casing including a primary casing or spur gear casing 42, and a secondary casing or worm gear casing 44. The casings 42 and 44 are shown schematically in Figures 1 to 3 of the drawings.

The primary stage 38 comprises a pinion 46 which is drivingly connected to the electric motor 32 via a motor output 0 shaft 48 which serves as a pinion shaft in accordance with the invention. The pinion 46 meshes with a spur gear wheel connected to a spur gear wheel shaft 52 which shaft exits the primary casing 42 and enters the secondary casing 44 where a worm 54 is operatively mounted thereon. The spur gear wheel shaft 52 is rotationally supported in bearings 56 and 58.

It is to be noted that the axis 49 of the pinion 46 and the axis 53 of the spur gear wheel 50 and worm 54 are parallel.

1.

*\1 N! r The worm 54 is drivingly engaged with a worm wheel mounted on a worm wheel shaft serving as the output shaft 36, which is at right angles to the axes 49 and 53. The output shaft 36 exits the secondary casing 44 via a flange 62. The secondary casing 44, at a position opposite to the flange 62, is covered by means of a cover 64.

Conventionally, the casing of a drive corresponding to the drive 30 in accordance with the invention, is an integral casing in the form of casting. Because of the a-symmetrical nature of the drive, it is a dedicated left-hand drive, or a ooe dedicated right-hand drive.

o In accordance with the invention, and moro specifically with reference to Figures 4 to 7 of the drawings, it is now shown that the drive 30, in accordance with the invention, can be converted from a left-hand drive to a right-hand drive, and vice versa. In this regard, for ease of perception, the drive shown in solid lines in Figure 2 is a left-hand drive and the layout of the drive, after conversion to a right-hand drive, is shown in dotted at 30.1, also in Figure 2.

To convert the embodiment of Figures 4 arLnd 5, which is also the embodiment shown in Figures i, 2 and the flange 62 and the cover 64 are dismantled. The orientation of the worm gear casing 44 is maintained. The output shaft 36 and the worm wheel 60 are turned around such that the output shaft 36 extends out of the worm gear casing 44 at the opposed side. The flange q 62 and cover 64 are changed around which is rendered possible by having the tapped sockets in ends of the casing 44 and the corresponding holes through the flange 62 and cover 64 symmetrical and mirror images at opposed sides.

The spur gear casing 42 is of elongate shape having semi-circular ends. It is formed of cheek plates 66, 68 and a peripheral rim 70. It is dismounted froi the casing 44 and pivoted through 1800 about the axis 53. Also this is made possible by having the primary casing 42 symmetrical about a longitudinal centre line. It is to be appreciated that the S orientation and position of the spur gear 50, shaft 52 and worm 54 remain the same in both applications.

It is also to be appreciated that not only the casing S 42, but also the primary stage 38 as a whole is symmetrical about S its longitudinal centre line, thus no changes are required in respect of the shaft 48 and pinion 46, or in the motor 32.

Lastly, it is to be appreciated that mounting means for mounting the casing 44 on the conveyor frame will be duplicated on the casing 44 such that it can be mounted at either Lide of the conveyor £rame.

It is to be appreciated that no additional, or virtually no additional, components are required to enable the transmission system 30 to operate selectively in either left- I, cI 4 I0 hand or right-hand configuration. Thus, no distinction is made between left-hand and right-hand components and the components kept in stock, for example as spare parts, need not be duplicated such as is the case with conventional transmission systems of the kind described and which are known to the Applicant.

Furthermore, if desired, a transmission system set up in one configuration can easily be converted, at no or virtually no capital outlay, to a transmission system of the opposite hand.

Thus, for example, if it is the policy of a user to keep a transmission system on standby in case of a breakdown, only one transmission system need be kept instead of two as is the case with conventional systems.

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Claims

1. A high ratio reduction gear transmission system comprising, drivingly interconnected in series, a spur gear reduction stage and a worm gear reduction stage, the spur gear reduction stage including an input or pinion shaft and a pinion mounted thereon, an output or spur gear wheel shaft and a spur gear wheel mounted thereon, the pinion and spur gear wheel shafts being arranged parallel and transversely spaced to have the pinion and spur gear wheel in meshing arrangement, and a spur gear casing; the worm gear reduction stage including an input or worm shaft and a worm mounted thereon, an output or worm wheel shaft and a worm wheel mounted thereon, the worm and worm wheel shafts being at right angles and transversely spaced tc have the worm and worm wheel in meshing arrangement, and a worm gear casing; the worm gear reduction stage being convert'ble to have its worm wheel shaft projecting from its casing selectively to either side, and the spur gear reduction stage being pivotal about that one of the axes of its pinion shaft and its spur gear wheel shaft which is drivingly connected to the worm gear reduction stage, to render the transmission system selectively convertible between left and right handed configurations.

2. A high ratio reduction gear transmission system comprising, drivingyl interconnected in series, a spur gear reduction stage and a worm gear reduction stage, in which a 1 "'j ,,NT~ casing of the system is in the form of a composite casing comprising a worm gear casing accommodating a worm and worm wheel, the worm gear casing being convertible from a condition appropriate for drive to one side thereof to a condition appropriate for drive to an opposed side thereof, the worm gear casing including means for passing a worm shaft aligned with and connected to the worm, a worm wheel flange plate mountable selectively at either side of the worm gear casing to pass a worm wheel shaft C C aligned with and connected to the worm wheel, s o a cover plate mountable at either side of the worm gear casing to cover the side not occupied by the worm wheel flange plate; *a spur gear casing accommodating a pinion mounted on a pinion shaft and a spur gear wheel mounted on a spur gear wheel shaft in speed reducing meshing arrangement, the spur gear casing and the worm gear casing having complemental mounting means for mounting the spur gear casing on the worm gear casing selectively in orientations appropriate respectively for the two conditions of the worm gear casing.

3. A high ratio reduction gear transmission system as claimed in Claim 1 or Claim 2 in which the spur gear reduction stage Is a primary reduction stage, the worm gear reduction stage being a secondary reduction stage. 13

4. A high ratio reduction gear transmission system as claimed in claim 3 in which the pinion shaft provides an input shaft for the transmission system, the spur gear wheel shaft being aligned with and being drivingly connected to the worm shaft, and the worm wheel shaft being an output shaft of the reduction system as a whole. A high ratio reduction gear transmission system as claimed in claim 4 in which the spur gear wheel shaft and the worm shaft are provided by a common, intermediate shaft. 10 6. A high ratio reduction gear transmission system as claimed in claim 4 or claim in which when the system is converted from one condition to the other, the worm gear casing retains its orientation, the worm wheel shaft being arranged to extend from an S: opposite side. 15 7. A high ratio reduction gear transmission system as claimed in claim 6 in which S the spur gear casing is re-orientated or pivoted through 1800 around an ais defined by the spur gear wheel shaft and the room shaft.

8. A high ratio reduction gear transmission system, substantially as herein described with reference to the accompanying drawings. DATED THIS 1st day of November, 1993. EIMCO MINING MACHINERY (PROPRIETARY) LIMITED By Its Patent Attorneys DAVIES COLLISON CAVE 01\l 1090/92\lgl 3 ABSTRACT A power drive 30 comprises a high ratio reduction gear transmission system 34 transmitting drive at highly reduced speed and correspondingly highly increased torque from an electric motor 32 via an output shaft 36 to a conveyor of a coal shuttle car. The reduction gear system 34 has a primary stage utilizing a pinion 46 meshed to a spur gear wheel 50, and a secondary stage S40 utilizing a worm 54 and a worm wheel 60. The motor 32 is

555.5. mounted on a spur gear casing 42, which in turn is mounted on a worm casing 44. The worm casing 44 is mounted on the coal shuttle car. To change the drive from one hand a left e hand) to another hand a right hand) configuration, the casing 44, while its orientation is retained, is mounted on the other side of the shuttle car, the direction of extension of the shaft 36 is turned through 1800, and the spur gear stage, i.e. S" its casing 42 with the motor 32, is pivoted through 1800 about the axis of the spur gear wheel. Tapped holes and like mounting means are appropriately duplicated to render the conversion possible.