GB2604910A

GB2604910A - Electric golf trolley transmissions

Info

Publication number: GB2604910A
Application number: GB2103805.4A
Authority: GB
Inventors: Straker Paul; Simpson Cris
Original assignee: Motocaddy Ltd
Current assignee: Motocaddy Ltd
Priority date: 2021-03-18
Filing date: 2021-03-18
Publication date: 2022-09-21
Also published as: GB202103805D0; WO2022194962A1

Abstract

A differential 10 suitable for an electric golf trolley, having two opposing driven shafts 12 each rotating a wheel 40, a gearset (may be a crown gear 18) arranged to drive the driven shafts; and a one-way over-running clutch bearing mechanism 24 coupled to at least one of the driven shafts 12 transmitting torque from the gearset to the shaft(s) 12 in only one direction and permitting freewheeling in the opposite direction. Also claimed: crown gear 18 being supported by two support bearings 32 one on each side of the ring gear 18 so the crown wheel does not contact the differential casing 16; and driven shafts 12 may be supported by multiple auxiliary bearings (fig 2, 36a & 36b). A drive coupling (fig 3, 42), which may be a tongue 48 and groove 46 connection, may compensate for misalignment and prevent damage to the gearbox.

Description

Electric Golf Trolley Transmissions

Field

[001] The present invention relates to electric golf trolley transmissions and electric golf trolleys comprising the same.

Background

[002] Electric golf trolleys typically require means to allow the independent rotation of a pair of driven wheels so that they are permitted to follow paths of different lengths when, for example, turning a corner or traversing an uneven path or road.

[3] Known electric golf trolleys typically comprise two driven wheels which are attached to and located towards opposing ends of a single-piece driven axle, or shaft, which is directly connected to and driven via a gearbox. Given that the axle is directly connected to the gearbox, usually via a crown wheel or similar mounted to the driven shaft, a one-way bearing (sometimes known as a clutch bearing) is typically provided at each driven wheel in order to permit separate rotation speed of each driven wheel.

[4] A one-way bearing, which is usually located on the axle immediately adjacent each driven wheel, allows each wheel to rotate on the axle more quickly than the driven rotation actuated by the gearbox. Thus, an outside' wheel is able to rotate more quickly than an 'inside' wheel when the electric golf trolley is turning a corner, for example. The quicker rotation of the 'outside' wheel is often referred to as over-speeding. Other bearings or clutches may work in a similar way.

[5] However, the Applicant has found that existing transmissions for electric golf trolleys and their components, e.g. the bearings, typically have a shorter than expected lifespan. One-way bearings in particular are often worn more quickly than would be expected if used normally in line with the manufacturer's instructions.

[6] After in-depth investigation, the Applicant found that these components are often damaged by a user when cleaning their golf trolley. For example, users are typically instructed to minimise exposure to water as much as possible and to remove excess water from the trolley prior to storage. Importantly, they are instructed to never use a pressurised gas or fluid to clean the trolley in order to prevent damage to seals and the moving components in particular. It has been found that user's frequently do not read or disregard these instructions.

[007] Such bearings have thus been found to be particularly susceptible and are a common cause of transmission refurbishment or replacement in electric golf trolleys.

[008] In an attempt to prolong the lifetime of these components, and electric golf trolleys more generally, a more recent development included providing a wheel for an electric golf trolley having a wheel hub housing a one-way bearing. An aim of this development was to shield the bearing from the water damage typically seen in bearings which are distinct from the wheel.

[009] However, the Applicant has also found that user's still frequently damage the bearings, and other components, even where a bearing is housed in the wheel hub. Pressure washing in particular has proven to pose a significant problem. Bearings still get clogged with water and dirt which leads to jamming, potential breaking and squeaking under continued application of force, and the electric golf trolley not operating correctly. This problem is even sometimes exacerbated due to the relative inaccessibility of the bearing in each wheel, over previous iterations. Usually, therefore, the entire wheel needs to be replaced or refurbished.

[010] Therefore, the transmissions of existing electric golf trolleys have inadequate lifespans and too frequently require mechanical attention. As well as overall lifespan, the risk of damage and resultant seizure of these components must be minimised to avoid the risk of an electric golf trolley becoming disabled during use.

[011] The Applicant has also found that a further problem with existing electric golf trolleys, which typically have a single continuous axle and one-way bearings located towards each wheel, is that parts of the transmission, including the gearbox, are too frequently damaged and wear more quickly than expected due to excessive forces being transmitted from the wheels into the gearbox. This may repeatedly occur when the trolley travels over uneven ground, for example.

[12] Accordingly, there is an ongoing need to address the problem of increased damage and wear of existing electric golf trolley transmissions due, amongst other things, to existing transmission arrangements and poor user maintenance.

[13] The present invention aims to solve these and other problems with the prior art. 10 Summary [14] Accordingly, in a first aspect, the present invention provides an electric golf trolley transmission comprising two opposing driven shafts for rotating a wheelset of the electric golf trolley; a gearset arranged to drive rotation of the driven shafts; wherein each driven shaft has a gearset end and an opposing wheel end which is connectable to a wheel; at least one said driven shaft having a clutch mechanism coupled thereto; wherein the clutch mechanism is configured to transmit torque from the gearset to the at least one shaft in one direction and freewheel in the opposite direction and wherein the gearset end of the or each driven shaft is proximal to the clutch mechanism.

[15] As used herein, the term "coupled" refers to either permanent or temporary, i.e. releasable, attachment. In embodiments, the clutch mechanism is releasably attached to the driven shaft.

[16] This configuration is particularly advantageous because it provides a transmission for an electric golf trolley in which at least one clutch mechanism is provided to transmit torque from the gearset to the at least one driven shaft in one direction and freewheel in the opposite direction, and the gearset end of the or each driven shaft is proximal to the clutch mechanism. Therefore, the clutch mechanism is much less likely to become damaged by a user because it is not located at or adjacent the wheel and is thus less likely to be damaged by overzealous cleaning. Therefore, both the life of a transmission and performance are improved, as is the lifespan and performance of electric golf trolleys more generally.

[17] In embodiments, each driven shaft may have a clutch mechanism coupled thereto and each clutch mechanism may be configured to transmit torque from the gearset to the respective driven shaft to which it is coupled in one direction and freewheel in the opposite direction, and the gearset end of each driven shaft may be proximal to the respective clutch mechanism.

[18] Thus, the electric golf trolley transmission may comprise a single clutch mechanism which is coupled to at least one said driven shaft, or the electric golf trolley transmission may comprise more than one clutch mechanism wherein each clutch mechanism is attached to one (only) of the driven shafts such that each driven shaft has one clutch mechanism coupled thereto.

[19] In embodiments, the or each clutch mechanism may be located substantially between the gearset and the gearset end of the respective driven shaft. Therefore, the clutch mechanisms are located far away from the wheels of an electric golf trolley and are thus less susceptible to damage by power washing, for example [20] In embodiments, the transmission may comprise a gearbox casing, and the or each clutch mechanism may be located substantially inside the gearbox casing. The protection of a clutch mechanism is thereby further improved, because it is concealed inside the gearbox casing.

[21] In embodiments, the or each clutch mechanism may be directly connected to the gearset. This configuration is particularly advantageous because a greater proportion of the transmission is located at or near the gearset. Therefore, the number of components located proximal to the wheels is minimised. The risk of damage to these components is thus minimised further.

[022] In embodiments, the or each clutch mechanism may comprise a one-way clutch bearing. In embodiments, the transmission may comprise two one-way clutch bearings, one said one-way clutch bearing being coupled to each driven shaft.

[23] As used herein, the term "one-way clutch bearing" refers to a bearing which allows unidirectional rotation of a driven shaft. For example, where the gearset is arranged to drive forward rotation of each driven shaft, the one-way clutch bearing may be configured to allow 'over-speeding' of a driven shaft, i.e. increased forward rotation, whilst substantially preventing rotation of a driven shaft against the forward rotation driven by the gearbox. The one-way clutch bearing may also be referred to as an overrunning clutch. Thus, each one-way clutch bearing is configured to transmit torque from the gearset to the respective driven shaft in one direction and freewheel in the opposite direction.

[24] In embodiments, the or each one-way clutch bearing may be annular and may have an inside diameter of around 14mm, an outside diameter of around 20mm and a width of around 16mm. In embodiments, the or each one-way clutch bearing may comprise a roller clutch. In embodiments, the or each one-way clutch bearing may comprise a drawn cup roller clutch. In embodiments, the or each one-way clutch bearing may comprise a drawn cup needle roller clutch. Advantageously, drawn cup roller clutches have low mass and resulting low moment of inertia of their clamping elements. Drawn cup roller clutches also have low overrunning frictional torque. In embodiments, the or each one-way clutch bearing comprises a spring set configured to facilitate the transmission of torque from the gearset to the respective driven shaft in one direction of rotation.

[25] In embodiments, the or each clutch mechanism may be formed substantially of metal, plastic or a combination thereof For example, in embodiments, the or each clutch mechanism may be substantially formed of steel.

[26] In embodiments, the or each one-way clutch bearing may have an outer race, an inner race, a plurality of rolling bearing elements and a rolling bearing elements cage. In embodiments, the outer race, inner race and rolling bearing elements may be formed of metal, for example steel, and the rolling bearing elements cage may be formed of plastic.

[27] In embodiments, the or each clutch mechanism may be connected to the respective driven shaft by a drive coupling. A drive coupling transmits torque from the gearset to the driven shaft whilst absorbing misalignment and other undesirable forces. Therefore, the potential damage to the gearbox and clutch mechanism is minimised if an electric golf trolley including the transmission traverses uneven ground, for example. Any undesirable forces transferred through either driven shaft are substantially minimised or neutralised by the drive coupling which connects the or each clutch mechanism to the respective driven shaft.

[28] In embodiments, the or each clutch mechanism may comprise a one-way clutch bearing, and the or each one-way clutch bearing may have an outer race connected to the gearset and an inner race; wherein the or each drive coupling may include a coupler which may be connected to the inner race of the respective one-way clutch bearing; and wherein the or each coupler may be releasably attached to the gearset end of the respective driven shaft. Each driven shaft may therefore be straightforwardly detached from the one-way clutch bearing for maintenance or replacement, without the need to replace the one-way clutch bearing. Each coupler may be substantially bounded by the inner race of the respective one-way clutch bearing.

[29] In embodiments the coupler may be releasably attached to the inner race of the one-way clutch bearing.

[30] In embodiments, the or each drive coupling may comprise a tongue and groove connection. A tongue and groove connection provides a straightforward drive coupling which may be intuitively attached and detached by a user. In embodiments, the gearset end of the driven shaft may comprise the tongue part of the tongue and groove connection and the coupler may comprise the groove part of the tongue and groove connection, or vice versa. In embodiments, the coupler may incorporate the groove part of the tongue and groove connection and the groove may extend across the entire diameter of the coupler such that the groove is substantially open at a side surface of the coupler.

[31] In embodiments, the transmission may further comprise a seal configured to substantially seal the or each clutch mechanism from the external environment. Thus, the or each clutch mechanism is protected from potential damage by a user or from the environment. This may include preventing the ingress of water into the or each clutch mechanism. In embodiments, the seal is a water-tight seal. In embodiments, the seal comprises a gasket.

[032] In embodiments, the or each drive coupling may include a seal configured to substantially seal the or each clutch mechanism from the external environment. In embodiments, the or each clutch mechanism comprises a one-way clutch bearing and the or each respective drive coupling includes a seal configured to substantially seal the or each one-way clutch bearing from the external environment.

[33] In embodiments, the or each clutch mechanism may comprise a one-way clutch bearing and the coupler of the or each drive coupling may comprise a seal configured to seal the respective one-way clutch bearing from the external environment. In embodiments, the seal of the coupler is located immediately adjacent the interface between the coupler and the driven shaft. In embodiments, the drive coupling includes a tongue and groove connection and the seal of the coupler is immediately adjacent the groove of the coupler.

[34] In embodiments, each coupler may be substantially cylindrical and may comprise an annular seal which extends substantially about the circumference thereof.

Thus, each coupler may be slidably engaged with the respective one-way clutch bearing and the seal of each coupler may be configured to seal the respective one-way clutch bearing from the external environment when the coupler is inserted.

[035] In embodiments, the gearset may include a crown wheel configured to drive rotation of each driven shaft; wherein the crown wheel may be flanked and supported within the gearbox casing by a pair of support bearings. Thus, the crown wheel may be substantially free from contact with the gearbox casing. The support bearings may provide the only support to the crown wheel.

[36] In embodiments, the crown wheel may be substantially formed of plastic.

[37] In embodiments, the or each clutch mechanism may be operatively connected to the crown wheel. In embodiments, the or each clutch mechanism may be directly connected to the crown wheel. A more compact transmission is therefore provided, because the or each clutch mechanism may be directly connected to the crown wheel.

[38] In embodiments, each support bearing may comprise an outer race and an inner race. In embodiments, the or each clutch mechanism may be substantially surrounded by the inner race of the respective support bearing about the circumference thereof. A more compact transmission is therefore provided. The or each clutch mechanism therefore transfers torque from the crown wheel to the respective driven shaft, whilst each support bearing supports the crown wheel and facilitates rotation thereof.

[39] In embodiments, the or each clutch mechanism may comprise a one-way clutch bearing, and the or each one-way clutch bearing may be directly connected to the crown wheel and may be substantially surrounded by the inner race of a respective support bearing about the circumference thereof.

[40] In embodiments, each support bearing may be bidirectional. In embodiments, each support bearing may comprise a low profile bearing. In embodiments, each support bearing may have an inside diameter of around 35mm, an outside diameter of around 55mm and a width of around lOmm. In embodiments, each support bearing may be substantially formed of metal, plastic or a combination thereof. For example, in embodiments, each support bearing may be substantially formed of steel.

[41] In embodiments the crown wheel, support bearings and the or each clutch mechanism may be substantially formed into a single piece. In other words, the crown wheel, support bearings and the or each clutch mechanism bearing may be permanently fixed to one another. In alternative embodiments, two or more of the crown wheel, support bearings and the or each clutch mechanism may be detachable from one another.

[42] In embodiments, the transmission may further comprise one or more auxiliary bearings coupled to each driven shaft. The one or more auxiliary bearings improve the alignment of the driven shafts and facilitate smooth rotation of the driven shafts, in use. In embodiments, each auxiliary bearing may be bidirectional.

[43] In embodiments, a said auxiliary bearing may be located substantially at or near the gearset end of each driven shaft. In embodiments, a said auxiliary bearing may substantially flank the or each clutch mechanism such that the or each clutch mechanism is located substantially between the gearset and a said auxiliary bearing on each respective driven shaft.

[44] In embodiments, each auxiliary bearing may have an inside diameter of around 15mm, an outside diameter of around 35mm and a width of around 10mm. In embodiments, each auxiliary bearing may comprise a needle roller or ball bearing.

Thus, each auxiliary bearing improves the ability of the transmission to accommodate heavy axial loads [45] In embodiments, each auxiliary bearing may be substantially formed of metal, plastic or combination thereof. For example, in embodiments, each auxiliary bearing may be substantially formed of steel.

[46] In embodiments, the or each auxiliary bearing may be located substantially inside said gearbox casing. Thus, each of the bearings is located inside the gearbox 20 and is more protected from potential damage.

[47] In embodiments, the gearbox casing may be sealed in a manner that substantially prevents liquid from entering the gearbox casing from the outside environment.

[48] In a further aspect, the present invention provides an electric golf trolley comprising a transmission according to any preceding aspect. An electric golf trolley comprising a transmission according to any preceding aspect has an improved life span and performance. In particular, the or each clutch mechanism is less susceptible to potential damage by a user.

[49] In a further aspect, the present invention provides a gearbox for an electric golf trolley transmission, comprising a gearset arranged to drive rotation of a pair of driven shafts of an electric golf trolley; a gearbox casing which houses the gearset; and at least one clutch mechanism; the or each clutch mechanism being configured to couple to a driven shaft and being configured to transmit torque from the gearset to the at least one driven shaft in one direction and freewheel in the opposite direction; wherein the or each clutch mechanism is located substantially inside the gearbox casing.

[50] The gearbox is particularly advantageous because the or each clutch mechanism is located inside the gearbox casing and is thus in a location where potential damage by a user is less likely. A user is less likely to clean a gearbox with power washing tools.

[51] In embodiments, the gearbox may comprise two clutch mechanisms, each clutch mechanism being configured to couple a driven shaft of an electric golf trolley and being configured to transmit torque from the gearset to the driven shaft in one direction and freewheel in the opposite direction.

[52] In embodiments, the or each clutch mechanism may comprise a one-way clutch bearing.

[53] In embodiments, the gearbox casing may be configured such that a gearset end of a driven shaft of an electric golf trolley is housed within the gearbox casing and an opposing wheel end of the driven shaft is external to the gearbox casing.

[54] In embodiments, the gearbox casing may comprise an external wall including one or more apertures configured to allow a driven shaft of an electric golf trolley to pass therethrough. Thus, the gearset end of a driven shaft may be located inside the gearbox casing and the driven shaft may extend through the aperture of the gearbox casing such that the opposing wheel end of the driven shaft is external to the gearbox casing. Therefore, the or each clutch mechanism is configured to couple to a driven shaft whilst located within the gearbox casing so that the clutch mechanism is better protected against the external environment.

[55] In embodiments, the gearset may comprise a crown wheel configured to drive rotation of a pair of driven shafts, in use; wherein the crown wheel may be flanked and supported within the gearbox casing by a pair of support bearings [56] In embodiments, the or each clutch mechanism may be operatively connected to the crown wheel. In embodiments, the or each clutch mechanism may be directly connected to the crown wheel.

[57] In embodiments, each support bearing may comprise an outer race and an inner race. In embodiments, the or each clutch mechanism may be substantially surrounded by the inner race of the respective support bearing about the circumference thereof. A more compact gearbox is therefore provided.

[58] In embodiments, the crown wheel may be substantially formed of plastic.

[59] In embodiments, the or each one-way clutch bearing may be annular and may have an inside diameter of around 14mm, an outside diameter of around 20mm and a width of around 16mm. In embodiments, the or each one-way clutch bearing may comprise a roller clutch. In embodiments, the or each one-way clutch bearing may comprise a drawn cup roller clutch. In embodiments, the or each one-way clutch bearing may comprise a drawn cup needle roller clutch.

[060] In embodiments, each support bearing may be bidirectional. In embodiments, each support bearing may comprise a low profile bearing. In embodiments, each support bearing may have an inside diameter of around 35mm, an outside diameter of around 55mm and a width of around lOmm. In embodiments, each support bearing may be substantially formed of metal, plastic or a combination thereof For example, in embodiments, each support bearing may be substantially formed of steel.

[061] In embodiments, the gearbox may further comprise one or more auxiliary bearings which are configured to attach to opposing driven shafts, in use. The auxiliary bearings improve the ability of the gearbox to accommodate misalignment of driven shafts, to facilitate smoother rotation of each driven shaft and to assist in dampening forces which would otherwise damage the gearbox, for example as an electric golf trolley traverses uneven ground.

[62] In a further aspect, the invention provides a gearbox for an electric golf trolley transmission, comprising a gearbox casing which houses a gearset arranged to drive rotation of one or more driven shafts of an electric golf trolley; the gearset including a crown wheel which is connectable to the one or more driven shafts; wherein the crown wheel is flanked and supported within the gearbox casing by a pair of support bearings such that the crown wheel is substantially free from contact with the gearbox casing, in use.

[63] Thus, the crown wheel may be substantially free from contact with the gearbox casing. The support bearings may provide the only support to the crown wheel.

[64] In embodiments, each support bearing may be bidirectional.

[65] In embodiments, each support bearing may have an outer diameter which is substantially less than that of the crown wheel. In embodiments, each support bearing may have an outer diameter which is substantially greater than half the diameter of the crown wheel. In embodiments, each support bearing may have an outer diameter which is substantially similar to the diameter of the crown wheel.

[066] In embodiments, each support bearing may comprise a low profile bearing. In embodiments, each support bearing may have an inside diameter of around 35mm, an outside diameter of around 55mm and a width of around 10mm. In embodiments, each support bearing may be substantially formed of metal, plastic or a combination thereof. For example, in embodiments, each support bearing may be substantially formed of steel.

[67] In embodiments, the crown wheel may be formed of plastic.

[68] In embodiments, the gearbox may further comprise at least one clutch mechanism configured to couple to a driven shaft. In embodiments, the clutch mechanism may be configured to transmit torque from the gearset to the driven shaft in one direction and freewheel in the opposite direction. The or each clutch mechanism may substantially share an axis of rotation with the or each driven shaft. In embodiments, the or each clutch mechanism may comprise a one-way clutch bearing.

In embodiments, the gearbox may comprise a pair of one-way clutch bearings arranged to couple to and transmit torque from the gearset to the respective driven shaft in one direction and freewheel in the opposite direction.

[069] In embodiments, each support bearing may comprise an outer race and an inner race; wherein the or each clutch mechanism may be directly connected to the crown wheel and is substantially surrounded by the inner race of the respective support bearing about the circumference thereof.

[070] In a further aspect, the present invention provides an electric golf trolley comprising a gearbox according to any preceding aspect.

[71] In a further aspect, the invention provides an electric golf trolley transmission comprising one or more driven shafts for rotating a wheelset of the electric golf trolley; a gearset arranged to drive rotation of the or each driven shaft; wherein each driven shaft has a gearset end and an opposing wheel end which is connectable to a wheel; wherein the or each driven shaft has a plurality of bearings coupled thereto.

[72] In embodiments, each of the plurality of bearings may be coupled to the respective driven shaft distal from the wheel end thereof.

[73] Providing a plurality of bearings connected to the or each driven shaft between the gearset end and wheel end thereof improves the alignment of the or each driven shaft and facilitates smooth rotation thereof.

[74] In embodiments, the transmission comprises a gearbox casing which houses the gearset and each bearing of the or each driven shaft is located substantially inside the gearbox casing. Thus, each bearing is better protected against the elements and against potential damage by a user.

[75] In embodiments, a said bearing coupled to each driven shaft comprises a one-way clutch bearing.

[076] In embodiments, at least one said bearing connected to each driven shaft comprises an auxiliary bearing. In embodiments, the or each auxiliary bearing may be bidirectional.

[077] In embodiments, the transmission comprises a one-way clutch bearing and two auxiliary bearings connected to each driven shaft between the gearset and each wheel.

[78] In embodiments, the transmission comprises a one-way clutch bearing, a support bearing and two auxiliary bearings connected to each driven shaft between the gearset and each wheel. In embodiments, each support bearing may comprise an outer race and an inner race; wherein each one-way clutch bearing may be substantially surrounded by the inner race of the respective support bearing about the circumference thereof.

[79] In a further aspect, the present invention provides an electric golf trolley comprising a transmission according to any preceding aspect.

[80] For the avoidance of doubt, features of aspects and embodiments described herein may be combined, and still fall within the scope of the present invention.

Brief Description of Figures

[81] Preferred features of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: [82] Figure 1 illustrates a cross sectional view of part of a transmission according to the present invention.

[083] Figure 2 illustrates a cross sectional view of a transmission according to the present invention.

[084] Figure 3 shows an exploded view of part of a transmission according to the present invention.

[85] Figure 4 shows a side view of a coupler of a transmission according to the present invention.

Detailed Description

[86] Figure 1 shows a diagrammatic cross sectional view of part of a transmission 10 for an electric golf trolley. The transmission is configured to drive rotation of a wheelset, and more specifically drive rotation of two opposing wheels of an electric golf trolley, in use, and permit independent rotation thereof in order that one wheel may rotate more quickly than the other when, for example, the electric golf trolley turns a corner or traverses uneven ground.

[87] The transmission 10 includes two opposing driven shafts 12 which are each 15 connected to and extend from a gearbox 14. The driven shafts 12 are configured to rotate a wheelset of the electric golf trolley. The gearbox 14 has a gearbox casing 16. The gearbox casing encases a gearset including a crown wheel 18. In the transmission of Figure 1 part of each driven shaft 12 is located within the gearbox casing 16 and each driven shaft 12 extends therefrom towards two opposing wheels (not shown). 20 [88] Each driven shaft 12 comprises a wheel end 20 which is proximal to a wheel and a gearset end 22 which is distal from a wheel.

[89] The transmission 10 comprises two one-way clutch bearings 24. A one-way clutch bearing 24 is coupled to each driven shaft 12. In the transmission 10 of Figure 1, each one-way clutch bearing 24 is located inside the gearbox casing 16 and is embedded within the crown wheel 18. In the transmission of Figure 1, a central portion of the crown wheel 18 therefore is coupled to each one-way clutch bearing 24, and the rotational axis of each one-way clutch bearing 24 is substantially aligned with the rotational axis of the crown wheel 18.

[90] The crown wheel 18 is configured to drive forward rotation of the driven shafts 12. Each one-way clutch bearing 24 is configured to transmit torque from the gearset to each driven shaft 12 in one direction and freewheel in the opposite direction. Thus, each one-way clutch bearing 24 is configured to allow the respective driven shaft 12 to overspeed if required, i.e. rotate in the same direction as the forward rotation driven by the crown wheel 18 but at a greater speed. This may be necessary if, for example, an electric golf trolley to which the transmission is a part of turns a corner. The one-way clutch bearings 24 are also configured to substantially prevent rotation of each driven shaft 12 opposite to the direction of rotation driven by the crown wheel 18.

[91] Each one-way clutch bearing 24 comprises an outer race 26, an inner race 28 and a plurality of rolling bearing elements (not shown) which are arranged to allow the outer race 26 and inner race 28 to rotate relative to one another in one direction but not in the other. The outer race 26 of each one-way clutch bearing 24 is fixed to the crown wheel 18 and the inner race 28 is coupled to the respective driven shaft 12.

[92] In the transmission of Figure 1, each one-way clutch bearing 24 is a drawn cup needle roller clutch. In the transmission of Figure 1, each one-way clutch bearing 24 has an outside diameter of around 20mm and an inside diameter of around 14mm. In the transmission of Figure 1, each one-way clutch bearing 24 has an axial width of around 16mm.

[093] Each one-way clutch bearing 24 is located between the gearset and the gearset end 22 of the respective driven shaft 12. In other words, the gearset end of each driven shaft 12 is proximal to the respective one-way clutch bearing. Each one-way clutch bearing is thus distal from the wheel end of the respective driven shaft 12.

[094] The crown wheel 18 has a central portion including an outwardly facing surface having a plurality of teeth which are configured to interact with a worm gear (not shown). The transmission 10 further comprises a pair of support bearings 32 which flank and support the crown wheel 18 within the gearbox casing 16. The support bearings 32 substantially bound side portions 34 of the crown wheel 18. The side portions 34 in turn bound the one-way clutch bearings 24. In the transmission of Figure 1, the support bearings 32 are configured such that the crown wheel 18 does not contact the gearbox casing 16 in use. Each support bearing 32 comprises an outer race which contacts the gearbox casing 16 and an inner race which is attached to the crown wheel 18. The support bearings 30 thus substantially surround the one-way clutch bearing 24 on the respective side of the crown wheel 18.

[095] A number of seals (not shown) are provided to seal each one-way clutch bearing 24 from the external environment. Typically, the gearbox casing 16 is also configured to seal each one-way clutch bearing 24 from the external environment.

[096] The transmission 10 of Figure 1 further comprises an auxiliary bearing 36 coupled to each driven shaft 12. The auxiliary bearings 36 facilitate aligned rotation of the driven shafts 12. In the transmission 10 of Figure 1, the auxiliary bearings 36 are located towards the gearset end of each driven shaft 12 and are adjacent the gearbox casing 16. Thus, each auxiliary bearing 36 acts as an additional barrier for preventing liquids and other contaminants from entering the gearbox casing 16 via the apertures in the gearbox casing 16 provided for the driven shafts 12. In the transmission 10 of Figure 1, the auxiliary bearings 36 are located outside the gearbox casing 16, but it is envisaged that the auxiliary bearings 36 may be located inside the gearbox casing 16.

[097] Referring to Figure 2, it can be seen that each driven shaft 12 is coupled to two auxiliary bearings 36a, 36b. The support provided to each driven shaft 12 is therefore increased. In the transmission of Figure 2, each auxiliary bearing 36a, 36b is a ball bearing having an inner diameter of around 15mm, i.e. a diameter suitable for connecting to the driven shafts 12, and an outer diameter of around 32mm. In the transmission of Figure 2, each auxiliary bearing has an axial width of around 12mm. Typically, the auxiliary bearings 36a, 36b are ball bearings to increase the capacity of the transmission to withstand axial loads. As shown in Figure 2, each auxiliary bearing 36a, 36b may be located inside the gearbox casing 16.

[098] In the transmission 10 of Figure 2, each driven shaft 12 is connected to a one-way clutch bearing 24 and two auxiliary bearings 36a, 36b, and the crown wheel 18 is connected to a pair of support bearings 32. The one-way clutch bearings 24 are located inside the gearbox casing 16 between the gearset and the gearset end 22 of the respective driven shaft 12. On each drive shaft 12, the outermost auxiliary bearing 36b, i.e. the auxiliary bearing located furthest from the gearset, is located proximal to the respective wheel 40.

[99] Referring to Figure 3, which shows an exploded view of part (approximately half) of a transmission 10, it can be seen that the transmission 10 comprises a drive coupling 42 for coupling the driven shaft 12 to the one-way clutch bearing 24. In the transmission 10 of Figure 3, the drive coupling 42 comprises a coupler 44 which is connected to the inner race of the one-way clutch 24. The coupler 44 is slidably engaged with the one-way clutch bearing 24 in use. In the transmission 10 of Figure 3, the coupler 44 comprises a groove 46 which, in use, cooperates with a tongue 48 located at the gearset end 22 of the driven shaft 12. Thus, the driven shaft 12 is releasably attached to the one-way clutch bearing 24 via the coupler 44. The drive coupling 42 comprises a tongue and groove connection between the driven shaft 12 and the coupler 44. The driven shaft 12 includes the tongue part of the tongue and groove connection and the coupler 44 includes the groove part of the tongue and groove connection.

[100] In the transmission 10 of Figure 3, the drive coupling 42 is a loose drive coupling which is arranged such that undesirable forces are not transmitted (or their transmission is minimised) to the gearbox 14. The loose drive coupling also minimises the effect of any misalignment between the two driven shafts 12, as they rotate in use.

Typically, as discussed, the transmission 10 of Figure 3 comprises a gearbox casing (not shown) which substantially surrounds and houses the crown wheel 18, support bearing 32, each one-way clutch 24 and auxiliary bearings 36.

[101] The coupler 44 comprises a seal 50 to substantially seal the one-way clutch bearing 24 from the external environment when the coupler 44 is inserted therein.

[102] Figure 4 shows a side view of the coupler 44 of the transmission of Figure 3. In the coupler 44 of Figure 4, the seal 50 is located immediately adjacent the groove 46 such that the coupler 44 seals the one-way clutch bearing 24 from the external environment when the coupler 44 is inserted therein. Thus, only the portion of the coupler 44 including the groove 46 is exposed to the external environment when the coupler 44 is inserted in the one-way clutch bearing 24.

[103] As described above, the crown wheel 18 has a central portion including an outwardly facing surface 30 having a plurality of teeth which are configured to interact with a worm gear (not shown) in use to drive rotation of the driven shaft 12. The support bearing 32 flanks and supports the crown wheel 18 within the gearbox casing 16. The support bearing 32 substantially bounds a side portion 34 of the crown wheel 18. The side portion 34 in turn bounds the one-way clutch bearing 24. The support bearing 32 is configured such that the crown wheel 18 does not contact the gearbox casing 16 in use.

Claims

Claims 1 An electric golf trolley transmission comprising two opposing driven shafts for rotating a wheelset of the electric golf trolley; a gearset arranged to drive rotation of the driven shafts; wherein each driven shaft has a gearset end and an opposing wheel end which is connectable to a wheel; at least one said driven shaft having a clutch mechanism coupled thereto; wherein the clutch mechanism is configured to transmit torque from the gearset to the at least one shaft in one direction and to permit freewheeling in the opposite direction, and wherein the gearset end of the or each driven shaft is proximal to the clutch mechanism.
2 An electric golf trolley transmission according to claim 1, wherein each driven shaft has a clutch mechanism attached thereto; each clutch mechanism being configured to transmit torque from the gearset to the respective shaft in one direction and to permit freewheeling in the opposite direction and wherein the gearset end of each driven shaft is proximal to the respective clutch mechanism.
3. An electric golf trolley transmission according to claim 1 or claim 2, wherein the or each clutch mechanism is located substantially between the gearset and the gearset end of the respective driven shaft.
4. An electric golf trolley transmission according to any preceding claim, comprising a gearbox casing which houses the gearset, wherein the or each clutch mechanism is located substantially inside the gearbox casing.
5. An electric golf trolley transmission according to any preceding claim, wherein the or each clutch mechanism is directly connected to the gearset.
6. An electric golf trolley transmission according to any preceding, wherein the or each clutch mechanism comprises a one-way clutch bearing configured to transmit torque from the gearset to the respective shaft in one direction and freewheel in the opposite direction.
7. An electric golf trolley transmission according to any preceding claim, wherein the or each clutch mechanism is connected to the respective driven shaft by a drive coupling.
8 An electric golf trolley transmission according to claim 7, wherein the or each clutch mechanism comprises a one-way clutch bearing, and the or each one-way clutch bearing has an outer race connected to the gearset and an inner race; wherein the or each drive coupling includes a coupler which is connected to the inner race of the respective one-way clutch bearing; and wherein the coupler is releasably attached to the gearset end of the respective driven shaft.
9. An electric golf trolley transmission according to claim 7 or claim 8, wherein the or each drive coupling includes a tongue and groove connection.
10. An electric golf trolley transmission according to any preceding claim, further comprising a seal configured to substantially seal the or each clutch mechanism from the external environment.
11.An electric golf trolley transmission according to any of claims 7 to 10, wherein the or each drive coupling includes a seal configured to substantially seal the respective clutch mechanism from the external environment.
12.An electric golf trolley transmission according to any preceding claim, wherein the gearset includes a crown wheel configured to drive rotation of each driven shaft; preferably wherein the crown wheel is supported within the gearbox casing by a pair of support bearings.
13.An electric golf trolley transmission according to claim 12, wherein the or each clutch mechanism is operatively connected to the crown wheel, preferably the or each clutch mechanism is directly connected to the crown wheel.
14.An electric golf trolley transmission according to claim 12 or claim 13, wherein each support bearing comprises an outer race and an inner race, and wherein the or each clutch mechanism is substantially surrounded by the inner race of a said support bearing about the circumference thereof.
15. An electric golf trolley transmission according to any of claims 4 to 14, further comprising one or more auxiliary bearings coupled to each driven shaft; preferably the or each auxiliary bearing being located substantially inside said gearbox casing.
16.A gearbox for an electric golf trolley transmission, comprising a gearset arranged to drive rotation of a pair of driven shafts of an electric golf trolley; a gearbox casing which houses the gearset; and at least one clutch mechanism; the or each clutch mechanism being configured to couple to a driven shaft and being configured to transmit torque from the gearset to the driven shaft in one direction and permit freewheeling in the opposite direction; wherein the or each clutch mechanism is located substantially inside the gearbox casing.
17.A gearbox according to claim 16, comprising two clutch mechanisms, each clutch mechanism being configured to couple to a driven shaft of an electric golf trolley and being configured to transmit torque from the gearset to the driven shaft in one direction and freewheel in the opposite direction.
18.A gearbox according to claim 16 or claim 17, wherein the or each clutch mechanism comprises a one-way clutch bearing.
19.A gearbox according to any of claims 16 to 18, wherein the gearbox casing is configured such that a gearset end of a driven shaft of an electric golf trolley is housed within the gearbox casing and an opposing wheel end of the driven shaft is external to the gearbox casing.
20.A gearbox according to any of claims 16 to 19, wherein the gearset comprises a crown wheel configured to drive rotation of a pair of driven shafts of an electric golf trolley; preferably wherein the crown wheel is supported within the gearbox casing by a pair of support bearings.
21.A gearbox according to claim 20, wherein the or each clutch mechanism is operatively connected to the crown wheel, preferably the or each clutch mechanism is directly connected to the crown wheel.
22.A gearbox according to claim 20 or claim 21, wherein each support bearing comprises an outer race and an inner race; and wherein the or each clutch mechanism is substantially surrounded by the inner race of a said support bearing about the circumference thereof.
23.A gearbox for an electric golf trolley transmission, comprising a gearbox casing which houses a gearset arranged to drive rotation of one or more driven shafts of an electric golf trolley; the gearset including a crown wheel which is connectable to the one or more driven shafts; wherein the crown wheel is flanked and supported within the gearbox casing by a pair of support bearings such that the crown wheel is substantially free from contact with the gearbox casing, in use.
24.An electric golf trolley transmission, comprising one or more driven shafts for rotating a wheelset of the electric golf trolley; a gearset arranged to drive rotation of the or each driven shaft; wherein each driven shaft has a gearset end and an opposing wheel end which is connectable to a wheel; wherein the or each driven shaft has a plurality of bearings coupled thereto.
25.An electric golf trolley comprising a transmission according to any of claims 1 to 15, or 24, or a gearbox according to any of claims 16 to 23.