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Title:
PLANETARY GEARING ARRANGEMENT
Document Type and Number:
WIPO Patent Application WO/2018/203093
Kind Code:
A1
Abstract:
A kitchen appliance has a noise reduction system for a planetary gearing arrangement(100). The planetary gearing arrangement (100) comprises one or more planet gears (103) having respective first rotational axes that are each configured to rotate about a second rotational axis, and a sound insulation element (200) which is also configured to rotate about the second axis, for example occupying part of a volume swept by the planet gear(s) (103), and/or a volume between the planet gear(s) (103) and the second axis.

Inventors:
SEALY JAMES JOSEPH (GB)
Application Number:
PCT/GB2018/051220
Publication Date:
November 08, 2018
Filing Date:
May 04, 2018
Export Citation:
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Assignee:
KENWOOD LTD (GB)
International Classes:
A47J43/07; A47J43/08; B01F7/00; F16H57/028
Foreign References:
CN201256896Y2009-06-17
GB2465834A2010-06-09
KR101659307B12016-09-23
Attorney, Agent or Firm:
HECTOR, Annabel Mary (The Shard 32 London Bridge Street, London Greater London SE1 9SG, GB)
Download PDF:
Claims:
CLAIMS:

1 . A planetary gearing arrangement comprising one or more planet gears having respective first rotational axes that are each configured to rotate about a second rotational axis, and a sound insulation element which is also configured to rotate about the second axis.

2. The planetary gearing arrangement of claim 1 , in which the sound insulation element is configured to occupy at least part of a volume swept by the planet gear(s).

3. The planetary gearing arrangement of claim 1 or 2, in which the sound insulation element is configured to occupy at least a part of a volume between the planet gear(s) and the second axis.

4. The planetary gearing arrangement of claim 1 , 2 or 3, wherein the one or more planet gears and the sound insulation element are mounted to a carrier plate configured to carry them about the second axis.

5. The planetary gearing arrangement of any preceding claim, further comprising a sun gear configured to drive the one or more planet gears to move bodily about the second axis, and wherein the sound insulation element is mounted to the sun gear and/or the planet gear.

6. The planetary gearing arrangement of any preceding claim, wherein the one or more planet gears are each configured to rotate about the respective first axis through interaction with a static ring gear.

7. The planetary gearing arrangement of any preceding claim, wherein a volume defined by the movement of the one or more planet gears about the second axis is substantially filled by the sound insulation element and the one or more planet gears for substantially reducing air space through which sound may propagate.

8. The planetary gearing arrangement of any preceding claim, wherein the sound insulation element comprises a fibrous material or open-pored foam, particularly foamed urea-formaldehyde resin, polyurethane foam, or non-rigid PVC foam.

9. The planetary gearing arrangement of any one of claims 1 -7 wherein the sound insulation element comprises a dimensionally stable plastic or rubber material.

10. The planetary gearing arrangement of claim 9 wherein the dimensionally stable plastic or rubber has a Shore A hardness rating of at least 70.

1 1 . The planetary gearing arrangement of claim 10 wherein the dimensionally stable plastic or rubber is a substance chosen from a group consisting of polyurethane, vinyl acetate copolymer, polyethylene, polyamide, a PTFE such as Teflon™, nylon, a polyacetate and acrylonitrile butadiene styrene blend such as Terblend™, and PVC.

12. The planetary gearing arrangement of any preceding claim, wherein the insulation element is substantially impermeable to viscous fluids, including lubrication fluids such as greases or oils.

13. The planetary gearing arrangement of any preceding claim wherein the sound insulation element defines voids within it for attenuating sound transmission through the element.

14. The planetary gearing arrangement of any preceding claim, wherein the sound insulation element has a thickness arranged to attenuate noise transmitted to an external environment from a level of up to 80dB(A) absent the sound insulation element down to 65dB(A) or below, and particularly from a level of up to 85dB(A) down to 65dB(A) or below, preferably from a level of up to 90dB(A) down to 65dB(A) or below, and more preferably still from a level of up to 95dB(A) down to 65dB(A) or below.

15. The planetary gearing arrangement of any preceding claim wherein the sound insulation element comprises a heat-resistant and/or food-safe material.

16. A kitchen appliance comprising the planetary gearing arrangement of any preceding claim.

17. The kitchen appliance of claim 16, wherein at least one of the one or more planet gears is configured to drive a food processing tool.

18. The kitchen appliance of claim 17 comprising a blender, in which the tool is a cutting tool.

19. The kitchen appliance of any of claims 16 to 18, wherein the sound insulation element is removably attached to the kitchen appliance.

20. The planetary gearing arrangement of any of claims 1 to 15 configured for use in a kitchen appliance.

Description:
Planetary Gearing Arrangement

Field The present invention relates to a planetary gearing arrangement for noise reduction, and in particular to noise reduction for a planetary gearing arrangement such as may be used in a kitchen appliance

Background

Planetary gearing arrangements typically featuring a sun gear driving one or more planet gears around a ring-gear, thus resulting in a tool receiving drive from the planet gear rotating about a rotational axis of the planet gear whilst simultaneously moving bodily about the rotational axis of the sun gear, are widely used in kitchen appliances. However, this is not the only way of implementing a planetary gear arrangement and the term planetary gear arrangement should be understood as including any arrangement in which one axle is driven to rotate whilst simultaneously moving bodily about another axle. Whilst often used for speed/torque increase and reduction, planetary gearing arrangements are also often used to add versatility to a kitchen appliance for processing food by increasing a working area or volume swept by a rotary tool. Alternatively or additionally they may be used to mechanically simulate the complicated stirring, shredding, and folding actions carried out by hand by professional chefs using kitchen utensils. Because of this planetary gear arrangement within kitchen appliances are typically arranged proximate to an exterior of the appliance, and are directly connected to an external tool, meaning that sound generated by them is easily propagated directly to an external environment. Unfortunately, as these planetary gearing arrangements often involve at least two or more gear-gear interactions (i.e., between the sun gear and the planet gear, and between the planet gear and the ring gear in a typical planetary gear arrangement), large amounts of noise may be generated through repeated gear interaction. This is especially the case when the gears are of metal construction, as they often are for reasons of durability and cost.

This noise-generation is exacerbated by the requirement for air spaces within planetary gear arrangements to allow the gears to move freely within or through, particularly to allow the planet gear to move about the sun gear in a typical planetary gear arrangement. Noise generated within these air spaces is propagated directly to the casing of the kitchen appliance, and then directly to the exterior where it may cause discomfort or even harm to the user. Whilst noise levels may be around 80 dB(A) for typical kitchen appliances (e.g., blenders), these noise levels may be higher. In some cases they can exceed 80 dB(A) (the first action level under EU directive 2003/10/EC, which requires that employers make hearing protection available if their workers are exposed to it) or even 85 dB(A) (the second action level, at which use of hearing protection becomes mandatory for employees and this requirement should be enforced by employers). The noisiest kitchen appliances can reach sound levels of 95 dB(A). These noises are especially unpleasant to users as they are at frequencies (2000-5000Hz) that the human auditory system is most sensitive to (i.e., those corresponding to shrieks, screams, or roaring). An ideal level is below 65dB(A) (i.e., that of normal conversation).

The present invention is directed to at least partially ameliorating the above-described problems.

Summary of the Invention

The invention provides a planetary gearing arrangement, in particular for use in a kitchen appliance, and a kitchen appliance including such an arrangement. The planetary gearing arrangement comprises one or more planet gears that are configured to simultaneously rotate about a first axis whilst moving bodily about a second axis, and a sound insulation block, wherein the sound insulation block is configured to move bodily with the one or more planet gears about the second axis. This can achieve sound insulation that follows the planet gear for thorough insulation of sound emanated from it.

Thus according to the invention, there is provided a planetary gearing arrangement comprising one or more planet gears having respective first rotational axes that are each configured to rotate about a second rotational axis, and a sound insulation element which is also configured to rotate about the second axis. The sound insulation element is preferably configured to occupy at least part of a volume swept by the planet gear(s), and/or at least a part of a volume between the planet gear(s) and the second axis.

Preferably, the one or more planet gears and the sound insulation element or block are attached to a carrier plate configured to carry them bodily about the second axis. This can achieve deadening of sound emanated both from the carrier plate and from the planet gear.

Preferably, the planetary gearing arrangement further comprises a sun gear configured to drive the one or more planet gears to move bodily about the second axis, and wherein the sound insulation block is attached to the sun gear and/or the planet gear. This arrangement allows deadening of sound emanated from both the sun gear and the planet gear.

Preferably, the one or more planet gears are configured to rotate about the first axis through interaction with a static ring gear.

Preferably, a volume defined by the bodily movement of the one or more planet gears about the second axis is substantially filled by the sound insulation block and the one or more planet gears for substantially reducing air space through which sound may propagate.

Preferably, at least one of the one or more planet gears is directly connected to a food processing tool of a kitchen appliance for driving the tool. Sound emanated through the food processing tool is thus attenuated by the insulation block. Preferably, the sound insulation block is made of a fibrous material or open-pored foam, particularly foamed urea-formaldehyde resin, polyurethane foam, or non-rigid PVC foam. These are cheap substances with good acoustic properties.

Preferably, the sound insulation block is made of a dimensionally stable plastic or rubber. This is suitable for high-speed operation.

Preferably, the dimensionally stable plastic or rubber has a Shore A hardness rating of at least 70. This helps avoid deformation of the block during operation.

Preferably, the dimensionally stable plastic or rubber is a substance chosen from a group consisting of polyurethane, vinyl acetate copolymer, polyethylene, polyamide, a PTFE such as Teflon™, nylon, a polyacetate and acrylonitrile butadiene styrene blend such as Terblend™, and PVC. These substances have good acoustic properties and resist deformation.

Preferably, the insulation block is substantially impermeable to lubrication fluids such as greases or oils. This prevents soaking of the sound insulation block with lubricant. Preferably, the sound insulation block defines voids within it for attenuating sound transmission through the block. This lowers material used and helps attenuate sound.

Preferably, the sound insulation block is of sufficient thickness to attenuate noise transmitted to an external environment from a level of up to 80dB(A) absent the sound insulation block down to 65dB(A) or below, and particularly from a level of up to 85dB(A) down to 65dB(A) or below, preferably from a level of up to 90dB(A) down to 65dB(A) or below, and more preferably still from a level of up to 95dB(A) down to 65dB(A) or below. This lowers the sound to easily-tolerable levels. Preferably, the sound insulation block is made of a heat-resistant and/or food-safe material.

Preferably, the sound insulation block is removably attached to the kitchen appliance. The invention also encompasses a kit of parts for constructing any of the apparatuses or apparatus elements herein described, and extends to the drawings.

Any apparatus feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure, such as a suitably programmed processor and associated memory.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination. It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

In this specification the word Or' can be interpreted in the exclusive or inclusive sense unless stated otherwise.

Furthermore, features implemented in hardware may generally be implemented in software, and vice versa. Any reference to software and hardware features herein should be construed accordingly.

Whilst the invention has been described in the field of domestic food processing and preparation machines, it can also be implemented in any field of use where efficient, effective and convenient preparation and/or processing of material is desired, either on an industrial scale and/or in small amounts. The field of use includes the preparation and/or processing of: chemicals; pharmaceuticals; paints; building materials; clothing materials; agricultural and/or veterinary feeds and/or treatments, including fertilisers, grain and other agricultural and/or veterinary products; oils; fuels; dyes; cosmetics; plastics; tars; finishes; waxes; varnishes; beverages; medical and/or biological research materials; solders; alloys; effluent; and/or other substances, and any reference to "food" herein may be replaced by such working mediums. It will be appreciated that the processing of food may include the processing and/or blending of liquid, and may also include the processing of solid food or ice into a liquid form.

The invention described here may be used in any kitchen appliance and/or as a stand- alone device. This includes any domestic food-processing and/or preparation machine, including both top-driven machines (e.g. stand-mixers) and bottom-driven machines (e.g. blenders). It may be implemented in heated and/or cooled machines. It may be used in a machine that is built-in to a work-top or work surface, or in a stand-alone device. The invention can also be provided as a stand-alone device, whether motor-driven or manually powered.

Brief Description of Drawings One or more aspects will now be described, by way of example only and with reference to the accompanying drawings having like-reference numerals, in which:

Figure 1 a shows a perspective sketch of a sound-insulated planetary gearing arrangement for a kitchen appliance according to a first embodiment of the invention; Figure 1 b shows a top-down sketch of the sound insulated planetary gearing arrangement of Fig. 1 a;

Figure 1 c shows a side-on sketch of the sound-insulated planetary gearing arrangement of Fig. 1 a;

Figure 2a shows a top-down view of a sound insulation block for an idler-gear-type planetary gearing arrangement for a kitchen appliance according to a second embodiment of the invention;

Figure 2b shows a top-down view of sound insulation block for a multi-planet-gear planetary gearing arrangement for a kitchen appliance according to a third embodiment of the invention;

Figure 2c shows a perspective view of a sound insulation block for a single-planet-gear planetary gearing arrangement for a kitchen appliance according to a fourth embodiment; Figure 2d shows a side-on view of the sound insulation block of Fig. 2c;

Figure 3a shows a top-down view of a single-planet-gear planetary gearing arrangement for a kitchen appliance for receiving the sound insulation block of Fig. 2c;

Figure 3b shows a perspective view of a single-planet-gear planetary gearing arrangement for a kitchen appliance for receiving the sound insulation block of Fig. 2c;

Figure 3c shows a top-down view of a single-planet-gear planetary gearing arrangement for a kitchen appliance with the sound insulation block of Fig. 2c inserted into it;

Figure 4a shows a perspective view of an idler-gear-type planetary gearing arrangement for a kitchen appliance for receiving the sound insulation block of Fig. 2a;

Figure 4b shows a top-down view of an idler-gear-type planetary gearing arrangement for a kitchen appliance for receiving the sound insulation block of Fig. 2a;

Figure 4c shows a top-down view of an idler-gear-type planetary gearing arrangement for a kitchen appliance with the sound insulation block of Fig. 2a inserted;

Figure 5a shows a top-down view of a multi-planet-gear planetary gearing arrangement for a kitchen appliance for receiving the sound insulation block of Fig. 2b;

Figure 5b shows a perspective view of a multi-planet-gear planetary gearing arrangement for a kitchen appliance for receiving the sound insulation block of Fig. 2b; and,

Figure 5c shows a top-down view of a multi-planet-gear planetary gearing arrangement for a kitchen appliance with the sound insulation block of Fig. 2b inserted.

Specific Description

Figs. 1 a-1 d illustrate an exemplary carrier-wheel-type planetary gearing mechanism 100. When attached to a kitchen appliance, the carrier wheel 102 receives rotary drive from a motor (not shown) attached to the drive shaft 101 . As the carrier wheel 102 rotates, the planet wheel/gear 103 that is rotatably-attached near a periphery of the carrier wheel 102 is also driven to rotate through its teeth (which can be seen in Fig. 1 c) being in intermeshed contact with those of a static ring gear (not shown).

The planet wheel 103 is attached via a rotary axle that extends through a through-hole in the carrier wheel 102 to a rotary food processing tool 104 located on the opposite side of the carrier wheel 101 . Thus, as the carrier wheel 101 rotates it drives the planet wheel 103 to rotate, and as the planet wheel 103 rotates it in turn drives the rotary tool 104 to rotate to carry out food processing within a given container of a kitchen appliance.

To reduce noise during operation of the planetary gearing mechanism 100, a sound insulation element in the form of a block 105 is attached to the carrier wheel by suitable screws. The block 105 acts to limit air-space within the kitchen appliance which incorporates the planetary gearing mechanism 100 by substantially filing the volume through which the planet wheel 103 travels during its rotation about the drive shaft 101 , thus reducing noise-emission. An additional sound insulation block 106 may substantially surround the planet wheel 103 to limit noise-transmission directly from the planet wheel. Where the block is directly attached to the carrier plate 102, it helps to deaden vibrations and noise transmitted directly through the carrier plate 102. As the sound insulation block 105 co-rotates with the planet wheel 103, moving bodily about the central axis of drive shaft 101 , it may abut the planet gear 103 much more closely than sound insulation that is stationary relative to the planet gear 103. Filling the volume defined by the movement of planet gear 103 about the drive shaft 101 is also not possible with static sound insulation, as it would obstruct the movement of the planet gear 103 about the drive shaft 101 .

The sound insulation block 105 may be formed integrally with the additional block 106. Alternatively they may be provided as separate components. Whilst the sound insulation block 105 may be removably attached to the carrier wheel 102 using screws (or any other suitable removable attachment means) as illustrated, it may alternatively be attached permanently or semi-permanently using, for example, glue.

Figs 2a-2d show three sound insulation blocks 200, 300, and 400 suited for different gearing arrangements.

Figs. 2c-2d shows a sound insulation block 400 shaped for a single-planet-gear-type planetary gearing arrangement 500. A shown in Figs. 3a-3c the insulation block 400 is inserted with its peripheral hole 401 located around the planet gear 502. Insulation block 400 fills the entire space within the ring-gear 501 except for the area immediately abutting the ring gear 501 and the planet gear 502, leaving a gap of roughly 2 mm between the insulation block 400 and the teeth of the ring gear 501 /planet gear 502.

The planet gear 502 may receive rotary drive from a sun gear or from being attached to a carrier wheel as in Figs. 1 a-1 d. Where a sun gear is used, the insulation block 500 should form a similar clearance with it. The insulation block may extend both above and below the planet gear 502. Where a sun gear is used, insulation block 500 is preferably attached to an axle extending from the planet gear 502 so that it co-rotates about the central sun gear with the planet gear 502. Alternatively or additionally it may be attached to the sun gear in such a fashion that it can rotate relative to the sun gear. Fig. 2a shows sound insulation block 200 configured for attachment to a idler-gear type planetary gearing arrangement 600. As shown in Figs. 4a-4c, as well as having a static ring gear 601 and planet gear 604, the gearing arrangement 600 also includes a sun gear 602 and an idler gear 603 for transmitting rotary drive from the sun gear 602 to the planet gear 604 whilst ensuring that the planet gear 604 rotates about its central axis in the same direction as the sun gear 602 rotates about its central axis. This has the effect of reversing the direction that planet gear 604 travel around the inner circumference of ring gear 601 relative to the direction in which it would otherwise have travelled were it directly driven by the sun gear 602.

When inserted into the gearing arrangement as shown in Fig. 4c, the inner hole 201 defined in the middle of the sound insulation block 200 locates around the sun gear 602, the outer hole defined in the periphery of the sound insulation block 200 locates around the planet gear 604, and the intermediate hole 202 interconnecting the inner hole 201 and the outer hole 203 locates around the idler gear 603. In this way all of the gears are substantially surrounded by the sound insulation block 200 and noise caused by the teeth of the gears contacting with each other is substantially attenuated before being transmitted to an exterior of a kitchen appliance accommodating the gearing arrangement 500.

Fig. 2b shows an insulation block 300 shaped for a multiple-planet-gear-type planetary gearing arrangement 700. As can be seen in Figs. 5a-5c, the multiple-planet-gear-type planetary gearing arrangement 700 has multiple planet gears 702 contacting the ring gear 701 at different points within its inner circumference. These planet gears 702 may be driven directly by a central sun-gear 703 , and may be connected by a connecting arm 703. As shown in Fig. 5c, the arms 302 of the sound insulation insert 300 that form between peripheral holes 301 extend over the air-gaps between the planet gears 702, and may also depend down between them.

The sound insulation blocks (105, 200, 300, 400) described above may be formed of soft, fibrous, open pored substances for lightness and to enhance sound-absorbance. Examples of this would include foamed urea-formaldehyde resin, polyurethane foam, or non-rigid PVC foam. Alternatively, where more durable substances are required (e.g., where high operation speeds are a concern) the sound insulation block is preferably made of a dimensionally stable plastic (i.e., a plastic that won't deform easily under typical operating conditions). Preferably this is a plastic or composite with a Shore A hardness rating of 70 or over. Examples of this include polyurethane, vinyl acetate copolymer, polyethylene, polyamide, a PTFE such as Teflon™, nylon, a polyacetate and acrylonitrile butadiene styrene blend such as Terblend™ (available from the Styrolution Group company of Frankfurt-am -Main, Germany), and PVC. Terblend™ is particularly suitable due to its good acoustic properties, its lack of a "tinny" sound when tapped or otherwise struck, impact strength, chemical resistance, coatability and ease of processing.

Where the sound insulation block is to be used in a gearing arrangement containing lubrication fluids such as oils and greases, it is desirable that the sound insulation block should not absorb the fluid to prevent the fluid being wasted and performance of the block being impaired. In this case the block is preferably made of (or coated with) a substance that it impermeable to the lubrication fluid being used.

To save on cost, and prevent sound transmission through the block, it may have voids defined in it filled with air or another suitable sound-attenuation filing. Preferably, the insulation block is heat-resistance so that it will not suffer harm from the heat of the machine's typical operation. Additionally it should be suitable for contact with food (i.e., meet the EU MICwF - materials in contact with food - requirements), since it is possible that material may leak from the gearing arrangement housing of the kitchen appliance into the food being processed.

For particularly loud machines, preferably the insulation block is of sufficient thickness to attenuate sound that would otherwise be emitted by the gearing arrangement they are used with from as much as 95dB(A) down to 65dB(A). For less noisy machines a thickness sufficient to attenuate 90dB(A), or 85 dB(A), or 80dB(A) down to 65dB(A) or below may be sufficient.

It will be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.




 
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