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- USA
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Ships within 48 hours · Estimated delivery Jul 8 - Jul 13
For Your Every Summer RSVP, with Code: SUMMER15
Description
R & D Flexible Shaft Coupling f/4" B/W, Hurth - 5HP/100RPM CapacityFlexible Shaft Coupling for 4" B W, Hurth 5HP 100RPM Capacity The R&D Flexible Couplings are fabricated from a contoured flexible disc molded in tough yet resilient new type polyurethane. The contoured disc gives clearance for the bolt heads, and is able to flex freely to take up any temporary misalignment of the engine and shaft, due to flexing of the boat structure or the engine moving on its rubber vibration isolation mountings. Forward thrust is
Flexible Shaft Coupling for 4" B/W, Hurth - 5HP/100RPM CapacityThe R&D Flexible Couplings are fabricated from a contoured flexible disc molded in tough yet resilient new type polyurethane. The contoured disc gives clearance for the bolt heads, and is able to flex freely to take up any temporary misalignment of the engine and shaft, due to flexing of the boat structure or the engine moving on its rubber vibration isolation mountings. Forward thrust is taken in compression on the disc between the two half couplings and reverse thrust is taken again in compression on the disc between the two fail straps. In the unlikely event of a disc failure the steel straps make the coupling fail safe and ensure drive is maintained in both forward and reverse.
To calculate power of coupling required:
Horse Power of Engine x Reduction Ratio x 100 = HP/100RPM
Engine Speed
Example:
Ford 150 HP at 2500 RPM with Borg Warner Velvet Drive 72C 2:1 Reduction Ratio
Engine Horse Power is 150 HP, Max Rated RPM is 2500, Reduction Ratio is 2:1
150/2500 X 2 x 100 = 12hp per 100RPM
Coupling required is 910-009
The R & D Marine Flexible Coupling fits between the transmission output flange and shaft coupling. It is designed to protect a boat's drivetrain. The unit will reduce vibration, compensate for some misalignment, isolate the shaft and absorb shock loads.
The flexible disc is machined from a resilient and durable polyurethane. It allows the unit to flex, absorbing vibrations and temporary misalignment of the shaft and engine due to movement of the engine or flexing in the vessel's structure.
The polyurethane disc is backed up by two metal compression straps, one on either side of the flexible coupling. These metal straps hold the system in constant compression whether the drivetrain is in forward or reverse. This feature extends the life of the system dramatically.
The R & D Marine Flexible Coupling will also absorb shockloads resulting from gear changes, or the propeller striking a submerged object. The polyurethane disk will distort with light shock loads and is designed to be sacrificial in the event of severe shock load, saving on expensive drivetrain repairs. If the disc is destroyed from massive shockload the metal compression straps keep the coupling intact ensuring that the drive system is functional in both forward and reverse.
Why R&D Marine Flexible Shaft Couplings?
- Polyurethane flange creates a flexible barrier to reduce drivetrain noise and vibration to quiet your drivetrain
- Absorbs transmission shock load caused by the propeller and high speed gear changes. This helps to reduce and avoid costly transmission damage
- Fail safe design, both forward and reverse thrust is taken in compression from the steel straps, giving a durable design even in extreme conditions
Manufacturer : R & D Marine
Manufacturer Part No : 910-001
UPC : 839662003735
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.4 ★★★★★
Based on 1215 reviews
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Product Reviews
★★★★★ 5
Great For Dogs With High Prey Instincts
My high prey instinct, Husky/Malamute, loves it. The moment it started moving she was on it. Wouldn't let her brother near it. Not noisy. Has USB port so you can recharge it. It's Very cute. Easy to clean you just pop off the covering and toss it in the washer. Great Brain stimulation - that also allows them to get their energy out - without having to talk a long walk in the middle of winter. Just what I was looking for.
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Reviewed in the United States on February 6, 2026
★★★★★ 5
Love
Great little toy, the dogs really love it. Works great for kids also, they like to watch it wiggle around.
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Reviewed in the United States on June 1, 2026
★★★★★ 3
Good toy
My dog really loves toys, technically he loves to kill toys. This toy is supposed to be chew proof but after 1 day my dog managed to pry it open where the Velcro is to hold the ball inside and rip the Velcro out. Now when he shakes it the plastic ball comes flying out so it had to be removed. It also gets super slimy after he chews on it. He still loves to chew and shake the toy itself so overall it was a good buy since I don’t have to spend most of my day walking through my house picking up stuffing that he has pulled out of his other toys. He is not a big dog by the way just a Boston terrier with stuffed animal issues lol.
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Reviewed in the United States on February 4, 2026
★★★★★ 4
My puppy loves this!!!
UPDATE: my puppy still loves this toy, but I’m not super impressed with the craftsmanship. The fabric around the Velcro started to fray after just a few days and within a week the Velcro was completely detached from the fabric. She’s still able to play with it for now though. I’ll probably end up taking the ball out of the inside and putting it into a different toy and I’ll just sew some Velcro on so I can open and close it. It does stay charged a long time and my puppy enjoys playing with it but the novelty wears off a lot quicker now that she’s had it a couple of weeks. She’s usually into it for about 5 min and then it just vibrates its way into a corner until I turn it off.
My 4 month old chorkie (6 pounds) absolutely loves this toy! I was afraid it might scare her at first but no, as soon as we turned it on she was like “LET ME AT IT!!” We’ve only had a it a few days but so far, it’s been a godsend when we are eating dinner or working or other times when we can’t entertain her as much as we would like to. It wears her out too, and after playing with it for about 20 minutes, it’s nap time. So far the battery life has been great. I fully charged it when it arrived and 3 days later it still hasn’t needed to be charged, and she has played with it for about an hour a day, in 15-20 min increments. I like that it has Velcro instead of a zipper, I think it’s a lot safer. The initial “Hello” when you turn it on is kind of loud but other than that, the noises it makes aren’t super loud. It repeats back the things you say, which took me a while to figure out. My puppy hasn’t barked at it but if you have a barker just keep that in mind, it will basically double the barks. It feels like it’s made pretty well, and my dog is kind of an aggressive chewer (she’s a teething puppy so of course she is) but so far it’s held up really well and she hasn’t been able to get the Velcro undone and get to the ball in the middle but if you have a bigger dog they might be able to. The Velcro is pretty strong though. Overall, it’s super cute and it makes my puppy happy which makes me happy! I definitely recommend to anyone who has a puppy or a dog with a lot of energy and needs something to keep them occupied for a while. I will say, after about 30 minutes max, my puppy is kind of over it but that’s a lot longer than anything else has kept her attention so I consider that a win. If I remember, I will update after a month or so to say how it’s holding up as far as charging goes and the overall quality of the toy, but so far I’m super impressed.
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Reviewed in the United States on February 1, 2026
★★★★★ 2
Major flaw
My dog liked this, but the charging port part is at the perfect position for dog teeth to catch on (there's a very large indented part with the on/off switch and that), so after only about two weeks of play, the usb C port is ruined and the toy can no longer be charged.
Larger dogs or very small dogs might have fewer issues. My dog is a miniature dachshund and he could pick up the toy by biting at that indented part.
(Also that "hello" is incredibly grating and if I forgot to turn off the toy would sound hours later, like in the middle of the night when we're sleeping and then my dog wakes up and freaks out.)
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Reviewed in the United States on January 18, 2026