Here we go. With the summer's earnings season now in full swing, a host of fresh dividend declarations have hit the market.

As ever, last week more than a few of these represented increases over their predecessors. We've got quite a few to choose from in this installment, and whittling the number down to three was tough. Regardless, here are the winners:

Enterprise Products Partners (NYSE:EPD)
Some companies habitually lift their distributions occasionally... and some do it every time they declare a payout.

Enterprise Products Partners is very much in the latter category. It just declared a $0.38-per-unit distribution, although that only represents a 1% increase over the previous payout.

The partnership didn't have much more to distribute, because its latest quarterly results were weak. Revenue cratered by 45% on a year-over-year basis to $75 billion, while the bottom line slid 20% to $636 million. Neither met analyst expectations. 

The obvious culprit for the declines was the comparatively lower prices for oil, which have had a ripple effect across the broader oil and gas industry. A relatively mild winter that helped keep prices low wasn't a boon, either.

Despite that, Enterprise is still in a very good position on the market. It provides many of its services on the basis of long-term, fixed-fee contracts, insulating against some of the wilder swings of the commodities it specializes in.

So I think its distribution is safe. We probably won't see the big quarter-over-quarter raises in the payout as we did previously, but it should rise nevertheless. Meanwhile, in terms of operations and management, the partnership is among the most solid in its industry.

Enterprise's upcoming disbursement will be paid on August 7 to holders of record as of July 31.

Paccar (NASDAQ:PCAR)
Paccar, which concentrates on the manufacturing of heavy trucks, has been motoring along smoothly in recent times. Excellent results fuel a rising dividend; last week, the company raised this by 9% to $0.24 per share. 

Following a fiscal 2014 where Paccar notched an all-time record revenue figure, it also reported a strong Q1 2015. Net profit rose a mighty 38% over the year-ago result to hit $378 million, while the top line advanced by 10% to $4.8 billion. Both beat analyst expectations.

A rising economy needs the vehicles to move its goods. Paccar has benefited from new purchases and refurbishments of existing trucks, and it anticipates it'll continue to do so.The company's lifted its forecast for North American unit truck sales slightly, to 260,000 to 290,000 vehicles (up from the previous 250,000 to 280,000).

Paccar's strengthening business will add to its cash and equivalents position, giving it the increased financial muscle to keep that dividend on the road. By the way, it's paid a distribution consistently since 1941.

Paccar's next dividend will be dispensed on September 4 to shareholders of record as of August 14. 

Duke Energy (NYSE:DUK)
This popular dividend stock is delivering for income investors, with the company enacting the latest in a series of annual raises. It's hiked the payout by 4% to nearly $0.83 per share.

Duke Energy's fundamentals have been mixed of late, however. It reported a Q1 that missed revenue expectations, but trounced bottom-line estimates. Although domestic operations are doing well, its international unit suffered a steep income drop during the quarter.

On our shores, Duke has gotten itself in hot water over environmental issues, specifically its disposal of coal ash in North Carolina. It's already paid fines totaling over $100 million for this.

As an eager and generous dividend payer, the company might struggle to keep that distribution up if those negatives worsen.

But I think it considers its payout to be of utmost importance, plus over the years it's managed to raise it on a consistent basis. Those factors considered, I think the dividend is secure for now.

Duke Energy will pay out its new distribution on September 16 to stockholders of record as of August 14.

Eric Volkman has no position in any stocks mentioned. The Motley Fool recommends Enterprise Products Partners and Paccar, and owns shares of Paccar. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.